SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0118 AM CST Tue Dec 23 2025
Valid 241200Z - 251200Z
...Synopsis...
A mid-level ridge will persist across the central U.S., with a
highly amplified mid-level trough poised to gradually drift eastward
across the Interior West tomorrow (Wednesday). Lee troughing across
the High Plains will intensify through the day, promoting a modestly
stronger surface wind field across the southern High Plains compared
to Day 1. 15 mph sustained westerly surface winds will coincide with
15-20 percent RH during the afternoon across northeast New Mexico
into the Texas Panhandle and far southwestern Kansas. Given dry
fuels over this region, Elevated highlights have been introduced.
..Squitieri.. 12/23/2025
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0118 AM CST Tue Dec 23 2025
Valid 241200Z - 251200Z
...Synopsis...
A mid-level ridge will persist across the central U.S., with a
highly amplified mid-level trough poised to gradually drift eastward
across the Interior West tomorrow (Wednesday). Lee troughing across
the High Plains will intensify through the day, promoting a modestly
stronger surface wind field across the southern High Plains compared
to Day 1. 15 mph sustained westerly surface winds will coincide with
15-20 percent RH during the afternoon across northeast New Mexico
into the Texas Panhandle and far southwestern Kansas. Given dry
fuels over this region, Elevated highlights have been introduced.
..Squitieri.. 12/23/2025
...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
0118 AM CST Tue Dec 23 2025
Valid 231200Z - 241200Z
...NO CRITICAL AREAS...
...Synopsis...
Upper ridging will remain in place east of the Rockies while a
highly amplified mid-level trough impinges on the West Coast today.
Surface lee troughing will encourage moisture return across the
Plains states, with relatively drier air meandering along the
immediate lee of the Rockies. Surface winds along the southern into
central High Plains will be relatively weak on a large-scale basis
though, with wildfire-spread concerns remaining localized at best.
..Squitieri.. 12/23/2025
...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
0118 AM CST Tue Dec 23 2025
Valid 231200Z - 241200Z
...NO CRITICAL AREAS...
...Synopsis...
Upper ridging will remain in place east of the Rockies while a
highly amplified mid-level trough impinges on the West Coast today.
Surface lee troughing will encourage moisture return across the
Plains states, with relatively drier air meandering along the
immediate lee of the Rockies. Surface winds along the southern into
central High Plains will be relatively weak on a large-scale basis
though, with wildfire-spread concerns remaining localized at best.
..Squitieri.. 12/23/2025
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CST Tue Dec 23 2025
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG PARTS OF
THE CALIFORNIA COAST AND INLAND IN THE SAN JOAQUIN VALLEY...
...SUMMARY...
Thunderstorms with marginally severe wind gusts, hail and
potentially a brief tornado will be possible from Wednesday into
Wednesday night along parts of the California coast, and inland
across the San Jouquin Valley.
...California...
A ridge aloft will move eastward across the central U.S. on
Wednesday, as a mid-level trough moves eastward across the eastern
Pacific. Ahead of this large-scale feature, a subtle shortwave
trough will approach the California coast Wednesday afternoon. As
heights gradually fall, large-scale ascent and mid-level moisture
will overspread most of California during the day. Thunderstorm
development will be possible along the central and southern
California coast, and inland across the San Joaquin Valley. The
greatest chance for severe storms will be as the left exit region of
a 90 to 100 knot mid-level jet moves across the San Joaquin Valley
during the mid to late afternoon. Near this feature, very strong
deep-layer shear will exist and MUCAPE is expected to peak in the
500 to 750 J/kg range. This should be enough for a few
semi-organized storms with a threat for hail and marginally severe
gusts. A brief tornado will also be possible. An isolated severe
threat is expected to continue into the overnight period, and may
shift southward along the coast into southern California, as a
second minor impulse approaches and moves inland.
..Broyles.. 12/23/2025
Read more
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1119 PM CST Mon Dec 22 2025
Valid 231200Z - 241200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorm potential will increase along the California coast late
tonight. Organized severe is not currently forecast.
...CA...
