156
ACUS48 KWNS 310850
SWOD48
SPC AC 310848

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0348 AM CDT Fri Jul 31 2026

Valid 031200Z - 081200Z

...DISCUSSION...
...Day 4/Monday...

A short-wave trough and associated mid-level jet streak are forecast
to move through the northern Plains into the upper MS Valley in
tandem with a surface cold front. The combination of steep lapse
rates and a moist boundary layer is expected to yield moderate to
strong instability by afternoon ahead of the front, amidst a
kinematic environment featuring 40-50+ kt of deep-layer. As such,
the potential will exist for organized storm modes capable of a more
concentrated severe weather event from eastern ND into northwest MN.
More isolated severe storms appear possible southwest along the
front into NE.

Elsewhere, a mid-level trough is forecast to intensify over western
QC into the St. Lawrence Valley with an attending belt of
strengthening mid-level flow overspreading northern New England. At
the surface, a front is expected to settle south through northern
New England and the northern Mid-Atlantic. Where stronger
destabilization can occur, isolated severe storms appear possible
along the front, aided by 30-40 kt of deep-layer shear.


...Days 5 and 6/Tuesday and Wednesday...

A broader-scale trough over central Canada into the north-central
states on Tuesday is forecast to amplify slightly while moving into
the upper Great Lakes by Wednesday. Meanwhile, a downstream trough
across the upper OH Valley is expected to weaken while accelerating
into the Northeast. At the surface, a cold front will move through
the Great Lakes with the trailing extension of the boundary stalling
over the central High Plains. The degree of instability ahead of the
front remains uncertain; however, sufficient vertical shear is
expected along the front to support a conditional threat for at
least isolated severe storms.


...Days 7 and 8/Thursday and Friday...

The 00Z ensemble means indicate a flattened upper ridge over the
southwest and south-central U.S. with a belt of modestly enhanced
mid-level flow across the northern tier of states. However, there is
considerable model spread in the location and movement of
disturbances embedded within that pattern that may focus a severe
weather threat. That being said, there is a fairly consistent signal
across AI guidance for some severe weather threat across parts of
the Mid-Atlantic on Thursday/Day 7. Model trends will continue to be
monitored for that time period.

..Mead.. 07/31/2026