SPC Mesoscale Discussion

SPC MD 309

MD 0309 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR SOUTHEAST ARKANSAS...CENTRAL MISSISSIPPI...AND CENTRAL ALABAMA
MD 0309 Image


Mesoscale Discussion 0309
NWS Storm Prediction Center Norman OK
1213 PM CDT Wed Apr 08 2020

Areas affected...Far southeast Arkansas...central Mississippi...and
central Alabama

Concerning...Severe potential...Watch possible 

Valid 081713Z - 081915Z

Probability of Watch Issuance...60 percent

SUMMARY...A cluster of storms moving out of southeast AR and into
central MS will continue to intensify through early afternoon.
Additionally, new storm development is likely across parts of
central MS and AL.

DISCUSSION...Recent satellite and radar trends show a cluster of
storms moving out of southeast AR and into central MS. Although
storm interactions have largely limited storm growth, a gradual
increase in storm intensity is likely through the early afternoon as
this cluster moves into central MS where negligible MLCIN and
1500-2000 J/kg MLCAPE are noted in recent SPC Mesoanalysis. Despite
weak low level winds, strong upper level flow has allowed for 45-55
knots of effective bulk shear and elongated hodographs that will
support organized convection, including discrete to semi-discrete
modes. In this environment, these storms will pose a risk for severe
hail and strong winds. 

Across central AL, visible satellite imagery shows a field of
agitated cumulus developing in response to boundary layer
destabilization. This destabilization is being driven by modest
northeastward low-level warm/moist advection and increasing daytime
heating - two factors that will continue through mid afternoon.
Although exact timing remains somewhat uncertain, convective
initiation is expected within the next 1-2 hours. As with the AR/MS
cluster of storms, any storms that develop in this region will pose
a risk for hail and wind (barring destructive interactions from
neighboring storms). A watch may be needed.

..Moore/Guyer.. 04/08/2020

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

ATTN...WFO...TAE...BMX...MOB...MEG...JAN...LZK...SHV...

LAT...LON   33439213 33749170 33849050 33878901 33848713 33858610
            33688558 33448535 33018527 32628514 32098510 31848525
            31598550 31548644 31538707 31548801 31608925 31759028
            31999091 32369137 32709175 32989206 33439213 

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SPC MD 308

MD 0308 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF NORTHERN AND EASTERN KY...FAR SOUTHERN OH...SOUTHERN WV INTO WESTERN VA
MD 0308 Image


Mesoscale Discussion 0308
NWS Storm Prediction Center Norman OK
1139 AM CDT Wed Apr 08 2020

Areas affected...portions of northern and eastern KY...far southern
OH...southern WV into western VA

Concerning...Severe potential...Watch possible 

Valid 081639Z - 081815Z

Probability of Watch Issuance...60 percent

SUMMARY...Widely scattered thunderstorms will continue to increase
in intensity through this afternoon. Large hail and isolated
damaging wind gusts will be the main threat associated with these
storms.

DISCUSSION...Isolated to widely scattered thunderstorms are
developing ahead of a southward-advancing cold front from northern
KY/IN into far southern OH and western WV. Strong heating ahead of
the boundary has allowed temperatures to climb into the mid 60s to
mid 70s with lwo 60s dewpoints across the region, resulting in
MLCAPE from 500-1500 J/kg. Modestly steep midlevel lapse rates
around 7-7.5 C/km and strong vertical shear, resulting in long,
straight hodographs, will favor supercells capable of large hail.
Furthermore, steepening low level lapse rates could increase
potential for damaging wind gusts. This convection will track
east/southeast through broad northwesterly flow regime, and may
spread into western VA by late afternoon/early evening.

..Leitman/Guyer.. 04/08/2020

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

ATTN...WFO...RNK...RLX...JKL...ILN...LMK...

LAT...LON   37758320 38598494 38718494 38928471 39068434 39098377
            39088315 38838231 38728184 38218042 38008014 37677999
            37258007 37048043 36928093 37028149 37358229 37758320 

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