Rain may cool us off some
Posted by JAC on 6/9/2011, 9:15 am



DAY 1 CONVECTIVE OUTLOOK  
  NWS STORM PREDICTION CENTER NORMAN OK
  0720 AM CDT THU JUN 09 2011
 
  VALID 091300Z - 101200Z
 
  ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS TO NEW
  ENGLAND...
 
  ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF EASTERN WYOMING...
 
  ...SYNOPSIS...
  WHILE PRIMARY UPPER TROUGH/LOW INITIALLY NRN ROCKIES MOVES EWD INTO
  NRN HIGH PLAINS TONIGHT...A WEAK S/W IMPULSE IS LIFTING NEWD ACROSS
  CENTRAL ROCKIES TO CENTRAL PLAINS TODAY. FURTHER E THE LARGE UPPER
  RIDGE IS FLATTENED AS WEAK PERTURBATIONS MOVE ACROSS THE GREAT LAKES
  AND THE NERN STATES.
 
  COLD FRONT EXTENDS WSW ACROSS LH TO SRN IA AND SRN KS AND THEN NWWD
  ALONG E SLOPES CENTRAL ROCKIES.  SURFACE HI OVER ONTARIO WILL PUSH
  FRONT SEWD ACROSS NEW ENGLAND STATES TO MID OH VALLEY...HOWEVER W OF
  MS RIVER FRONT WILL MOVE LITTLE FURTHER SWD AS TROUGHS APPROACH FROM
  THE W.
 
  LARGE MOIST WARM SECTOR EXTENDS FROM CENTRAL PLAINS TO E COAST AHEAD
  OF THE FRONT AND IS CHARACTERIZED BY EXTENSIVE AREA OF STEEP MID
  LEVEL LAPSE RATES AND POTENTIALLY MDT TO STRONG INSTABILITY.
 
  ...MID MS VALLEY/CNTRL PLAINS...
 
  S/W TROUGH AND ASSOCIATED 40-50KT MID LEVEL WIND MAX LIFTS NEWD
  ACROSS CENTRAL PLAINS TODAY ENHANCING BOTH THE SHEAR AND LARGE SCALE
  ASCENT IN SUPPORT OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
  EVENING. WITH A WELL DEFINED FRONTAL ZONE DRAPED FROM NERN KS INTO
  SRN IA/NRN MO...COUPLED WITH STRONG LOW LEVEL HEATING IN THE WARM
  SECTOR...SEVERE THUNDERSTORMS SHOULD ERUPT BY MID AFTERNOON
  BEGINNING IN NERN KS NEAR THE FRONTAL BOUNDARY AND THEN SPREADING
  NEWD INTO NWRN MO/SRN IA WITH SUPERCELLS LIKELY.
 
  WITH SBCAPES AOA 3000 J/KG AND ENHANCED LOW LEVEL SHEAR VICINITY
  BOUNDARY NOT ONLY WILL VERY LARGE HAIL BE A POSSIBILITY BUT BRIEF
  TORNADOES AS WELL. IN ALL LIKELIHOOD ONE OR MORE
  MCSS SHOULD DEVELOP ACROSS THIS REGION DURING THE LATTER HALF OF THE
  PERIOD.
 
  FARTHER SOUTH...SFC TEMPERATURES WILL ONCE AGAIN SOAR ABOVE 100F
  ALONG THE DRYLINE ACROSS SCNTRL KS/NWRN OK INTO NWRN TX.  THIS WILL
  RESULT IN A VERY DEEP BOUNDARY LAYER THAT SHOULD FAVOR HIGH BASED
  THUNDERSTORMS CAPABLE OF PRODUCING AT LEAST ISOLATED SEVERE
  DOWNBURSTS OR PERHAPS EVEN SOME HAIL.
 
 
  ...UPPER OH VALLEY/NERN U.S...
  OVERALL THE AIR MASS FROM OH VALLEY TO NEW ENGLAND REMAINS FAVORABLE
  FOR STRONG/SEVERE THUNDERSTORMS PRIOR TO PASSAGE OF THE FRONTAL ZONE
  LATER TONIGHT.  WITH AROUND 30KT  OF SHEAR AND MID LEVEL LAPSE RATES
  GENERALLY IN EXCESS OF 7C/KM...DAMAGING WIND POTENTIAL WILL BE THE
  PRIMARY THREAT...HOWEVER LARGE HAIL IS ALSO LIKELY WITH THE STRONGER
  CORES GIVEN THE EXPECTED INSTABILITY.
 
  HAVE ENLARGED THE AREA OF 30 PERCENT WIND DAMAGE GIVEN THE LARGE
  AREA COVERED BY THE POTENTIALLY VERY UNSTABLE AIR MASS WHERE SBCAPES
  WILL INCREASE TO AOA 3000 J/KG BY MID DAY.  THE UNCERTAINTY AS TO
  THE BEST CORRIDOR OF SEVERE STORMS GIVEN THE SOMEWHAT
  MARGINAL...PRIMARILY UNIDIRECTIONAL SHEAR PROFILES PRECLUDES ATTM
  HIGHLIGHTING A SPECIFIC AREA FOR A HIGHER RISK THAN SLIGHT.  BY MID
  MORNING THE CONVECTIVE EVOLUTION COULD BECOME CLEARER POSSIBLY
  IDENTIFYING AN AREA OF GREATER RISK BY THE 1630Z OUTLOOK.
 
  SURFACE BASED STORMS WILL DEVELOP EARLY AS TEMPERATURES WARM INTO
  THE LOWER 80S...POSSIBLY BY 16-17Z TIME FRAME ALONG THE COLD FRONT
  FROM NWRN PA INTO UPSTATE NY.  ONCE THIS ACTIVITY DEVELOPS IT WILL
  PROPAGATE SEWD WITH AN ATTENDANT THREAT FOR DAMAGING WINDS AND HAIL.
 
 
  ...ERN WY...
 
  RESIDUAL LOW LEVEL MOISTURE WILL HOLD WITHIN ELY LOW LEVEL FLOW
  ACROSS THE HIGH PLAINS OF NERN CO INTO ERN WY.  WITH THE APPROACH OF
  THE COLD UPPER TROUGH/LOW WRN WY IT NOW APPEARS THERE WILL BE
  SUFFICIENT INSTABILITY FOR POTENTIAL OF SEVERE THUNDERSTORMS AND
  POSSIBLY SUPERCELLS THIS AFTERNOON ERN WY.  WITH MLCAPE STILL
  GENERALLY LESS THAN 1000 J/KG...LARGE HAIL WILL BE THE MAIN THREAT
  ALONG WITH A BRIEF TORNADO OR TWO WITH ANY SUPERCELL.
 
  ..HALES/JEWELL.. 06/09/2011
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Blast Furance for the 2nd day in a row - TFG, 6/8/2011, 4:56 pm
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