Storm Prediction Center

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1109 AM CDT Sat Jun 20 2026 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS THIS AFTERNOON AND TONIGHT.... ...SUMMARY... Severe thunderstorms are likely across parts of the central Plains mainly this afternoon and evening. Large to very large hail, severe winds (some 75+ mph), and a few tornadoes are possible. ...Central Plains... Water vapor imagery shows a shortwave trough over ID/UT tracking eastward toward the central High Plains. Southerly/southeasterly low-level winds ahead of this feature over parts of eastern CO/western NE/KS will help to maintain a moist and moderately unstable air mass across the region, especially as low clouds continue to burn off and afternoon heating commences. Scattered thunderstorm development is expected by mid-afternoon over central WY down into central CO in favored terrain/convergence areas. This activity will spread eastward into a progressively more moist/unstable air mass and intensify into supercells. A corridor of favorable vertical shear will develop later today from northeast CO into southwest NE/northwest KS for isolated tornadoes. Otherwise, very large hail and damaging winds will be the main concerns. Activity is likely to organize upscale during the evening and spread across KS with a damaging wind risk persisting much of the night. ...Southeast... A very moist and moderately unstable air mass is present again today over much of the southeast US. Most CAM solutions suggest scattered afternoon thunderstorms across this area, including along the FL east coast. Dewpoints in the 70s and PWAT values around 2 inches, coupled with strong daytime heating and steep low-level lapse rates suggest a risk of locally gusty/damaging wind gusts in the most intense cores. ..Hart/Moore.. 06/20/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1109 AM CDT Sat Jun 20 2026 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS THIS AFTERNOON AND TONIGHT.... ...SUMMARY... Severe thunderstorms are likely across parts of the central Plains mainly this afternoon and evening. Large to very large hail, severe winds (some 75+ mph), and a few tornadoes are possible. ...Central Plains... Water vapor imagery shows a shortwave trough over ID/UT tracking eastward toward the central High Plains. Southerly/southeasterly low-level winds ahead of this feature over parts of eastern CO/western NE/KS will help to maintain a moist and moderately unstable air mass across the region, especially as low clouds continue to burn off and afternoon heating commences. Scattered thunderstorm development is expected by mid-afternoon over central WY down into central CO in favored terrain/convergence areas. This activity will spread eastward into a progressively more moist/unstable air mass and intensify into supercells. A corridor of favorable vertical shear will develop later today from northeast CO into southwest NE/northwest KS for isolated tornadoes. Otherwise, very large hail and damaging winds will be the main concerns. Activity is likely to organize upscale during the evening and spread across KS with a damaging wind risk persisting much of the night. ...Southeast... A very moist and moderately unstable air mass is present again today over much of the southeast US. Most CAM solutions suggest scattered afternoon thunderstorms across this area, including along the FL east coast. Dewpoints in the 70s and PWAT values around 2 inches, coupled with strong daytime heating and steep low-level lapse rates suggest a risk of locally gusty/damaging wind gusts in the most intense cores. ..Hart/Moore.. 06/20/2026 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1105 AM CDT Sat Jun 20 2026 Valid 231200Z - 281200Z CORRECTED FOR TYPO ...DISCUSSION... An extended period of moderate northwesterly flow across the High Plains will lead to severe weather potential across the central High Plains. Upslope flow amid 30 to 50 knots mid-level winds should result in a severe weather environment, potentially on Tuesday, and particularly Wednesday and Thursday. The front will shift based on small-scale embedded shortwave disturbances and the prior day's convection, which will shift the location of the unstable warm sector. This results in uncertainty regarding the location of the threat for each day. This will continue to be monitored for potential areas to be added later. Ridging will slide east across the Rockies and into the Plains by next weekend. Some severe weather threat may exist through this time as multiple embedded shortwave troughs will be within this region as instability increases across the Plains. While it is mostly beyond Day 8, it is worth noting that deterministic, ensemble, and AI guidance all indicate a strong jet streak and mid-level trough traversing the Rockies toward the end of next weekend and into early next week. A strong lee cyclone would accompany this with strong instability across the Plains. There is still uncertainty with the timing and location of the trough, but given the agreement in this general pattern change, a substantial severe weather threat seems possible by the end of next weekend and early into the following week across portions of the central/northern Plains into the Upper Midwest. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1105 AM CDT Sat Jun 20 2026 Valid 231200Z - 281200Z CORRECTED FOR TYPO ...DISCUSSION... An extended period of moderate northwesterly flow across the High Plains will lead to severe weather potential across the central High Plains. Upslope flow amid 30 to 50 knots mid-level winds should result in a severe weather environment, potentially on Tuesday, and particularly Wednesday and Thursday. The front will shift based on small-scale embedded shortwave disturbances and the prior day's convection, which will shift the location of the unstable warm sector. This results in uncertainty regarding the location of the threat for each day. This will continue to be monitored for potential areas to be added later. Ridging will slide east across the Rockies and into the Plains by next weekend. Some severe weather threat may exist through this time as multiple embedded shortwave troughs will be within this region as instability increases across the Plains. While it is mostly beyond Day 8, it is worth noting that deterministic, ensemble, and AI guidance all indicate a strong jet streak and mid-level trough traversing the Rockies toward the end of next weekend and into early next week. A strong lee cyclone would accompany this with strong instability across the Plains. There is still uncertainty with the timing and location of the trough, but given the agreement in this general pattern change, a substantial severe weather threat seems possible by the end of next weekend and early into the following week across portions of the central/northern Plains into the Upper Midwest. