SPC AC 020059
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0759 PM CDT THU MAY 01 2008
VALID 020100Z - 021200Z
...THERE IS A MDT RISK OF SVR TSTMS FROM N CNTRL THROUGH NERN OK
INTO ERN KS AND EXTREME WRN MO...
...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE SRN PLAINS
THROUGH THE MID-UPPER MS VALLEY REGION...
...SYNOPSIS...
EARLY THIS EVENING A DRYLINE EXTENDS FROM A SURFACE LOW IN SERN SD
THROUGH WRN IA...NWRN MO...ERN KS THROUGH CNTRL OK AND N CNTRL TX.
COLD FRONT EXTENDS FROM THE SURFACE LOW THROUGH ERN NEB...CNTRL AND
SWRN KS. A WARM FRONT EXTENDS EWD FROM THE LOW THROUGH NRN IA. A
VORTICITY MAXIMA WAS LIFTING NWD THROUGH ERN SD. EXIT REGION OF A
STRONG MID LEVEL JET WAS ADVANCING EAST THROUGH WRN KS AND WRN OK.
...CNTRL AND ERN OK THROUGH ERN KS AND WRN MO...
LOW TO MID 60S DEWPOINTS HAVE ADVECTED THROUGH WARM SECTOR ACROSS
CNTRL AND ERN OK THROUGH ERN KS AND WRN MO BENEATH STEEP MID LEVEL
LAPSE RATES ASSOCIATED WITH THE EML. THESE PROCESSES ALONG WITH
DIABATIC HEATING HAVE RESULTED IN MLCAPE FROM 3500 J/KG OVER CNTRL
AND ERN OK TO AROUND 2000 J/KG ACROSS ERN KS AND WRN MO.
SLY LOW LEVEL JET CONTINUES TO BACK AND STRENGTHEN ACROSS OK IN
RESPONSE TO AGEOSTROPHIC FORCING AND ASCENT WITHIN EXIT REGION OF
APPROACHING UPPER JET. THIS IS RESULTING IN NWWD RETREAT OF THE
DRYLINE THROUGH OK AND SRN KS. NUMEROUS STORMS HAVE DEVELOPED ALONG
THE DRYLINE ACROSS ERN KS WITH MORE ISOLATED ACTIVITY ACROSS N CNTRL
AND NE OK. A WINDOW OF OPPORTUNITY EXISTS THIS EVENING FOR A FEW
TORNADOES...ESPECIALLY ACROSS CNTRL THROUGH NERN OK INTO ERN KS AND
NW MO BEFORE THE BOUNDARY LAYER DECOUPLES. LOW LEVEL HODOGRAPH SIZE
HAS BEEN INCREASING OVER OK AND SRN KS DUE TO THE STRENGTHENING LOW
LEVEL JET. THIS ALONG WITH THE NWWD ADVECTION OF RICHER MOISTURE AND
LOWERING LCL HEIGHTS ARE CONTRIBUTING TO A THREAT OF STRONG
TORNADOES IN THIS REGION NEXT FEW HOURS. VERY LARGE HAIL WILL ALSO
ACCOMPANY THE STRONGER AND MORE ORGANIZED STORMS.
STORMS WILL LIKELY INCREASE IN COVERAGE LATER THIS EVENING FROM
CNTRL OK NEWD THROUGH ERN KS AS THE EWD ADVANCING COLD FRONT
OVERTAKES THE DRYLINE. AN UPSCALE GROWTH INTO LINEAR MODES IS
LIKELY...BUT WITH EMBEDDED ORGANIZED STORM STRUCTURES STILL LIKELY
INCLUDING SUPERCELLS AND BOW ECHOES. PRIMARY THREATS WILL TRANSITION
TO DAMAGING WIND AND LARGE HAIL LATER TONIGHT...BUT ISOLATED
TORNADOES WILL REMAIN POSSIBLE.
...SERN SD THROUGH IA...
STORMS HAVE DEVELOPED ALONG OCCLUDED BOUNDARY WITHIN ZONE OF ASCENT
ENHANCED BY VORT MAX LIFTING NWD THROUGH THIS REGION. BACKED LOW
LEVEL FLOW EAST AND NORTH OF SURFACE LOW AND NORTH OF WARM FRONT HAS
CONTRIBUTED TO FAVORABLE 0-1 KM HODOGRAPHS FOR SUPERCELLS WITH LOW
LEVEL MESOCYCLONES...ISOLATED TORNADOES AND LARGE HAIL. OTHER SEVERE
STORMS MAY DEVELOP NORTH OF WARM FRONT ACROSS PARTS OF NRN IA AND
SWRN MN DURING THE EVENING AS WELL AS ALONG COLD FRONT AS IT
ADVANCES EWD THROUGH IA.
..DIAL.. 05/02/2008
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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