RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Feb 17 20:17:02 UTC 2026.
No Mesoscale Discussions are in effect as of Tue Feb 17 20:17:02 UTC 2026.
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1031 AM CST Tue Feb 17 2026
Valid 171630Z - 181200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG THE
CENTRAL AND SOUTHERN CALIFORNIA COAST...
...SUMMARY...
Isolated strong thunderstorms will be possible across parts of the
West today through tonight. Isolated thunderstorms are also
anticipated across the Upper Midwest late this afternoon and
tonight.
...Synopsis...
Recent satellite imagery shows several disturbances across the
western CONUS, including a pair of low-amplitude shortwave troughs
within the belt of strong southwesterly flow extending from the
central Pacific into the central Plains and a deepening upper low
off the Pacific Northwest coast. Intense surface cyclogenesis is
anticipated ahead of the lead shortwave as it moves quickly
northeastward, with the resulting surface low forecast to move
across SD/NE, ending the period over southern MN. Evolution of this
surface low and parent shortwave, which will become increasingly
negatively tilted throughout the day and overnight, will result in
strong forcing for ascent from the Mid MO Valley into the Upper
Midwest this evening and overnight.
Farther west, the previously mentioned upper low is expected to drop
slowly southward as a strong jet (i.e. 100 kt at 500 mb) pivots
around its western and southern periphery. Very cold mid-level
temperatures and strong/persistent forcing for ascent will support
isolated thunderstorms along across much of the West coast
throughout the day and tonight.
...Coastal California...
Limited buoyancy is expected to develop along the near coastal areas
of CA as very cold mid-level temperatures (i.e. -25 to -30 deg C at
500 mb) associated with the upper low continue to advect into the
region. This buoyancy coupled with the strong forcing for ascent
could result in some deeper, more persistent updrafts across the
region today, both within the primary frontal band and any more
bowing line segments that may follow it. Given the robust deep layer
flow across the region, any deeper, more persistent updrafts could
result in some stronger, convectively augmented gusts. Additionally,
there appears to be enough low-level curvature to support a brief
tornado or two within the immediate coastal regions. Highest
potential for either hazards currently appears to be after 00Z in
the San Luis Obispo/Santa Barbara county areas.
...Upper Midwest...
Some low-level moisture return is anticipated across the region
ahead of the previously mentioned shortwave trough and associated
forcing for ascent. Even so, low-level moisture will still be
limited, with dewpoints likely remaining in the upper 40s to perhaps
low 50s. This is not expected to be enough moisture for surface
destabilization across most of the region, despite strong surface
heating/boundary-layer mixing and steepening low-level lapse rates
in vicinity of the surface low/front. The only exception is across
far southeast SD and far northeast NE where a high-based storm or
two cannot be completely ruled out. Any that does develop could
produce an strong gust or two, although coverage will likely remain
less than 10%.
Across the Upper Midwest, capping may tend to largely prevail during
the day, with elevated thunderstorms becoming more probable
east-northeastward of IA into the MN/WI throughout the evening and
overnight. Instability does not appear strong enough to support
severe hail with this elevated activity.
..Mosier/Bunting.. 02/17/2026
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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0213 PM CST Tue Feb 17 2026
Valid 172000Z - 181200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL
CALIFORNIA AND PORTIONS OF NEBRASKA AND IOWA...
CORRECTED FOR NDFD COLOR FILL ISSUE
...SUMMARY...
Isolated strong thunderstorms will be possible across parts of the
West today through tonight. Isolated thunderstorms are also
anticipated across the Upper Midwest late this afternoon and
tonight.
...Eastern Nebraska and southwestern Iowa...
Near the base of a negative-tilt shortwave trough and a pronounced
100+ kt mid-level jet, strong ascent is expected to develop late
this afternoon amid a mixed and modestly moist air mass. Cool
mid-level temperatures and surface dewpoints in the 40s and 50s F
may allow a few hundred J/kg of buoyancy to develop. This
destabilization and strong ascent may support a fast-moving arc of
high-based showers/thunderstorms, particularly where surface
temperatures reach into the 60s and dewpoints hold above 40 F.
While buoyancy will be weak, dry low-levels and strong
dynamics/background flow could support efficient downward mixing of
momentum to the surface. Isolated severe/damaging gusts are possible
this afternoon and evening from parts of eastern NE into
west-central IA. Convection should weaken rapidly with eastward
extent
Elsewhere, isolated strong storms remain possible across portions of
the CA coast ahead of a strong secondary upper trough. This is most
likely overnight with a few damaging gusts or a brief tornado the
primary risks owing to very strong flow and modest inland moisture
advection. No changes were made to the outlook here, see the prior
discussion for more info.
..Lyons.. 02/17/2026
.PREV DISCUSSION... /ISSUED 1031 AM CST Tue Feb 17 2026/
...Synopsis...
