[MCD] SWOMCD

Thu Apr 20 16:31:52 UTC 2006

ACUS11 KWNS 201619
SWOMCD
SPC MCD 201619 
GAZ000-ALZ000-MSZ000-201745-

MESOSCALE DISCUSSION 0580
NWS STORM PREDICTION CENTER NORMAN OK
1119 AM CDT THU APR 20 2006

AREAS AFFECTED...NRN/CENTRAL MS...NRN/CENTRAL AL...NRN GA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 201619Z - 201745Z

ON THE SRN FRINGE OF AN UPPER WAVE MOVING ACROSS TN...CONVECTION MAY
CONTINUE TO DEVELOP AND INTENSIFY ALONG AN OUTFLOW BOUNDARY OVER NRN
MS/NRN AL AND AN ADDITIONAL BOUNDARY OVER NWRN GA OVER THE NEXT FEW
HRS. SLIGHTLY GREATER INSTABILITY AND SHEAR OVER THIS AREA WILL
SUPPORT A POTENTIALLY MORE SIGNIFICANT HAIL THREAT. A WW MAY BE
REQUIRED SOON FOR PARTS OF THE AREA.

LATEST SFC ANALYSIS SHOWS AN OUTFLOW BOUNDARY EXTENDING FROM GLH TO
TUP IN NRN MS...ENEWD TO FAR NRN AL. AN ADDITIONAL BOUNDARY IS NOTED
OVER FAR NERN AL/NWRN GA. WEAKER DEEP LAYER SHEAR WAS EVIDENT OVER
ALL OF THIS AREA THAN IS PRESENT FURTHER NORTH...WITH AREA VWP/S
INDICATING AROUND 30 KTS OF MID LEVEL FLOW AS OPPOSED TO THE 40-50
KTS OF FLOW OVER TN AND NRN AR. HOWEVER...STRONGER FLOW WILL
CONTINUE TO APPROACH THE AREA FORM THE SW AHEAD OF ANOTHER UPPER
WAVE OVER THE ARKLATEX. MODERATE INSTABILITY EXISTED OVER THIS AREA
WITH STEEP MID LEVEL LAPSE RATES /7.5-8 DEG C/KM/ NOTED ON BMX AND
SHV 12Z SOUNDINGS. MAIN QUESTION REMAINS HOW MUCH CAN THE BOUNDARY
LAYER DESTABILIZE AND REMOVE REMAINING CINH OVER NRN MS/AL GIVEN
EXTENSIVE MID-HIGH LEVEL CLOUDS CURRENTLY IN PLACE OR MOVING INTO
THE AREA. ASSUMING SUFFICIENT ADDITIONAL HEATING DOES
OCCUR...FOCUSED CONVERGENCE ALONG AFOREMENTIONED OUTFLOW BOUNDARIES
SHOULD RESULT IN ADDITIONAL SVR TSTM DEVELOPMENT ACROSS NRN MS/AL
AND NWRN GA IN THE NEXT FEW HRS.

..CROSBIE.. 04/20/2006

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

ATTN...WFO...FFC...BMX...HUN...MEG...JAN...

34948535 34748795 34588818 33799062 33589067 33269092
32459031 32898701 33148549 33858421 34838411 