Mesoscale Discussion 1827
NWS Storm Prediction Center Norman OK
1113 AM CDT Mon Aug 03 2026

Areas affected...portions of New England

Concerning...Severe potential...Watch unlikely 

Valid 031613Z - 031815Z

Probability of Watch Issuance...20 percent

SUMMARY...Sporadic strong wind gusts, and possibly a weak/brief
tornado, are possible through the afternoon. The overall risk is
expected to remain limited, and a watch is not currently expected.

DISCUSSION...Convection is gradually increasing in
coverage/intensity ahead of a surface cold near the NY/VT border
early this afternoon. Broken clouds have muted stronger heating, but
temperatures have risen modestly into the mid 70s to near 80 F amid
a very moist airmass (upper 60s to low 70s dewpoints). This is
resulting in a corridor of weak destabilization across portions of
New England, with continued destabilization expected through the
afternoon with eastward extent toward western ME. Increasing
southwesterly flow aloft is aiding in effective shear magnitudes
greater than 45 kt across the region, with will allow for transient
storm organization despite weak instability. 

Sporadic strong wind gusts will be possible through the afternoon as
the surface front gradually pushes eastward. Where pockets of
stronger heating occur and where backed surface flow is maintained,
a brief/weak spin-up also is possible. However, given weak
instability and poor lapse rate environment, the overall severe risk
should remain limited, and a watch is not currently expected.

..Leitman/Gleason.. 08/03/2026

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

ATTN...WFO...GYX...BOX...BTV...ALY...

LAT...LON   44997322 45457160 45347063 44787023 43767015 42657105
            41987217 41957276 42177333 42497367 42947387 44997322 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1130 AM CDT Mon Aug 03 2026

Valid 031630Z - 041200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS INTO THE UPPER MIDWEST...AND SOUTHERN ARIZONA...

...SUMMARY...
Scattered severe thunderstorms are possible today into tonight
across parts of the eastern Dakotas into northern Minnesota, as well
as across portions of southern Arizona.

...Northern/Central Plains into the Upper Midwest...
Post-frontal thunderstorms occurring this morning across ND have
remained mostly sub-severe over the past couple of hours. A stout
low-level inversion noted on the observed 12Z INL sounding will
likely inhibit surface-based thunderstorms from developing until
late this afternoon or early evening across the eastern Dakotas into
northern MN. Still, gradual airmass destabilization is anticipated
across this region along/ahead of a cold front through the
afternoon. Large-scale ascent attendant to an ejecting mid-level
shortwave trough from MT into ND will eventually aid scattered
convective development along/near the front, most likely by 22-01Z.
Moderate instability coupled with strong deep-layer shear will
support some threat for supercells and large hail initially, before
upscale growth into clusters supports an increasing severe/damaging
wind threat with eastward extent into northern MN this evening. A
tornado or two may also occur as low-level shear gradually increases
in a narrow corridor ahead of the front this evening.

Isolated to widely scattered thunderstorm development is forecast
with southward extent into the central High Plains. A hot and very
well-mixed low-level airmass ahead of the front/surface trough
across this area may support occasional severe gusts with convective
outflow. But, weaker mid-level winds and related modest deep-layer
shear should result in only loosely organized clusters/cells. This
activity should weaken with the loss of daytime heating.

...Southwest...
Around 15-25 kt of east-northeasterly mid-level winds will persist
today across far southern AZ/NM, to the south of prominent upper
ridging that will remain anchored over the Southwest. Recent visible
satellite imagery shows mostly clear conditions across southeast AZ,
with latest surface observations showing ample low-level moisture
present (surface dewpoints generally in the low to mid 60s across
lower elevations). Ample heating of this moist airmass will support
moderate instability by mid afternoon. Current expectations are for
thunderstorms to initially develop over the higher terrain of
southeast AZ as convective temperatures are reached, and
subsequently spread west-southwestward into the lower deserts
through the evening. Some organization/clustering appears possible
with this activity, and the Slight Risk for severe wind gusts up to
60-75 mph has been maintained with no changes. Isolated hail may
also occur with the strongest cores that develop initially.

...Northeast/Northern Mid-Atlantic...
An upper trough with enhanced mid-level south-southwesterly flow
will advance eastward across the Northeast and northern Mid-Atlantic
today. A weak surface low should develop northward into southern
Quebec, with a trailing cold front advancing eastward across the
Northeast this afternoon/evening. Filtered daytime heating of a
seasonably very moist airmass (reference 12Z observed soundings from
OKX/ALB/GYX) will support modest MLCAPE up to 500 J/kg, even though
mid-level lapse rates remain quite poor. Thunderstorms developing
along and ahead of the cold front may pose an isolated threat for
damaging winds given the enhanced flow present at low/mid levels. A
brief tornado or two could also occur across parts of New England
where effective SRH may be locally greater in tandem with a
southerly low-level jet. Still, the overall poor thermodynamic
environment should limit a greater severe wind threat from
developing this afternoon.

