SPC Jun 22, 2025 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1215 PM CDT Sun Jun 22 2025

Valid 231200Z - 241200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
PLAINS NORTHEASTWARD TOWARD THE UPPER GREAT LAKES...

...SUMMARY...
Strong to potentially severe storms are possible Monday from parts
of the Great Lakes into the central Plains.

...Synopsis...
A prominent upper high will be centered over the Appalachians,
providing hot conditions over much of the eastern CONUS. Early in
the day, a shortwave trough will exit the far northern Plains,
ejecting across Ontario. Meanwhile, a shortwave trough will move
from parts of CA into the Great Basin, within a broader upper
trough.

At the surface, High pressure will exist over much of the East
beneath the upper ridge, though weak troughing will occur during the
day over the Mid Atlantic. Another area of high pressure behind the
northern Plains wave will push east into the upper MS Valley, with a
cold front roughly from central WI into western KS by 00Z. A very
moist air mass will exist east of this cold front, and, over much of
the East. Strong to severe storms are most likely along the Plains
front, although scattered storms will also be likely over the TN
Valley and Mid South, though with less severe potential. Finally,
isolated storms may occur over parts of the Appalachians beneath the
upper High.

...Central Plains into the upper Great Lakes...
Strong heating will occur ahead of the cold front, where dewpoints
will range from the upper 60s F to lower 70s F. This region will
also be within a plume of midlevel moisture spreading northward west
of the upper ridge. As such, the high PW air mass along with surface
convergence near the front should easily support afternoon storms,
most likely from WI southwestward to perhaps the OK/TX Panhandles by
00Z.

Deep-layer shear and mean winds in general will not be very strong
along the frontal zone, but perhaps a bit stronger over northern
areas as the upper wave glances the area. The end result should be
an elongated area of afternoon storms. Some of these storms may
briefly contain marginal hail due to moderate instability and modest
midlevel lapse rates, but storms will likely merge quickly over most
of the area with strong to locally damaging gusts.

..Jewell.. 06/22/2025

StormPrep