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U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 211551
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1051 AM CDT Tue Apr 21 2026
Valid 211700Z - 221200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL FLORIDA AND
THE WEST FLORIDA COAST...
...Morning Update...
The previous forecast remains on track. Despite good overnight
humidity recoveries across both risk areas, RH values are dropping
quickly as surface heating ensues and the dry airmass persists
aloft. A weak upper level disturbance currently shifting east of
central TX will bring increasing cloud cover later this afternoon to
parts of the Mid-Mississippi valley. However, deeper mixing is
expected to occur prior to the cloud shield arrival and subsequent
moisture surge this evening, allowing for dry and breezy conditions
supportive of Elevated fire weather highlights. Farther south, wind
gusts of up to 25 mph are already being observed across portions of
central/western FL. As RH values decrease to less than 35 percent
and combine with easterly sustained winds of up to 15 mph atop
receptive fuels, a Critical fire weather threat will emerge this
afternoon.
..Elizalde-Garcia.. 04/21/2026
.PREV DISCUSSION... /ISSUED 1220 AM CDT Tue Apr 21 2026/
...Synopsis...
Broad northwest flow aloft will encompass much of Northeast and Mid
Atlantic in the wake of a departing upper-trough. A dry airmass will
remain in place across the eastern U.S., Southeast and Deep South as
surface high pressure shifts into the Atlantic. Farther west, a
negatively-tilted upper trough will surge into the Western U.S.,
with dry and breezy conditions focused over the Great Basin ahead of
an advancing cold front.
...Florida into Southern Georgia...
East to northeast winds of 10-15 mph on the southern fringe of the
surface high are expected today across portions of southern GA into
FL. Stronger sustained east winds of 15 mph (with higher gusts) will
be located farther south across the FL Peninsula, while drier
conditions including relative humidity as low as 15% amid higher
temperatures in the lower 80s will be displaced to the north over
the FL Panhandle and southern GA. Critical fire weather conditions
are expected across portions of central FL and the West FL Coast
where sustained winds are likely to reach 15 mph and RH falls into
the 25-35% range. Elevated fire weather concerns were extended into
much of the FL Panhandle where offshore trajectories will maintain a
dry boundary layer through much of the afternoon. Fuels remain very
receptive amid worsening drought conditions with ongoing fire
activity.
...Lower Mississippi Valley...
A relative minimum in recent rainfall and existing dry fuels
coupled with dry return flow on the western periphery of the broad
surface high pressure moving off the Mid Atlantic, will bring a fire
weather threat to portions of western TN/MS and eastern AR. South to
southwest winds of 10-15 mph amid relative humidity of 20-25%
supports a continuation of Elevated fire weather highlights across
portions of the lower MS River Valley.
...East-Central Wyoming...
A limited fire weather threat will emerge across east-central WY
with a weak downslope warming and drying regime in place across the
central High Plains. A shallow near-surface temperature inversion
will quickly mix out under mostly sunny skies through the late
morning hours, following possible poor RH recoveries overnight in
eastern WY/CO. RH of 10% or below is likely by the afternoon across
the central High Plains. However, weak boundary layer flow and lack
of substantial surface lee troughing across the region should limit
spatial extent and duration of sustained west winds of up to 15 mph
across east-central WY, precluding introduction of Elevated
Highlights.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 211943
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0243 PM CDT Tue Apr 21 2026
Valid 221200Z - 231200Z
...CRITICAL FIRE WEATHER AREA FOR EAST-CENTRAL NEW MEXICO INTO THE
NORTHERN HIGH PLAINS...
...Portions of the High Plains...
An expansive fire weather threat is expected to impact a large
portion of the High Plains into areas west of the Rockies and
Southwest. Broad west-southwesterly flow aloft and a strengthening
associated mid-level shortwave will result in a moderately strong
lee surface trough and a deepening surface low over eastern MT.
Southeast of the surface low, large scale ascent is expected to
promote high based convection along an emerging dryline. Forecast
soundings depict a prominent dry sub-cloud layer and precipitable
water between 0.5"-0.75", allowing for some threat of dry
thunderstorms to evolve where fuels remain receptive. IsoDryT
highlights have been introduced from southwestern SD into far
northwest KS to account for this threat.
A strong upper jet will push into the Rocky Mountain region on
Wednesday supportive of downslope enhanced winds as lee surface
pressure gradients tighten. Critical highlights were expanded west
to encompass the San Luis Valley where single digit RH and strong
gusts of up to 45 mph are likely. Critical conditions are expected
to last up to 12 hours for portions of central-eastern CO and
southeastern WY. Locally extremely critical conditions are possible
where mountain wave influence could enhance downslope drying to
single digits and sustained winds up to 30 mph with terrain-driven
gusts up to 70 mph. Elevated highlights were expanded into eastern
MT through central MN where 20-30 percent RH and 15-20 mph
west-southerly winds will overlap drying fuels. Additionally,
elevated highlights were expanded farther west to cover eastern UT,
western CO, and portions of central WY for westerly sustained winds
up to 30 mph amid 10-15 percent RH and drying fuels. A cold front
will push through WY during the afternoon and evening, and likely
through much of CO and the central High Plains overnight. Cooler
temperatures, higher RH, and scattered showers are likely behind the
front in WY into northern CO, west of the Divide/Front Range.
However, strong winds will continue across southeast WY into western
NE and northeast CO overnight with RH increasing to 30-50 percent
after midnight. These conditions will likely persist through nearly
the entire overnight period, further exacerbating the fire
environment.
The rest of the forecast remains on track, see the previous
discussion for more information.
..Elizalde-Garcia.. 04/21/2026
.PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Apr 21 2026/
...Synopsis...
A pronounced, eastward progressing upper-level trough, accompanying
55-65 knot mid-level jet and deepening lee surface troughing over
the High Plains will promote a broad fire weather threat across the
central/southern High Plains and portions of the Southwest
Wednesday. A surface trough and associated frontal boundary will
traverse the Southern Great Lakes and Mid Atlantic regions.
Increased southwesterly flow south of the trough will contribute to
fire weather concerns across the Mid Atlantic.
...Southwest into the Southern and North-Central Plains...
A lee surface low will deepen across the northern High Plains as the
robust mid-level trough advances into Intermountain West, with the
associated mid-level jet moving over the Upper CO River Basin. An
expansive fire weather concern will emerge across portions of the
Southwest into the central and southern Plains as southwest winds
accelerate beginning late Wednesday morning. Downslope enhanced
southwest winds of 20-25 mph with higher gusts aligning with
critically low relative humidity below 10% should be most pronounced
across eastern WY/CO and into portions of northeastern NM and
adjacent TX/OK Panhandle areas, where Critical Highlights were
introduced. Locally extremely critical fire weather conditions
including southwest winds of 30-35 mph and single digit RH are
possible in favored terrain gaps along and east of the Sangre De
Cristo Mountains and the CO Front Range where fuels remain receptive
to wildfire spread.
...Piedmont and portions of Mid Atlantic...
Dry and breezy conditions ahead of an approaching trough and
associated cold front will bring a fire weather threat to portions
of the Carolinas and southern VA Wednesday. Persistent northwest
flow aloft and tighter surface pressure gradients will support
increasing winds and downslope drying in the lee of the
Appalachians. West to southwest winds of 10-20 mph along with RH
falling to 20-30% during peak heating will align with a receptive
fuelscape to promote several hours of elevated fire weather
conditions. Elevated Highlights were expanded slightly northward and
eastward based on latest forecast guidance.
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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