Strong short-wave trough is forecast to approach the northern CA
coast after 24/06z, then eject inland by sunrise as midlevel speed
max intensifies and translates into northern CA. Latest model
guidance suggests this feature will induce a surface low that should
deepen as it approaches the northern CA/OR coast. This evolution
will allow a notable surface front to surge inland toward the end of
the period, around 24/12z. Wind profiles are expected to increase
markedly ahead of this feature, but pre frontal buoyancy will remain
quite limited. Forecast soundings support this with roughly 100-200
J/kg MUCAPE expected just ahead of the front. Given the strength of
the wind field there is some concern that a few strong gusts could
be noted with deeper convection; however, this activity should
develop very late (after 09z), possibly becoming more problematic
during the day2 period. At this time will not introduce severe
probabilities due to the expected late-period development, but will
continue to monitor for possible upgrade.
...South TX...
Weak midlevel disturbance is lifting north into deep south TX late
this evening. Forecast soundings suggest modest SBCAPE will develop
by mid day as this feature progresses north of the international
border. Wind fields should remain weak, along with forcing, so the
risk of severe is expected to remain low this period.
..Darrow/Squitieri.. 12/23/2025
Read more
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1119 PM CST Mon Dec 22 2025
Valid 231200Z - 241200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorm potential will increase along the California coast late
tonight. Organized severe is not currently forecast.
...CA...
Strong short-wave trough is forecast to approach the northern CA
coast after 24/06z, then eject inland by sunrise as midlevel speed
max intensifies and translates into northern CA. Latest model
guidance suggests this feature will induce a surface low that should
deepen as it approaches the northern CA/OR coast. This evolution
will allow a notable surface front to surge inland toward the end of
the period, around 24/12z. Wind profiles are expected to increase
markedly ahead of this feature, but pre frontal buoyancy will remain
quite limited. Forecast soundings support this with roughly 100-200
J/kg MUCAPE expected just ahead of the front. Given the strength of
the wind field there is some concern that a few strong gusts could
be noted with deeper convection; however, this activity should
develop very late (after 09z), possibly becoming more problematic
during the day2 period. At this time will not introduce severe
probabilities due to the expected late-period development, but will
continue to monitor for possible upgrade.
...South TX...
Weak midlevel disturbance is lifting north into deep south TX late
this evening. Forecast soundings suggest modest SBCAPE will develop
by mid day as this feature progresses north of the international
border. Wind fields should remain weak, along with forcing, so the
risk of severe is expected to remain low this period.
..Darrow/Squitieri.. 12/23/2025
Read more
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0627 PM CST Mon Dec 22 2025
Valid 230100Z - 231200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorm probabilities are low tonight.
...01z Update...
Water-vapor imagery depicts a notable short-wave trough advancing
inland along the Pacific Northwest coast. A few flashes of lighting
have been observed with deeper convection ahead of this feature,
primarily across more buoyant regions offshore. While an isolated
thunderstorm can not be ruled out for the next few hours, lightning
probabilities appear too low to warrant a categorical risk of
thunderstorms the rest of tonight.
Lighting has decreased notably across the western Gulf basin in
association with a weak disturbance lifting north toward deep South
TX. 00z sounding at BRO does exhibit uninhibited SBCAPE, but loss of
daytime heating and weak forcing does not appear particularly
favorable for more than a rogue flash of lightning, and that is
primarily over the next few hours.
..Darrow.. 12/23/2025
Read more
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0627 PM CST Mon Dec 22 2025
Valid 230100Z - 231200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorm probabilities are low tonight.
...01z Update...
Water-vapor imagery depicts a notable short-wave trough advancing
inland along the Pacific Northwest coast. A few flashes of lighting
have been observed with deeper convection ahead of this feature,
primarily across more buoyant regions offshore. While an isolated
thunderstorm can not be ruled out for the next few hours, lightning
probabilities appear too low to warrant a categorical risk of
thunderstorms the rest of tonight.
Lighting has decreased notably across the western Gulf basin in
association with a weak disturbance lifting north toward deep South
TX. 00z sounding at BRO does exhibit uninhibited SBCAPE, but loss of
daytime heating and weak forcing does not appear particularly
favorable for more than a rogue flash of lightning, and that is
primarily over the next few hours.
