Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Thu Jun 26 2025
Valid 262000Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
FROM NORTHWEST MISSOURI INTO SOUTHERN MINNESOTA/WISCONSIN...AND FROM
THE MID-ATLANTIC TO THE SOUTHERN APPALACHIANS...
...SUMMARY...
Isolated wind damage and a few tornadoes will be possible this
afternoon from northwest Missouri into Iowa, southeast Minnesota,
and southern Wisconsin. Scattered wind damage will be possible from
the Mid-Atlantic into the southern Appalachians.
...20Z Update...
The forecast remains on track, and only minor adjustments were made
with this update. In particular, the Slight risk was expanded
eastward in IA and northern MO -- where warm/moist boundary-layer
conditions should support the maintenance of an eastward-moving line
of storms (with an associated severe-wind risk) into this evening.
Reference Severe Thunderstorm Watch 465 for more information on the
severe risk here. Farther north, the potential for tornadoes will
continue with both pre-frontal cells within the baroclinic zone in
southern WI and with the primary confluence band advancing eastward
out of southeastern MN. An upgrade to 10-percent tornado
probabilities was considered, but overall confidence in this
scenario was too low for the upgrade at this time. For more details,
see Tornado Watch 463 and MCD 1458. Finally, the damaging wind gusts
will remain possible with evolving storms in the Mid-Atlantic
(within Severe Thunderstorm Watch 464).
..Weinman.. 06/26/2025
.PREV DISCUSSION... /ISSUED 1109 AM CDT Thu Jun 26 2025/
...Upper Midwest...
A shortwave trough is evident this morning over NE/SD moving
eastward. Lift ahead of this feature will encourage scattered
thunderstorm development by early afternoon near the surface low and
along a weak cold front over western IA. These storms will track
southeastward into a warm and very moist air mass, where MLCAPE
values will be 2000-3000 J/kg. Steep low-level lapse rates will
promote a risk of damaging winds as the storms spread southeastward
through early evening.
From the surface low eastward into southern WI, a corridor of backed
low-level winds and enhanced shear along the warm front will be
favorable for a few discrete supercells. Similar to yesterday
(although perhaps not quite as favorable), there is a risk of a few
tornadoes through the afternoon and early evening.
...Mid-Atlantic to Southern Appalachians...
Full sunshine is occurring again today from southeast PA to the
western Carolinas and north GA. This corridor will be hot/humid
again today, leading to scattered thunderstorms. Winds aloft are
weak, suggesting disorganized/pulse convective modes. However,
steep low-level lapse rates and moderate CAPE values will once again
result in a risk of locally damaging wind gusts through the
afternoon and early evening. Despite the expected weak winds aloft,
will introduce a SLGT risk for this corridor given the consensus of
model guidance supporting the threat.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TLZwxF
