SPC AC 040740
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0240 AM CDT MON JUN 04 2007
VALID 061200Z - 071200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS ERN SD...ERN NEB...SWRN
MN...AND WRN IA...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A LARGE PORTION OF THE
CENTRAL AND NRN PLAINS AND INTO THE UPPER MS VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID OH VALLEY ESEWD
ACROSS THE CAROLINAS...
...SYNOPSIS...
POTENT MID-LEVEL TROUGH IS FORECAST TO EMERGE FROM THE ROCKIES INTO
THE PLAINS THIS PERIOD...ACCOMPANIED BY AN UNSEASONABLY-STRONG SWLY
JET STREAK. AS THIS LOW MOVES INTO THE PLAINS...STRONG CYCLOGENESIS
IS FORECAST OVER THE NRN PLAINS -- YIELDING A 975 MB LOW OVER ERN ND
LATE IN THE PERIOD. ASSOCIATED/TRAILING COLD FRONT IS FORECAST TO
SWEEP EWD/SEWD ACROSS THE PLAINS THROUGH THE PERIOD...WITH THIS
FRONT -- AND A LEADING DRYLINE -- LIKELY TO SERVE AS FOCI FOR THE
DEVELOPMENT OF WIDESPREAD SEVERE STORMS.
...CENTRAL AND NRN PLAINS INTO THE UPPER MS VALLEY...
MODELS CONTINUE TO DEPICT THE POTENTIAL FOR A WIDESPREAD/SIGNIFICANT
SEVERE WEATHER OUTBREAK ACROSS PARTS OF THE PLAINS STATES THIS
PERIOD.
VERY MOIST BOUNDARY LAYER /UPPER 60S TO LOW 70S DEWPOINTS/ IS
FORECAST TO STREAM NWD ACROSS THE PLAINS THIS PERIOD...BENEATH
ELEVATED MIXED-LAYER AND ASSOCIATED CAPPING INVERSION. BY
AFTERNOON...MOISTENING BOUNDARY LAYER COMBINED WITH STRONG HEATING
AND STEEP LAPSE RATES ALOFT SHOULD YIELD EXTREME INSTABILITY ACROSS
PARTS OF THE CENTRAL AND NRN PLAINS. CAPPING WILL LIKELY HINDER
CONVECTIVE DEVELOPMENT IN MOST AREAS UNTIL LATE AFTERNOON...WHEN
SCATTERED STORMS SHOULD DEVELOP OVER THE DAKOTAS AND SWD INTO NEB.
CAP MAY BE BREACHED LOCALLY ALLOWING ISOLATED STORM DEVELOPMENT
ALONG DRYLINE AS FAR S AS SRN KS/OK/WRN N TX.
WITH 60 TO 80 KT SWLY MID-LEVEL FLOW FORECAST TO SPREAD NEWD ACROSS
THE PLAINS DURING THE AFTERNOON/EVENING ABOVE STRONG/INTENSIFYING
SLY LOW-LEVEL FLOW...SHEAR SHOULD BE EXCEPTIONALLY-FAVORABLE --
GIVEN DEGREE OF AVAILABLE INSTABILITY -- FOR LARGE/INTENSE SUPERCELL
STORMS. ALONG WITH THE POTENTIAL FOR VERY LARGE HAIL AND WIDESPREAD
DAMAGING WINDS...TORNADOES ARE ALSO ANTICIPATED -- WITH A FEW
SIGNIFICANT/LONG-TRACK TORNADOES POSSIBLE. GREATEST THREAT APPEARS
TO EXIST ATTM ACROSS THE ERN HALVES OF SD AND NEB AND INTO SWRN
MN/WRN IA.
OVERNIGHT...SEVERE THREAT IS FORECAST TO SPREAD EWD INTO THE UPPER
MS VALLEY REGION...AS COLD FRONT SURGES EWD AND LOW-LEVEL JET
INTENSIFIES TO 70 KT INTO THIS AREA. SEVERE THREAT SHOULD CONTINUE
THROUGH THE NIGHT...PERHAPS EXTENDING AS FAR E AS THE WRN UPPER
GREAT LAKES BY THE END OF THE PERIOD.
...MID OH VALLEY SEWD INTO THE CAROLINAS...
SCATTERED STORMS ARE FORECAST TO DEVELOP ALONG BAROCLINIC ZONE
EXTENDING ESEWD ACROSS THE OH VALLEY AND INTO THE CAROLINAS...AS
AIRMASS DESTABILIZES THROUGH THE AFTERNOON AND WEAK SHORT-WAVE
TROUGH MOVES EWD THROUGH LARGER-SCALE RIDGE. WITH MID-LEVEL WNWLY
FLOW NEAR 40 KT...POTENTIAL FOR A FEW ORGANIZED STORMS/STORM
CLUSTERS WILL EXIST...ACCOMPANIED BY A THREAT FOR LOCALLY-DAMAGING
WINDS AND/OR HAIL THROUGH EARLY EVENING.
..GOSS.. 06/04/2007
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z
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