SPC Feb 18, 2026 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1029 AM CST Wed Feb 18 2026

Valid 181630Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Organized severe weather is not expected today or tonight.

...Synopsis...
Recent satellite imagery shows a very active upper pattern with
numerous shortwave troughs embedded within the broad troughing that
covers the CONUS. Lead shortwave in this series is currently
maturing over the Upper Midwest, with evolution into a cyclone
expected by this evening. A pair of lower amplitude shortwaves exist
farther west, one entering the central Plains and another over the
southern Great Basin. Lastly, a strong shortwave is currently
dropping quickly southward through the northeast Pacific, preceded
by yet another low-amplitude shortwave moving into the central CA
Coast.

All of these waves are displaced either north or west of the better
low-level moisture, which is in place from central TX to the central
Gulf Coast. This displacement will mitigate the overall severe
potential, although thunderstorms are still expected across several
areas, including the central Intermountain West into the central
Rockies ahead of the southern Great Basin shortwave, and along the
West Coast as the northeast Pacific shortwave drops south along the
coast. Highest coverage ahead of the Great Basin wave will likely
occur along the UT/CO this evening. Highest coverage along the West
Coast is anticipated along OR coast where multiple bands should move
through during the period. A secondary max is likely farther south
in the Monterey Bay Vicinity late tonight/early tomorrow morning.

Isolated elevated thunderstorms also remain possible this afternoon
from Lower MI into northeast OH/northwestern PA as the vorticity max
currently over OH moves into the region. Mid-levels will be dry but
lapse rates will be steep, and there could be just enough low-level
moisture to support limited buoyancy and a few thunderstorms as the
vorticity max moves through.

Lastly, strengthening low-level flow within the moistening low-level
airmass could support a few isolated thunderstorms across Middle TN
and adjacent far south-central KY tonight.

..Mosier/Thompson.. 02/18/2026


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SPC Feb 18, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0632 AM CST Wed Feb 18 2026

Valid 181300Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Organized severe weather is not expected today or tonight.

...Discussion...
With an amplified large-scale pattern over the CONUS, an upper low
will continue to cross the Upper Midwest toward Lake Superior, with
preceding warm/moist advection and DPVA contributing to isolated
thunderstorms across parts of the Great Lakes region, mainly early
today.

In the West, a band of convection will continue to move inland early
this morning across coastal southern California in association with
a cold front. Diminishing convective potential is otherwise expected
today across most of California. However, isolated thunderstorm will
be possible later this afternoon and tonight across the coastal
Pacific Northwest and northern California as a secondary shortwave
trough digs southward along the coast. Isolated thunderstorms will
also be possible across the eastern Great Basin and central Rockies
mainly this afternoon. Here, sufficient diurnal mixing and a zone of
stronger mid-level southwesterly flow aloft could account for some
convectively enhanced wind gusts, but overall severe potential
should remain minimal.

..Guyer/Grams.. 02/18/2026


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SPC Feb 18, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1108 PM 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, southern Great Basin, central Rockies, and the
lower Great Lakes regions. Severe weather is not anticipated.

...Discussion...
A series of mid-level troughs will traverse the CONUS Wednesday
morning through late Thursday. Across the western US, a trough will
gradually shift across the Great Basin with enhanced mid-level flow
overspreading the Desert Southwest into the central/southern High
Plains. Forcing for ascent and cooling temperatures aloft will bring
scattered thunderstorm activity across the central California coast
to the Oregon/Washington Coast. Additional thunderstorm development
will be possible across the southern Great Basin into the central
Rockies. Generally weak thermal profiles will limit severe potential
with this activity.

A secondary trough will continue to shift northeast across the Great
Lakes Region. Scattered thunderstorm development will be possible
along an eastward moving front within a narrow region of warm air
advection. Given the generally narrow/weak region of marginal
instability, activity is this region is expected to remain
sub-severe.

..Thornton/Squitieri.. 02/18/2026


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SPC Feb 18, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0654 PM CST Tue Feb 17 2026

Valid 180100Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN CALIFORNIA COAST...

...SUMMARY...
Isolated strong thunderstorms will be possible across parts of
coastal Southern California through tonight.

...Discussion...
Thunderstorm activity continues across portions of Southern
California this evening as mid-level flow increases with the
approaching upper-level low. Thunderstorm activity is expected to
continue overnight, with potential for occasional stronger bands
that may produce some instances of damaging wind. A low tornado risk
was maintained with this outlook, owing to the strong deep layer
flow progged to increase overnight.

High-based convection across far eastern Nebraska has showed signs
of weakening over the last hour, with a downward trend in lightning.
Guidance shows little in the way of additional development through
the rest of the evening. The Marginal Risk across this region was
removed with this outlook.

..Thornton.. 02/18/2026


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