..Gleason/Lyons.. 08/03/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1222 PM CDT Mon Aug 03 2026

Valid 041200Z - 051200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHEAST 
ARIZONA...SOUTH-CENTRAL COLORADO...NORTH-CENTRAL AND NORTHEAST NEW
MEXICO...AND PORTIONS OF THE CAROLINAS......

...SUMMARY...
Isolated severe storms capable of severe wind gusts and marginally
severe hail appear possible in southeast Arizona, south-central
Colorado, and north-central and northeast New Mexico Tuesday
afternoon and evening. Locally damaging winds may occur with
stronger storms in the Carolinas.

...Synopsis...
A broad trough across southern Canada will bring enhanced westerly
flow aloft across the Northern Rockies into Upper Midwest and
Central Plains. A shortwave trough will move across the Mid-Missouri
Valley late in the period. Weak troughing will be in place across
the eastern US, with a weak upper-level low across northern Georgia
into the Carolinas. At the surface, a cold front will extend for the
Great Lakes Region south and west into the Mid-Missouri Valley and
into the Southern High Plains. 

...Southeast Arizona...
Widely scattered thunderstorm development is expected across the
high terrain in southeastern Arizona Tuesday afternoon. Convection
will likely build along the high terrain before moving into the
lower deserts by the late afternoon. A deeply mixed and hot air mass
will be in place with steep low to mid-level lapse rates. Guidance
suggests that at least moderate instability will be available. This
may allow for a few isolated stronger clusters with potential for
damaging winds through the late afternoon/early evening.

...South-central Colorado and north-central and northeast New
Mexico...
A narrow corridor of instability will overlap with sufficient deep
layer shear near the Sangre De Cristo Mountains in northern New
Mexico/southern Colorado Tuesday afternoon. This will be in the
region where a surface front intersects the terrain within a favored
upslope region. Marginally severe hail and strong to severe wind
gusts will be possible. 

...Carolinas...
A vort max will rotate through weak upper-level flow across portions
of the Carolinas and northern Georgia, providing an increase in
forcing for ascent. Scattered thunderstorm activity is expected
across the region amid a very moist and unstable air mass. Deep
layer flow will be fairly weak but steepening low level lapse rates
and moist profiles may support a few isolated wet downbursts. 

...Middle and Lower Missouri Valley into the upper Midwest...
Convection is likely to be ongoing at the start of the period
Tuesday morning across portions of the Mid-Missouri Valley, which
may linger into the early afternoon. Forcing for ascent will remain
fairly weak during the daytime before a mid-level shortwave rotates
through the flow late in the period. Guidance continues to suggest
that new convective development will be primarily north of the
surface boundary and within a region of poor lapse rates and
marginal instability. Nonetheless, strong deep layer shear will be
present. A few stronger cells may produce gusty winds.

..Thornton.. 08/03/2026

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1032 AM CDT Mon Aug 03 2026

Valid 031700Z - 041200Z

The Elevated area was expanded into the Four Corners as
elevated/locally critical fire weather conditions are expected over
increasingly receptive fuels. A recent downturn in monsoonal
thunderstorms have allowed fuels to cure quickly in portions of the
Four Corners, and westerly winds of 15-25 mph amid minimum RH of
5-15% are likely to overspread this area with 80-90%+ probabilities
of the Hot, Dry, Windy Index exceeding the 95th percentile.

Isolated high-based, drier thunderstorms are possible across
portions of the Colorado Rockies, but confidence in dry thunderstorm
development over receptive fuels is too low to include an IsoDryT
area. Deep pyroconvection is also possible on active large wildfires
in the Colorado Rockies due to this somewhat favorable dry
thunderstorm environment.

..Nauslar.. 08/03/2026

.PREV DISCUSSION... /ISSUED 0202 AM CDT Mon Aug 03 2026/

...Synopsis...
A strong shortwave trough will traverse the northern Plains through
the day today, resulting in surface low pressure development across
the Dakotas and in the lee of the Rockies across the central High
Plains. This will result in breezy conditions across portions of the
central and northern High Plains as well as the Rockies and Great
Basin. An expansive Elevated area has been maintained for this
region.

...Northern High Plains...
A cold front will push southward throughout the day with 20-30 mph
sustained northerly winds to its north and dry fuels in the area for
this time of year. Locally Critical conditions may occur, though
increasing RH behind the front will limit the duration of the
Critical fire weather risk. However, given the winds and dry fuels,
have maintained the Elevated in this area.

...Central/Southern High Plains...
Hot temperatures of 100-105 F and modest southerly flow will be in
place throughout the afternoon. Fuels in the area are quite dry for
mid-summer, resulting in Elevated fire weather risk this afternoon.

...Rockies/Great Basin...
Fuels in this area are seasonably dry, and 5-15% RH is expected by
afternoon. Winds are generally relatively weak, though some pockets
of stronger winds and any terrain-driven flows will result in
Elevated fire weather conditions this afternoon.

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