RSS Mesoscale Discussions from Storm Prediction Center
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 AM CST Sat Feb 21 2026
Valid 221200Z - 231200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorms will be possible across portions of the Florida
Peninsula during the day on Sunday. Lightning may also occur across
coastal areas from North Carolina north toward Massachusetts.
... Discussion ...
A strong shortwave trough and attendant speed max over the Ohio
Valley at the start of the period will quickly dig east/southeast
during the day on Sunday, before pivoting north toward southern New
England overnight. At the surface, a low, initially over the coastal
waters of North Carolina, will deepen through the day as strong
large-scale ascent increases with the approaching shortwave trough.
The rate of deepening of the surface low will only increase
overnight as the shortwave trough takes on a neutral to negative
tilt and large-scale ascent increases further.
As the surface low deepens along the coast, the intensifying warm
conveyor belt to the north and west of the low, drawing warm, moist
Gulf Stream air inland. The combination of strong large-scale
ascent, strong low-level warm-air advection, and cooling mid-level
temperatures may result in enough elevated instability to support a
few lightning strikes within the warm conveyor belt as the low lifts
northward along the coast.
Farther south and west, the deepening surface low will drive a cold
front south across the Florida Peninsula. Surface temperatures in
the 70Fs and dewpoints in the low-to-mid 60Fs may support a narrow
ribbon of most-unstable CAPE between 500 and 1000 J/kg ahead of the
southward advancing front. As a result, showers and a few
thunderstorms may develop along and ahead of the front. Forecast
soundings show pronounced mid-and-upper-level warming, which will
limit the overall instability and a more robust lightning threat.
Across the West, strong ascent and some moisture advection
associated with the next upper-trough may lead to very isolated
lightning strikes along and off the Pacific Northwest coast.
However, coverage should remain sparse enough to preclude the need
for delineation.
..Marsh.. 02/21/2026
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SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0200 AM CST Sat Feb 21 2026
Valid 231200Z - 241200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorms are not expected across the United States on Monday.
... Discussion ...
As the East Coast cyclone departs on Monday, a cool, dry airmass
will settle over much of the country, suppressing thunderstorm
activity.
..Marsh.. 02/21/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0331 AM CST Sat Feb 21 2026
Valid 241200Z - 011200Z
...DISCUSSION...
At the start of the forecast period, a dry airmass will remain
across much of the United States. The culprit being a large surface
anticyclone located across the northern Gulf Coast states
suppressing moisture return. By late Tuesday (Day 4), the
anticyclone will have moved into the eastern Gulf, with southerly
winds advecting moisture northward into the Southern Plains.
Thunderstorm chances may return to portions of the Southern Plains
into the Southeast overnight Wednesday into Thursday as a surface
cold front pushes south into the area. At this time, the quality of
the moisture return and poor lapse rates suggests limited, if any,
severe potential as the front moves through.
The aforementioned front will stall/wash out across the northern
Gulf states late on Thursday into Friday (Days 6 and 7) with modest
moisture return developing across the Southern Plains Friday into
Saturday (Days 7 and 8). This will be short lived as ensemble
guidance suggests a seasonably strong cold front moving into/through
the Southern Plains next weekend or early the following week. Once
again, current guidance indicates the quality of moisture return and
poor lapse rates should limit any severe potential.
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