ZCZC SPCSWOMCD ALL
ACUS11 KWNS 312135 
SPC MCD 312135 
ALZ000-FLZ000-MSZ000-312330-

MESOSCALE DISCUSSION 1912
NWS STORM PREDICTION CENTER NORMAN OK
0435 PM CDT SAT OCT 31 2015

AREAS AFFECTED...PORTIONS OF SRN AL AND THE FL PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 312135Z - 312330Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ONGOING ORGANIZED CONVECTION ACROSS PARTS OF THE LOWER MS
VALLEY WILL SPREAD EWD ACROSS PARTS OF THE CNTRL GULF COAST AND
VICINITY INTO THE LATE AFTERNOON AND EVENING HOURS. THE RISK FOR
DMGG WIND GUSTS AND PERHAPS A COUPLE OF TORNADOES MAY CONTINUE WITH
THIS ACTIVITY...AND THIS MAY WARRANT WW ISSUANCE.

DISCUSSION...AN ORGANIZED...PRE-FRONTAL SQUALL LINE LIES FROM NEAR
MERIDIAN MS TO NEW ORLEANS LA AND WWD ACROSS S-CNTRL LA -- WITH
EMBEDDED LEWP ELEMENTS/MESOVORTICES -- AND THIS ACTIVITY IS
SPREADING EWD. WITH SFC PRESSURE FALLS ON THE ORDER OF 1.5-3.0 MB
PER 2 HRS ACROSS PARTS OF THE TN VALLEY REGION AND
MID-SOUTH...ISALLOBARIC FORCING FOR POLEWARD MOISTURE FLUXES WILL
CONTINUE FOSTERING THE CONCERN FOR SUFFICIENT INSTABILITY TO BE
MAINTAINED FOR SVR POTENTIAL EWD INTO THE EVENING HOURS. THIS IS
PARTICULARLY THE CASE NEAR AND S OF A WARM FRONT ANALYZED FROM S OF
MERIDIAN TO S-CNTRL AL -- WHICH COULD CONTINUE TO ADVANCE NWD. THE
MOB VWP IS SAMPLING AROUND 55 KT OF DEEP SHEAR WITH AMPLE CURVATURE
OF THE LOW-LEVEL HODOGRAPH IN SUPPORT OF CONTINUED ORGANIZED
CONVECTION CAPABLE OF DMGG WIND GUSTS AND PERHAPS A COUPLE OF
TORNADOES. WHILE THERE EXISTS MITIGATING FACTORS OF A
DIFFUSE/ILL-DEFINED SYNOPTIC CYCLONE IN THE GENERAL REGION AND
GENERALLY MARGINAL INSTABILITY...THE AREA WILL CONTINUE TO BE
MONITORED FOR POSSIBLE WW ISSUANCE.

..COHEN/MEAD.. 10/31/2015

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

ATTN...WFO...TAE...BMX...MOB...

LAT...LON   30298834 31508846 32148808 32318689 31788581 30678564
            30468625 30298834 

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