SPC AC 040536
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1236 AM CDT MON JUN 04 2007
VALID 041200Z - 051200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN HIGH PLAINS TO THE
CNTRL GULF COAST...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CENTRAL
PLAINS...
...SRN HIGH PLAINS TO CNTRL GULF COAST...
PERSISTENT NWLY CYCLONIC MID LEVEL FLOW WILL ONCE AGAIN PROVIDE DEEP
LAYER SHEAR FOR SUSTAINING ORGANIZED UPDRAFTS MONDAY. MULTIPLE
MCS-TYPE CONVECTIVE CLUSTERS HAVE EVOLVED OFF THE HIGHER TERRAIN THE
LAST FEW DAYS...INITIATING IN THE STEEPER LAPSE RATE ENVIRONMENT
OVER SERN CO/ERN NM WHERE WEAK MOIST/UPSLOPE COMPONENT EXISTS.
THERE IS REASON TO BELIEVE THIS SCENARIO WILL REPEAT AGAIN DURING
THE UPCOMING DAY1 PERIOD...ALTHOUGH DAYTIME INITIATION MAY ALSO
OCCUR ALONG WEAK SFC BOUNDARY THAT WILL STRETCH E-W ACROSS SRN LA
INTO SCNTRL TX.
ONGOING THUNDERSTORM ACTIVITY OVER SCNTRL/SERN TX SHOULD SPREAD OFF
THE TX COAST AND WEAKEN BEFORE SUNRISE...LIKELY LEAVING SOME
RESIDUAL OUTFLOW BOUNDARY IN ITS WAKE. THIS BOUNDARY COULD EASILY
SERVE AS THE PRIMARY FOCUS FOR INITIATION...ALTHOUGH EXACT LOCATION
WILL NOT BE KNOWN UNTIL LATER IN THE DAY. RAPID HEATING OF THE
BOUNDARY LAYER SHOULD RESULT IN SBCAPE VALUES ON THE ORDER OF
2500-3500 J/KG...CERTAINLY ADEQUATE FOR ROBUST SEVERE UPDRAFTS GIVEN
SFC-6KM BULK SHEAR ON THE ORDER OF 40-50KT. LARGE HAIL AND DAMAGING
WINDS ARE THE MOST LIKELY SEVERE THREATS.
...CENTRAL PLAINS...
EARLY MORNING WV IMAGERY SUGGESTS WRN FRINGE OF DIGGING SHORTWAVE
WILL CLIP THE NRN/CNTRL PLAINS DURING THE AFTERNOON HOURS WITHIN
OTHERWISE DEEP NNWLY FLOW REGIME. THIS DIGGING FEATURE WILL ALLOW
SFC PRESSURES TO RISE OVER THE CANADIAN PRAIRIE REGION...BUILDING
SWD INTO THE NRN PLAINS FORCING A SFC FRONT...OR PREFRONTAL WIND
SHIFT...INTO THE BLACK HILLS REGION BY PEAK HEATING. ENHANCED
CONVERGENCE AND VERY STEEP SFC-3KM LAPSE RATES SHOULD RESULT IN
CONVECTIVE DEVELOPMENT ALONG ADVANCING FRONTAL ZONE BY MID
AFTERNOON. FORECAST SOUNDINGS SUGGEST CAPE WILL BE LIMITED TO
ROUGHLY 1000 J/KG...BUT CERTAINLY ADEQUATE FOR ROBUST UPDRAFTS
CAPABLE OF GENERATING HAIL AND GUSTY WINDS.
...PACIFIC NW...
MODELS CONTINUE TO INDICATE A VERY STRONG UPPER TROUGH WILL APPROACH
THE PACIFIC NW COAST BY LATE AFTERNOON...WITH MEANINGFUL HEIGHT
FALLS EXPECTED TO SPREAD INLAND DURING THE OVERNIGHT HOURS. FRONTAL
ZONE SHOULD TIGHTEN DURING THE EARLY EVENING HOURS ACROSS INTERIOR
WA/ORE AS SUSTAINED ASCENT/COOLING ALLOW PROFILES TO MOISTEN
SUFFICIENTLY FOR DEEP CONVECTION. A FEW STRONG THUNDERSTORMS
CAPABLE OF PRODUCING SOME HAIL COULD EVOLVE ALONG ADVANCING COLD
FRONT MAINLY DURING THE LATTER HALF OF THE PERIOD.
...ELSEWHERE...
THUNDERSTORMS WILL ONCE AGAIN DEVELOP WITHIN DEEP CYCLONIC FLOW
ACROSS MUCH OF THE OH VALLEY REGION...STRONGLY INFLUENCED BY DIURNAL
HEATING. MEAGER INSTABILITY/SHEAR SUGGEST MOST THUNDERSTORMS WILL
PRODUCE LITTLE MORE THAN BRIEF HEAVY RAIN POSSIBLY ACCOMPANIED BY
MARGINALLY SEVERE HAIL AND GUSTY WINDS.
..DARROW/CROSBIE.. 06/04/2007
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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