ACUS01 KWNS 262002

SWODY1

SPC AC 262000



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.



$$