Recent satellite imagery shows several disturbances across the
western CONUS, including a pair of low-amplitude shortwave troughs
within the belt of strong southwesterly flow extending from the
central Pacific into the central Plains and a deepening upper low
off the Pacific Northwest coast. Intense surface cyclogenesis is
anticipated ahead of the lead shortwave as it moves quickly
northeastward, with the resulting surface low forecast to move
across SD/NE, ending the period over southern MN. Evolution of this
surface low and parent shortwave, which will become increasingly
negatively tilted throughout the day and overnight, will result in
strong forcing for ascent from the Mid MO Valley into the Upper
Midwest this evening and overnight.
Farther west, the previously mentioned upper low is expected to drop
slowly southward as a strong jet (i.e. 100 kt at 500 mb) pivots
around its western and southern periphery. Very cold mid-level
temperatures and strong/persistent forcing for ascent will support
isolated thunderstorms along across much of the West coast
throughout the day and tonight.
...Coastal California...
Limited buoyancy is expected to develop along the near coastal areas
of CA as very cold mid-level temperatures (i.e. -25 to -30 deg C at
500 mb) associated with the upper low continue to advect into the
region. This buoyancy coupled with the strong forcing for ascent
could result in some deeper, more persistent updrafts across the
region today, both within the primary frontal band and any more
bowing line segments that may follow it. Given the robust deep layer
flow across the region, any deeper, more persistent updrafts could
result in some stronger, convectively augmented gusts. Additionally,
there appears to be enough low-level curvature to support a brief
tornado or two within the immediate coastal regions. Highest
potential for either hazards currently appears to be after 00Z in
the San Luis Obispo/Santa Barbara county areas.
...Upper Midwest...
Some low-level moisture return is anticipated across the region
ahead of the previously mentioned shortwave trough and associated
forcing for ascent. Even so, low-level moisture will still be
limited, with dewpoints likely remaining in the upper 40s to perhaps
low 50s. This is not expected to be enough moisture for surface
destabilization across most of the region, despite strong surface
heating/boundary-layer mixing and steepening low-level lapse rates
in vicinity of the surface low/front. The only exception is across
far southeast SD and far northeast NE where a high-based storm or
two cannot be completely ruled out. Any that does develop could
produce an strong gust or two, although coverage will likely remain
less than 10%.
Across the Upper Midwest, capping may tend to largely prevail during
the day, with elevated thunderstorms becoming more probable
east-northeastward of IA into the MN/WI throughout the evening and
overnight. Instability does not appear strong enough to support
severe hail with this elevated activity.
Read more
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1108 AM CST Tue Feb 17 2026
Valid 181200Z - 191200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated to widely scattered thunderstorms are possible along parts
of the West Coast, lower Ohio/mid-Mississippi Valley, and lower
Great Lakes regions. Severe weather is not anticipated.
...Synopsis...
A pair of successive shortwave troughs are expected to progress
north-northeastward on Wednesday into Thursday morning. The initial,
weaker perturbation will move from the mid-Mississippi Valley into
the upper Ohio Valley. Some thunderstorm potential will exist ahead
of this feature within a warm advection regime in lower Michigan
into northeast Ohio and northwest Pennsylvania.
Farther west, a more potent shortwave will move from the lower
Colorado Valley/western Great Basin into the central Plains by
Thursday morning. In its wake, general troughing will in the West.
Cold temperatures aloft will foster potential for isolated
thunderstorms along much of the West Coast. A few lightning flashes
may also occur ahead of the progressing shortwave trough in the
eastern Great Basin. However, ample cloud cover and cool/cold
temperatures will keep such activity quite sparse.
A surface low will develop late in the period in the central High
Plains and shift into eastern Kansas/western Missouri by Thursday
morning. Mid-level ascent and warm/moist advection will gradually
increase from the Mississippi/Ohio confluence into parts of the
lower Ohio Valley. There is some signal from both global and
regional CAM guidance for development very late in the period near
the Mississippi/Ohio confluence. Farther north and east, capping may
prevail given more nebulous forcing. Severe weather is not
anticipated with any of the activity in these regions.
..Wendt.. 02/17/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0127 PM CST Tue Feb 17 2026
Valid 191200Z - 201200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
LOWER/MIDDLE OHIO VALLEY...
...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.
...Synopsis...
Two shortwave troughs are expected to quickly lift
north-northeastward through the central Plains and into the Ohio
Valley region on Thursday. The initial perturbation will reach
Illinois/Indiana by early afternoon. The intensity of this feature
will remain modest with perhaps some gradual weakening in time. The
second trough will evolve in the lower Missouri Valley during the
evening and intensify as it approaches the lower Ohio Valley by
Friday morning. At the surface, a cyclone will deepen as it lifts
northeastward from eastern Kansas into the Great Lakes region. At
least partially modified Gulf moisture will advect northward ahead
of the surface cold front from the Upper Midwest into the southern
Plains.
