Jun 8, 2011 2000 UTC Day 1 Convective Outlook
Updated: Wed Jun 8 20:04:10 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110608 2000 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110608 2000 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
20110608 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
20110608 2000 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
   SPC AC 082000
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0300 PM CDT WED JUN 08 2011
   
   VALID 082000Z - 091200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NEW ENGLAND WSWWD INTO
   KS/OK...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE FRONT RANGE REGION
   OF CO......
   
   ...THE NORTHEAST...
   MOST SUBSTANTIAL CHANGES TO THE FORECAST HAVE BEEN MADE ACROSS THE
   NORTHEAST...WITH A SWD EXPANSION OF THE SLIGHT RISK AND THE ADDITION
   OF 30% HAIL/WIND PROBABILITY ACROSS NY/VT/WRN NY AND INTO NWRN MA. 
   AIRMASS ACROSS THIS REGION HAS BECOME MODERATELY UNSTABLE...BENEATH
   FAIRLY STRONG/QUASI-UNIDIRECTIONAL FLOW FIELD ALOFT.  
   
   A VERY WELL-ORGANIZED MCS HAS DEVELOPED OVER SRN ONTARIO THIS
   AFTERNOON...AND IS MOVING ESEWD AT NEAR 50 KT TOWARD LAKE ONTARIO
   AND UPSTATE NY.  ADDITIONAL CONVECTIVE CLUSTERS ARE INCREASING
   ACROSS SERN LK SUPERIOR...AND ACROSS LK HURON WHICH MAY ALSO AFFECT
   THIS REGION LATER TONIGHT.
   
   WITH THIS INITIAL STORM CLUSTER LIKELY TO MOVE ACROSS NY AND INTO
   SRN NEW ENGLAND OVER THE NEXT SEVERAL HOURS...SEVERE WEATHER APPEARS
   INCREASINGLY LIKELY -- THUS SUPPORTING THE AFOREMENTIONED INCREASE
   IN SEVERE PROBABILITIES ACROSS THIS AREA.
   
   ...UPPER GREAT LAKES REGION SWWD INTO NERN KS...
   CONVECTION IS DEVELOPING ATTM FROM LK SUPERIOR ACROSS THE UPPER
   PENINSULA OF MI...WITH SHALLOWER CU EXTENDING SWWD ALONG THE FRONT
   FROM WI INTO SERN NEB/NWRN MO/NERN KS.  MODELS CONTINUE TO FORECAST
   STORM DEVELOPMENT INVOF THE FRONT -- FROM WITHIN THIS CU BAND -- AND
   WITH FAVORABLE SHEAR AND MODERATE INSTABILITY IN PLACE...POTENTIAL
   FOR LARGE HAIL...DAMAGING WINDS...A POSSIBLY A COUPLE OF TORNADOES
   REMAINS EVIDENT. 
   
   ...CENTRAL KS SWWD INTO THE SRN HIGH PLAINS...
   SEVERE THREAT ACROSS THIS REGION REMAINS CONDITIONAL -- DEPENDENT
   UPON HIGH-BASED STORM DEVELOPMENT ATOP A VERY HOT/DRY/VERY DEEP
   BOUNDARY LAYER.  NO CUMULUS ARE EVIDENT ATTM E OF THE
   DRYLINE...HOWEVER ALL MODELS CONTINUE TO SUGGEST AT LEAST ISOLATED
   CONVECTIVE DEVELOPMENT LATER THIS AFTERNOON.  ANY STORM WHICH COULD
   DEVELOP WOLD BE CAPABLE OF PRODUCING DAMAGING WINDS -- DRIVEN BY
   EVAPORATIVE COOLING IN THE DRY SUB-CLOUD LAYER -- AND THUS WILL
   MAINTAIN SEVERE PROBABILITIES FROM CENTRAL KS SWWD INTO THE SRN HIGH
   PLAINS REGION.
   
   ...ERN CO AND VICINITY...
   BOUNDARY-LAYER DEWPOINTS REMAIN LOW /30S TO LOW 40S/ ALONG THE FRONT
   RANGE...THOUGH VERY LIMITED INCREASE IS NOTED WITH TIME DUE TO
   NELY/ELY ADVECTION FROM POINTS FARTHER E.  SHEAR PROFILES REMAIN
   FAVORABLE FOR SUPERCELLS...WHICH -- COMBINED WITH A DEEP MIXED LAYER
   -- SUGGEST THAT ANY STORMS WHICH DO DEVELOP WOULD BE ACCOMPANIED BY
   A SEVERE THREAT.  CU ARE INCREASING ALONG THE FRONT RANGE FROM THE
   PALMER RIDGE AREA NWD TO W OF CYS /CHEYENNE WY/...AND THUS WILL
   MAINTAIN SLIGHT RISK ACROSS THIS AREA -- PRIMARILY FOR ISOLATED
   DAMAGING WIND POTENTIAL.
   
