RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Feb 17 10:53:02 UTC 2026.
No Mesoscale Discussions are in effect as of Tue Feb 17 10:53:02 UTC 2026.
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0231 AM CST Tue Feb 17 2026
Valid 191200Z - 201200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY AFTERNOON
INTO EARLY EVENING ACROSS PARTS OF CENTRAL AND SOUTHERN
ILLINOIS...SOUTHERN INDIANA...WESTERN/NORTHERN KENTUCKY...AND
SOUTHWESTERN OHIO...
...SUMMARY...
Severe thunderstorms with potential to produce a few tornadoes and
damaging wind gusts are possible across parts of the middle
Mississippi into lower Ohio Valleys Thursday afternoon into early
evening.
...Discussion...
Considerable spread persists within latest model output concerning
short wave developments within the evolving pattern across North
America through this period. In general, though, guidance indicates
that larger-scale mid-level troughing will slowly begin to shift
inland of the Pacific coast Thursday through Thursday night, while
being maintained downstream across the Rockies, Great Plains and
Mississippi Valley, and slowly developing toward the lower Great
Lakes and Appalachians vicinity. The center of a subtropical high
is likely to shift from the Gulf Basin into the Bahamas/Caribbean,
with its northern periphery maintaining an influence across parts of
the Southeast.
One or two short wave perturbations emerging from the Intermountain
West may be in the process of progressing into and across the
central Great Plains and lower Missouri Valley vicinity at the
outset of the period. The lower amplitude lead perturbation may
continue into and across the Ohio Valley during the day, as the
stronger upstream perturbation pivots across the mid to lower
Missouri Valley toward the Great Lakes region. This appears a bit
to the north, and at somewhat lower amplitudes, than what prior runs
of at least some model output has been indicating. However, this is
still likely to be accompanied by a sub-1000 mb surface cyclone,
which may undergo one or two periods of additional deepening while
migrating northeast of the lower Missouri Valley toward the Great
Lakes region Thursday through Thursday night.
...Middle Mississippi/Lower Ohio Valley...
Latest model output continues to indicate better low-level moisture
return (but still marginal for severe convective development) to
portions of the warm sector of the developing cyclone as it migrates
across and northeast of the lower Missouri Valley Thursday
afternoon. It appears that this may include a corridor of mid 50s
to near 60F surface dew points advecting northeast and east of the
confluence of the Mississippi and Ohio Rivers. However, it now
appears that much of this moistening may occur beneath relatively
warm mid/upper levels, associated with subsidence to the south of
the upper jet axis.
This is not reflected in the latest RRFS forecast soundings, which
indicate rather potent thermodynamic profiles evolving by Thursday
afternoon across the lower Ohio Valley vicinity, in terms of both
conditional and convective instability. A general consensus of
other model output suggests the development of much more modest
CAPE. This includes NAM forecast soundings, which depict CAPE at or
below 500 J/kg where the low-level moistening occurs, mostly due to
low equilibrium levels below the 500 mb level. It remains unclear
if this environment will become supportive of convection capable of
producing lightning.
Even so, NAM forecast soundings still depict boundary-layer based
CAPE supportive of low-topped convection which could acquire
supercellular structure in the presence of strong cloud bearing
shear. Aided by the evolution of sizable clockwise-curved low-level
hodographs beneath 30-50 kt southerly 850 mb flow, and a relatively
moist boundary-layer with steep lapse rates, a few tornadoes appear
possible, in addition to small to marginally severe hail. The
evolution of a small organizing cluster may still not be out of the
question, which probably would be accompanied by better potential
for damaging surface gusts.
..Kerr.. 02/17/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0350 AM CST Tue Feb 17 2026
Valid 201200Z - 251200Z
...DISCUSSION...
In general, the latest medium-range guidance indicates that an
initially notable surface cyclone over the upper Great Lakes region
at the outset of the period will undergo substantive weakening, as a
supporting short wave impulse becomes sheared and weakens to the
south of a blocking mid-level ridge centered over southern Hudson
Bay. It appears that secondary cyclogenesis across and offshore of
the Mid Atlantic coast Friday through Friday night will be subdued,
with a trailing cold front stalling across the southern Atlantic
through Gulf coast vicinity into Saturday, near the southern
periphery of the seasonably strong westerlies.