..Darrow.. 12/23/2025
Read more
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0347 PM CST Mon Dec 22 2025
Valid 241200Z - 301200Z
...Synopsis...
An upper-level ridge over the central U.S. should begin to deamplify
through the end of the week as an mid/upper trough gradually moves
into Intermountain West. Well above normal temperatures under the
ridge will likely be daily occurrences with minimal precipitation
expected, particularly across the southern Great Plains where
expanding rainfall deficits, dry fuels and dry and breezy conditions
could align to support an increased fire weather threat. A
descending upper-level trough into the Northeast along with a
deepening surface cyclone should drive a strong cold front through
the Great Plains and eastern U.S. over the weekend. Precipitation
should be limited to the TN Valley/Appalachians region where deeper
boundary layer moisture and stronger upper-level support exists. A
more diffuse surface pressure gradient and generally lighter wind
regime emerges as high pressure settles in east of the Continental
Divide early next week although initial dry post-frontal flow could
reinvigorate a fire weather threat across the southern Plains and TX
early next week.
...Day 3-5/Wednesday-Friday - Southern Plains...
Lee troughing across the Central Plains and persistent southwesterly
flow aloft will promote dry and breezy conditions across the OK/TX
Panhandle and northeastern NM on Day 3/Wednesday. Deeper return flow
moisture from the Gulf will limit fire weather concerns to the
southern High Plains Wednesday. A breakdown in the upper-level ridge
across the central U.S. along with increasing west-southwest flow
aloft will continue to support breezy conditions across the southern
High Plains Thursday. A plume of Pacific moisture and mid/upper
cloud cover associated with an impinging western U.S. trough should
arrive Day 4/Thursday across the Southern High Plains. Additional
cloud cover, increasing surface dewpoints and limited RH reductions
could limit the fire weather threat to an extent, but near record
warmth along with an increasingly dry fuelscape and breezy
west-southwest winds supports introduction of 40% critical
probabilities for Thursday for portions of the TX Panhandle and far
eastern NM. Increasing west/southwest flow aloft from a mid-level
jet and continued lee troughing should keep a dry downslope regime
across the southern Plains through Day 5/Friday. A better boundary
layer mixing environment with less cloud cover and persistently warm
temperatures should support low daytime RH across the Southern
Plains Friday. A 40% critical probability area was added to cover
this likely fire weather concern across far eastern NM and portions
of the TX Panhandle.
...Days 6-8/Saturday-Monday...
Some forecast uncertainty remains in the timing and intensity of
pre/post-frontal winds across the central and southern Plains over
the weekend. This could present ongoing fire weather threats across
the south-central CONUS and even the Southeast where minimal
rainfall and above normal temperatures allow more receptive fuels to
develop through early next week. Critical probabilities were
withheld due to ongoing uncertainty and longer term ensemble
guidance.
..Williams.. 12/22/2025
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0347 PM CST Mon Dec 22 2025
Valid 241200Z - 301200Z
...Synopsis...
An upper-level ridge over the central U.S. should begin to deamplify
through the end of the week as an mid/upper trough gradually moves
into Intermountain West. Well above normal temperatures under the
ridge will likely be daily occurrences with minimal precipitation
expected, particularly across the southern Great Plains where
expanding rainfall deficits, dry fuels and dry and breezy conditions
could align to support an increased fire weather threat. A
descending upper-level trough into the Northeast along with a
deepening surface cyclone should drive a strong cold front through
the Great Plains and eastern U.S. over the weekend. Precipitation
should be limited to the TN Valley/Appalachians region where deeper
boundary layer moisture and stronger upper-level support exists. A
more diffuse surface pressure gradient and generally lighter wind
regime emerges as high pressure settles in east of the Continental
Divide early next week although initial dry post-frontal flow could
reinvigorate a fire weather threat across the southern Plains and TX
early next week.
...Day 3-5/Wednesday-Friday - Southern Plains...