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1105 AM CDT Sat Jun 20 2026 Valid 231200Z - 281200Z CORRECTED FOR TYPO ...DISCUSSION... An extended period of moderate northwesterly flow across the High Plains will lead to severe weather potential across the central High Plains. Upslope flow amid 30 to 50 knots mid-level winds should result in a severe weather environment, potentially on Tuesday, and particularly Wednesday and Thursday. The front will shift based on small-scale embedded shortwave disturbances and the prior day's convection, which will shift the location of the unstable warm sector. This results in uncertainty regarding the location of the threat for each day. This will continue to be monitored for potential areas to be added later. Ridging will slide east across the Rockies and into the Plains by next weekend. Some severe weather threat may exist through this time as multiple embedded shortwave troughs will be within this region as instability increases across the Plains. While it is mostly beyond Day 8, it is worth noting that deterministic, ensemble, and AI guidance all indicate a strong jet streak and mid-level trough traversing the Rockies toward the end of next weekend and into early next week. A strong lee cyclone would accompany this with strong instability across the Plains. There is still uncertainty with the timing and location of the trough, but given the agreement in this general pattern change, a substantial severe weather threat seems possible by the end of next weekend and early into the following week across portions of the central/northern Plains into the Upper Midwest. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1105 AM CDT Sat Jun 20 2026 Valid 231200Z - 281200Z CORRECTED FOR TYPO ...DISCUSSION... An extended period of moderate northwesterly flow across the High Plains will lead to severe weather potential across the central High Plains. Upslope flow amid 30 to 50 knots mid-level winds should result in a severe weather environment, potentially on Tuesday, and particularly Wednesday and Thursday. The front will shift based on small-scale embedded shortwave disturbances and the prior day's convection, which will shift the location of the unstable warm sector. This results in uncertainty regarding the location of the threat for each day. This will continue to be monitored for potential areas to be added later. Ridging will slide east across the Rockies and into the Plains by next weekend. Some severe weather threat may exist through this time as multiple embedded shortwave troughs will be within this region as instability increases across the Plains. While it is mostly beyond Day 8, it is worth noting that deterministic, ensemble, and AI guidance all indicate a strong jet streak and mid-level trough traversing the Rockies toward the end of next weekend and into early next week. A strong lee cyclone would accompany this with strong instability across the Plains. There is still uncertainty with the timing and location of the trough, but given the agreement in this general pattern change, a substantial severe weather threat seems possible by the end of next weekend and early into the following week across portions of the central/northern Plains into the Upper Midwest. Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1048 AM CDT Sat Jun 20 2026 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHEASTERN GREAT BASIN FOR SCATTERED DRY THUNDERSTORMS... ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE EASTERN GREAT BASIN INTO THE FOUR CORNERS FOR DRY AND WINDY CONDITIONS... The existing Isolated Dry Thunderstorm area was trimmed slightly along it's northern boundary to account for ongoing showers with accumulating precipitation and persistent cloud cover this morning. This activity, over east-central OR and far western ID, will stifle chances for dry thunderstorm re-development later today as indicated in the latest forecast guidance and will also limit fuel receptivity. Across portions of this same area, this accumulating precipitation may also prevent afternoon RHs from dipping low enough to meet Elevated wind/RH criteria. However, the latest forecast guidance still maintains Elevated criteria (with RHs dipping below 20%) will be met this afternoon over much of the drawn area. Farther south over the rest of the Great Basin, Southwest, and neighboring areas, the forecast remains on track. Northern portions of the Scattered Dry Thunderstorm area did receive transitory precipitation this morning, but it is not expected to have a significant impact unlike the longer duration showers over areas farther northwest. ..Stearns.. 06/20/2026 .PREV DISCUSSION... /ISSUED 0147 AM CDT Sat Jun 20 2026/ ...Synopsis... Zonal mid-level flow will overspread the CONUS today, with multiple embedded impulses poised to traverse the zonal flow from the Pacific Northwest to the mid-Mississippi Valley. At least one pronounced mid-level impulse will overspread the Great Basin during the afternoon hours, encouraging surface troughing over the Interior West, resulting in dry/windy conditions over the Great Basin toward the Four Corners region. Strong westerly mid-level flow behind the mid-level impulse will overspread the Cascades, supporting dry/breezy conditions over and to the lee of the higher terrain. Finally, deep-layer ascent and enough mid-level moisture (hence buoyancy) accompanying the passing mid-level impulse will encourage high-based thunderstorm development from northern California to western Wyoming. The combination of these meteorological scenarios will support widespread wildfire ignition and/or growth concerns across much of the Intermountain West today. ...Eastern Great Basin to the Four Corners region... By afternoon peak heating, the aforementioned surface lee troughing will support widespread southwesterly surface winds in the 15-25 mph range amid 5-15 percent RH. Widespread Elevated highlights have been continued, with Critical highlights in place where guidance shows the highest likelihood of 20+ mph winds and 5-10 percent RH overlapping for several hours. Across both Elevated and Critical highlights, ERCs should easily exceed the 80th percentile, and thus would support wildfire spread. ...Along and to the lee of the Cascades... Strong flow westerly flow along the higher terrain, along with downslope flow to the lee of the Cascades, will result in 15-25 mph sustained westerly surface winds coinciding with RH as low as 15 percent in spots. Stronger surface winds and lower RH may occur in localized, terrain favoring areas. Either way, the aforementioned ambient surface conditions and dry fuels warrant Elevated highlights. ...Far northern California to far western Wyoming... During the afternoon, diurnal heating, upper support, and orographic lift will all support at least isolated thunderstorm development amid precipitable water values around 0.75 inches. Given dry fuels and potentially light rainfall accumulations with some of the storm cores, a few cells may be associated with efficient lightning-induced ignitions given cloud-to-ground strikes, warranting isolated dry thunderstorm highlights. Across northeastern portions of the Great Basin, storms closer to stronger mid-level flow may move faster, potentially supporting a regionally greater lightning-ignition rate given dry fuels and a lesser chance for rainfall accumulations. As such, scattered dry thunderstorm highlights have been continued. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1048 AM CDT Sat Jun 20 2026 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHEASTERN GREAT BASIN FOR SCATTERED DRY THUNDERSTORMS... ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE EASTERN GREAT BASIN INTO THE FOUR CORNERS FOR DRY AND WINDY CONDITIONS... The existing Isolated Dry Thunderstorm area was trimmed slightly along it's northern boundary to account for ongoing showers with accumulating precipitation and persistent cloud cover this morning. This activity, over east-central OR and far western ID, will stifle chances for dry thunderstorm re-development later today as indicated in the latest forecast guidance and will also limit fuel receptivity. Across portions of this same area, this accumulating precipitation may also prevent afternoon RHs from dipping low enough to meet Elevated wind/RH criteria. However, the latest forecast guidance still maintains Elevated criteria (with RHs dipping below 20%) will be met this afternoon over much of the drawn area. Farther south over the rest of the Great Basin, Southwest, and neighboring areas, the forecast remains on track. Northern portions of the Scattered Dry Thunderstorm area did receive transitory precipitation this morning, but it is not expected to have a significant impact unlike the longer duration showers over areas farther northwest. ..Stearns.. 06/20/2026 .PREV DISCUSSION... /ISSUED 0147 AM CDT Sat Jun 20 2026/ ...Synopsis... Zonal mid-level flow will overspread the CONUS today, with multiple embedded impulses poised to traverse the zonal flow from the Pacific Northwest to the mid-Mississippi Valley. At least one pronounced mid-level impulse will overspread the Great Basin during the afternoon hours, encouraging surface troughing over the Interior West, resulting in dry/windy conditions over the Great Basin toward the Four Corners region. Strong westerly mid-level flow behind the mid-level impulse will overspread the Cascades, supporting dry/breezy conditions over and to the lee of the higher terrain. Finally, deep-layer ascent and enough mid-level moisture (hence buoyancy) accompanying the passing mid-level impulse will encourage high-based thunderstorm development from northern California to western Wyoming. The combination of these meteorological scenarios will support widespread wildfire ignition and/or growth concerns across much of the Intermountain West today. ...Eastern Great Basin to the Four Corners region... By afternoon peak heating, the aforementioned surface lee troughing will support widespread southwesterly surface winds in the 15-25 mph range amid 5-15 percent RH. Widespread Elevated highlights have been continued, with Critical highlights in place where guidance shows the highest likelihood of 20+ mph winds and 5-10 percent RH overlapping for several hours. Across both Elevated and Critical highlights, ERCs should easily exceed the 80th percentile, and thus would support wildfire spread. ...Along and to the lee of the Cascades... Strong flow westerly flow along the higher terrain, along with downslope flow to the lee of the Cascades, will result in 15-25 mph sustained westerly surface winds coinciding with RH as low as 15 percent in spots. Stronger surface winds and lower RH may occur in localized, terrain favoring areas. Either way, the aforementioned ambient surface conditions and dry fuels warrant Elevated highlights. ...Far northern California to far western Wyoming... During the afternoon, diurnal heating, upper support, and orographic lift will all support at least isolated thunderstorm development amid precipitable water values around 0.75 inches. Given dry fuels and potentially light rainfall accumulations with some of the storm cores, a few cells may be associated with efficient lightning-induced ignitions given cloud-to-ground strikes, warranting isolated dry thunderstorm highlights. Across northeastern portions of the Great Basin, storms closer to stronger mid-level flow may move faster, potentially supporting a regionally greater lightning-ignition rate given dry fuels and a lesser chance for rainfall accumulations. As such, scattered dry thunderstorm highlights have been continued. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1048 AM CDT Sat Jun 20 2026 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHEASTERN GREAT BASIN FOR SCATTERED DRY THUNDERSTORMS... ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE EASTERN GREAT BASIN INTO THE FOUR CORNERS FOR DRY AND WINDY CONDITIONS... The existing Isolated Dry Thunderstorm area was trimmed slightly along it's northern boundary to account for ongoing showers with accumulating precipitation and persistent cloud cover this morning. This activity, over east-central OR and far western ID, will stifle chances for dry thunderstorm re-development later today as indicated in the latest forecast guidance and will also limit fuel receptivity. Across portions of this same area, this accumulating precipitation may also prevent afternoon RHs from dipping low enough to meet Elevated wind/RH criteria. However, the latest forecast guidance still maintains Elevated criteria (with RHs dipping below 20%) will be met this afternoon over much of the drawn area. Farther south over the rest of the Great Basin, Southwest, and neighboring areas, the forecast remains on track. Northern portions of the Scattered Dry Thunderstorm area did receive transitory precipitation this morning, but it is not expected to have a significant impact unlike the longer duration showers over areas farther northwest. ..Stearns.. 06/20/2026 .PREV DISCUSSION... /ISSUED 0147 AM CDT Sat Jun 20 2026/ ...Synopsis... Zonal mid-level flow will overspread the CONUS today, with multiple embedded impulses poised to traverse the zonal flow from the Pacific Northwest to the mid-Mississippi Valley. At least one pronounced mid-level impulse will overspread the Great Basin during the afternoon hours, encouraging surface troughing over the Interior West, resulting in dry/windy conditions over the Great Basin toward the Four Corners region. Strong westerly mid-level flow behind the mid-level impulse will overspread the Cascades, supporting dry/breezy conditions over and to the lee of the higher terrain. Finally, deep-layer ascent and enough mid-level moisture (hence buoyancy) accompanying the passing mid-level impulse will encourage high-based thunderstorm development from northern California to western Wyoming. The combination of these meteorological scenarios will support widespread wildfire ignition and/or growth concerns across much of the Intermountain West today. ...Eastern Great Basin to the Four Corners region... By afternoon peak heating, the aforementioned surface lee troughing will support widespread southwesterly surface winds in the 15-25 mph range amid 5-15 percent RH. Widespread Elevated highlights have been continued, with Critical highlights in place where guidance shows the highest likelihood of 20+ mph winds and 5-10 percent RH overlapping for several hours. Across both Elevated and Critical highlights, ERCs should easily exceed the 80th percentile, and thus would support wildfire spread. ...Along and to the lee of the Cascades... Strong flow westerly flow along the higher terrain, along with downslope flow to the lee of the Cascades, will result in 15-25 mph sustained westerly surface winds coinciding with RH as low as 15 percent in spots. Stronger surface winds and lower RH may occur in localized, terrain favoring areas. Either way, the aforementioned ambient surface conditions and dry fuels warrant Elevated highlights. ...Far northern California to far western Wyoming... During the afternoon, diurnal heating, upper support, and orographic lift will all support at least isolated thunderstorm development amid precipitable water values around 0.75 inches. Given dry fuels and potentially light rainfall accumulations with some of the storm cores, a few cells may be associated with efficient lightning-induced ignitions given cloud-to-ground strikes, warranting isolated dry thunderstorm highlights. Across northeastern portions of the Great Basin, storms closer to stronger mid-level flow may move faster, potentially supporting a regionally greater lightning-ignition rate given dry fuels and a lesser chance for rainfall accumulations. As such, scattered dry thunderstorm highlights have been continued. