Mesoscale Discussion 239

Issued

Mar 1, 2017, 8:28 AM EST (13:28 UTC)

Expired

Mar 1, 2017, 10:00 AM EST

In force

92 min

Issued by

the Storm Prediction Center

The Knoxville radar (KMRX), 127 km from the middle of the area, began a volume at 13:31 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

086 
ACUS11 KWNS 011328
SWOMCD
SPC MCD 011328 
WVZ000-VAZ000-OHZ000-TNZ000-KYZ000-ALZ000-011500-

Mesoscale Discussion 0239
NWS Storm Prediction Center Norman OK
0728 AM CST Wed Mar 01 2017

Areas affected...Parts of middle/eastern TN...ern KY...sern OH...and
WV...swrn VA

Concerning...Severe Thunderstorm Watch 54...55...

Valid 011328Z - 011500Z

The severe weather threat for Severe Thunderstorm Watch 54, 55
continues.

SUMMARY...Strong surface gusts and, perhaps, an isolated tornado or
two will remain possible with a squall line overspreading the region
through 15-17Z.

DISCUSSION...The forward motion of the southern flank of the ongoing
squall line has slowed some, but movement of the line as a whole
still appears around 50 kt.  Activity likely will continue into and
through the Cumberland Plateau region by 15-17Z.  Although the
boundary layer air mass appears progressively less unstable with
eastward extent across the Cumberland Plateau into the crest of the
Appalachians, breaks in cloud cover could still allow for some
boundary layer warming and destabilization prior to the arrival of
the squall line.  Regardless, given the strength of the ambient
lower/mid tropospheric flow (including 50-70 kt southwesterly around
850 mb), the environment appears conducive to a continuing risk for
potentially damaging surface gusts as the squall line overspreads
the region.

..Kerr.. 03/01/2017

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

ATTN...WFO...RNK...RLX...MRX...JKL...ILN...LMK...OHX...HUN...
MEG...

LAT...LON   35228805 35688674 36338627 36858602 37198472 37978387
            38588331 39058141 38598026 37298112 36318302 35688446
            35268535 34898741 35228805

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The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.