[BNAWX] Severe Storm Outlook Narrative

[EMWIN Server]

ACUS11 KWNS 302201
SWOMCD
SPC MCD 302201
TNZ000-ALZ000-KYZ000-MSZ000-ARZ000-302300-

MESOSCALE DISCUSSION 1727
NWS STORM PREDICTION CENTER NORMAN OK
0501 PM CDT THU JUL 30 2009

AREAS AFFECTED...NRN/CNTRL MS...WRN/MIDDLE TN...NRN/CNTRL AL

CONCERNING...SEVERE THUNDERSTORM WATCH 639...640...

VALID 302201Z - 302300Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
639...640...CONTINUES.

SEVERE LINE OF THUNDERSTORMS MOVING EWD AT APPROXIMATELY 40 KTS WILL
APPROACH THE EDGE OF WW639 AND WW640 IN THE NEXT TWO HOURS. A NEW WW
WILL LIKELY BE NEEDED DOWNSTREAM ACROSS PORTIONS OF AL.

CONVECTION HAS INCREASED SIGNIFICANTLY IN A VERY MOIST/MODERATELY
UNSTABLE AIRMASS AHEAD OF A STRONG VORTICITY MAXIMUM PROGRESSING
ENEWD THROUGH AR. STRONG PRESSURE FALLS HAVE BEEN NOTED AHEAD OF
THIS...WITH NEAR 3 MB/2 HR ACROSS WRN TN/NRN MS/NRN AL. SURFACE
WINDS HAVE BEEN STEADILY BACKING IN RESPONSE TO THE SYSTEM...WHICH
COMBINED WITH INCREASING SWLY LOW LEVEL WINDS VEERING TO WLY AT MID
LEVELS...WILL CONTINUE TO STRENGTHEN THE VERTICAL SHEAR ACROSS
PORTIONS OF TN/AL AS THE SYSTEM PROGRESSES ENEWD. THIS WILL SUPPORT
ISOLD SUPERCELLS AHEAD OF AND EMBEDDED WITHIN THE MAIN LINE OF
CONVECTION...EVIDENCED BY RECENT SUPERCELLS/TORNADIC STORMS IN
DESOTO AND SHELBY COUNTIES IN NRN MS/SWRN TN. TROPICAL AIRMASS
CHARACTERIZED BY DEW POINTS IN THE 70S SUGGESTS LITTLE RADIATIONAL
COOLING WILL OCCUR THIS EVENING/TONIGHT...AND INSTABILITY WILL
LINGER AFTER DARK. GIVEN THE UNSEASONABLY STRONG EFFECTIVE SHEAR IN
ASSOCIATION WITH THE UPPER SYSTEM AND LINGERING BUOYANCY...EXPECT
THE THREAT TO CONTINUE...LIKELY NECESSITATING A WW DOWNSTREAM.

..HURLBUT.. 07/30/2009

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

ATTN...WFO...MRX...LMK...OHX...BMX...HUN...MOB...PAH...MEG...
JAN...

LAT...LON   32258835 32588954 33429086 35179044 36208948 36698770
            36708629 35998538 33928597 32908613 32628689 32258835



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