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1048 AM CDT Sat Jun 20 2026 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHEASTERN GREAT BASIN FOR SCATTERED DRY THUNDERSTORMS... ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE EASTERN GREAT BASIN INTO THE FOUR CORNERS FOR DRY AND WINDY CONDITIONS... The existing Isolated Dry Thunderstorm area was trimmed slightly along it's northern boundary to account for ongoing showers with accumulating precipitation and persistent cloud cover this morning. This activity, over east-central OR and far western ID, will stifle chances for dry thunderstorm re-development later today as indicated in the latest forecast guidance and will also limit fuel receptivity. Across portions of this same area, this accumulating precipitation may also prevent afternoon RHs from dipping low enough to meet Elevated wind/RH criteria. However, the latest forecast guidance still maintains Elevated criteria (with RHs dipping below 20%) will be met this afternoon over much of the drawn area. Farther south over the rest of the Great Basin, Southwest, and neighboring areas, the forecast remains on track. Northern portions of the Scattered Dry Thunderstorm area did receive transitory precipitation this morning, but it is not expected to have a significant impact unlike the longer duration showers over areas farther northwest. ..Stearns.. 06/20/2026 .PREV DISCUSSION... /ISSUED 0147 AM CDT Sat Jun 20 2026/ ...Synopsis... Zonal mid-level flow will overspread the CONUS today, with multiple embedded impulses poised to traverse the zonal flow from the Pacific Northwest to the mid-Mississippi Valley. At least one pronounced mid-level impulse will overspread the Great Basin during the afternoon hours, encouraging surface troughing over the Interior West, resulting in dry/windy conditions over the Great Basin toward the Four Corners region. Strong westerly mid-level flow behind the mid-level impulse will overspread the Cascades, supporting dry/breezy conditions over and to the lee of the higher terrain. Finally, deep-layer ascent and enough mid-level moisture (hence buoyancy) accompanying the passing mid-level impulse will encourage high-based thunderstorm development from northern California to western Wyoming. The combination of these meteorological scenarios will support widespread wildfire ignition and/or growth concerns across much of the Intermountain West today. ...Eastern Great Basin to the Four Corners region... By afternoon peak heating, the aforementioned surface lee troughing will support widespread southwesterly surface winds in the 15-25 mph range amid 5-15 percent RH. Widespread Elevated highlights have been continued, with Critical highlights in place where guidance shows the highest likelihood of 20+ mph winds and 5-10 percent RH overlapping for several hours. Across both Elevated and Critical highlights, ERCs should easily exceed the 80th percentile, and thus would support wildfire spread. ...Along and to the lee of the Cascades... Strong flow westerly flow along the higher terrain, along with downslope flow to the lee of the Cascades, will result in 15-25 mph sustained westerly surface winds coinciding with RH as low as 15 percent in spots. Stronger surface winds and lower RH may occur in localized, terrain favoring areas. Either way, the aforementioned ambient surface conditions and dry fuels warrant Elevated highlights. ...Far northern California to far western Wyoming... During the afternoon, diurnal heating, upper support, and orographic lift will all support at least isolated thunderstorm development amid precipitable water values around 0.75 inches. Given dry fuels and potentially light rainfall accumulations with some of the storm cores, a few cells may be associated with efficient lightning-induced ignitions given cloud-to-ground strikes, warranting isolated dry thunderstorm highlights. Across northeastern portions of the Great Basin, storms closer to stronger mid-level flow may move faster, potentially supporting a regionally greater lightning-ignition rate given dry fuels and a lesser chance for rainfall accumulations. As such, scattered dry thunderstorm highlights have been continued. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1048 AM CDT Sat Jun 20 2026 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHEASTERN GREAT BASIN FOR SCATTERED DRY THUNDERSTORMS... ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE EASTERN GREAT BASIN INTO THE FOUR CORNERS FOR DRY AND WINDY CONDITIONS... The existing Isolated Dry Thunderstorm area was trimmed slightly along it's northern boundary to account for ongoing showers with accumulating precipitation and persistent cloud cover this morning. This activity, over east-central OR and far western ID, will stifle chances for dry thunderstorm re-development later today as indicated in the latest forecast guidance and will also limit fuel receptivity. Across portions of this same area, this accumulating precipitation may also prevent afternoon RHs from dipping low enough to meet Elevated wind/RH criteria. However, the latest forecast guidance still maintains Elevated criteria (with RHs dipping below 20%) will be met this afternoon over much of the drawn area. Farther south over the rest of the Great Basin, Southwest, and neighboring areas, the forecast remains on track. Northern portions of the Scattered Dry Thunderstorm area did receive transitory precipitation this morning, but it is not expected to have a significant impact unlike the longer duration showers over areas farther northwest. ..Stearns.. 06/20/2026 .PREV DISCUSSION... /ISSUED 0147 AM CDT Sat Jun 20 2026/ ...Synopsis... Zonal mid-level flow will overspread the CONUS today, with multiple embedded impulses poised to traverse the zonal flow from the Pacific Northwest to the mid-Mississippi Valley. At least one pronounced mid-level impulse will overspread the Great Basin during the afternoon hours, encouraging surface troughing over the Interior West, resulting in dry/windy conditions over the Great Basin toward the Four Corners region. Strong westerly mid-level flow behind the mid-level impulse will overspread the Cascades, supporting dry/breezy conditions over and to the lee of the higher terrain. Finally, deep-layer ascent and enough mid-level moisture (hence buoyancy) accompanying the passing mid-level impulse will encourage high-based thunderstorm development from northern California to western Wyoming. The combination of these meteorological scenarios will support widespread wildfire ignition and/or growth concerns across much of the Intermountain West today. ...Eastern Great Basin to the Four Corners region... By afternoon peak heating, the aforementioned surface lee troughing will support widespread southwesterly surface winds in the 15-25 mph range amid 5-15 percent RH. Widespread Elevated highlights have been continued, with Critical highlights in place where guidance shows the highest likelihood of 20+ mph winds and 5-10 percent RH overlapping for several hours. Across both Elevated and Critical highlights, ERCs should easily exceed the 80th percentile, and thus would support wildfire spread. ...Along and to the lee of the Cascades... Strong flow westerly flow along the higher terrain, along with downslope flow to the lee of the Cascades, will result in 15-25 mph sustained westerly surface winds coinciding with RH as low as 15 percent in spots. Stronger surface winds and lower RH may occur in localized, terrain favoring areas. Either way, the aforementioned ambient surface conditions and dry fuels warrant Elevated highlights. ...Far northern California to far western Wyoming... During the afternoon, diurnal heating, upper support, and orographic lift will all support at least isolated thunderstorm development amid precipitable water values around 0.75 inches. Given dry fuels and potentially light rainfall accumulations with some of the storm cores, a few cells may be associated with efficient lightning-induced ignitions given cloud-to-ground strikes, warranting isolated dry thunderstorm highlights. Across northeastern portions of the Great Basin, storms closer to stronger mid-level flow may move faster, potentially supporting a regionally greater lightning-ignition rate given dry fuels and a lesser chance for rainfall accumulations. As such, scattered dry thunderstorm highlights have been continued. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sat Jun 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are likely across parts of the central Plains mainly this afternoon and evening. Large to very large hail, severe winds (some 75+ mph), and a few tornadoes are possible. ...Central Plains... Recent surface observations show a front extending from the central High Plains of eastern CO into KS, and continuing east-northeastward into the mid MS Valley/Upper Midwest. Isolated/elevated thunderstorms are ongoing this morning to the north of the front across parts of central NE into north-central KS, likely aided by weak low-level warm advection over the southern/central Plains. While isolated hail may occur in the short-term with this activity given weak MUCAPE and strong shear in the cloud-bearing layer, current expectations are for a more robust severe threat to develop across the central Plains later this afternoon and evening. Initially high-based thunderstorms will likely form by early to mid afternoon along/east of the higher terrain of eastern CO/southeast WY in a weak low-level upslope flow regime, and as modest large-scale ascent preceding an eastward-moving shortwave trough overspreads the central Rockies/High Plains. Greater low-level moisture (60s surface dewpoints) will be in place with eastward extent across KS/NE, and these thunderstorms should gradually strengthen as they move eastward. Deep-layer shear appears strong enough to support supercells with an attendant threat for large hail, with steep mid-level lapse rates and ample instability in the hail-growth zone possibly supporting isolated very large hail (2+ inches). While exact details of subsequent convective evolution remain somewhat unclear, these initial supercells will probably tend to interact/grow upscale in some form along and near the surface front from late afternoon through the evening as a southerly low-level jet strengthens over the central High Plains. An increasing threat for at least scattered severe/damaging winds should be realized as one or more bowing clusters spreads east-southeastward across NE/KS. Isolated significant gusts (75+ mph) may occur with the more intense portions of these clusters. Some risk for a few tornadoes should also exist, mainly late this afternoon into the evening with either persistent supercells or embedded within clusters as 0-1 km SRH increases in tandem with the low-level jet. A severe wind threat may continue through the overnight hours farther east across KS and perhaps into parts of western MO. ...Northern Utah/Eastern Idaho into Western/Central Wyoming... A weak mid-level shortwave trough over the northern Great Basin this morning will continue to move eastward across the northern/central Rockies today. Although low-level moisture is expected to remain limited along/west of the higher terrain, steepened low/mid-level lapse rates will exist with a very well-mixed boundary layer this afternoon. Modestly enhanced mid-level flow will support east-northeastward developing convection through the afternoon/evening across parts of northern UT/eastern ID into western/central WY. This activity may pose a threat for occasional strong to severe winds, but the overall severe threat should tend to remain isolated due to the weak instability forecast. ...Gulf Coast/Southeast... Modest flow aloft (generally 25 kt or less) will exist today across much of the Gulf Coast/Southeast, as a mid-level anticyclone remains anchored over the Gulf. A very moist low-level airmass, with surface dewpoints in the mid/upper 70s to low 80s, exists along/south of convection ongoing from parts of coastal/east TX into the lower MS Valley. Given the weak mid-level flow and related deep-layer shear, overall thunderstorm organization and intensity should remain fairly limited. Even so, occasional damaging winds could occur as the loosely organized cluster spreads east-southeastward into a destabilizing airmass across the lower MS Valley/central Gulf Coast states through the afternoon. ...Western Pennsylvania... Within west-northwesterly mid-level flow, low-topped thunderstorms should develop/move across parts of western PA and vicinity this afternoon. Instability will remain weak, but modestly enhanced flow and steep low-level lapse rates may support occasional strong gusts from convective downdrafts. The overall magnitude of the threat still appears too limited for low severe wind probabilities. ..Gleason/Broyles.. 06/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sat Jun 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are likely across parts of the central Plains mainly this afternoon and evening. Large to very large hail, severe winds (some 75+ mph), and a few tornadoes are possible. ...Central Plains... Recent surface observations show a front extending from the central High Plains of eastern CO into KS, and continuing east-northeastward into the mid MS Valley/Upper Midwest. Isolated/elevated thunderstorms are ongoing this morning to the north of the front across parts of central NE into north-central KS, likely aided by weak low-level warm advection over the southern/central Plains. While isolated hail may occur in the short-term with this activity given weak MUCAPE and strong shear in the cloud-bearing layer, current expectations are for a more robust severe threat to develop across the central Plains later this afternoon and evening. Initially high-based thunderstorms will likely form by early to mid afternoon along/east of the higher terrain of eastern CO/southeast WY in a weak low-level upslope flow regime, and as modest large-scale ascent preceding an eastward-moving shortwave trough overspreads the central Rockies/High Plains. Greater low-level moisture (60s surface dewpoints) will be in place with eastward extent across KS/NE, and these thunderstorms should gradually strengthen as they move eastward. Deep-layer shear appears strong enough to support supercells with an attendant threat for large hail, with steep mid-level lapse rates and ample instability in the hail-growth zone possibly supporting isolated very large hail (2+ inches). While exact details of subsequent convective evolution remain somewhat unclear, these initial supercells will probably tend to interact/grow upscale in some form along and near the surface front from late afternoon through the evening