Mesoscale Discussion 1713
NWS Storm Prediction Center Norman OK
0643 PM CDT Wed Jul 22 2026

Areas affected...northeast Colorado

Concerning...Severe potential...Watch unlikely 

Valid 222343Z - 230145Z

Probability of Watch Issuance...20 percent

SUMMARY...The potential for a few severe wind gusts is expected to
increase across the discussion area this evening. The areal coverage
of the threat is expected to remain too limited to warrant a watch
issuance.

DISCUSSION...Recent radar trends indicate thunderstorms gradually
increasing in areal coverage across portions of Lincoln and Kit
Carson Counties, to the north of a stalled front. The storms are
developing within the western edge of a more moist and unstable
boundary layer (i.e., MLCAPE up to 1000-2000 J/kg), and within a
zone of stronger east to southeast surface winds. Aided by a gust
front approaching from the west, latest CAM guidance suggests the
potential for upscale growth into a loosely organized complex or
line by 01-02Z.

The current KGLD VWP is sampling a 1-km deep layer of southeast
winds, which will enhance storm-relative inflow into the developing
storms. When coupled with steep low/mid-level lapse rates and
boundary-layer temperature-dewpoint spreads of 30+ degrees, the
setup appears supportive of a few severe wind gusts this evening.

..Mead/Mosier.. 07/22/2026

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

ATTN...WFO...GLD...BOU...

LAT...LON   39160355 39870376 40620387 40970359 40870269 39790245
            39030262 38870309 39160355 

MOST PROBABLE PEAK WIND GUST...55-70 MPH

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0300 PM CDT Wed Jul 22 2026

Valid 222000Z - 231200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE MID ATLANTIC AND NEW ENGLAND...SOUTHEAST TEXAS...THE CENTRAL
HIGH PLAINS AND CENTRAL OREGON....

...SUMMARY...
Isolated to widely scattered storms remain possible across the
Carolinas and southern Mid-Atlantic, as well as New England this
afternoon and early evening, with damaging winds as the primary
concern. Isolated strong to severe wind gusts are also possible in
the central High Plains, southeast Texas and central Oregon, where
isolated large hail will also be possible.

...20z Update New England...
A broken band of strong to occasionally severe convection remains
ongoing ahead of a progressive cold front over northern and eastern
New England this afternoon. Weak buoyancy, but fairly strong
deep-layer shear (35-45 kt) should support isolated hail, and
damaging winds with stronger clusters or supercell structures this
afternoon. A brief tornado also remains possible across northern ME
where low-level shear is locally stronger. The primary change this
outlook cycle was to lower overall severe probabilities and remove
them behind the front where the air mass has stabilized.

...Mid Atlantic and Carolinas...
Farther south, the cold front has become increasingly zonally
oriented and slowed as the upper trough has lifted away to the
northeast. A warm and very moist environment remains in place across
southeastern VA into northern NC. However, poor mid-level lapse
rates and decreasing vertical shear have limited convective
organization and intensity. Some renewed intensity is possible along
the convectively modified boundary/differential heating axis along
the NC/VA border this afternoon and evening. However, the severe
threat (predominately damaging gusts) is expected to remain isolated
into this evening. Severe probabilities have been lowered and
adjusted to better match the main focal area for severe storms near
the VA/NC border through this evening.

Elsewhere, isolated severe gusts/hail remain possible over parts of
the central High Plains and the southeast TX. Isolated hail is also
possible over parts of central OR. Scattered storms are expected
late this afternoon through the evening. No changes were made to
theses areas, see the previous discussion for more information.

..Lyons.. 07/22/2026

.PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Jul 22 2026/

...Northern New England this afternoon...
Per water vapor imagery and morning upper air observations, a
pronounced midlevel trough will progress east-northeastward from
PA/NY/Saint Lawrence Valley toward New England through this
afternoon.  An associated surface cold front will likewise move
eastward and provide a focus for thunderstorm development by early
afternoon into Maine.  A few cloud breaks developing from
west-to-east through the afternoon will allow surface temperatures
to warm into the 70s with boundary-layer dewpoints in the mid 60s,
resulting in MLCAPE in the 1000-1500 J/kg range.  Deep-layer,
south-southwesterly shear will be sufficient for a mix of clusters
and supercells with a primary threat for occasional wind damage.

