139
ACUS48 KWNS 190830
SWOD48
SPC AC 190828

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0328 AM CDT Wed Aug 19 2026

Valid 221200Z - 271200Z

...DISCUSSION...
For the Sat/D4 to Wed/D8 period, an upper ridge will persist from
the Southern Plains into the Southwest, while various shortwave
troughs affect the northern Plains, Great Lakes, and Northeast. The
primary trough amplification will occur from the Upper MS
Valley/Great Lakes on Sat/D4 into the Northeast through Mon/D6, with
moisture and instability supportive of strong storms generally
persisting over parts of the Southeast and Mid Atlantic. Shear will
remain weak over the East on Sat/D4, with areas of storms producing
strong gusts, perhaps marginal/isolated severe.  By Sun/D5, strong
winds and cooling aloft will move across the Mid Atlantic and
Northeast, though antecedent precipitation will affect the warm
sector, as will veering low-level winds. Frontal timing will depend
on the upper trough speed, and overall predictability is low for
Sun/D5.

To the west, daily corridors of thunderstorms are also likely over
parts of the central to northern Plains, with northwest flow
strongest on Sat/D4 and weakening into D5/D6. At least marginal
risk/low probabilities are likely in later outlooks for isolated
wind/hail.

..Jewell.. 08/19/2026