as a southerly low-level jet strengthens over the central High Plains. An increasing threat for at least scattered severe/damaging winds should be realized as one or more bowing clusters spreads east-southeastward across NE/KS. Isolated significant gusts (75+ mph) may occur with the more intense portions of these clusters. Some risk for a few tornadoes should also exist, mainly late this afternoon into the evening with either persistent supercells or embedded within clusters as 0-1 km SRH increases in tandem with the low-level jet. A severe wind threat may continue through the overnight hours farther east across KS and perhaps into parts of western MO. ...Northern Utah/Eastern Idaho into Western/Central Wyoming... A weak mid-level shortwave trough over the northern Great Basin this morning will continue to move eastward across the northern/central Rockies today. Although low-level moisture is expected to remain limited along/west of the higher terrain, steepened low/mid-level lapse rates will exist with a very well-mixed boundary layer this afternoon. Modestly enhanced mid-level flow will support east-northeastward developing convection through the afternoon/evening across parts of northern UT/eastern ID into western/central WY. This activity may pose a threat for occasional strong to severe winds, but the overall severe threat should tend to remain isolated due to the weak instability forecast. ...Gulf Coast/Southeast... Modest flow aloft (generally 25 kt or less) will exist today across much of the Gulf Coast/Southeast, as a mid-level anticyclone remains anchored over the Gulf. A very moist low-level airmass, with surface dewpoints in the mid/upper 70s to low 80s, exists along/south of convection ongoing from parts of coastal/east TX into the lower MS Valley. Given the weak mid-level flow and related deep-layer shear, overall thunderstorm organization and intensity should remain fairly limited. Even so, occasional damaging winds could occur as the loosely organized cluster spreads east-southeastward into a destabilizing airmass across the lower MS Valley/central Gulf Coast states through the afternoon. ...Western Pennsylvania... Within west-northwesterly mid-level flow, low-topped thunderstorms should develop/move across parts of western PA and vicinity this afternoon. Instability will remain weak, but modestly enhanced flow and steep low-level lapse rates may support occasional strong gusts from convective downdrafts. The overall magnitude of the threat still appears too limited for low severe wind probabilities. ..Gleason/Broyles.. 06/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sat Jun 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are likely across parts of the central Plains mainly this afternoon and evening. Large to very large hail, severe winds (some 75+ mph), and a few tornadoes are possible. ...Central Plains... Recent surface observations show a front extending from the central High Plains of eastern CO into KS, and continuing east-northeastward into the mid MS Valley/Upper Midwest. Isolated/elevated thunderstorms are ongoing this morning to the north of the front across parts of central NE into north-central KS, likely aided by weak low-level warm advection over the southern/central Plains. While isolated hail may occur in the short-term with this activity given weak MUCAPE and strong shear in the cloud-bearing layer, current expectations are for a more robust severe threat to develop across the central Plains later this afternoon and evening. Initially high-based thunderstorms will likely form by early to mid afternoon along/east of the higher terrain of eastern CO/southeast WY in a weak low-level upslope flow regime, and as modest large-scale ascent preceding an eastward-moving shortwave trough overspreads the central Rockies/High Plains. Greater low-level moisture (60s surface dewpoints) will be in place with eastward extent across KS/NE, and these thunderstorms should gradually strengthen as they move eastward. Deep-layer shear appears strong enough to support supercells with an attendant threat for large hail, with steep mid-level lapse rates and ample instability in the hail-growth zone possibly supporting isolated very large hail (2+ inches). While exact details of subsequent convective evolution remain somewhat unclear, these initial supercells will probably tend to interact/grow upscale in some form along and near the surface front from late afternoon through the evening as a southerly low-level jet strengthens over the central High Plains. An increasing threat for at least scattered severe/damaging winds should be realized as one or more bowing clusters spreads east-southeastward across NE/KS. Isolated significant gusts (75+ mph) may occur with the more intense portions of these clusters. Some risk for a few tornadoes should also exist, mainly late this afternoon into the evening with either persistent supercells or embedded within clusters as 0-1 km SRH increases in tandem with the low-level jet. A severe wind threat may continue through the overnight hours farther east across KS and perhaps into parts of western MO. ...Northern Utah/Eastern Idaho into Western/Central Wyoming... A weak mid-level shortwave trough over the northern Great Basin this morning will continue to move eastward across the northern/central Rockies today. Although low-level moisture is expected to remain limited along/west of the higher terrain, steepened low/mid-level lapse rates will exist with a very well-mixed boundary layer this afternoon. Modestly enhanced mid-level flow will support east-northeastward developing convection through the afternoon/evening across parts of northern UT/eastern ID into western/central WY. This activity may pose a threat for occasional strong to severe winds, but the overall severe threat should tend to remain isolated due to the weak instability forecast. ...Gulf Coast/Southeast... Modest flow aloft (generally 25 kt or less) will exist today across much of the Gulf Coast/Southeast, as a mid-level anticyclone remains anchored over the Gulf. A very moist low-level airmass, with surface dewpoints in the mid/upper 70s to low 80s, exists along/south of convection ongoing from parts of coastal/east TX into the lower MS Valley. Given the weak mid-level flow and related deep-layer shear, overall thunderstorm organization and intensity should remain fairly limited. Even so, occasional damaging winds could occur as the loosely organized cluster spreads east-southeastward into a destabilizing airmass across the lower MS Valley/central Gulf Coast states through the afternoon. ...Western Pennsylvania... Within west-northwesterly mid-level flow, low-topped thunderstorms should develop/move across parts of western PA and vicinity this afternoon. Instability will remain weak, but modestly enhanced flow and steep low-level lapse rates may support occasional strong gusts from convective downdrafts. The overall magnitude of the threat still appears too limited for low severe wind probabilities. ..Gleason/Broyles.. 