MESO: Mesoscale Discussion 1693

ACUS11 KWNS 032319
SWOMCD
SPC MCD 032319
MNZ000-IAZ000-NEZ000-SDZ000-NDZ000-040045-

MESOSCALE DISCUSSION 1693
NWS STORM PREDICTION CENTER NORMAN OK
0619 PM CDT FRI AUG 03 2012

AREAS AFFECTED...ERN ND/SD...WRN MN...N-CNTRL/NERN NEB...NWRN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 553...

VALID 032319Z - 040045Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 553
CONTINUES.

SUMMARY...CLUSTERS OF THUNDERSTORMS OVER ERN ND/SD WILL CONTINUE TO
POSE A SVR THREAT INTO THE EVENING...WITH UPSCALE GROWTH INTO A MORE
SOLID LINE POSSIBLE AS ACTIVITY ENTERS WRN MN AND NWRN IA. A NEW WW
MAY BE NEEDED E OF WW 553 DURING THE NEXT FEW HRS. FARTHER S OVER
N-CNTRL/NERN NEB...THUNDERSTORM DEVELOPMENT ACCOMPANIED BY AN
ISOLATED SVR WEATHER THREAT WILL BE POSSIBLE ALONG A COLD FRONT
DURING THE EVENING/NIGHT.

DISCUSSION...AT 23Z...THUNDERSTORM CLUSTERS WERE ONGOING ALONG A
SURFACE COLD FRONT FROM NERN SD INTO ERN ND AND FAR NWRN MN.
INSTABILITY AXIS EXTENDED NWD ALONG THE MN/DAKOTAS BORDER...WITH
RESERVOIR OF HIGHEST MLCAPE VALUES IN EXCESS OF 2000 J/KG LOCATED
OVER ERN SD...SWRN MN AND NWRN IA. COMBINATION OF STRONG
CONVERGENCE/ASCENT ALONG THE COLD FRONT...FAVORABLE LAPSE
RATES/INSTABILITY...AND 0-6 KM BULK SHEAR AOA 40 KT MAY FAVOR THE
DEVELOPMENT OF A SVR SQUALL LINE AS THE EVENING PROGRESSES. GIVEN
THE PRESENCE OF LARGER CAPE VALUES AND A WIDER WARM SECTOR OVER ERN
SD INTO SWRN MN/NWRN IA...THREAT FOR DAMAGING WINDS AND LARGE HAIL
WILL BE MOST FAVORED IN THIS AREA DURING THE NIGHT. THUS...AREAS E
OF WW 553 WILL BE MONITORED FOR A NEW WW DURING THE NEXT FEW HRS.

FARTHER S OVER N-CNTRL/NERN NEB...SURFACE OBSERVATIONS AND AREA
PROFILERS/VWP/S INDICATE STRONG DEEP-LAYER CONVERGENCE ALONG COLD
FRONTAL SEGMENT ADVANCING SEWD INTO THE AREA. THIS WILL FAVOR
ISOLATED/SCATTERED THUNDERSTORM DEVELOPMENT DURING THE
EVENING...WITH A FEW STORMS POSING A THREAT FOR DAMAGING WINDS/LARGE
HAIL GIVEN THE PRESENCE OF A DRY SUB-CLOUD LAYER AND STEEP LAPSE
RATE ENVIRONMENT. CONVECTIVE TRENDS WILL BE MONITORED FOR POSSIBLE
INCLUSION IN FUTURE WW.

..GARNER.. 08/03/2012

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

ATTN...WFO...MPX...DMX...FGF...FSD...OAX...ABR...BIS...LBF...
UNR...

LAT...LON 48229924 48239604 44499421 42869471 42259692 41660133
42610118 43329952 48229924

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.