[BNAWX] Severe Storm Outlook Narrative

[EMWIN Server]

ACUS11 KWNS 232159
SWOMCD
SPC MCD 232158
KYZ000-INZ000-TNZ000-ALZ000-MSZ000-ARZ000-LAZ000-232330-

Mesoscale Discussion 1223
NWS Storm Prediction Center Norman OK
0458 PM CDT Sun Jun 23 2019

Areas affected...portions of western and central KY/TN...far
northwest AL...northern and central MS...far southern AR and
northern LA

Concerning...Severe potential...Watch possible

Valid 232158Z - 232330Z

Probability of Watch Issuance...40 percent

SUMMARY...A severe threat may extend downstream of WW 433 from parts
of western/central KY into middle TN, far northwest AL, northern and
central MS and perhaps far southern AR/northern LA. Trends will be
monitored but one or more additional watches may be needed in the
next 1-2 hours.

DISCUSSION...The intensity of convection across WW 433 has decreased
over the last 30-60 minutes in some area from western TN into
eastern AR. Other areas, mainly western KY/southern IL and portions
of southern AR, have increased in intensity. In the short term, WFOs
PAH, MEG and LZK have addressed the continued strong wind threat
will local aerial extensions as needed. Further south and east, the
need for additional watch issuance still remains somewhat unclear.
There is a well-established cold pool across AR behind the line with
a well-defined meso high noted in surface analysis. Ahead of the
line, a very warm and strongly unstable downstream airmass is in
place across southern AR/northern LA into northern and central MS
and portions of western and middle TN. This may allow for a
continued sporadic damaging wind threat downstream of WW 433.

That being said, effective shear diminishes rapidly with south and
eastward extent and is not forecast to increase dramatically this
evening, though a 30-40 kt southwesterly low level jet will
overspread the region. VWP data from LZK does show evidence of a
rear-inflow jet, but it is not overly strong or deep, at around
35-50 kt between .5-1.5 km.

Further north, across western KY/southern IL, the line has been
intensifying and surging eastward. This is likely being driven by
the expansive cold pool across AR/MO as well as stronger deep flow
in the vicinity of stronger forcing occurring with a weak shortwave
impulse migrating across the mid-MS Valley region. This portion of
the line may continue to produce damaging wind gusts and PAH has
addressed this by expanding WW 433. A line of storms moved across
parts of western/central KY early today, but recent observations
show conditions have likely recovered somewhat across western
portions of WFO LMK. This may require an additional watch later this
evening depending on trends as the line approaches this previously
disturbed airmass.

Overall trends will be monitored, and at at least portions of the
MCD area may need to be addressed with one or more new watches
within the next 1-2 hours.

..Leitman.. 06/23/2019

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

ATTN...WFO...LMK...OHX...BMX...HUN...PAH...MEG...JAN...LZK...
SHV...

LAT...LON   35908882 37798739 38028683 37828633 37198636 35638723
            34198804 33018903 32449028 32259202 32399306 32609350
            32889362 33169353 33459340 33419235 33589143 34119074
            34998970 35908882
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