Lee troughing across the Central Plains and persistent southwesterly
flow aloft will promote dry and breezy conditions across the OK/TX
Panhandle and northeastern NM on Day 3/Wednesday. Deeper return flow
moisture from the Gulf will limit fire weather concerns to the
southern High Plains Wednesday. A breakdown in the upper-level ridge
across the central U.S. along with increasing west-southwest flow
aloft will continue to support breezy conditions across the southern
High Plains Thursday. A plume of Pacific moisture and mid/upper
cloud cover associated with an impinging western U.S. trough should
arrive Day 4/Thursday across the Southern High Plains. Additional
cloud cover, increasing surface dewpoints and limited RH reductions
could limit the fire weather threat to an extent, but near record
warmth along with an increasingly dry fuelscape and breezy
west-southwest winds supports introduction of 40% critical
probabilities for Thursday for portions of the TX Panhandle and far
eastern NM. Increasing west/southwest flow aloft from a mid-level
jet and continued lee troughing should keep a dry downslope regime
across the southern Plains through Day 5/Friday. A better boundary
layer mixing environment with less cloud cover and persistently warm
temperatures should support low daytime RH across the Southern
Plains Friday. A 40% critical probability area was added to cover
this likely fire weather concern across far eastern NM and portions
of the TX Panhandle.
...Days 6-8/Saturday-Monday...
Some forecast uncertainty remains in the timing and intensity of
pre/post-frontal winds across the central and southern Plains over
the weekend. This could present ongoing fire weather threats across
the south-central CONUS and even the Southeast where minimal
rainfall and above normal temperatures allow more receptive fuels to
develop through early next week. Critical probabilities were
withheld due to ongoing uncertainty and longer term ensemble
guidance.
..Williams.. 12/22/2025
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0146 PM CST Mon Dec 22 2025
Valid 231200Z - 241200Z
...NO CRITICAL AREAS...
An amplifying mid/upper level ridge over the central U.S. and a
deepening trough heading into the West Coast will maintain broad
southwest flow aloft over the western U.S. However, somewhat weaker
mid-level winds coupled with lower magnitude lee troughing in the
central High Plains will limit development of a broader downslope
wind event along the wind-prone areas of the CO Rockies. Localized
accelerations of winds are expected within favorable terrain gaps,
but widespread elevated fire weather conditions appear to remain
low. Additional upper-level cloud cover streaming ahead of the
trough across the western U.S. will also inhibit optimal boundary
layer mixing and stronger surface wind potential. Farther south,
very dry conditions and anomalously warm temperatures in the 70s and
lower 80s will prevail across much of the southern High Plains but
lighter winds should mitigate the overall fire weather threat.
..Williams.. 12/22/2025
.PREV DISCUSSION... /ISSUED 1246 AM CST Mon Dec 22 2025/
...Synopsis...
Upper ridging will persist across the central and eastern U.S. as a
mid-level trough impinges on the West Coast tomorrow (Tuesday).
Surface lee troughing will continue across the central U.S., with
gradual moisture return from the Gulf expected. A dry low-level
airmass will continue to linger along the central and southern High
Plains. However, surface wind fields over the western portions of
the Plains will be weaker compared to Day 1, with no fire weather
highlights introduced for this outlook.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0146 PM CST Mon Dec 22 2025
Valid 231200Z - 241200Z
...NO CRITICAL AREAS...
An amplifying mid/upper level ridge over the central U.S. and a
deepening trough heading into the West Coast will maintain broad
southwest flow aloft over the western U.S. However, somewhat weaker
mid-level winds coupled with lower magnitude lee troughing in the
central High Plains will limit development of a broader downslope
wind event along the wind-prone areas of the CO Rockies. Localized
accelerations of winds are expected within favorable terrain gaps,
but widespread elevated fire weather conditions appear to remain
low. Additional upper-level cloud cover streaming ahead of the
trough across the western U.S. will also inhibit optimal boundary
layer mixing and stronger surface wind potential. Farther south,
very dry conditions and anomalously warm temperatures in the 70s and
lower 80s will prevail across much of the southern High Plains but
lighter winds should mitigate the overall fire weather threat.
..Williams.. 12/22/2025
.PREV DISCUSSION... /ISSUED 1246 AM CST Mon Dec 22 2025/
...Synopsis...
Upper ridging will persist across the central and eastern U.S. as a
mid-level trough impinges on the West Coast tomorrow (Tuesday).
