670
ACUS48 KWNS 160857
SWOD48
SPC AC 160855

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0355 AM CDT Mon Jun 16 2025

Valid 191200Z - 241200Z

...DISCUSSION...
...Thursday/Day 4 and Friday/Day 5...
A mid-level trough is forecast to move into the Northeast on
Thursday, as a cold front advances eastward into the central
Appalachians. Ahead of the front, a moist airmass will be in place.
Moderate instability is expected to develop ahead of the front
across the Carolinas and Mid-Atlantic. As surface temperatures warm
during the day, scattered convective initiation will likely take
place along and ahead of the front. Moderate deep-layer shear and
steep low-level lapse rates should support a severe threat during
the afternoon, with the primary threat being damaging wind gusts.

On Friday, a mid-level ridge is forecast to move eastward across the
northern Plains. Beneath the ridge, a moist airmass will likely be
in place, and moderate instability is expected to develop within
this airmass. Ahead of the ridge, thunderstorm development will be
possible in the upper Mississippi Valley during the afternoon.
Although a severe threat may develop in areas that become moderately
unstable, there is some uncertainty concerning convective coverage
due to the presence of the ridge.

...Saturday/Day 6 to Monday/Day 8...
Mid-level heights are forecast to rise on Saturday and Sunday across
the eastern half of the nation, as a large area of high pressure
dominates. In the western U.S. over the weekend, a mid-level trough
is forecast to move northeastward from the Intermountain West into
the northern High Plains. Ahead of the trough, strong to severe
thunderstorms will be possible Saturday afternoon and evening across
parts of eastern Montana. In spite of the potential, there is still
spatial uncertainty concerning the timing of the trough. The severe
threat is expected to shift northeastward into Canada on Sunday.

On Monday, southwest mid-level flow is forecast over much of the
north-central U.S. Isolated to scattered thunderstorms will be
possible over parts of the northern Plains and upper Mississippi
Valley. An isolated severe threat will again be possible, but there
is considerable uncertainty on any potential scenario.

..Broyles.. 06/16/2025