SPC MD 2058

MD 2058 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR NE TX...NRN LA...SE AR...NW MS AND WRN TN

MESOSCALE DISCUSSION 2058
NWS STORM PREDICTION CENTER NORMAN OK
1124 PM CST THU DEC 24 2015

AREAS AFFECTED...FAR NE TX...NRN LA...SE AR...NW MS AND WRN TN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 250524Z - 250800Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A MARGINAL THREAT FOR A TORNADO...WIND DAMAGE AND HAIL
SHOULD CONTINUE TO DEVELOP FROM NRN LA NEWD INTO WRN TN. WW ISSUANCE
IS NOT CURRENTLY EXPECTED BUT THE ACTIVITY WILL CONTINUE TO BE
MONITORED.

DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING
FROM THE ARKLATEX NEWD INTO THE MID MS VALLEY ALONG WHICH SCATTERED
THUNDERSTORMS ARE DEVELOPING LATE THIS EVENING. THE STORMS WILL
CONTINUE TO EXPAND IN COVERAGE OVER THE NEXT FEW HOURS AS LOW-LEVEL
FLOW INCREASES ACROSS THE REGION. THE LATEST WRF-HRRR MODEL SUGGESTS
THAT STORMS WILL MOVE NEWD ACROSS SE AR...NW MS AND INTO WRN TN OVER
THE NEXT FEW HOURS. MESOSCALE ANALYSIS IS SHOWING WEAK INSTABILITY
ALONG THE CORRIDOR BUT STRONG DEEP-LAYER SHEAR IS EVIDENT ON
REGIONAL WSR-88D VWPS. THE WSR-88D VWP AT SHREVEPORT HAS 50 KT OF
0-6 KM SHEAR ALONG WITH STRONG SPEED SHEAR IN THE LOW TO MID-LEVELS.
THIS SHOULD BE SUFFICIENT FOR A MARGINAL SEVERE THREAT AND POSSIBLY
STORM ROTATION. STEEP LAPSE RATES WILL BE CONDUCIVE FOR HAIL AND
ISOLATED WIND DAMAGE WITH THE MORE INTENSE CORES. IN ADDITION...0-3
KM STORM RELATIVE HELICITIES NEAR 200 M2/S2 MAY BE ENOUGH FOR A
BRIEF TORNADO.

..BROYLES/THOMPSON.. 12/25/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MEG...JAN...LZK...SHV...

LAT...LON   33619045 32519222 31899348 31889400 32259422 32869374
            34649098 35708943 35578877 35278859 34808891 33619045 

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