MESO: Mesoscale Discussion 1200

ACUS11 KWNS 172253
SWOMCD
SPC MCD 172252
MNZ000-SDZ000-NDZ000-180015-

MESOSCALE DISCUSSION 1200
NWS STORM PREDICTION CENTER NORMAN OK
0552 PM CDT SUN JUN 17 2012

AREAS AFFECTED...NERN SD INTO W CNTRL MN

CONCERNING...TORNADO WATCH 404...

VALID 172252Z - 180015Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 404 CONTINUES.

SUMMARY...SEVERE WEATHER POTENTIAL SHOULD INCREASE ACROSS NORTHEAST
SOUTH DAKOTA INTO WEST CENTRAL MINNESOTA BETWEEN NOW AND 00-02Z.

DISCUSSION...INTENSE CONVECTIVE DEVELOPMENT IS NOW UNDERWAY EAST OF
THE SURFACE LOW CENTER...WITHIN A BROAD WARM FRONTAL ZONE...WHERE
THE THERMAL GRADIENT HAS BEEN ENHANCED BY OUTFLOW ASSOCIATED WITH
EARLY DAY CONVECTION TO THE EAST...AND STRONG BOUNDARY LAYER HEATING
TO NEAR 100F TO THE WEST. STRONG LOWER/MID TROPOSPHERIC WARM
ADVECTION IS EXPECTED TO CONTRIBUTE TO UPSCALE CONVECTIVE GROWTH
INTO AN ORGANIZED MESOSCALE CONVECTIVE SYSTEM BY EARLY EVENING...AS
ACTIVITY DEVELOPS EAST SOUTHEASTWARD INTO WEST CENTRAL MINNESOTA ON
STRONGLY SHEARED 30-40 KT...AND STRENGTHENING...DEEP LAYER WESTERLY
MEAN FLOW. HOWEVER... DISCRETE SUPERCELL DEVELOPMENT MAY REMAIN
PROMINENT INTO THE 00-02Z TIME FRAME.

SOME UNCERTAINTY DOES EXIST CONCERNING THE DEGREE OF SATURATION OF
THE LOW-LEVEL ENVIRONMENT...EVEN AS STORMS PROPAGATE EASTWARD TO THE
COOL SIDE OF THE GRADIENT ACROSS WEST CENTRAL MINNESOTA...TO THE
WEST/SOUTHWEST OF ALEXANDRIA. HOWEVER...WITH THE SOUTHWESTERLY 850
MB JET FORECAST TO STRENGTHEN IN EXCESS OF 40-50 KT...LOW-LEVEL
HODOGRAPHS...AT LEAST...APPEAR LIKELY TO BECOME INCREASINGLY
SUPPORTIVE OF TORNADIC POTENTIAL.

..KERR.. 06/17/2012

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

ATTN...WFO...MPX...FGF...ABR...

LAT...LON 45549837 45919797 46129653 45999574 45559538 45049555
44689651 44839735 45549837

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