[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 081108
SWOMCD
SPC MCD 081108 
IAZ000-MNZ000-SDZ000-081345-

MESOSCALE DISCUSSION 2162
NWS STORM PREDICTION CENTER NORMAN OK
0608 AM CDT THU SEP 08 2005

AREAS AFFECTED...PORTIONS EXTREME E-CENTRAL SD...SWRN MN...NWRN
THROUGH CENTRAL IA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 081108Z - 081345Z

LINE OF TSTMS WITH HISTORY OF HAIL AND SUB-50KT GUSTS WILL CONTINUE
MOVING GENERALLY ESEWD ACROSS NWRN AND PORTIONS CENTRAL/NRN IA
THROUGH MIDMORNING...WITH POTENTIAL FOR MORE HAIL.  6 INCH DEEP
ACCUMULATION OF UP TO 1 INCH DIAMETER HAIL WAS REPORTED IN LYON
COUNTY AT ABOUT 1015Z. ALSO...THREAT FOR DAMAGING WIND MAY INCREASE
WITH TIME AFTER SUNRISE.  AREA IS BEING MONITORED FOR POSSIBLE WW.

SFC MESOANALYSIS SHOWS WEAK MESOLOW REMAINING NEAR PIR...WITH
QUASISTATIONARY FRONTAL ZONE SEWD ACROSS YKN AREA THEN DOWN MO RIVER
VALLEY TOWARD NERN MO. MCS IS LIKELY TO REMAIN NE OF THIS FRONT IN
THERMODYNAMIC ENVIRONMENT CHARACTERIZED BY ELEVATED MUCAPES AROUND
1500 J/KG.  MU-EFFECTIVE SHEARS 50-60 KT FAVOR MAINTAINING
ORGANIZATION OF THIS ACTIVITY. LLJ WILL DIMINISH WITH WEAKENING
STATE OF DECOUPLING ATOP NOCTURNAL BOUNDARY LAYER...AS FOREGOING AIR
MASS DIABATICALLY WARMS.  HOWEVER STORM-RELATIVE INFLOW SHOULD
CHANGE LITTLE GIVEN THAT LLJ IS PERPENDICULAR TO MOTION OF ACTIVITY
AND THAT MCS IS NOW COLD-POOL DRIVEN --I.E. PRIMARILY FORWARD
PROPAGATIONAL. MODIFIED MODEL SOUNDINGS SUGGEST SFC-BASED
CONVECTIVE PARCELS ARE UNLIKELY UNTIL TEMPS RISE INTO AT LEAST MID
70S F...THOUGH DIABATICALLY DRIVEN BOOST IN BOUNDARY LAYER THETAE
SHOULD GRADUALLY INCREASE PROBABILITY THAT STRONG-SEVERE GUSTS
GENERATED ALOFT MAY PENETRATE RELATIVELY STABLE SUBCONVECTIVE LAYER
AND REACH SFC.

ISOLATED LARGE HAIL ALSO IS POSSIBLE WITH MULTICELLULAR CLUSTERS
MOVING FROM E-CENTRAL SD INTO SWRN MN...ATOP FRONTAL LAYER
REINFORCED BY OUTFLOW FROM NWRN IA MCS.  DAMAGING WIND
POTENTIAL...HOWEVER...WILL BE GREATLY LIMITED BY DEPTH OF STABLE
BOUNDARY LAYER.

..EDWARDS.. 09/08/2005

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

ATTN...WFO...ARX...MPX...DMX...FSD...ABR...

42479572 43039605 43819572 44449753 45069709 44829584
44449440 43769425 42929270 41679393 

WWWW