RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Wed Jul 22 15:22:01 UTC 2026.
No Mesoscale Discussions are in effect as of Wed Jul 22 15:22:01 UTC 2026.
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Wed Jul 22 2026
Valid 221300Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN MID-ATLANTIC AND MAINE...
...SUMMARY...
Isolated to scattered storms are 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 and central Oregon.
...Carolinas/Mid-Atlantic...
The region will influenced by the base of the eastern CONUS trough
and moderately strong belt of cyclonically curved westerlies,
although subtle mid-level warming is expected across the Carolinas
and southern Virginia. Storm redevelopment and re-intensification
today will tend to favor a persistent west-east zone of pre-frontal
convergence and existing convection across southern Virginia and
northern North Carolina, with additional development possible this
afternoon farther north closer to the southeastward-moving cold
front. Cloud breaks and a moisture-rich environment will support
moderate destabilization this afternoon. Around 30-40 kt of
effective shear will support some organized clusters and
conditionally support some supercells, especially with somewhat
stronger wind profiles with northward extent across southern/eastern
Virginia toward the Delmarva. Damaging winds are the most probable
severe hazard regionally, but some tornado risk may exist as well.
...New England...
A shortwave trough/moderately strong mid-level jet streak will be
favorably timed with diurnal destabilization during the afternoon,
particularly for New Hampshire into Maine. As the cold front
progresses eastward, scattered storms are expected to develop.
Effective shear of 30-40 kt and strong upper-level winds will
support the possibility of some supercells aside from organized
multicells. Damaging winds, marginally severe hail, and perhaps a
tornado are all possible this afternoon until around sunset.
...Central High Plains...
Southeasterly surface winds will combine with increasingly
westerly/northwesterly flow aloft to promote modest deep-layer shear
(around 30 kt 0-6 km) during the afternoon/evening. The development
of a weak lee low and low-level moisture moving northwest around the
Midwest anticyclone will aid in storm development within the region.
Temperature-dewpoint spreads at the surface will allow for efficient
outflow production. A strengthening southeasterly low-level jet
across western Kansas may also help maintain convection farther east
during the evening. Severe wind gusts are possible with this
activity.
...Oregon...
Weak height falls will influence the region via an upper low off the
coastal Pacific Northwest. Modest large-scale ascent and diurnal
heating/orographic influences will contribute to thunderstorm
development across central Oregon during the afternoon. Large
temperature-dewpoint spreads will promote a risk for strong to
severe wind gusts despite relatively limited overall buoyancy and
vertical shear.
...Gulf Coast...
Tropical Storm Bertha will continue to slowly drift westward across
the northern Gulf of America, grazing the southern Louisiana coast
through tonight. Several factors suggest that inland/near-shore
supercell potential will remain limited including an expected
gradual weakening of Bertha and poor thermal profiles inland where
southerly low-level winds will develop toward the coast on its
eastern periphery.
..Guyer/Broyles.. 07/22/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1020 AM CDT Wed Jul 22 2026
Valid 221700Z - 231200Z
Minor modifications were made to the IsoDryT area based on the
latest observations and forecast guidance. The forecast remains on
track, and please see the previous discussion for more details.
..Nauslar.. 07/22/2026
.PREV DISCUSSION... /ISSUED 1201 AM CDT Wed Jul 22 2026/
...Synopsis...
Upper-level troughing will remain in place across the eastern U.S.
as a southward progressing cold front promotes widespread chances of
rainfall along the Eastern Seaboard today. Meanwhile, tropical
remnants will continue to translate northward along the western
periphery of a large-scale ridge across the western CONUS. As high
pressure shifts towards the Four Corners, additional monsoonal
moisture will advect into the Pacific Northwest.
A mix of wet/dry thunderstorms are expected across the IsoDryT area,
with overall coverage likely exceeding 50% across central/southern
Oregon--perhaps approaching 80% in central Oregon. PWAT values are
expected to approach 0.9-1.3" amid southerly flow induced training
of storms, indicating wetting rain is likely across portions of the
area. However, given a drought-stressed fuelscape and numerous
ongoing wildfires, lightning-induced ignitions will remain a concern
on the periphery of heavier precipitation. The lightning threat will
then shift northward into southwestern WA through the evening and
overnight hours. Forecast soundings depict dry sub-cloud layers up
to 700 mb, ample instability (MUCAPE greater than 500 J/kg), and
15-25 kt storm motions. This meteorological setup greatly increases
fire weather concerns as several days of dry and windy conditions
are expected to follow, potentially impacting nascent wildfires born
from thunderstorm activity.
...Please see www.spc.noaa.gov/fire for graphic product...
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