Severe Storm Outlook Narrative (AC)
Issued by NWS

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
571
ACUS02 KWNS 150602
SWODY2
SPC AC 150600

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Mon Jul 15 2024

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
HIGH PLAINS...AND FROM THE UPPER OH VALLEY INTO WESTERN NY...

...SUMMARY...
Strong to severe thunderstorms are possible from the central Plains
across the Mid Mississippi and Ohio Valleys into the Northeast on
Tuesday. Greater severe-thunderstorm potential is anticipated across
the central High Plains and from the Upper Ohio Valley into western
New York.

...Synopsis...
Western CONUS upper ridging is expected to build on Tuesday,
reaching into much of western Canada by early Wednesday morning.
Upper troughing is anticipated downstream across eastern Canada and
the northeast CONUS, anchored by a cyclone initially over far
northwest Ontario. This cyclone and associated troughing are
expected to progress eastward throughout the day, maintaining a
belt of moderate cyclonic flow aloft from the Upper Midwest across
the Upper Great Lakes, and into the Northeast.

Surface low associated with the Canadian cyclone will likely be
over eastern Ontario and southwest Quebec early Tuesday morning,
with a cold front extended southwestward from the low to another low
in central KS. A moist airmass will be in place ahead of this front,
with dewpoints ranging from the mid/upper 60s across KS increasing
into the low 70s across the OH Valley and then decreasing again into
the upper 60s across the Northeast. Thunderstorm development is
probable along the length of this front as it continues
southward/southeastward and the airmass diurnally destabilizes.
Thunderstorm development is also anticipated across the central
Rockies with progression into the central High Plains and central
Plains possible during the afternoon and evening.

...Central High Plains into the Central Plains...
Expectation is for thunderstorms to develop across the high terrain
of the central Rockies, within the westerly/northwesterly flow aloft
along the northern periphery of the Southwest ridge. Post-frontal
upslope flow is anticipated across the central High Plains, bringing
upper 50s/low 60s dewpoints into the Colorado Plains and supporting
moderate buoyancy. This may help support the development of strong
to severe storms as thunderstorms move off the higher terrain and
into this moderately buoyant airmass downstream. Moderate vertical
shear could help support greater updraft persistence and the
potential for organization into a more organized linear system, with
maintenance into western and central KS possible. Damaging gusts are
the primary severe risk, but some isolated hail is possible as well.

Additional thunderstorm development appears possible Tuesday
afternoon in the north-central NE vicinity, near a secondary surface
low expected to drift southeastward from southwest SD into
north-central NE. Moderate buoyancy and vertical shear (supported by
deep northwesterly flow aloft) could help support cold-pool
organization with the resulting convective line progress
southeastward across NE and potentially into northern KS.

...North-Central OK through Lower MO and OH Valleys into the
Northeast...
Scattered to numerous thunderstorms are expected along the length of
the front Tuesday afternoon and evening. Much of the stronger
mid-level flow will be displaced north of the front and better
low-level moisture. However, despite relatively modest vertical
shear, strong buoyancy could still support robust updrafts and the
potential for precipitation loading and damaging gusts along the
length of the front. Some overlap between the stronger mid-level
flow and better buoyancy is possible from the Upper OH Valley into
western NY. Shear vector should be more orthogonal to the front
across this region as well. As a result, there appears to be a
greater potential for strong to severe storms here than areas
farther west, where generally weaker flow aloft and more
front-parallel vertical shear will limit storm organization.

..Mosier.. 07/15/2024

$$