SPC Day 2 Fire Weather Outlook

Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0108 AM CDT Fri Apr 17 2026

Valid 181200Z - 191200Z

...Synopsis...
An amplified upper trough will move towards the upper Great Lakes
and Ohio Valley as temporary upper ridging builds over the West.
Enhanced southwest winds ahead of an eastward progressing cold front
will pose an Elevated fire weather threat across parts of the
Southeast and Mid-Atlantic. In the wake of the aforementioned upper
trough, a post-frontal dry airmass and northerly flow will promote
Elevated fire weather conditions across portions of the central
Plains.

...Central Plains...
Within a post-frontal environment, northwesterly winds of 15-20 mph
and RH of 15-25 percent over dry fuels will pose an Elevated fire
weather threat for portions of central NE, eastern CO, and western
KS on Saturday. However, the areal extent of fire weather highlights
may change as forecast precipitation (and perhaps some snowfall) on
Day 1/Friday may provide some relief to fuel conditions. 

...Southeast and Mid-Atlantic...
Increasing southwest flow ahead of an advancing cold front coupled
with the lack of Gulf moisture return and resultant low RH are
expected to promote an Elevated fire weather threat across much of
the Southeast into the Mid-Atlantic. At peak heating, widespread RH
of less than 30 percent will combine with southwesterly winds of
10-15 mph atop receptive fuels. A prolonged period of above normal
temperatures and lack of appreciable rainfall continues to
exacerbate fuel conditions across this region.

..Elizalde-Garcia/Lyons.. 04/17/2026

...Please see www.spc.noaa.gov/fire for graphic product...

SPC Day 1 Fire Weather Outlook

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0107 AM CDT Fri Apr 17 2026

Valid 171200Z - 181200Z

...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN HIGH
PLAINS...

...Synopsis...
An upper trough will move into the central U.S. and deepen Friday as
an associated mid-level speed max intensifies over the central
Plains. During the afternoon, surface pressure gradients will
tighten across much of the High Plains with a cold front progressing
southwestward into southern Kansas and the Oklahoma Panhandle. This
will promote Critical fire weather conditions throughout eastern New
Mexico, Texas Panhandle, and West Texas. A second shortwave impulse
will exit the eastern U.S. supporting above normal temperatures and
some lingering dry/breezy conditions over the central Appalachians
and Mid-Atlantic.

...Southern Plains...
As the upper trough moves east of the Rockies, increasing mid level
flow will overspread much of the southern High Plains. At the
surface, a strengthening low will quickly traverse the upper
Midwest, dragging a cold front southward. Poor expected overnight
humidity recoveries will encourage RH in the single digits by peak
afternoon heating combined with strong southwest winds of 20-25 mph
(gusts up 40 mph). These conditions amid receptive fuels will
support Critical fire weather conditions for much of the region on
Friday. As the cold front passes through Friday evening, an abrupt
northerly wind shift with strong gusts of up to 40 mph continuing
for a few hours could impact any ongoing wildfires. However, higher
relative humidity and cooler temperatures behind the front are
expected to improve the fire weather environment into the overnight
hours. 

Farther north, gusty post-frontal northerly winds are expected over
parts of the central Plains. RH values will climb quickly throughout
the day as temperatures cool. Brief locally elevated fire weather
conditions are possible where fuels have remained dry.

...Central Appalachians and Mid-Atlantic...
In the wake of the departing shortwave trough, westerly flow aloft
will linger over the Appalachians with weak lee surface troughing.
Westerly winds of 10 mph (gusts up to 20 mph) and decreasing RH to
less than 30 percent are expected by peak heating. These conditions
atop a drought ridden landscape and exceptionally dry fuels will
support an Elevated fire weather threat this afternoon.

..Elizalde-Garcia/Lyons.. 04/17/2026

...Please see www.spc.noaa.gov/fire for graphic product...

No watches are valid as of Fri Apr 17 06:10:02 UTC 2026.

No Mesoscale Discussions are in effect as of Fri Apr 17 06:10:03 UTC 2026.

SPC 0600Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1225 AM CDT Fri Apr 17 2026

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE UPPER OHIO RIVER VALLEY....

...SUMMARY...
Scattered strong to severe thunderstorms capable of damaging winds
and hail will be possible on Saturday across the upper Ohio Valley.

...Synopsis...
A mid-level trough will move from the Upper Midwest to the Great
Lakes on Friday. A surface cold front will move from the Great
Lakes/Ohio Valley to the Appalachians. In its wake, high pressure
will build into the Intermountain West and Plains. 

Remnant showers/storms will likely be ongoing at the beginning of
the period ahead of the cold front. The extensive cloudcover and
potential outflow from Day 1 storms has resulted in considerable
uncertainty for the Saturday forecast. Most 00Z guidance shows
extensive outflow moving across Ohio during the morning. If this
occurs, additional storm development is not anticipated until
farther east across western Pennsylvania and southwest New York. If
these morning storms/outflow are less progressive, some moisture
advection ahead of the cold front is expected to bring somewhat
greater instability. This could result in some stronger storms, and
potentially sufficient instability for some transient supercell
structures. 

