Severe Storm Outlook Narrative (AC)
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ACUS11 KWNS 172206
SPC MCD 172206

Mesoscale Discussion 0128
NWS Storm Prediction Center Norman OK
0506 PM CDT Sat Mar 17 2018

Areas affected...Portions of middle/eastern TN...northern GA...far
northeastern AL...and far southwestern NC

Concerning...Severe potential...Watch unlikely

Valid 172206Z - 180000Z

Probability of Watch Issuance...20 percent

SUMMARY...An isolated severe hail/wind threat may extend to the
south of Severe Thunderstorm Watch 10. New watch issuance is
unlikely, but a small local extension of the ongoing Watch southward
into more of eastern TN is possible.

DISCUSSION...A couple of thunderstorms have recently strengthened
across middle TN on the southern fringes of large-scale forcing for
ascent associated with a shortwave trough moving eastward across the
OH Valley. This convection currently resides in a relatively better
thermodynamic environment compared to farther north, as surface
dewpoints have increased into the low to mid 50s, and temperatures
have warmed into the mid to upper 70s. MLCAPE of 500-1000 J/kg along
with westerly flow strengthening at mid levels should allow for an
isolated severe hail/wind threat to persist with ongoing convection
for at least the next several hours. The loss of diurnal heating
should cause a weakening trend to occur later this evening as this
activity spreads into northern GA and perhaps far southwestern NC.
While additional WW issuance is not anticipated, a small local
extension of WW 10 southward to include more of eastern TN may be
needed if current trends continue.

..Gleason/Thompson.. 03/17/2018

...Please see for graphic product...


LAT...LON   35498622 35698571 35678495 35498406 35258364 34858376
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