Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1253 AM CDT Mon Jul 13 2026

Valid 131200Z - 141200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN ATLANTIC SEABOARD AND IN WESTERN MONTANA...

...SUMMARY...
Thunderstorms with isolated severe wind gusts will be possible from
mid afternoon into early this evening across parts of the southern
Atlantic Seaboard and in western Montana.

...Southern Atlantic Seaboard...
Very moist air will be in place today from the Southeast eastward to
the southern Atlantic Seaboard. Surface dewpoints across Georgia and
South Carolina will be mostly in the 70s F. As surface temperatures
warm today, moderate instability will develop across much of the
region. Scattered thunderstorms will form in the higher terrain of
the southern Appalachians and within zones of low-level convergence
across the moist airmass. As instability maximizes and low-level
lapse rates steepen this afternoon, a few severe wind gusts will be
possible with the stronger cells.

...Western Montana...
Southwesterly mid-level flow will be in place today across the
northwestern U.S. At the surface, upslope flow will be located from
the northern High Plains westward to the northern Rockies. As
surface temperatures warm today, a pocket of instability will
develop across western Montana adjacent to the higher terrain. Some
storms that form in the northern Rockies will move northeastward
toward and through this pocket of instability in the lower
elevations, where SBCAPE could approach 1000 J/kg late this
afternoon. The instability and very steep low to mid-level lapse
rates will contribute to a potential for isolated severe wind gusts.

..Broyles/Halbert.. 07/13/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
0100 AM CDT Mon Jul 13 2026

Valid 141200Z - 151200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
NEW ENGLAND...

...SUMMARY...
Severe thunderstorms will be possible during the afternoon and
evening across portions of New England on Tuesday. Additional
strong-to-severe thunderstorms will be possible across parts of
western and central Montana.

... Synopsis ...

The expansive mid-level ridge centered across the north-central
United States will begin to quickly retrograde on Tuesday in
response to a strong short-wave trough digging southeast across the
Northeast. Enhanced mid-level flow will surround the center of this
mid-level ridge, with multiple vorticity/speed maxima moving through
this enhanced flow. 


... New England ...

A strong short-wave trough will move across New England during the
evening and overnight hours. Ahead of this trough, southwesterly
low-level flow will allow temperatures to warm into the 80Fs and
90Fs across northern New England. Additionally, the orientation of
the low-level flow will allow rich boundary layer moisture to advect
northeastward, through the St. Lawrence Valley, and into northern
New England. (HREF ensemble mean dewpoints are greater than 70F
across northern New York into western Maine.) The combination of a
warm, moist boundary layer and modest mid-level lapse rates should
yield strong instability by the afternoon, with HREF probabilities
of exceeding 2000 J/kg MUCAPE greater than 50% across portions of
the area. 

Thunderstorms are expected to develop along and ahead of an
approaching surface cold front during the afternoon within the St.
Lawrence Valley. At the same time, vertical wind shear will be
increasing throughout the day as the mid-level trough approaches.
Given strong instability and effective-layer shear in excess of 50
knots by late afternoon, multiple clusters of severe storms are
expected north of New England. These storms will eventually grow
upscale into one or more linear clusters as they move into and
across portions of New England during the late afternoon, evening,
and overnight. 

Given the degree of instability and strength of the flow, severe
thunderstorm winds are likely (some significant). Large hail will
also be possible with any storms. Additionally, forecast soundings
show enough low-level curvature to support a tornado threat,
including a strong tornado or two, with any sustained surface-based
supercell. 


... Portions of Western and Central Montana ...

Strong mid-level flow will persist across the northern Rockies,
bringing an influx of low- and mid-level moisture compared to recent
days. An embedded shortwave trough moving across the region will
combine with daytime heating over the higher terrain to support
widely scattered to scattered thunderstorms. However, increasing
cloud cover may limit these storms from fully rooting in the
boundary layer. Despite this limitation, the strongest storms will
be capable of producing severe wind gusts and marginally severe
hail.

..Marsh.. 07/13/2026

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0149 AM CDT Mon Jul 13 2026

Valid 131200Z - 141200Z

...Synopsis...
A mid-level trough and associated jet streak is forecast to
translate across the Canadian prairie today, with much of the U.S.
dominated by strong ridging. Monsoonal moisture transported
northward along the western periphery of this ridge will be
responsible for a mix of wet and dry thunderstorms across much of
the Intermountain West, and east-southeasterly flow ahead of a
surface low developing in the northern High Plains will bring dry
and breezy conditions to eastern Wyoming into portions of northern
Colorado and western South Dakota. Dry and breezy conditions are
also forecast for far northern Minnesota. 

...Eastern Wyoming into western South Dakota and far northern
Colorado...
East-southeasterly surface winds across northern Colorado into
eastern Wyoming and portions of western South Dakota are forecast to
be 15-20 MPH. Combined with relative humidity of 10-15%, and
critically receptive fuels (ERCs exceeding the 95th annual
percentile), at least Elevated fire-weather concerns can be expected
this afternoon.  

...Far Northern Minnesota...
The expectation is for 10-15 mph southwesterly winds (gusts up to 25
mph) within a modestly dry boundary layer with 20-30% relative
humidity across northern Minnesota. Fuels guidance indicates
receptiveness to wildfire ignition and spread, with ERCs above the
95th annual percentile across the region and both the ignition and
spread component indices nearly maxed out. Given the receptiveness
of fuels, even the more modest combination of wind and relative
humidity will result in at least Elevated fire-weather concerns this
afternoon. 

...Southwestern Montana into northern Wyoming and portions of
eastern Idaho...
Along the northwestern periphery of the mid-level ridge, column
precipitable water content will largely be in the range of 0.5-0.75
inches with strong signal for thunder in the HREF/REFS calibrated
thunder probabilities. Proximity soundings in southwestern Montana
show deep inverted-V profiles and LCL-EL mean wind speeds in excess
of 30-35 kts, suggesting limited precipitation efficiency. Given the
critically receptive fuels (ERCs exceeding the 95th-98th annual
percentiles), lightning-based ignitions are possible. 

...Northeastern California into northwestern Nevada and far southern
Oregon...
While thunderstorm activity is forecast, this should be much more of
a mix of wet and dry thunderstorms. However, deep inverted-V
profiles and LCL-EL mean wind speeds in excess of 30 kts should
limit overall precipitation efficiency, even with higher
precipitable water content closer to 1 inch. With fuels guidance
showing ERCs at or above the 80th annual percentile, lightning-based
ignitions are possible.

..Halbert.. 07/13/2026

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