Forcing for ascent associated with trailing short wave
perturbations, emerging from larger-scale mid-level troughing
progressing out of the West, may remain largely to the cool side of
the surface frontal zone. However, further moistening along it
could support sufficient destabilization for vigorous, perhaps
upscale growing and training, thunderstorm development, which could
pose at least some risk for producing severe hail and wind. While
severe thunderstorm probabilities are being maintained at less than
15 percent in this outlook, it is still possible that this could
change in later outlook updates for the Friday/Saturday time period.
Thereafter, amplifying mid/upper flow across the eastern
mid-latitude Pacific into North America through early next week
appears likely to include building large-scale ridging inland of the
Pacific coast through the Mississippi Valley. Beneath the confluent
regime in the wake of digging downstream troughing, cold surface
ridging is forecast to build southward to the lee of the Rockies,
through much of the Gulf Basin. Associated low-level drying and
stabilization probably will tend to limit convective potential
through the remainder of the period.
Read more
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0145 AM CST Tue Feb 17 2026
Valid 171200Z - 181200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHEASTERN
COLORADO INTO SOUTHWESTERN NEBRASKA AND EXTREME NORTHWESTERN
KANSAS...
...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND SOUTHERN
HIGH PLAINS...
...Synopsis...
The first in a series of mid-level troughs will eject into the
Plains today, resulting in the rapid deepening of a surface low over
the northern Plains, with pronounced surface troughing over the
remainder of the Plains states. The combination of strong
isallobaric and downslope flow associated with this weather pattern
will promote a broad area of surface conditions highly supportive of
significant, dangerous wildfire-spread potential.
...Central High Plains...
As the surface low deepens over the northern Plains, sustained
westerly winds should peak in the 30-40 mph range, with higher gusts
for several hours, coinciding with boundary-layer mixing and
subsequent RH reductions, down to the 10-15 percent range in spots,
warranting widespread Critical highlights. Extremely Critical
highlights remain in place where guidance consensus continues to
show the longest term overlap of 30+ mph sustained westerly winds
and at least 15 percent or lower RH atop fuels with ERCs approaching
or exceeding the 90th percentile. Such conditions will support the
potential for very rapid and dangerous wildfire spread.
...Southern High Plains...
Widespread westerly sustained winds of at least 25 to 30 mph should
become common by afternoon as a near 120 kt 500 mb jet streak
overspreads the region. Concern remains for mid- and high-level
cloud cover to accompany the jet streak, which may dampen RH
reductions (i.e. 25-30 percent), particularly west of the Amarillo,
TX longitude. Even with a more moist scenario, the strong winds atop
very dry fuels will compensate to support Critical wildfire-spread
conditions. East of Amarillo, RH should drop to at least 15-20
percent, suggesting that high-end Critical conditions will develop
and support significant, rapid wildfire-spread potential.
..Squitieri.. 02/17/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0213 AM CST Tue Feb 17 2026
Valid 181200Z - 191200Z
...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE SOUTHERN HIGH
PLAINS...
...Synopsis...
A second, pronounced mid-level impulse, embedded in a broader and
active upper troughing pattern, is poised to eject into the central
Plains tomorrow (Wednesday). A surface low will traverse the Upper
Mississippi Valley while a second surface low develops and quickly
deepens over the central High Plains. Strong isallobaric flow over
portions of the Midwest, and downslope flow along lee of the
southern Rockies into the southern High Plains, will promote
appreciable wildfire spread conditions over both locales.
...Southern High Plains...
The deepening of the surface low will augment downslope flow by
afternoon, resulting in widespread sustained southwesterly surface
winds around 25 mph amid 10-15 percent RH for at least a few hours.
Fuels in this region continue to cure given a lack of appreciable
rainfall prior exposure to dry and windy days, warranting the
introduction of Critical highlights for the second day in a row.
...Portions of the Midwest...
As a surface low tracks toward the Great Lakes, sustained westerly
surface winds will reach the 15-25 mph range while advecting dry air
from the west. RH may reduce to 15-25 percent by afternoon peak
heating. Given an appreciable lack of rainfall from eastern
Nebraska, Iowa, and western/northern Illinois over the past month,
the aforementioned dry and windy conditions may certainly support
wildfire spread, necessitating high-end Elevated highlights. If a
greater consensus among guidance members can depict 20+ mph winds
better overlapping with 20 percent or lower RH, Critical highlights
will be needed.
..Squitieri.. 02/17/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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