[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 121833
SWOMCD
SPC MCD 121833 
MOZ000-IAZ000-KSZ000-NEZ000-MNZ000-SDZ000-122000-

MESOSCALE DISCUSSION 2403
NWS STORM PREDICTION CENTER NORMAN OK
1233 PM CST SAT NOV 12 2005

AREAS AFFECTED...SE SD/SW MN/ERN NEB/WRN IA...ERN KS AND PARTS OF
WRN MO

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 121833Z - 122000Z

SEVERE THREAT WILL INCREASE WITHIN NEXT COUPLE OF HOURS.  ONE OR
MORE TORNADO WWS WILL BE LIKELY BY THE 20-22Z TIME FRAME.

SHORT WAVE TROUGH CONTINUES TO LIFT ACROSS THE CENTRAL PLAINS TOWARD
THE MID MISSOURI VALLEY.  DRY SLOT...EAST OF WEAKENING MID-LEVEL
CIRCULATION CENTER ASSOCIATED WITH THIS FEATURE...HAS ALLOWED FOR
SUBSTANTIAL SURFACE HEATING ALONG WESTERN GRADIENT OF NARROW
LOW-LEVEL MOIST TONGUE RETURNING NORTHWARD THROUGH THE CENTRAL
PLAINS.  THIS EXTENDS ACROSS EASTERN KANSAS/NEBRASKA INTO THE
VICINITY OF DEEPENING SURFACE LOW...WHICH WILL CONTINUE TO MIGRATE
TOWARD THE SIOUX FALLS AREA LATE THIS AFTERNOON.

AS LOW-LEVEL CONVERGENCE INCREASES ALONG DRY LINE/COLD FRONT
TRAILING TO THE SOUTH OF SURFACE LOW...AND MID-LEVEL CAPPING IS
ELIMINATED...STEEPENING LOW-LEVEL LAPSE RATES AND SURFACE DEW POINTS
AROUND 60F LIKELY WILL SUPPORT MIXED BOUNDARY LAYER CAPE AROUND 1000
J/KG.  LATEST MODEL AND OBSERVATIONAL DATA SUGGEST THIS WILL OCCUR
AROUND 21Z...PERHAPS A BIT EARLIER.

THEREAFTER...RELATIVELY RAPID EVOLUTION OF SQUALL LINE WITH EMBEDDED
SUPERCELLS IS EXPECTED FROM SURFACE LOW CENTER SOUTHWARD ALONG/EAST
OF THE MISSOURI RIVER THROUGH WESTERN IOWA.  BROKEN LINE MAY EXTEND
AS FAR SOUTH AS THE MISSOURI OZARKS BY EARLY EVENING.  EMBEDDED
WITHIN FAVORABLE SHEARED MEAN FLOW REGIME ON THE ORDER OF 50+
KT...DAMAGING WINDS/ISOLATED TORNADOES SEEM LIKELY...IN ADDITION TO
RISK FOR LARGE HAIL.

..KERR.. 11/12/2005

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

ATTN...WFO...SGF...DMX...EAX...FSD...OAX...TOP...ICT...

43289815 44139756 44109584 42309486 39669400 38109429
37279520 37209617 39149599 41199682 

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