Severe Storm Outlook Narrative (AC)
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000
ACUS03 KWNS 220728
SWODY3
SPC AC 220727

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 AM CDT Sun Apr 22 2018

Valid 241200Z - 251200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are possible across portions of the southern Plains as
well as the Mid-Atlantic states and Florida Peninsula.

...Discussion...
A shortwave trough is expected to progress southeastward from the
central High Plains into the central/southern Plains. The movement
of this shortwave will encourage a southward surge of a cold
continental airmass into the southern Plains. Airmass ahead of the
front isn`t expected to be particularly moist but enough instability
will likely exist to support thunderstorms. The stronger flow aloft
will lag behind the front and the current prospects for severe
thunderstorms during the afternoon and evening are low. Elevated
thunderstorms may develop overnight in response to an strengthening
low-level jet with the increased mid-level flow contributing to some
severe potential. However, current guidance is inconsistent on the
development of these storms and, even if they do develop,
instability will likely be quite limited.

Farther east, a mature cyclone is expected to move from central
KY/middle TN northeastward through the central Appalachians. At the
sane time, an attendant surface low will track northeastward through
the Mid-Atlantic states. Warm sector associated with this low will
be confined to the coastal areas of the Carolinas. A strong storm or
two is possible in this area as well as along and just north of the
warm front. However, anticipated low coverage and numerous
uncertainties inherent to forecasts at this range preclude
introducing any severe probabilities with this outlook.

Lastly, thunderstorms are anticipated across the central and
southern FL Peninsula as modest ascent, provided by both the
eastward progression of the cyclone mentioned above and a surface
trough traversing the region, interacts with the unstable airmass
over the area. A strong storm or two is possible during the
afternoon and severe probabilities may be needed in subsequent
outlooks if confidence in sufficient severe coverage increases.

..Mosier.. 04/22/2018

$$



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