Surface lee troughing will continue across the central U.S., with
gradual moisture return from the Gulf expected. A dry low-level
airmass will continue to linger along the central and southern High
Plains. However, surface wind fields over the western portions of
the Plains will be weaker compared to Day 1, with no fire weather
highlights introduced for this outlook.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0136 PM CST Mon Dec 22 2025
Valid 222000Z - 231200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected today.
...20z Update...
The previous outlook reasoning remains on track and no changes were
made with this update.
..Bunting.. 12/22/2025
.PREV DISCUSSION... /ISSUED 1008 AM CST Mon Dec 22 2025/
...Synopsis...
A pronounced midlevel shortwave trough and associated baroclinic
zone will move across the WA coast later this afternoon.
Low-midlevel lapse rates will contribute to weak buoyancy of
sufficient depth (through -20 C at the equilibrium level) for charge
separation and isolated lightning flashes with low-topped convection
along and behind the front. Shallow, weakly rotating convection
will be possible near the WA coast per the KLGX VWP/hodograph, but
the threat for severe storms appears too limited to warrant an
outlook area. Farther south, the potential for isolated lightning
flashes will slowly wane through the day across the northern Sierra
Nevada, where weak buoyancy rooted above the surface will likewise
diminish.
Otherwise, a broad subtropical ridge (with unusually high
geopotential heights) covers the southern Plains/Gulf coast. An
embedded/weak midlevel trough will rotate slowly north-northwestward
around the periphery of the ridge, bringing weak ascent and an
associated moisture plume into south TX. Per the observed deepening
of the moist layer at BRO in the past 12 hours, pockets of surface
heating/destabilization could support isolated thunderstorm
development across south TX this afternoon.
Read more
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0136 PM CST Mon Dec 22 2025
Valid 222000Z - 231200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected today.
...20z Update...
The previous outlook reasoning remains on track and no changes were
made with this update.
..Bunting.. 12/22/2025
.PREV DISCUSSION... /ISSUED 1008 AM CST Mon Dec 22 2025/
...Synopsis...
A pronounced midlevel shortwave trough and associated baroclinic
zone will move across the WA coast later this afternoon.
Low-midlevel lapse rates will contribute to weak buoyancy of
sufficient depth (through -20 C at the equilibrium level) for charge
separation and isolated lightning flashes with low-topped convection
along and behind the front. Shallow, weakly rotating convection
will be possible near the WA coast per the KLGX VWP/hodograph, but
the threat for severe storms appears too limited to warrant an
outlook area. Farther south, the potential for isolated lightning
flashes will slowly wane through the day across the northern Sierra
Nevada, where weak buoyancy rooted above the surface will likewise
diminish.
Otherwise, a broad subtropical ridge (with unusually high
geopotential heights) covers the southern Plains/Gulf coast. An
embedded/weak midlevel trough will rotate slowly north-northwestward
around the periphery of the ridge, bringing weak ascent and an
associated moisture plume into south TX. Per the observed deepening
of the moist layer at BRO in the past 12 hours, pockets of surface
heating/destabilization could support isolated thunderstorm
development across south TX this afternoon.
Read more
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0127 PM CST Mon Dec 22 2025
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
COASTAL CALIFORNIA AND PORTIONS OF THE CENTRAL VALLEY...
...SUMMARY...
Isolated strong to occasionally severe thunderstorms are possible on
Wednesday and Wednesday night across portions of California.
...Synopsis...
A pronounced upper ridge will remain anchored over the central and
eastern US while strong troughing persists over the West Coast. A
series of embedded impulses will move onshore Wednesday and
Wednesday night, coincident with their attendant deepening surface
lows. A cold front and persistent southwesterly low-level flow
should support isolated thunderstorms over much of the West Coast
through early Thursday.
...California...