   ..GOSS.. 06/08/2011
   
   .PREV DISCUSSION... /ISSUED 1126 AM CDT WED JUN 08 2011/
   
   ..NERN PA/ERN NY INTO NRN NEW ENGLAND...
   STRONG HEATING OF MOISTENING BOUNDARY LAYER WILL RESULT IN MLCAPES
   UP TO 2000 J/KG. THIS INSTABILITY AND DEEP LAYER SHEAR AT 30-40 KT
   WILL BE FAVORABLE FOR MULTICELLS WITH HAIL/DAMAGING WINDS.
   HOWEVER...BUILDING 500 MB HEIGHTS AND CAPPING INVERSION ARE EXPECTED
   TO LIMIT CONVECTIVE DEVELOPMENT. THE BEST CHANCES FOR STORMS WILL BE
   IN MAINE LATER THIS AFTERNOON AS SHORTWAVE TROUGH...CURRENTLY OVER
   QUEBEC...SHIFTS EWD ACROSS AT LEAST NRN ME. AS THE RIDGE BREAKS DOWN
   IN THE NERN STATES LATER TODAY... STORMS LOCATED OVER LOWER MI
   REGION MAY MOVE EWD INTO PORTIONS OF NRN/WRN NY THIS EVENING.
   ELSEWHERE...STORMS ARE EXPECTED TO BE TOO ISOLATED FOR A SLIGHT RISK
   ISSUANCE.
   
   ...GREAT LAKES TO IA/NRN MO SWWD INTO NERN KS...
   LIGHTNING HAS BEEN DECREASING IN STORMS IN IA...THOUGH NEW STORMS
   HAVE RECENTLY DEVELOPED IN ERN WI. THESE STORMS APPEAR TO STILL BE
   SLIGHTLY ELEVATED...BUT MAY CONTINUE WITH A SEVERE POTENTIAL AS THEY
   SHIFT EWD INTO LOWER MI THIS AFTERNOON.
   
   ELSEWHERE ACROSS AREA...AT MID MORNING...COLD FRONT STRETCHED FROM
   THE FAR WRN U/P SWWD INTO NRN KS. STRONG HEATING AHEAD OF SEWD
   MOVING FRONT WILL RESULT IN AIR MASS TO BECOME MODERATELY TO
   STRONGLY UNSTABLE. SMALL CLUSTERS OF SURFACE BASED STORMS ARE
   FORECAST TO DEVELOP ALONG AND AHEAD OF THE FRONT. THE STRONGER WINDS
   ALOFT WILL REMAIN BEHIND THE FRONT...THE DEEP LAYER SHEAR WILL BE
   MOST FAVORABLE FOR MULTICELLS. HOWEVER...SUPERCELL STRUCTURES ARE
   POSSIBLE OVER THE WRN GREAT LAKES...WHERE EFFECTIVE BULK SHEAR WILL
   BE STRONGER...AND PERHAPS SWWD INTO IA WHERE INSTABILITY WILL BE
   QUITE STRONG. LARGE HAIL...AND DAMAGING WINDS WILL BE POSSIBLE WITH
   STRONGER STORMS AND A BRIEF TORNADO OR TWO.
   
   ...CENTRAL KS SWWD INTO NWRN OK...
   DESPITE A RELATIVELY DRY BOUNDARY LAYER...DEWPOINTS MOSTLY IN THE
   40S TO LOWER 50S...COMBINATION OF STRONG SURFACE HEATING AND SURFACE
   CONVERGENCE ALONG SEWD MOVING COLD FRONT MAY BE ENOUGH FOR A FEW
   STORMS TO DEVELOP NEAR THE FRONT LATE AFTERNOON. FORECAST SOUNDINGS
   INDICATE ANY STORMS THAT DEVELOP WILL BE HIGH BASED AND SUPPORTIVE
   OF SEVERE WINDS. THE THREAT SHOULD DISSIPATE QUICKLY AFTER SUNSET
   WITH LOSS OF DAYTIME HEATING.
   
   ...CENTRAL PLAINS...
   SURFACE HIGH PRESSURE WILL BUILD INTO PORTIONS OF WRN CENTRAL PLAINS
   AS COLD FRONT MOVES SWD INTO THE TX PANHANDLE AND EWD THROUGH
   CENTRAL KS. BOUNDARY LAYER MOISTURE HAS DRIED OUT WITH PASSAGE OF
   FRONT AND WITH LACK OF DYNAMICAL FORCING...SEVERE PROBABILITIES HAVE
   BEEN LOWERED ACROSS NEB/NERN CO AND SERN WY. FARTHER SOUTH ACROSS
   THE NERN CO FOOTHILLS...THERE MAY BE ENOUGH MOISTURE IN ELY UPSLOPE
   FLOW FOR A STORM OR TWO DEVELOP LATE AFTERNOON. ANY STORMS THAT
   DEVELOP WILL HAVE SUFFICIENT SHEAR TO ROTATE. THE RELATIVELY DRY
   BOUNDARY LAYER INDICATES THAT SEVERE HAIL WOULD BE THE PRIMARY
   THREAT.
   
   ...GREAT BASIN...
   HIGH BASED STORMS WITH GUSTY WINDS ARE LIKELY THIS AFTERNOON AHEAD
   OF APPROACHING UPPER TROUGH. SEVERE COVERAGE ATTM IS EXPECTED TO BE
   ISOLATED.
   
   ...LOWER/MID MS VALLEY REGION...
   THUNDERSTORMS SHOULD ONCE AGAIN DEVELOP IN MOIST AIR MASS WITHIN 
   VERY WEAKLY SHEARED ENVIRONMENT. AIR MASS DOES APPEAR A LITTLE MORE
   STABLE THAN TUE...ESPECIALLY ACROSS MS...BUT PULSE TYPE SEVERE
   STORMS ARE POSSIBLE. ISOLATED SEVERE STORMS ALSO POSSIBLE ACROSS
   NERN AR/SERN MO LATER TODAY AHEAD OF WEAK MCV.
   
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