06/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sat Jun 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are likely across parts of the central Plains mainly this afternoon and evening. Large to very large hail, severe winds (some 75+ mph), and a few tornadoes are possible. ...Central Plains... Recent surface observations show a front extending from the central High Plains of eastern CO into KS, and continuing east-northeastward into the mid MS Valley/Upper Midwest. Isolated/elevated thunderstorms are ongoing this morning to the north of the front across parts of central NE into north-central KS, likely aided by weak low-level warm advection over the southern/central Plains. While isolated hail may occur in the short-term with this activity given weak MUCAPE and strong shear in the cloud-bearing layer, current expectations are for a more robust severe threat to develop across the central Plains later this afternoon and evening. Initially high-based thunderstorms will likely form by early to mid afternoon along/east of the higher terrain of eastern CO/southeast WY in a weak low-level upslope flow regime, and as modest large-scale ascent preceding an eastward-moving shortwave trough overspreads the central Rockies/High Plains. Greater low-level moisture (60s surface dewpoints) will be in place with eastward extent across KS/NE, and these thunderstorms should gradually strengthen as they move eastward. Deep-layer shear appears strong enough to support supercells with an attendant threat for large hail, with steep mid-level lapse rates and ample instability in the hail-growth zone possibly supporting isolated very large hail (2+ inches). While exact details of subsequent convective evolution remain somewhat unclear, these initial supercells will probably tend to interact/grow upscale in some form along and near the surface front from late afternoon through the evening as a southerly low-level jet strengthens over the central High Plains. An increasing threat for at least scattered severe/damaging winds should be realized as one or more bowing clusters spreads east-southeastward across NE/KS. Isolated significant gusts (75+ mph) may occur with the more intense portions of these clusters. Some risk for a few tornadoes should also exist, mainly late this afternoon into the evening with either persistent supercells or embedded within clusters as 0-1 km SRH increases in tandem with the low-level jet. A severe wind threat may continue through the overnight hours farther east across KS and perhaps into parts of western MO. ...Northern Utah/Eastern Idaho into Western/Central Wyoming... A weak mid-level shortwave trough over the northern Great Basin this morning will continue to move eastward across the northern/central Rockies today. Although low-level moisture is expected to remain limited along/west of the higher terrain, steepened low/mid-level lapse rates will exist with a very well-mixed boundary layer this afternoon. Modestly enhanced mid-level flow will support east-northeastward developing convection through the afternoon/evening across parts of northern UT/eastern ID into western/central WY. This activity may pose a threat for occasional strong to severe winds, but the overall severe threat should tend to remain isolated due to the weak instability forecast. ...Gulf Coast/Southeast... Modest flow aloft (generally 25 kt or less) will exist today across much of the Gulf Coast/Southeast, as a mid-level anticyclone remains anchored over the Gulf. A very moist low-level airmass, with surface dewpoints in the mid/upper 70s to low 80s, exists along/south of convection ongoing from parts of coastal/east TX into the lower MS Valley. Given the weak mid-level flow and related deep-layer shear, overall thunderstorm organization and intensity should remain fairly limited. Even so, occasional damaging winds could occur as the loosely organized cluster spreads east-southeastward into a destabilizing airmass across the lower MS Valley/central Gulf Coast states through the afternoon. ...Western Pennsylvania... Within west-northwesterly mid-level flow, low-topped thunderstorms should develop/move across parts of western PA and vicinity this afternoon. Instability will remain weak, but modestly enhanced flow and steep low-level lapse rates may support occasional strong gusts from convective downdrafts. The overall magnitude of the threat still appears too limited for low severe wind probabilities. ..Gleason/Broyles.. 06/20/2026 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Sat Jun 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... An extended period of moderate northwesterly flow across the High Plains will lead to severe weather potential across the central High Plains. Upslope flow amid 30 to 50 knots mid-level winds should result in a severe weather environment, potentially on Tuesday, and particularly Wednesday and Thursday. The front will shift based on small-scale embedded shortwave disturbances and the prior day's convection, which will shift the location of the unstable warm sector. This results in uncertainty regarding the location of the threat for each day. This will continue to be monitored for potential areas to be added later. Ridging will slide east across the Rockies and into the Plains by next weekend. Some severe weather threat may exist through this time as multiple embedded shortwave troughs will be within this region as instability increases across the Plains. While it is mostly beyond Day 8, it is worth nothing that deterministic, ensemble, and AI guidance all indicate a strong jet streak and mid-level trough traversing the Rockies toward the end of next weekend and into early next week. A strong lee cyclone would accompany this with strong instability across the Plains. There is still uncertainty with the timing and location of the trough, but given the agreement in this general pattern change, a substantial severe weather threat seems possible by the end of next weekend and early into the following week across portions of the central/northern Plains into the Upper Midwest. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Sat Jun 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... An extended period of moderate northwesterly flow across the High Plains will lead to severe weather potential across the central High Plains. Upslope flow amid 30 to 50 knots mid-level winds should result in a severe weather environment, potentially on Tuesday, and particularly Wednesday and Thursday. The front will shift based on small-scale embedded shortwave disturbances and the prior day's convection, which will shift the location of the unstable warm sector. This results in uncertainty regarding the location of the threat for each day. This will continue to be monitored for potential areas to be added later. Ridging will slide east across the Rockies and into the Plains by next weekend. Some severe weather threat may exist through this time as multiple embedded shortwave troughs will be within this region as instability increases across the Plains. While it is mostly beyond Day 8, it is worth nothing that deterministic, ensemble, and AI guidance all indicate a strong jet streak and mid-level trough traversing the Rockies toward the end of next weekend and into early next week. A strong lee cyclone would accompany this with strong instability across the Plains. There is still uncertainty with the timing and location of the trough, but given the agreement in this general pattern change, a substantial severe weather threat seems possible by the end of next weekend and early into the following week across portions of the central/northern Plains into the Upper Midwest. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Sat Jun 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... An extended period of moderate northwesterly flow across the High Plains will lead to severe weather potential across the central High Plains. Upslope flow amid 30 to 50 knots mid-level winds should result in a severe weather environment, potentially on Tuesday, and particularly Wednesday and Thursday. The front will shift based on small-scale embedded shortwave disturbances and the prior day's convection, which will shift the location of the unstable warm sector. This results in uncertainty regarding the location of the threat for each day. This will continue to be monitored for potential areas to be added later. Ridging will slide east across the Rockies and into the Plains by next weekend. Some severe weather threat may exist through this time as multiple embedded shortwave troughs will be within this region as instability increases across the Plains. While it is mostly beyond Day 8, it is worth nothing that deterministic, ensemble, and AI guidance all indicate a strong jet streak and mid-level trough traversing the Rockies toward the end of next weekend and into early next week. A strong lee cyclone would accompany this with strong instability across the Plains. There is still uncertainty with the timing and location of the trough, but given the agreement in this general pattern change, a substantial severe weather threat seems possible by the end of next weekend and early into the following week across portions of the central/northern Plains into the Upper Midwest. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0238 AM CDT Sat Jun 20 2026 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS AND SOUTHERN PLAINS TO THE MID-SOUTH AND INTO THE CAROLINAS AND MID-ATLANTIC.... CORRECTED FOR CAPITALIZATION IN THE SUMMARY ...SUMMARY... Isolated strong to severe storms are expected along a frontal zone that extends from the mid-Atlantic to the Mid-South and southern Plains and into the central High Plains on Monday. ...Synopsis... A flat ridge is forecast across the western CONUS with broad cyclonic flow from the southern Plains to the Mid-Atlantic. Within this zone, several embedded mid-level shortwave troughs are expected, the strongest of which will move from the Ohio Valley to the Mid-Atlantic during the day Monday. A weak surface low will likely be associated with this lead shortwave trough with an additional lee trough, likely across the southern High Plains. A frontal zone will extend between these 2 features and act as the primary focus for storm development through the period on Monday. ...Central/southern Plains... A MCS should be ongoing at the beginning of the period across parts of Oklahoma on the nose of the low-level jet. An outflow boundary will likely extend westward from this MCS into parts of Northwest Texas and into the Texas Panhandle. Very strong to extreme instability is forecast across the southern Plains on Monday with dewpoints in the mid to upper 70s and steep lapse rates. Model guidance is consistent showing a weak mid-level shortwave trough emerging across the southern Plains by 00Z Tuesday with 30 to 35 knots of mid-level flow. The combination of this shortwave trough and the potential for an outflow boundary intersecting the dryline may result in a more focused area of severe potential Monday afternoon/evening. However, due to the mesoscale nature of this potential, confidence is not high enough to add a Slight Risk at this time. ...Mid South... Moderate to strong instability is forecast to develop ahead of the MCS across Oklahoma and Arkansas Monday morning. Given the very moist airmass, inhibition should be eroded by mid-day. Therefore, reintensification of the morning MCS or additional development to the east along the front (likely a combination of both) is expected from near the Red River to northern Mississippi. This strong instability, combined with modest shear, will support some damaging wind threat with a southeastward moving cluster of storms Monday afternoon/evening. ...Carolinas to the Mid-Atlantic... A moist airmass will move into the Carolinas and Mid-Atlantic on Monday ahead of an eastward moving cold front. Mid-level lapse rates will be weak which will limit overall instability, but moderate shear and sufficient instability, combined with steep low-level lapse rates will support some damaging wind threat Monday afternoon/evening. In addition, a smaller area of greater low-level shear may exist closer to the surface low across northern Virginia and vicinity, which could have a localized region of greater tornado threat. ..Bentley.. 06/20/2026 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0238 AM CDT Sat Jun 20 2026 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS AND SOUTHERN PLAINS TO THE MID-SOUTH AND INTO THE CAROLINAS AND MID-ATLANTIC.... CORRECTED FOR CAPITALIZATION IN THE SUMMARY ...SUMMARY... Isolated strong to severe storms are expected along a frontal zone that extends from the mid-Atlantic to the Mid-South and southern Plains and into the central High Plains on Monday. ...Synopsis... A flat ridge is forecast across the western CONUS with broad cyclonic flow from the southern Plains to the Mid-Atlantic. Within this zone, several embedded mid-level shortwave troughs are expected, the strongest of which will move from the Ohio Valley to the Mid-Atlantic during the day Monday. A weak surface low will likely be associated with this lead shortwave trough with an additional lee trough, likely across the southern High Plains. A frontal zone will extend between these 2 features and act as the primary focus for storm development through the period on Monday. ...Central/southern Plains... A MCS should be ongoing at the beginning of the period across parts of Oklahoma on the nose of the low-level jet. An outflow boundary will likely extend westward from this MCS into parts of Northwest Texas and into the Texas Panhandle. Very strong to extreme instability is forecast across the southern Plains on Monday with dewpoints in the mid to upper 70s and steep lapse rates. Model guidance is consistent showing a weak mid-level shortwave trough emerging across the southern Plains by 00Z Tuesday with 30 to 35 knots of mid-level flow. The combination of this shortwave trough and the potential for an outflow boundary intersecting the dryline may result in a more focused area of severe potential Monday afternoon/evening. However, due to the mesoscale nature of this potential, confidence is not high enough to add a Slight Risk at this time. ...Mid South... Moderate to strong instability is forecast to develop ahead of the MCS across Oklahoma and Arkansas Monday morning. Given the very moist airmass, inhibition should be eroded by mid-day. Therefore, reintensification of the morning MCS or additional development to the east along the front (likely a combination of both) is expected from near the Red River to northern Mississippi. This strong instability, combined with modest shear, will support some damaging wind threat with a southeastward moving cluster of storms Monday afternoon/evening. ...Carolinas to the Mid-Atlantic... A moist airmass will move into the Carolinas and Mid-Atlantic on Monday ahead of an eastward moving cold front. Mid-level lapse rates will be weak which will limit overall instability, but moderate shear and sufficient instability, combined with steep low-level lapse rates will support some damaging wind threat Monday afternoon/evening. In addition, a smaller area of greater low-level shear may exist closer to the surface low across northern Virginia and vicinity, which could have a localized region of greater tornado threat. ..Bentley.. 06/20/2026 Read more