581
ACUS48 KWNS 300839
SWOD48
SPC AC 300837

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0337 AM CDT Sun Aug 30 2026

Valid 021200Z - 071200Z

...DISCUSSION...
An upper ridge will remain centered over the TN Valley/central
Appalachians through the end of the week before retrograding
westward toward the Plains by next weekend. Multiple mid-level
impulses and shortwave troughs will traverse the upper ridge this
week before upper troughing dominates the Interior West toward the
end of the extended forecast period. The best chances for severe
thunderstorms will be with the aforementioned impulses traversing
the ridge over the Great Lakes to the East Coast, particularly
during the middle of the week.

...Days 4-6 (Wednesday-Friday) - Northeast to Mid-Atlantic...
Severe probabilities have been maintained for portions of the lower
Hudson Valley into the Mid-Atlantic Day 4/Wednesday, as guidance
consensus continues to show a well-timed shortwave trough
overspreading this region. Medium-range guidance continues to show a
convective precipitation signal accompanying this impulse along with
appreciable buoyancy and vertical wind shear. It should be noted
that convective overturning from Day 3 (Tuesday) storms may
stabilize part of this area, with the specific location of storms
becoming dependent on residual baroclinic boundaries. As such, the
exact placement of Wednesday`s severe probabilities may need to be
adjusted accordingly.

Likewise, for Day 5/Thursday, another mid-level impulse will
traverse the northeast extent of the upper ridge and overspread the
Mid-Atlantic. Given adequate buoyancy and shear likely remaining in
place, 15 percent severe probabilities have been introduced. As with
the previous day, these probabilities may need some adjustment in
future outlooks based on where airmass modification along baroclinic
zones occurs.

Medium-range guidance continues to show a pronounced mid-level
impulse, accompanied by adequate deep-layer shear and buoyancy,
impinging on the Mid-Atlantic on Day 6/Friday, which would support
at least an isolated severe threat. ML/AI guidance also suggests
that the Friday severe threat would encompass the ending stages of a
potential multi-day severe episode. Given the multiple preceding
days of storms and constant shift in favorable corridors modulated
by baroclinic zones, confidence is very low for realistically
pinpointing a focused severe area. However, it appears the Delmarva
may be the most likely area for seeing organized storm activity.

..Squitieri.. 08/30/2026