Some 00Z CAM guidance (NAM/NSSL WRF) depicts low to mid 60s
dewpoints across eastern Ohio and western Pennsylvania on Saturday
afternoon. This seems to be the outlier, but if this does occur, a
more substantial severe weather threat, and a greater tornado threat
would exist across western Pennsylvania into southwest New York.
However, only weak instability seems most likely within this zone of
strong shear and therefore, expect damaging wind gusts as the
primary hazard.

..Bentley.. 04/17/2026

SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0100 AM CDT Fri Apr 17 2026

Valid 171200Z - 181200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT ACROSS PARTS CENTRAL AND SOUTHWESTERN WISCONSIN...FAR
SOUTHEASTERN MINNESOTA...EASTERN IOWA...MUCH OF NORTHERN AND CENTRAL
 ILLINOIS...NORTHERN AND CENTRAL MISSOURI...EASTERN AND SOUTHERN
KANSAS...AND NORTHERN OKLAHOMA...

...SUMMARY...
Widespread strong to severe thunderstorm development appears
possible today into tonight across parts of the Upper Midwest
southward across the lower Missouri Valley into central Great
Plains.  Initially this may be accompanied by a risk for large hail
and a few strong tornadoes, before damaging wind gusts become the
most prominent hazard by this evening.

...Discussion...
A couple of notable short wave perturbations have emerged from
splitting larger-scale mid-level troughing now overspreading the
northern Rockies and Great Basin.  One, including a remnant embedded
cyclonic circulation, is beginning to accelerate east-northeastward
into and across the central Canadian/U.S. border vicinity.  The
other is still digging into the eastern Great Basin, but forecast to
turn across the Wyoming/Colorado Rockies during the day, before
shearing northeastward toward the Upper Midwest.  It appears that
this will be preceded by several lower amplitude impulses already
emanating from the subtropical eastern Pacific.

In lower-levels, a significant cold front is already surging
southward to the lee of the northern Rockies and forecast to advance
across much of the remainder of the northern Great Plains by 12Z
this morning.  Models indicate that significant cyclogenesis may
subsequently ensue northwest/north of Lake Superior toward James Bay
later today through tonight.  At the same time, it appears that a
secondary frontal wave will migrate northeast of the mid Missouri
Valley through the Upper Midwest/Great Lakes vicinity.  Another lee
cyclone may attempt to form near/north of the Texas/Oklahoma
Panhandle vicinity, but probably will be overtaken by the southward
surging cold front before migrating out of the high plains.

The northward advection of relatively moist low-level air is ongoing
from the southern into central Great Plains and lower Missouri
Valley, and forecast to continue spreading northward within a
pre-cold frontal plume through portions of the Upper Midwest/Great
Lakes region by this afternoon.  Beneath steep lapse rates, this may
contribute to sizable mixed-layer CAPE within a corridor from the
east central Great Plains through the mid/upper Mississippi Valley
by this afternoon.

There is notable spread among the various model output concerning
most of these developments, which may have a significant impact on
the convective evolution and associated severe weather potential
today through tonight.  However, potential exists for widespread
convective development capable of producing damaging surface gusts,
large hail and a couple of strong tornadoes.

...Upper Mississippi Valley/Midwest vicinity...
It appears that a corridor of stronger surface pressure falls may
shift from western Iowa north-northeastward through western
Wisconsin by early this afternoon, accompanied by substantive
boundary-layer destabilization and strengthening southerly low-level
wind fields with enlarging hodographs.  Based on the latest model
output, including convection allowing guidance, it appears that this
may contribute to a window of opportunity for discrete supercell
development within an environment potentially conducive to strong
tornadoes, before activity grows upscale and eventually outpaces the
northeastward boundary-layer destabilization.

...Central Great Plains through middle Mississippi Valley/Midwest...

Uncertainty lingers concerning how quickly the surface cold front
will tend to undercut a developing corridor of stronger pre-frontal
surface heating and destabilization, particularly across the central
into southern Great Plains.  However, by early this afternoon, this
corridor appears likely to develop along an axis from south central
Kansas toward northwestern Missouri, providing a focus for rapidly
developing storms including supercells.  Initially this may include
hail exceeding 2 inches in diameter, and potential for a few
tornadoes before convection grows upscale, spreads east of the axis
of maximum instability and also become undercut by the front.

Perhaps aided by forcing associated with one of the perturbations
emerging from lower latitudes, there appears a signal in model
output that the upscale growing convection may eventually become
better organized with one or two notable mesoscale convective
vortices evolving while spreading ahead of the front across and
northeast of the lower Missouri Valley late this afternoon and
evening.  Downward mixing of strengthening rear-inflow, within a
sheared ambient southwesterly deep-layer mean flow already on the
order of 35-40 kt, widespread strong to severe wind gusts appear
possible, with strongest gusts and/or perhaps brief tornadoes
accompanying evolving mesovortices along the gust front.

The cold front/dryline intersection may become another focus for
discrete supercell development across parts of south central Kansas
into adjacent northwestern Oklahoma by late afternoon.  However, the
extent of the associated severe weather potential will depend on how
quickly this activity is overtaken by the cold front.

..Kerr/Lyons.. 04/17/2026