Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0230 AM CDT Fri Jul 31 2026

Valid 021200Z - 031200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LOWER GREAT
LAKES INTO THE CAROLINAS AND PARTS OF EASTERN GEORGIA...AND OVER
PARTS OF NORTH DAKOTA...

...SUMMARY...
Isolated occurrences of mainly damaging winds are possible from the
Lower Great Lakes into the Carolinas and parts of eastern Georgia
Sunday afternoon and evening. A conditional threat for large hail
and severe wind gusts exists across parts of North Dakota into far
northwest Minnesota late Sunday afternoon into night.

...Synopsis...

A mid-level trough will advance slowly through the lower Great
Lakes, OH and TN Valleys, and the central Gulf Coast states Sunday
and Sunday night. Ahead of the trough, south-southwest winds in the
mid levels will gradually strengthen through the forecast period. At
the surface, an area of low pressure will develop from the mid into
the upper OH Valley, while a trailing front edges east through the
TN Valley and central Gulf Coast.

Elsewhere, a seasonably strong short-wave trough is forecast to move
through the Canadian Prairie Provinces with an associated belt of
50-60 kt mid-level winds spreading from the northern Rockies into
the northern Plains. At the surface, a cold front will advance into
the northern Plains by Sunday afternoon into night.


...Lower Great Lakes into the Southeast...

Showers and thunderstorms are expected to be ongoing Sunday morning
from the lower Great Lakes into central Appalachians within a zone
of warm advection and moisture transport along a low-level jet. Some
of the early-day storms may linger into afternoon with associated
cloud cover limiting air mass destabilization. Where cloud breaks
can occur, increased daytime heating and boundary-layer dewpoints in
the 60s to mid 70s will contribute to corridors of moderate
instability, the highest confidence of which is from southern VA
into the Savannah River Valley.

Aided by forcing for ascent ahead of the mid-level trough,
thunderstorms are expected to increase in coverage and intensity
through the afternoon, especially in areas of greater instability
from the upper OH Valley into Carolinas. In general, storms may
remain somewhat disorganized, posing mainly a damaging wind risk
during the afternoon into evening. A possible exception is across
the upper OH Valley, where stronger vertical shear will be
supportive of organized storms modes, given sufficient
destabilization. 


...Northern Plains...

Boundary-layer dewpoints in the 60s to 70s locally will coincide
with steep low/mid-level lapse rates to yield a moderately to
strongly unstable, but capped air mass by afternoon ahead of the
front. The strongest forcing for ascent associated with the Canadian
short-wave trough is expected to remain north of the international
border, leading to uncertainty in whether the combination of daytime
heating and frontal convergence will be sufficient to initiate
surface-based storms. 

On the condition that storms develop and are sustained, the presence
of 30-40 kt of deep-layer shear across the frontal zone will support
organized storm modes, including supercells with an associated large
hail and severe wind gust threat. That conditional risk will exist
from late Sunday afternoon through Sunday night. However, given the
uncertainty in storm development, only 5% probabilities will be
included in this forecast.

..Mead.. 07/31/2026

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.

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0216 AM CDT Fri Jul 31 2026

Valid 311200Z - 011200Z

...NO CRITICAL AREAS...

...Synopsis...
A potent upper-level trough will begin to move onshore over the
Pacific Northwest tonight, with upper-level ridging ahead of this
trough extending from the Desert Southwest into the northern
Rockies. An embedded, mid-level shortwave trough is forecast to
precede the larger trough and move from northern California into the
northern Rockies through this afternoon while weakening. Hot, dry,
and locally breezy conditions are likely across much of the West,
especially the Intermountain West, this afternoon, with locally
elevated fire weather conditions possible. The lack of widespread,
sustained surface winds above 15 mph precludes the inclusion of
Elevated highlights, however.

Isolated, drier thunderstorms are possible across portions of
central/eastern Idaho and southwest Montana this afternoon and
evening, but the latest SREF/HREF guidance continues to suggest less
than a 20% chance and generally less than a 10% chance of
thunderstorms. Somewhat greater chances for thunderstorms exist
farther east into portions of Wyoming, but this activity is likely
to be wetter and over less receptive fuels. Elsewhere, monsoonal
thunderstorms remain likely over portions of southeastern Arizona
and along/east of the Continental Divide in Colorado and New Mexico.

..Chalmers.. 07/31/2026

...Please see www.spc.noaa.gov/fire for graphic product...