Tuesday, August 17, 2010

MESO: Mesoscale Discussion 1710

ACUS11 KWNS 172214
SWOMCD
SPC MCD 172213
MNZ000-NDZ000-SDZ000-172315-

MESOSCALE DISCUSSION 1710
NWS STORM PREDICTION CENTER NORMAN OK
0513 PM CDT TUE AUG 17 2010

AREAS AFFECTED...ERN ND...NWRN MN

CONCERNING...SEVERE THUNDERSTORM WATCH 624...

VALID 172213Z - 172315Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 624
CONTINUES.

STORMS MOVING E-SEWD ACROSS PORTIONS OF ERN ND AND NWRN MN MAY POSE
A BRIEF TORNADO THREAT. OTHERWISE...THUNDERSTORM INITIATION WILL
CONTINUE TO OCCUR ALONG COLD FRONT THROUGH THE AFTERNOON...WITH
DAMAGING WIND GUSTS AND LARGE HAIL THE PRIMARY SVR WEATHER THREATS.

AT 22Z...SURFACE OBSERVATIONS SHOWED A SURFACE LOW POSITIONED OVER
NERN ND...WITH A COLD FRONT TRAILING SWWD INTO SWRN ND/NWRN SD AND A
WEAK WARM FRONT EXTENDING SWD INTO WRN MN. STEEP LOW-LEVEL LAPSE
RATES RESIDE ALONG THE FRONT...WHICH ARE INDICATIVE OF STRONG
BOUNDARY LAYER DESTABILIZATION. AS A RESULT...CONVECTIVE INITIATION
APPEARS TO BE TAKING PLACE ALONG THE LENGTH OF THE FRONT PER
REGIONAL RADAR IMAGERY...POSSIBLY IN RESPONSE TO A WEAK UPPER
IMPULSE OBSERVED IN WV IMAGERY APPROACHING UPSTREAM OVER ERN MT.

THE COMBINATION OF SLIGHTLY STRONGER BACKING OF SURFACE WINDS ALONG
THE WEAK WARM FRONT OVER ERN ND AND NWRN MN VEERING TO SWLY AT 1 KM
AND INCREASING IN SPEED TO 30 KT IS YIELDING 0-1 KM SRH VALUES IN
EXCESS OF 100 M2 S-2 PER MVX VWP. THIS LOW-LEVEL SHEAR MAY AID IN
THE DEVELOPMENT OF BRIEF LOW-LEVEL UPDRAFT ROTATION AND A POSSIBLE
TORNADO THREAT. HOWEVER...STORMS WILL BE MOVING EWD ACROSS A STRONG
INSTABILITY GRADIENT...WHICH WILL LIKELY LIMIT THE OVERALL THREAT.
OTHERWISE...STORMS FORMING SWWD ALONG THE FRONT WILL POSE A THREAT
FOR DAMAGING WIND GUSTS AND LARGE HAIL AS THEY MATURE AND
STRENGTHEN.

..GARNER.. 08/17/2010

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

ATTN...WFO...FGF...ABR...BIS...UNR...

LAT...LON 46330350 48689695 48469536 47499607 45600236 46330350

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.

No comments: