
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1244 AM CDT THU JUN 05 2008
VALID 051200Z - 061200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS THE CENTRAL PLAINS AND
MID-UPPER MS VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
WRN OK INTO THE GREAT LAKES...
...SIGNIFICANT SEVERE WEATHER EVENT POSSIBLE ACROSS PORTIONS OF THE
PLAINS AND MID-UPPER MS VALLEY...
UPPER LOW ALONG THE UT/AZ BORDER IS FORECAST TO SHIFT EWD INTO SRN
CO LATER THIS MORNING AS UNUSUALLY STRONG SPEED MAX...H5 AOA
90KT...ROUNDS THE BASE OF THE TROUGH OVER SRN NM...THEN EJECTS NEWD
ACROSS THE SRN/CNTRL PLAINS BEFORE LIFTING INTO SERN MN LATE IN THE
PERIOD. THIS FEATURE WILL INDUCE STRONG SFC CYCLOGENESIS OVER WRN
KS WHICH WILL LIFT NNEWD INTO THE ERN DAKOTAS AS FOCUSED HEIGHT
FALLS SPREAD ACROSS THE CNTRL PLAINS. NEEDLESS TO SAY...VERTICAL
SHEAR WILL BE QUITE IMPRESSIVE ACROSS THE WARM SECTOR FROM THE
PLAINS INTO THE MS VALLEY REGION WITH PROFILES MORE RESEMBLING
STRUCTURES OF EARLY SPRING. LATEST MODEL GUIDANCE SUGGESTS THE
POSSIBILITY FOR SIGNIFICANT SEVERE WEATHER...ESPECIALLY ACROSS THE
MODERATE RISK REGION FROM
NEB INTO SRN MN WHERE TORNADOES AND
DAMAGING WINDS ARE CERTAINLY A POSSIBILITY. ONE COMPELLING FACTOR THAT HEAVILY INFLUENCED THE DECISION TO
MAINTAIN A MODERATE RISK IS THE EXPECTED STRONG CAP ACROSS THE WARM
SECTOR. AS OF MIDNIGHT THIS MORNING...16C 700 MB TEMPERATURES WERE
SPREADING NNEWD ACROSS KS. THIS VERY WARM AIR WILL SPREAD ACROSS
MUCH OF THE CNTRL PLAINS AND MID MS VALLEY REGION...EFFECTIVELY
CAPPING THE WARM SECTOR WELL INTO THE AFTERNOON HOURS BEFORE LARGE
SCALE COLD ADVECTION SHUNTS THE WARM PLUME EWD. IN FACT...AFTER
EARLY MORNING THUNDERSTORM CLUSTERS SHIFT NEWD INTO WI/MI ADDITIONAL
CONVECTION WILL STRUGGLE TO DEVELOP EAST OF THE IMMEDIATE WIND SHIFT
ACROSS THE PLAINS...AND MAY NOT DO SO UNTIL LATE FROM CNTRL NEB INTO
PORTIONS OF NWRN OK. LATEST NAMKF...WHICH IS USUALLY QUITE
AGGRESSIVE...INSISTS THE CAP WILL HOLD ACROSS MUCH OF OK INTO KS AND
GENERATES ONLY ISOLATED ACTIVITY THROUGH THE PERIOD. HOWEVER...BOTH
THE NAM AND GFS DO GENERATE PRECIPITATION LATE ACROSS THE WARM
SECTOR AT LOWER LATITUDES. THERE IS GREAT UNCERTAINTY REGARDING
COVERAGE SOUTH OF KANSAS. LATEST THINKING IS THE GREATEST
CONCENTRATION OF SEVERE THUNDERSTORMS WILL OCCUR ACROSS NEB/SERN
SD/WRN IA INTO SRN MN. THIS IS BASED ON MUCH COOLER THICKNESS
VALUES AND THE ENHANCED VERTICAL ASCENT/HEIGHT FALLS THAT WILL
SPREAD ACROSS THIS REGION ALONG RETREATING WARM FRONT. FORECAST
SOUNDINGS INDICATE VERY STRONG SHEAR...SEEMINGLY SUPPORTIVE OF LONG
TRACK TORNADIC SUPERCELLS. ALTHOUGH THERE IS SOME CONCERN THAT
STRONGLY FORCED CONVECTION MAY EVOLVE INTO BOW ECHOES. THESE BOW
ECHOES MAY ULTIMATELY EVOLVE INTO LEWP TYPE STRUCTURES THAT MAY
PRODUCE SIGNIFICANT DAMAGING WINDS OR PERHAPS EVOLVE INTO A DERECHO
AS IT MOVES ACROSS NEB INTO MN DURING THE EVENING/OVERNIGHT HOURS.
...UPPER OH VALLEY/UPSTATE NY...
SUSTAINED WARM ADVECTION AND MOISTENING WITHIN THE BOUNDARY LAYER
SHOULD ENHANCE THE PROSPECT FOR SCATTERED THUNDERSTORMS DURING THE
PERIOD. ALTHOUGH LARGE SCALE HEIGHT RISES ARE EXPECTED ACROSS THE
REGION IT APPEARS DAYTIME HEATING ALONG WITH TERRAIN INFLUENCES WILL
ENHANCE THE POSSIBILITY FOR A FEW STRONG/SEVERE THUNDERSTORMS.
LARGE HAIL OR PERHAPS STRONG WINDS COULD ACCOMPANY THIS ACTIVITY.
..DARROW/CROSBIE.. 06/05/2008