[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 162307
SWOMCD
SPC MCD 162307 
IAZ000-MNZ000-NEZ000-170100-

MESOSCALE DISCUSSION 0573
NWS STORM PREDICTION CENTER NORMAN OK
0607 PM CDT SAT APR 16 2005

AREAS AFFECTED...PORTIONS NWRN/N-CENTRAL IA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 162307Z - 170100Z

AREA IS BEING MONITORED FOR POSSIBILITY OF SFC-BASED CONVECTIVE
INITIATION IN NEXT COUPLE HOURS..IN A MESOBETA SCALE ENVIRONMENT
FAVORABLE FOR A SUPERCELL OR TWO.

23Z SFC MESOANALYSIS SHOWS MESOLOW OVER PALO ALTO COUNTY...AT
INTERSECTION OF FRONTAL ZONE AND OUTFLOW BOUNDARY FROM EARLIER MCS. 
FRONTAL ZONE EXTENDS SWWD ACROSS SUX AREA INTO NERN NEB AND IS
MOVING SEWD APPROXIMATELY 10-15 KT.  OUTFLOW BOUNDARY IS SHARPLY
DEFINED SEWD ACROSS WRN/SRN KOSSUTH COUNTY TO JASPER COUNTY...THEN
EWD ALONG I-80 TO CEDAR COUNTY.  EXPECT NW-SE ORIENTED OUTFLOW
SEGMENT N OF DSM TO DRIFT NEWD.  LARGEST SEVERE PROBABILITIES WOULD
BE WITH ANY DISCRETE/SUSTAINED STORM THAT CAN FORM NEAR MESOLOW OR
NEARBY OUTFLOW BOUNDARY...THEN DEVIATE RIGHTWARD ALONG BOUNDARY
WHERE LIFT/SHEAR/VORTICITY IS MAXIMIZED IN BOUNDARY LAYER.  LINE OF
CU/TCU IS EVIDENT IN VIS IMAGERY ALONG COLD FRONT AND MAY ALSO
DEVELOP INTO TSTMS...BUT WITH WEAKER STORM-RELATIVE INFLOW AND
VERTICAL SHEAR RESULTING FROM SWLY SFC FLOW IN FOREGOING WARM
SECTOR.


OPTIMAL LOW LEVEL FLOW PROFILES ARE INVOF OUTFLOW BOUNDARY...WHERE
ERN EDGE OF MOST FAVORABLE BUOYANCY IS JUXTAPOSED WITH RELATIVELY
BACKED SFC FLOW.  SLA PROFILER AND CMX VWP EACH APPEAR TO BE
SAMPLING THIS ZONE WELL AS OF 22Z...WITH 0-1 KM SRH IN 150-250 J/KG
RANGE AND 0-6 KM AGL SHEARS 40-50 KT.  SFC-BASED INSTABILITY AXIS
EXTENDS SWD FROM SFC LOW ACROSS IA.  MLCAPES ESTIMATED AROUND 1000
J/KG IN AREA OF CLEARING BETWEEN SFC LOW AND SWRN IA ELEVATED
SHOWERS...BASED ON RUC SOUNDINGS.  MARGINAL MIDLEVEL FLOWS SUGGEST 
POOR PRECIP VENTILATION ALOFT AND TRANSITION TO MESSY HP OR BOW
STRUCTURE AS A STORM MATURES.

..EDWARDS.. 04/16/2005

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

ATTN...WFO...MPX...DMX...FSD...OAX...

43369469 43519435 43529392 43259340 42649319 42049329
41869400 41969452 42089550 42429655 42929552 

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