As troughing deepens over the eastern Pacific, several embedded
disturbances will propagate eastward overspreading modest low-level
moisture from the CA coast to the central valley. Robust forcing for
ascent and cold temperatures aloft (-24 to -26 C) overspreading 50s
F dewpoints will likely support weak buoyancy along the southern CA
coast and central Valley. A prolonged period of scattered showers
and episodic periods of isolated thunderstorms are possible
Wednesday morning and afternoon. Of these storms, sufficient CAPE,
strong flow aloft and locally enlarged hodographs may allow for a
few semi-organized/weakly rotating storms to mature. Sporadic
damaging gusts, small hail and a brief tornado would be possible
with the strongest storms before convection weakens into the evening
and first part of the overnight hours.
Additional low-topped linear storms/localized squalls are also
possible ahead of the advancing cold front near the immediate
coastal portions of central and northern CA primarily late Wednesday
into Wednesday night. A few strong gusts are possible, though
instability should quickly decrease inland.
Elsewhere across the US, the prominent ridging will favor dry and
unseasonably warm conditions with little potential for
thunderstorms.
..Lyons.. 12/22/2025
Read more
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0127 PM CST Mon Dec 22 2025
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
COASTAL CALIFORNIA AND PORTIONS OF THE CENTRAL VALLEY...
...SUMMARY...
Isolated strong to occasionally severe thunderstorms are possible on
Wednesday and Wednesday night across portions of California.
...Synopsis...
A pronounced upper ridge will remain anchored over the central and
eastern US while strong troughing persists over the West Coast. A
series of embedded impulses will move onshore Wednesday and
Wednesday night, coincident with their attendant deepening surface
lows. A cold front and persistent southwesterly low-level flow
should support isolated thunderstorms over much of the West Coast
through early Thursday.
...California...
As troughing deepens over the eastern Pacific, several embedded
disturbances will propagate eastward overspreading modest low-level
moisture from the CA coast to the central valley. Robust forcing for
ascent and cold temperatures aloft (-24 to -26 C) overspreading 50s
F dewpoints will likely support weak buoyancy along the southern CA
coast and central Valley. A prolonged period of scattered showers
and episodic periods of isolated thunderstorms are possible
Wednesday morning and afternoon. Of these storms, sufficient CAPE,
strong flow aloft and locally enlarged hodographs may allow for a
few semi-organized/weakly rotating storms to mature. Sporadic
damaging gusts, small hail and a brief tornado would be possible
with the strongest storms before convection weakens into the evening
and first part of the overnight hours.
Additional low-topped linear storms/localized squalls are also
possible ahead of the advancing cold front near the immediate
coastal portions of central and northern CA primarily late Wednesday
into Wednesday night. A few strong gusts are possible, though
instability should quickly decrease inland.
Elsewhere across the US, the prominent ridging will favor dry and
unseasonably warm conditions with little potential for
thunderstorms.
..Lyons.. 12/22/2025
Read more
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1112 AM CST Mon Dec 22 2025
Valid 231200Z - 241200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Organized severe thunderstorms are not currently forecast across the
contiguous United States on Tuesday or Tuesday night.
...Synopsis...
An expansive and unseasonably strong upper ridge will dominate the
mid and upper-level flow pattern across the CONUS Day2/Tuesday. As
the ridge intensifies, troughing on the flanks of the ridge will
also strengthen. The western most trough, and a mid-level shortwave
trough embedded within it will likely reach the central and northern
CA coastal areas late Tuesday night. Strong ascent and flow aloft
will support a deepening surface low which will support onshore flow
and some thunderstorm potential over much of coastal CA/OR.
...West Coast...
As the upper trough deepens over the West Coast, strong onshore flow
will develop and support inland transport of low-level moisture
across much of coast and the CA central Valley. Cooling mid-level
temperatures and strong ascent associated with the embedded
shortwave will overspread this air mass contributing to weak
destabilization late Tuesday through early Wednesday. Low-topped
convection, capable of occasional lightning, is expected to increase
in coverage overnight. While a stronger storm is possible,
especially along and ahead of the surface cold front, the scant
buoyancy and overnight timing suggest severe potential is very low.
Elsewhere, moisture advection is likely over parts of the southern
Plains and far south TX beneath the upper ridge as the surface
reflection shifts eastward. Despite persistent southerly flow and
increasing surface dewpoints, little to no ascent and warm mid-level
temperatures should preclude thunderstorm development outside of far
south TX.
..Lyons.. 12/22/2025
Read more