...Lower/middle Ohio Valley...
Ahead of the cold front, a prefrontal trough/pseudo dryline is
expected to be the focus for convective development during the
afternoon. The degree/quality of moisture return ahead of this
feature will be key in terms of the overall magnitude of the severe
threat. Current observations (Tuesday) from soundings depict a very
modest moist layer along the Gulf coast. A modest shortwave trough
on Tuesday night into Wednesday will lift northward too quickly for
more substantial moisture return. The surface pattern on Thursday
will be more robust, but deeper moisture may still not reach far
enough north given that mid 60s F dewpoints are only as far north as
the central Gulf currently. Guidance suggests mid to upper 50s F
dewpoints are most probable, which does seem reasonable. That said,
temperatures aloft will not be overly cold and lapse rates will not
be overly steep. This will lead to convection that may remain
somewhat low topped in nature. Despite limiting factors within the
environment, 40-50 kts of effective shear roughly perpendicular to
the boundary will favor discrete storms. Low-level flow will be
increasing with time as well. Supercells capable of few tornadoes,
damaging winds, and isolated large hail are possible during the
afternoon/evening.
..Wendt.. 02/17/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1101 AM CST Tue Feb 17 2026
Valid 171700Z - 181200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR EASTERN
COLORADO...SOUTHWESTERN NEBRASKA...WESTERN KANSAS AND THE TEXAS AND
OKLAHOMA PANHANDLES...
...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND SOUTHERN
HIGH PLAINS...
...Central High Plains...
A deepening surface trough lee of the Rockies under broad westerly
flow aloft will support a dry, downslope regime across much of the
Central Plains through today. The most likely alignment of 30+ mph
westerly winds, rapidly falling relative humidity as low as 10
percent and receptive fuels remains across portions of eastern CO,
southwestern NE and western KS. Widespread Critical Highlights are
expected for the remainder of eastern CO into much of western NE and
KS amid westerly winds of 15-25 mph coinciding with relative
humidity ranging from 15-25 percent this afternoon and early
evening.
...Southern High Plains...
Poor relative humidity recoveries overnight were observed across
much of the Southern Plains under extensive cloud cover and minimal
boundary layer decoupling. Satellite imagery and short term model
guidance continue to indicate a clearing trend of denser cirrus
across northeastern NM into the TX/OK Panhandles. Better boundary
layer mixing under a pronounced 100-110 kt jet max and clearing
skies should result in somewhat stronger surface winds from the
southwest with relative humidity already approaching 10 percent.
Several hours of southwest winds of 25-35 mph with higher gusts,
relative humidity of 10-15 percent and abundant dry fuels could
support very rapid fire spread if ignitions occur. Therefore,
Extremely Critical Highlights were warranted given current observed
and short term forecast trends. Critical Highlights were maintained
for much of northwest TX, with Elevated fire weather conditions
likely across much of eastern NM and far west TX.
..Williams.. 02/17/2026
.PREV DISCUSSION... /ISSUED 0145 AM CST Tue Feb 17 2026/
...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.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0153 PM CST Tue Feb 17 2026
Valid 181200Z - 191200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE OF THE CENTRAL AND
SOUTHERN HIGH PLAINS...
...Southern and Central Plains...
A strengthening surface low across eastern CO along with strong
mid-level flow ahead of an approaching short wave will support
another day of Elevated to Critical fire weather conditions across
portions of the central and southern Plains Thursday. Less cloud
cover aiding in more efficient boundary layer mixing of stronger
winds aloft should support drier conditions overall, with single
digit relative humidity likely Thursday afternoon across parts of
eastern NM and the TX/OK Panhandles where recent fire activity has
emerged. Overall, a broad region of southwest winds of 15-25 mph
combined with critically low humidity in the 10 to 20 percent range
will promote high-end Critical fire weather conditions across much
of Southern High Plains Thursday. Some northward and eastward
expansion of Critical Highlights were warranted based on latest
short term model guidance and recent fire activity. Similarly,
existing Elevated Highlights were extended farther eastward into KS,
TX and OK, with fire weather concerns potentially extending well
into the evening.
...Portions of the Midwest...
A swath of dry and breezy conditions are still expected across
portions of the Midwest south of a surface low approaching the Great
Lakes, underneath a mid-level jet on the southern periphery of an
approaching short wave. West winds of 15-25 mph combined with
relative humidity around 20 percent will bring at least Elevated
fire weather concerns from eastern NE, much of IA into northwestern
IL. Preceding rain showers tonight into Wednesday morning should be
sporadic with limited effect on drying fuels.
..Williams.. 02/17/2026
.PREV DISCUSSION... /ISSUED 0213 AM CST Tue Feb 17 2026/
...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.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
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