DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 112001
SWODY1
SPC AC 111959

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0259 PM CDT MON JUN 11 2007

VALID 112000Z - 121200Z

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NORTHERN/CENTRAL
HIGH PLAINS...

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS GA/SC AND PORTIONS OF
THE FL PENINSULA...

..NORTHERN/CENTRAL PLAINS...
WITHIN BROAD UPPER TROUGH OVER THE PACIFIC NORTHWEST...WATER VAPOR
IMAGERY SHOWS PRONOUNCED SHORTWAVE TROUGH MOVING NEWD ACROSS WRN MT
INTO SRN SASKATCHEWAN. ALTHOUGH MAIN LARGE SCALE LIFT ASSOCIATED
WITH THIS FEATURE WILL BE NORTH OF THE BORDER... TRAILING PORTION OF
TROUGH SHOULD PROVIDE SUFFICIENT LIFT FOR THUNDERSTORMS TO DEVELOP
NEAR COLD FRONT...LOCATED NEAR THE MT/ND BORDER. ALTHOUGH THE
BOUNDARY LAYER IS RELATIVELY DRY...STEEP MID LEVEL LAPSE RATES ARE
EXPECTED TO RESULT IN AT LEAST MODERATE INSTABILITY BY LATE
AFTERNOON. THE STEEP LAPSE RATES AND MODERATE INSTABILITY...ALONG
WITH 50 KT MID LEVEL WINDS...WILL BE FAVORABLE FOR SUPERCELLS WITH
LARGE HAIL AND DAMAGING WINDS. AS STORMS INCREASE IN COVERAGE
THROUGH THE EVENING AND THE LOW LEVEL JET STRENGTHENS...THE ACTIVITY
SHOULD ORGANIZE INTO ONE OR MORE CONVECTIVE CLUSTERS...WITH A HIGHER
THREAT FOR WIND DAMAGE AS COLD POOLS DEVELOP AND PUSHES THE STORMS
EWD.

FARTHER SOUTH ACROSS THE CENTRAL HIGH PLAINS...CONVECTION HAS
ALREADY DEVELOPED OVER THE CO MTNS AND INTO SRN WY. THIS CONVECTION
IS OCCURRING WITHIN A VERY DEEP MIXED BOUNDARY LAYER RESULTING IN
HIGH CLOUD BASES. AS THIS ACTIVITY SHIFTS NEWD DURING THE LATE
AFTERNOON/EVENING HOURS...THE STORMS WILL INGEST A MORE MOIST
BOUNDARY LAYER AND INTENSIFY. ALTHOUGH VERTICAL SHEAR WILL BE WEAKER
THAN ACROSS MT/NRN WY/DAKOTAS...DEEP ADIABATIC LAPSE RATES TO 600 MB
SUGGEST THAT STRONG/SEVERE WIND GUSTS ARE POSSIBLE WITH STORMS.

..SRN VA SWWD INTO GA/FL PENINSULA...
SCATTERED THUNDERSTORMS WERE OCCURRING ACROSS THE REGION AND MOVING
SSEWD IN RESPONSE TO NWLY FLOW BETWEEN 500-700 MB. STORMS WERE MOST
NUMEROUS ALONG A BOUNDARY FROM NEAR ATL TO CLT TO CHS. ALONG AND
SOUTH OF THE BOUNDARY...STRONG INSTABILITY...VERY WARM SURFACE
TEMPERATURES AND A RELATIVELY STRONGER BELT OF MID LEVEL NWLY FLOW
WILL CONTRIBUTE TO SUSTAINED MULTICELL CLUSTERS. ALONG WITH SOME
HAIL...WET MICROBURSTS ARE ALSO LIKELY. ALTHOUGH THE DRIER BOUNDARY
LAYER FROM SRN VA TO NEAR THE SC/NC BORDER IS RESULTING IN LESS
INSTABILITY THAN SOUTH OF THE BOUNDARY...STEEPER LOW LEVEL LAPSE
RATES WILL SUPPORT A FEW STRONG/SEVERE WIND GUSTS INTO THE EARLY
EVENING HOURS.

..ELSEWHWERE...
IN THE SRN PLAINS...SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE
NM MOUNTAINS...AHEAD OF COMPACT UPPER LOW MOVING FROM MEXICO INTO
SRN AZ. LACK OF DEEP LAYER SHEAR INDICATES THE SEVERE WEATHER THREAT
IS LOW.

DUE TO STRONG INSTABILITY...ISOLATED STRONG STORMS ARE ALSO POSSIBLE
ACROSS ERN OK/WRN AR...THOUGH BUILDING HEIGHTS AND WEAKENING FLOW
ALOFT SUGGESTS THAT THE STORMS SHOULD BE LESS ORGANIZED THAN ON
SUNDAY.

.IMY.. 06/11/2007

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