May 10, 2011 0600 UTC Day 1 Convective Outlook
Updated: Tue May 10 05:56:08 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110510 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110510 1200 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
20110510 1200 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
20110510 1200 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 100552
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1252 AM CDT TUE MAY 10 2011
   
   VALID 101200Z - 111200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH
   VALLEY...SRN TO CNTRL APPALACHIAN MTNS AND CAROLINAS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS
   AND UPPER MS VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NORTHWEST TX...
   
   ...OH VALLEY/SRN APPALACHIAN MTNS/CAROLINAS...
   AN UPPER-LEVEL RIDGE WILL BE IN PLACE TODAY ACROSS THE MS VALLEY
   WITH NNWLY FLOW LOCATED ACROSS THE UPPER OH VALLEY...SRN TO CNTRL
   APPALACHIAN MTNS AND CAROLINAS. SEVERAL MODEL FORECASTS SUGGEST A
   SUBTLE SHORTWAVE TROUGH WILL MOVE SEWD ACROSS THE REGION. THIS ALONG
   WITH WARMING SFC TEMPS...SHOULD RESULT IN SCATTERED THUNDERSTORM
   INITIATION FROM ERN KY SEWD ACROSS THE CAROLINAS. SFC DEWPOINTS IN
   THE LOWER 60S F SHOULD ENABLE MODERATE TO STRONG INSTABILITY TO
   DEVELOP WHICH ALONG WITH SUBSTANTIAL DIRECTIONAL SHEAR SHOULD BE
   FAVORABLE FOR SEVERE THUNDERSTORM DEVELOPMENT.
   
   FORECAST SOUNDINGS ACROSS WRN NC AND CNTRL SC AT 00Z WEDNESDAY SHOW
   MLCAPE VALUES FROM 2000 TO 3000 J/KG WITH ABOUT 50 KT OF DEEP LAYER
   SHEAR. THIS ENVIRONMENT ALONG WITH 700 TO 500 MB LAPSE RATES AROUND
   8.0 C/KM SHOULD BE SUPPORTIVE OF SUPERCELL DEVELOPMENT WITH A THREAT
   FOR LARGE HAIL. SUPERCELLS THAT HAVE ACCESS TO LOCALLY ENHANCED
   INSTABILITY MAY ALSO HAVE AN ISOLATED THREAT FOR TORNADOES AND HAIL
   STONES GREATER THAN 2 INCHES IN DIAMETER. A WIND DAMAGE THREAT MAY
   ALSO DEVELOP ESPECIALLY IF LINE-SEGMENTS BECOME THE FAVORED STORM
   MODE. AT THIS POINT...MODEL FORECASTS DIFFER ON CONVECTIVE COVERAGE
   WITH THE GFS BEING THE MOST AGGRESSIVE SOLUTION. THE GFS APPEARS
   REASONABLE AND HAVE CONTINUED AN ENHANCED THREAT FOR WIND DAMAGE IN
   WRN NC AND CNTRL SC WHERE THE LOW-LEVEL FLOW AND DEEP LAYER SHEAR IS
   FORECAST TO BE THE STRONGEST.
   
   ...NRN PLAINS/UPPER-MS VALLEY...
   SOUTH SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE GREAT PLAINS AND
   UPPER MS VALLEY TODAY AS A 55 TO 70 KT MID-LEVEL JET MOVES NEWD INTO
   THE NRN PLAINS. THIS FEATURE WILL HELP TO CREATE STRONG DEEP LAYER
   SHEAR ACROSS THE NRN PLAINS AND UPPER MS VALLEY WHERE SCATTERED
   THUNDERSTORMS ARE FORECAST TO DEVELOP. STORM INITIATION WILL MOST
   LIKELY OCCUR LATE THIS AFTERNOON ON THE NOSE OF THE MID-LEVEL JET IN
   ERN ND AND NW MN. THE MODELS ARE ALSO IN AGREEMENT THAT SCATTERED
   THUNDERSTORMS WILL ALSO INITIATE SSEWD ALONG THE INSTABILITY AXIS
   FROM CNTRL MN TO NERN IA BY EARLY EVENING.
   
   FORECAST SOUNDINGS ALONG THIS CORRIDOR AT 00Z WEDNESDAY SHOW MLCAPE
   VALUES RANGING FROM 2000 J/KG IN NRN MN TO AROUND 4500 J/KG IN NRN
   IA WITH DEEP LAYER SHEAR DECREASING WITH SEWD EXTENT. THE
   COMBINATION OF SHEAR AND INSTABILITY SHOULD EASILY SUPPORT A LARGE
   HAIL THREAT ESPECIALLY WITH SUPERCELLS THAT DEVELOP. A WIND DAMAGE
   THREAT MAY ALSO DEVELOP ESPECIALLY IF A STORM CLUSTER CAN PERSIST
   INTO THE EARLY TO MID EVENING WITH LOW-LEVEL FLOW IS FORECAST TO
   STRENGTHEN.
   
   ...NORTHWEST TX...
   A HIGH-AMPLITUDE UPPER-LEVEL TROUGH WILL MOVE SLOWLY EWD ACROSS THE
   FOUR CORNERS REGION TODAY AS LOW-LEVEL FLOW INCREASES ACROSS THE SRN
   PLAINS. A LARGE CORRIDOR OF MODERATE INSTABILITY WILL BE IN PLACE BY
   MIDDAY WITH A RETREATING DRYLINE SHIFTING NWWD INTO NORTHWEST TX
   DURING THE AFTERNOON. SEVERE THUNDERSTORM DEVELOPMENT MAY OCCUR IN
   NORTHWEST TX ON THE ERN EDGE OF A 50 TO 65 KT MID-LEVEL JET. THE
   MID-LEVEL JET WILL HELP TO CREATE MODERATE DEEP LAYER SHEAR WHICH
   COMBINED WITH THE INSTABILITY AND VERY STEEP LAPSE RATES SHOULD BE
   SUFFICIENT FOR SUPERCELL DEVELOPMENT. A LARGE HAIL THREAT MAY EXIST
   IN THE LATE AFTERNOON AND EARLY EVENING AS THE LOW-LEVEL JET BECOMES
   BETTER DEFINED HELPING TO SUPPORT CONVECTIVE INITIATION. AT THIS
   POINT...THE MODELS KEEP CONVECTIVE DEVELOPMENT ISOLATED SUGGESTING
   THE SEVERE THREAT SHOULD REMAIN CONFINED TO THE LOW ROLLING PLAINS
   WHERE A NARROW SLIGHT RISK HAS BEEN OUTLOOKED.
   
   ..BROYLES/STOPKOTTE.. 05/10/2011
   
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