[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 252314
SWOMCD
SPC MCD 252313 
IAZ000-NEZ000-SDZ000-260215-

MESOSCALE DISCUSSION 1470
NWS STORM PREDICTION CENTER NORMAN OK
0613 PM CDT SAT JUN 25 2005

AREAS AFFECTED...ERN NEB...WRN/NCENTRAL IA AND FAR SERN SD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL...HEAVY RAINFALL 

VALID 252313Z - 260215Z

SCT STRONG TSTMS MAY DEVELOP PRIOR TO 01Z OVER ERN NEB/WRN
IA...ALONG AN OUTFLOW BOUNDARY EXTENDING FROM NEAR ONL SEWD TO OMA
AND EWD TO NEAR AIO. ISOLATED SVR HAIL/WIND WILL BE POSSIBLE WITH
THE STRONGEST STORMS. GREATER COVERAGE AND POTENTIAL FOR CONVECTION
IS ANTICIPATED AFTER 02Z...WHEN HVY RNFL WITH HRLY RATES OVER 1 INCH
WILL BECOME THE MAIN THREAT.

22Z SFC ANALYSIS AND RADAR IMAGERY INDICATES A BOUNDARY EXTENDING
FROM NEAR ONL SEWD TO NEAR OMA AND THEN EWD TO JUST NORTH OF DSM.
CONVERGENCE AND LITTLE REMAINING CINH ALONG THIS BOUNDARY MAY BE
SUFFICIENT IN THE NEXT COUPLE OF HOURS TO INITIATE ISO SVR
CONVECTION. MODERATE INSTABILITY WITH MLCAPES FROM 2500-3000 J/KG
WOULD SUPPORT SOME SVR HAIL AND WIND THREAT WITH THE STRONGEST
STORMS. LACK OF STRONG DEEP LAYER SHEAR SUGGESTS OVERALL THREAT WILL
BE SOMEWHAT UNORGANIZED. HOWEVER...MODERATE LOW LEVEL SHEAR/STRONGLY
CURVED HODOGRAPH PER RECENT OMA VWP SUGGESTS AN ISOLATED TORNADO
THREAT MAY EXIST AS WELL WITH ANY STORMS THAT MAY FORM ON THE
BOUNDARY PRIOR TO 02Z. 

IF SFC BASED CONVECTION FAILS TO MATERIALIZE OVER ERN NEB/WRN IA
EARLY THIS EVENING THEN AS THE LOW LEVEL JET INTENSIFIES LATER THIS
EVENING...MODERATE WAA AND CONVERGENCE NORTH OF THE SFC BOUNDARY AND
IN THE VICINITY OF THE 850 MB BOUNDARY OVER FAR SERN
SD...NWRN/NCENTRAL IA WOULD SUPPORT SCT TSTM DEVELOPMENT IN THIS
AREA. GIVEN MODERATE INSTABILITY... BUT WEAK VERTICAL SHEAR...ONLY
MARGINALLY SVR HAIL IS ANTICIPATED FROM ELEVATED CONVECTION THAT
FORMS. RELATIVELY SLOW STORM MOTIONS...AROUND 10 KTS PARALLEL TO LOW
LEVEL BOUNDARY/FRONTAL ZONE ORIENTATION...COMBINED WITH AMPLE DEEP
LAYER MOISTURE /PWAT VALUES AROUND 1.9 INCHES/ WOULD SUPPORT HVY
RAINFALL AS THE PRIMARY THREAT AFTER DARK.

..CROSBIE.. 06/25/2005

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

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

41019612 41659744 42419781 43109744 43309604 43509507
43419450 42679396 41599402 40879441 

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