RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1050 AM CDT Wed Mar 25 2026
Valid 251630Z - 261200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Organized severe thunderstorms appear unlikely through tonight.
...Synopsis...
Relatively dry and stable conditions will be present over most of
the CONUS today, but with several small areas of some concern for
thunderstorms. These include the Pacific Northwest, Northern
Plains, Mid/Upper MS Valley, and FL.
...Florida...
A weak surface front lies across the central FL peninsula, with
strong heating and dewpoints in the 60s leading to moderate
afternoon CAPE. Similar to yesterday, scattered thunderstorms are
expected along the east-coast sea-breeze and along/south of the
front. Winds aloft are weak, but cool temperatures aloft could be
sufficient for a strong storm or two capable of hail or gusty wind.
The overall threat appears too low to warrant severe probabilities
at this time.
...IL/IN...
Visible satellite imagery shows a zone of weak low-level warm
advection over IA, spreading eastward into IL. Several model
solutions suggest the risk of some lightning activity this afternoon
in this region, although it appears to be rooted in the mid-levels
and unlikely to produce any severe risk. After dark, more active
thunderstorms may develop over eastern IL and much of IN, but weak
instability will continue to limit any organized severe threat.
..Hart/Weinman.. 03/25/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1223 PM CDT Wed Mar 25 2026
Valid 261200Z - 271200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF NORTHERN AND CENTRAL ILLINOIS AND INDIANA INTO WESTERN OHIO...
...SUMMARY...
Scattered severe thunderstorms are expected late Thursday afternoon
and evening across parts of the Mid-Mississippi and Ohio Valleys.
Very large hail, a few tornadoes, and severe wind gusts will be
possible.
...Mid-MS/OH Valleys...
Several shortwave impulses are expected to migrate through initially
zonal/low-amplitude westerly flow across the Midwest/Great Lakes
region through late afternoon. Stronger height falls will occur
across the region after 00z as a midlevel shortwave trough deepens
across the Upper Midwest and Great Lakes. Despite the low-amplitude
nature of this regime, mid and upper-level flow will be somewhat
strong, with most guidance showing 40-60 kt at 850-700 mb
overspreading the Mid-MS/OH Valley/Great Lakes region by afternoon.
At the surface, a warm front will be oriented across central IA,
extending eastward along the IL/WI and IN/OH/MI border at midday. A
weak surface low/frontal wave will propagate along this zone, with
the front sagging southward as a cold front by late afternoon into
the evening. By the end of the period, the front will be oriented
from the northern Mid-Atlantic southwestward through the Lower OH
valley and into the southern Plains.
Forecast soundings indicate capping could preclude warm sector
convection for much of the daytime hours. In the absence of stronger
large-scale ascent and surface cyclogenesis, the region will
experience a broad warm advection regime, while low-level forcing
along the front increases as it begins to march southward.
Deep-layer flow will largely remain boundary-parallel, though
backing low-level flow is expected near the front across the warm
sector, enhancing low-level SRH. Boundary-layer moisture will be
somewhat modest, generally in the low 60s F, through some pockets of
mid-60s F dewpoints are possible, especially immediately ahead of
the front. A plume of steep midlevel lapse rates will already be in
place over the region, and this will aid in moderate
destabilization, with MLCAPE values reaching 1000-2000 J/kg by peak
heating.
Supercell wind profiles are evident in forecast soundings, with
enlarged/favorably curved low-level hodographs along the front and
45+ kt effective shear magnitudes. Given strong deep-layer flow,
hodographs also are elongated/straight. Supercells producing large
to very large hail (greater than 2+ inch) are possible, even with
potentially elevated convection to the cool side of the boundary. If
any supercell can stay to the warm side of the surface front and
maintain surface-based status, a tornado risk is also possible
(possibly strong tornadoes). With time, convection is expected to
develop into a line or bowing segments given orientation of
deep-shear vectors to the surface boundary. Given strength of
850-700 mb flow and steep lapse rates, damaging winds gusts are
possible.
The severe risk should diminish with south and east extent during
the nighttime hours as storms approach the Ohio River.
..Leitman.. 03/25/2026
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