...Mid-Atlantic this afternoon/evening...
A pre-frontal band of convection is ongoing across southern VA, with
a narrow zone of stronger surface heating/destabilization to the
north of the thicker clouds from northern VA into MD/DE in advance
of a cold front moving across PA.  The southern fringe of the
stronger (35-50 kt) midlevel flow extends to near the VA/NC border
on the south side of the thicker cloud band.  The ongoing convection
is likely persist through the afternoon while spreading slowly
southward.  Midlevel lapse rates will remain poor, but deep-layer
vertical shear will be sufficient for embedded/organized storms with
occasional wind damage.  Low-level shear will be marginally
favorable for rotating storms and perhaps an isolated tornado.

...Southeast TX late this afternoon through late evening...
Strong surface heating is underway with a general confluence zone
near the TX/LA border well to the west of highly-sheared Tropical
Storm Bertha.  As Bertha continues westward, this confluence zone
should support thunderstorm development into southeast TX late this
afternoon.  Steering flow from the northeast at ~35 kt will favor
storm clusters moving southwestward into a hot, deeply mixed
boundary layer where buoyancy will be sufficient to maintain the
storm clusters into late evening.  A few strong-severe outflow gusts
will be the main threats.

...Northeast CO and vicinity this afternoon/evening...
Low-level upslope flow on the cool side of a surface front, combined
with weak perturbations rotating around the northwest periphery of
the southern Plains midlevel high, will support afternoon
thunderstorm development over the foothills.  The storms will spread
east-southeastward onto the plains, with a tendency for clustering
with the potential for isolated severe outflow gusts.

...OR this afternoon/evening...
Along the northwest edge of the monsoonal moisture plume, a midlevel
shortwave trough will move northward from northern CA into OR.  Weak
forcing for ascent combined with daytime heating over the higher
terrain will support scattered thunderstorms later this
afternoon/evening from the Cascades into central OR.  An environment
with MLCAPE of 500-1000 J/kg, steepening low-level lapse rates and
effective bulk shear near 25 kt will support isolated strong outflow
gusts and marginally severe hail.

Day 3-8 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0443 PM CDT Wed Jul 22 2026

Valid 241200Z - 301200Z

Upper-level troughing will develop over the Pacific Northwest into
the northern Rockies late this week through the weekend. Mid-level
southwest-westerly flow of 30-60 knots will overspread the region
with a tightening onshore pressure gradient and lee troughing east
of the Cascades and northern Rockies. The Four Corners High will
likely slowly shift east-southeast towards the southern High Plains,
with daily monsoonal thunderstorms remaining likely across the
greater Four Corners region into early next week. 

...Northwestern US...
Overall, a critical fire weather pattern will continue to unfold
through the weekend across the northwestern US with lightning
followed by hot, dry, and windy conditions. Elevated to critical
fire weather conditions are expected across the Inland Northwest,
northwest Great Basin, and extending through northern Montana Day
3/Friday as west-southwest winds strengthen amid a drying and
warming airmass. Critical winds/RH are likely to develop across
portions of north-central and northeast Montana, but this will
likely act more as a curing event. 

Winds will strengthen on Day 4/Saturday across the Inland Northwest
and into northwest Montana, with critical conditions expected again
here and from south-central/southeast Oregon extending into
northeast California, northwest Nevada, and southwest Idaho.
Isolated to scattered mixed wet/dry thunderstorms are likely in
portions of central Montana on Day 4/Saturday, but there remains too
much uncertainty regarding the overlap of receptive fuels and drier
thunderstorm development to include dry thunderstorm probabilities
at this time. However, dry and breezy conditions are likely across
portions of western/central Montana Day 4/Saturday. 

Dry and breezy conditions will continue from the northwest Great
Basin through central/southern Idaho into Montana on Day 5/Sunday
and possibly Day 6/Monday. There remains forecast uncertainty
regarding lingering dry and breezy conditions across portions of the
Inland Northwest, and the likelihood of critical conditions in
portions of the northwest Great Basin and northern Montana. Much of
this depends on the evolution of the upper-level troughing over the
northwest US. Another source of forecast uncertainty is how areas
that currently have less receptive fuels in portions of northeast
Nevada, central/eastern Idaho, and southwest Montana will respond to
multiple consecutive days of hot, dry, and breezy conditions.

...Plains...
Hot, dry, and breezy conditions will likely develop across portions
of the Plains during the outlook period. Fuels, especially fine
fuels, will begin to cure and perhaps rapidly. How this pattern
affects these areas will continued to be monitored.

..Nauslar.. 07/22/2026

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