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U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 201553
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1053 AM CDT Mon Apr 20 2026
Valid 201700Z - 211200Z
...Morning Update...
No changes were made to the previous forecast. Current surface
observations depict widespread RH values of 10-30 percent across
portions of the central/southern Plains owing to poor overnight
humidity recoveries. Parts of the Southeast also experienced poor
humidity recoveries, with current RH values in the upper 20s. Any
new ignitions and ongoing wildfires in this region will experience
elevated to locally critical fire weather conditions this afternoon
as northeasterly winds increase and RH decreases atop exceptionally
dry fuels. See the previous discussion for more information.
..Elizalde-Garcia.. 04/20/2026
.PREV DISCUSSION... /ISSUED 0128 AM CDT Mon Apr 20 2026/
...Synopsis...
Upper-level ridging will gradually shift eastward from the Rockies
into the Plains through today as an upper-level trough departs the
East Coast and a second, closed upper trough approaches the West
Coast. Surface high pressure will shift east over the
Southeast/Mid-Atlantic while a lee trough deepens along the
central/northern High Plains.
...Portions of the central High Plains...
A deepening lee trough along the central High Plains will support
strengthening westerly downslope winds to the west of the trough
axis across portions of southeastern Wyoming into southwest South
Dakota and much of western/central Nebraska. Farther south/east,
high pressure over the Lower Mississippi Valley in conjunction with
the lee trough will yield a tightened surface pressure gradient and
strengthening southerly winds from the TX/OK Panhandle vicinity
northeastward into central Kansas and south-central Nebraska.
Sustained winds of 15-20 mph are expected within both of these
regimes. RH minimums of 10-15% (locally lower) are expected across
southeast Wyoming, southwest South Dakota, and western Nebraska
where downslope wind will depress moisture content within an
antecedent dry air mass. Farther south/east, the northern fringe of
returning moisture may limit RH reductions to some degree, but RH
minimums are still forecast to fall to 15-25% southeastern Colorado
northeastward into south-central Nebraska. With dry, receptive fuels
across much of the region, this will support widespread elevated
fire weather conditions for a few hours this afternoon. Locally
critical conditions will also be possible in the lee of the Laramie
Mountains in southeastern Wyoming where winds may occasionally gust
to 30-35 mph.
...Portions of the Southeast...
A dry air mass will continue to reside across much of the Southeast
where fuels remain exceptionally dry (ERCs above the 95th
percentile) amid continuing drought. Sustained northeasterly winds
of 10-15 mph along the southern periphery of surface high pressure
are forecast to overlap minimum RH values of 15-25% across much of
the Florida Panhandle and adjacent areas of southern
Alabama/Georgia. Farther north, modest westerly/northwesterly
downslope winds of 10-15 mph are forecast behind a dry, secondary
cold frontal passage, with minimum RH of 20-30% (locally lower)
expected. This combination of winds/RH is expected to support
elevated fire weather concerns across much of the Southeast this
afternoon.
...Portions of New Mexico into eastern Arizona...
Low to mid-level moisture return is forecast across southern Texas
into portions of the Southwest through this afternoon. Although
forcing for ascent will remain modest under an upper-level ridge, a
combination of localized orographic ascent, deeply mixed boundary
layers with minimal inhibition, and a weak, subtle mid-level
shortwave trough will support isolated thunderstorm development this
afternoon. Slow storm motions (around 10 kts) will likely support
pockets of wetting precipitation, but PWAT values of 0.4-0.7" atop a
dry sub-cloud layer will likely support dry lightning strikes while
largely limiting precipitation. With regional ERCs near the 75th to
80th percentile, lightning ignitions appear possible. While
prevailing flow is forecast to remain weak, gusty outflow winds may
create erratic fire behavior with any new ignitions.
...Portions of the Upper Midwest...
A tightened surface pressure gradient will promote sustained
southwesterly winds of 20-25 mph, with the potential for gusts to
30-35 mph, across portions of the Upper Midwest, especially across
the eastern Dakotas and much of Minnesota. RH values are forecast to
fall to 25-30% this afternoon, with lower values possible should
forecast cloud cover clear more quickly this morning/afternoon. This
combination of wind/RH may promote locally elevated fire weather
concerns this afternoon, especially in pockets of drier fine fuels.
Recent precipitation across portions of this area along with
marginal fuel receptiveness and uncertainty regarding cloud cover
preclude the addition of Elevated highlights at this time.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 201753
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1253 PM CDT Mon Apr 20 2026
Valid 211200Z - 221200Z
...Portions of the Mid-South...
