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U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 111644
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1144 AM CDT Mon May 11 2026
Valid 111700Z - 121200Z
...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN MONTANA INTO
WEST-CENTRAL NORTH DAKOTA...
...Northern and Central Plains...
A deepening lee trough across far eastern MT under a 60-70 knot
mid-level jet will contribute to fire weather concerns across
portions of the northern and central Plains through today. Stronger
south winds of 15-20 mph ahead of the eastward moving surface trough
are occurring over the Dakotas, with latest model guidance
suggesting this steady southerly flow being maintained through the
day. RH is trending lower with potential for broader instances of
20-25% by peak afternoon heating, particularly across eastern ND and
the Red River Valley of the North. Elevated Highlights have been
extended eastward to encompass all of ND and portions of western MN
today.
Farther west in the wake of the departing trough, dry and breezy
conditions including west/northwest winds 20-25 mph combined with
afternoon RH of 15-25% and dry fuels will support Critical fire
weather conditions for portions of northeastern MT into west-central
ND. A slight eastward expansion of Critical Highlights further into
ND was made based on latest surface observation and forecast
guidance trends.
..Williams.. 05/11/2026
.PREV DISCUSSION... /ISSUED 0151 AM CDT Mon May 11 2026/
...Synopsis...
Along the northern periphery of a large-scale ridge centered over
the West, a robust midlevel trough and accompanying 70-kt westerly
jet streak will advance eastward across MT and ND during peak
heating. In the low-levels, a lee trough will extend southward along
the northern/central Plains, before being overtaken by a cold front
during the evening.
...Northern and Central Plains...
Within the base of the midlevel trough, strong deep-layer westerly
flow will overspread the northern High Plains during the day. Here,
downslope flow trajectories and diurnal heating will result in a
deeply mixed boundary layer along/west of the lee trough --
characterized by surface temperatures in the middle/upper 70s and
20-25 percent RH. Despite the somewhat marginal RH reductions,
downward transport of the high-momentum flow and a tight pressure
gradient will contribute to 20-25 mph sustained west-northwesterly
surface winds (with gusts upwards of 35 mph). The greatest overlap
of these strong/gusty winds and low RH atop receptive fuels is
expected over parts of eastern MT into west-central ND -- where
Critical highlights are in place. A north-northwesterly surface wind
shift will accompany the frontal passage during the evening hours,
though substantial post-frontal RH recovery is expected.
Farther south along the lee trough into the central Plains, more
substantial downslope warming/drying will yield temperatures in the
lower/middle 80s and 15-20 percent RH. These warm/dry conditions
combined with around 15 mph sustained west-southwesterly surface
winds will yield elevated to locally critical fire-weather
conditions, given critically dry fuels here as well.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 111941
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0241 PM CDT Mon May 11 2026
Valid 121200Z - 131200Z
A dry, post-frontal northwest flow regime is still expected to bring
a broad fire weather threat to portions of the northern/central
Plains and Upper Midwest on Day 2/Tuesday. A swath of stronger
sustained northwest winds between 15 and 25 mph will impact the
eastern Dakotas into southwestern MN. However, this corridor of
stronger winds will be displaced to the east of a warmer, drier
boundary layer across the northern and central High Plains where
afternoon RH reductions below 20% will be more common. Nonetheless,
the breezy northwest winds and very dry fuels (ERC values in the
95-99th percentile) should support an elevated fire weather concern
for much of the Dakotas, southwest MN into northeastern NE and
northwestern IA. Additionally, some green up of fuels could mitigate
the otherwise Critical fire weather threat across eastern
NE/northwestern IA.
..Williams.. 05/11/2026
.PREV DISCUSSION... /ISSUED 0151 AM CDT Mon May 11 2026/
...Synopsis...
On the backside of a robust midlevel trough and attendant surface
low moving eastward from the northern Plains into the upper Midwest
and eventually the Great Lakes, strong deep-layer northwesterly flow
will overspread a well-mixed post-frontal air mass over the
upper/middle MO Valley during the day. While RH reductions will be
modest in the post-frontal air mass (around 25-30 percent), 20-25
mph sustained northwesterly surface winds (with higher gusts) will
compensate and support elevated to locally critical fire-weather
conditions -- given dry/receptive fuels. If guidance trends any
lower with RH reductions, a targeted Critical area could eventually
be warranted.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 102159
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0459 PM CDT Sun May 10 2026
Valid 121200Z - 181200Z
...Synopsis...
A more active upper-level wave pattern emerges later this week
across the CONUS. The upper ridge responsible for near record
setting heat early this week will shift into the central U.S. by
Thursday, saddled by an amplifying trough across the eastern U.S.
and another trough moving into the western states Days
4-5/Wednesday-Thursday, the latter of which will bring broader fire
weather concerns to a drying fuelscape across the West. Forecast
uncertainty increases as the weekend approaches with a more diffuse,
perhaps zonal, pattern returning to the CONUS.
...Day 3/Tuesday - Northern Plains and Upper Midwest...
Dry, post-frontal flow in the wake of a deep surface low across the
Great Lakes will bring a fire weather threat to portions of the
Northern Plains and Upper Midwest where frontal precipitation is
minimized and critically dry fuels remain. RH reductions will be
limited to 20-30% but northwest winds of 15-25 mph over receptive
fuels, supports a continuation (and slight expansion based on latest
model guidance) of 40% critical probabilities across the region.
...Day 4/Wednesday...
...Southern Great Basin and Southwest...
Fire weather concerns increase across portions of the Southwest and
Great Basin ahead of an advancing upper trough and attendant
increasing southwest flow aloft. Advection of mid and upper level
Pacific moisture and supportive kinematic environment should support
some high-based showers and thunderstorms across much of the
Intermountain West on Day 4/Wednesday. A 10% probability area for
dry thunderstorms has been introduced where fuels are expected to be
driest, reaching the 90th percentile by midweek under a few days of
abnormally warm temperatures. Farther west, drier southwest flow
should impact much of the eastern Great Basin and upper CO River
Basin regions allowing for a heightened fire weather concern under a
drying/curing fuelscape. A slight expansion of existing 40% critical
probabilities has been made into the AZ Strip area.
...Northeastern Montana...
A deepening surface low in the lee of the Northern Rockies will
promote stronger southerly flow over the northern High Plains on Day
4/Wednesday. Existing dry fuels amid a southerly dry return flow
will combine to bring enhanced fire weather concerns to northeastern
MT, where 40% critical probabilities have been introduced.
..Williams.. 05/10/2026
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