As an upper trough exits the Eastern Seaboard and the pattern
transitions to upper-level ridging, 20-30 kt south-southwesterly
flow aloft and tightening surface pressure gradients will promote
dry and breezy conditions for portions of the Mid-Mississippi valley
on Tuesday. Southwesterly winds of 10-15 mph (gusts up to 20 mph)
and low RH values of 20-30 percent amid drying fuels are supportive
of a fire weather threat, thus Elevated highlights have been
introduced.
The rest of the forecast remains on track, see the previous
discussion for more information.
..Elizalde-Garcia.. 04/20/2026
.PREV DISCUSSION... /ISSUED 0129 AM CDT Mon Apr 20 2026/
...Synopsis...
Upper-level ridging will gradually slide east over the Great Plains
on D2/Tuesday as a closed upper-level low moves onshore across the
West Coast. At the surface, high pressure will build into the
Southeast while a frontal system advances across the northern Great
Plains and Upper Midwest.
...Portions of Florida into southern Georgia...
Sustained easterly winds of 10-15 mph along the southeastern
periphery of high pressure building into the Southeast will overlap
reduced RH of 20-30% across much of the Florida Peninsula and into
southern Georgia Tuesday afternoon. Continued dry conditions amid
extreme to exceptional drought continues to promote receptive fuels
across this region, with ERCs currently at or above the 95th
percentile. This combination is expected to support elevated fire
weather concerns for at least a few hours. While winds are currently
forecast to remain below critical criteria, locally critical
conditions may be possible given the dryness/receptiveness of fuels
and potential for occasional wind gusts to 20 mph.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 202146
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0446 PM CDT Mon Apr 20 2026
Valid 221200Z - 281200Z
...Synopsis...
A large scale upper trough will traverse the Great Basin on Day
3/Wednesday and persist over the northwest and central CONUS through
the early weekend. Upper ridging will continue over the eastern U.S.
through Day 4/Thursday before transitioning to fairly zonal flow
over the Southeast through the weekend. Precipitation will be
possible for parts of the Mid-Atlantic and northern Appalachians
with an associated shortwave trough on Day 3/Wednesday. However,
much of the Piedmont into the Southeast will remain fairly dry this
week as surface high pressure builds across the region through Day
5/Friday. On Day 6/Saturday, a low-amplitude trough is forecast to
enter the southwestern U.S and traverse the High Plains early next
week. This pattern change could bring relief to portions of the
central/southern Plains and broader southeast as precipitation
chances increase. However, in areas that remain dry, fire weather
concerns are likely to linger given the overall pattern.
...Day 3-4/Wednesday-Thursday...
On Day 3/Wednesday, a shortwave impulse will bring precipitation
chances across portions of the Mid-Atlantic along a weak cold front.
Ahead of the front, strong mid-level flow aloft will support dry and
breezy downslope conditions where 97th-99th percentile ERCs have
been observed across the Carolinas. 40% Critical probabilities were
maintained where westerly winds of up to 15 mph and 20-30 percent RH
are forecast to overlap dry fuels.
A deepening surface low across the northern High Plains ahead of the
approaching upper-level trough and associated southwest flow aloft
will bring an expansive fire weather threat to much of the High
Plains and portions of the Southwest on Day 3/Wednesday. 70%
critical probabilities have been expanded where a mid-level jet
should align with tightening surface pressure gradients, promoting
strong southwesterly winds of up to 30 mph and RH of 10 percent or
less. Downslope enhanced drying and strong westerly winds will
continue across much of the Southwest and Southern Plains on Day
4/Thursday as the mid-level trough ejects into the Plains. Broad 40%
Critical probabilities were maintained for the Southwest and
Southern Plains, and 70% Critical probabilities were introduced on
Day 4/Thursday for eastern NM into the TX Panhandle where a corridor
of strong downslope winds and critically low RH will overlap dry
fuels.
...Day 5-7/Friday-Sunday...
As upper troughing persists across the northern U.S., strong zonal
flow over the Southwest should promote very breezy and continued dry
conditions on Day 5/Friday. 40% Critical probabilities were
introduced where ensemble guidance portrays an overlap of low RH and
strong winds. An incoming secondary trough may continue fire weather
concerns across the Southwest and south/central Plains this weekend
where fuels remain dry. However, model ambiguity in timing and
location of the trough precludes the introduction of probabilities
at this time.
..Elizalde-Garcia.. 04/20/2026
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