May 15, 2013 0600 UTC Day 1 Convective Outlook
Updated: Wed May 15 05:57:32 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20130515 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130515 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
20130515 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
20130515 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.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 28,670 450,041 Abilene, TX...San Angelo, TX...Brownwood, TX...Junction, TX...Munday, TX...
   SPC AC 150553
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1253 AM CDT WED MAY 15 2013
   
   VALID 151200Z - 161200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WCNTRL TX...
   
   ...SRN PLAINS...
   AN UPPER-LEVEL LOW IS FORECAST TO DEVELOP THIS AFTERNOON ACROSS OK
   WITH AN UPPER-LEVEL TROUGH EXTENDING SWD ACROSS WCNTRL TX. AT THE
   SFC...A LOW WILL DEEPEN ACROSS WEST TX AS LOW-LEVEL CONVERGENCE
   INCREASES ALONG A DRYLINE EXTENDING SWD FROM NEAR CHILDRESS TO
   AROUND SAN ANGELO. MODEL FORECASTS SUGGEST SCATTERED THUNDERSTORMS
   WILL INITIATE TO THE EAST OF THE DRYLINE THIS AFTERNOON BUT DIFFER
   ON THE NORTH TO SOUTH EXTENT OF STORM DEVELOPMENT. THE NAM SOLUTION
   IS FURTHER SOUTH MOVING A CLUSTER OF STORMS ESEWD ACROSS THE TX HILL
   COUNTRY WHILE THE GFS FOCUSES CONVECTIVE DEVELOPMENT NEAR THE RED
   RIVER. IT APPEAR REASONABLE THAT A CLUSTER OF STORMS COULD ORGANIZE
   AND PERSIST INTO THE EVENING BUT THE EXACT SCENARIO REMAINS
   UNCERTAIN.
   
   FORECAST SOUNDINGS TO THE EAST OF THE DRYLINE LATE THIS AFTERNOON
   SHOW MODERATE INSTABILITY /MLCAPE OF 1500 TO 2000 J/KG/...MODERATE
   TO STRONG DEEP LAYER SHEAR /0-6 KM OF 40 TO 55 KT/ AND STEEP
   MID-LEVEL LAPSE RATES. THIS ENVIRONMENT SHOULD SUPPORT SUPERCELL
   DEVELOPMENT WITH LARGE HAIL AND WIND DAMAGE POSSIBLE WITH THE MORE
   INTENSE CORES. IN SPITE OF THE MODEL UNCERTAINTY THE ENVIRONMENT
   SHOULD SUPPORT A SEVERE THREAT MAKING AN UPGRADE TO SLIGHT RISK
   WARRANTED. THE GREATEST SEVERE THREAT SHOULD EXIST FROM CHILDRESS
   SWD TO JUST SOUTH OF SAN ANGELO WHERE THE LOW-LEVEL JET IS FORECAST
   TO BECOME ENHANCED DURING THE EARLY EVENING AND THE DRYLINE MAY
   BULGE.
   
   ...UPPER OH VALLEY/MID-ATLANTIC...
   AN UPPER-LEVEL TROUGH WILL MOVE EWD ACROSS SERN CANADA AND THE LOWER
   GREAT LAKES TODAY. AT THE SFC... A LOW IS FORECAST TO DEEPEN THIS
   AFTERNOON TO THE NORTH OF LAKE ONTARIO WITH A COLD FRONT EXTENDING
   SWD FROM THE LOW ACROSS WRN NY AND WRN PA. AHEAD OF THE FRONT...SFC
   DEWPOINTS SHOULD BE IN THE UPPER 50S F ALLOWING FOR SOME
   DESTABILIZATION TO OCCUR. THUNDERSTORMS SHOULD INITIATE ALONG THE
   BOUNDARY WITH CONVECTION MOVING EWD ACROSS PA INTO THE MID-ATLANTIC
   REGION DURING THE AFTERNOON. FORECAST SOUNDINGS ACROSS THE SEE TEXT
   AREA AT 21Z SHOW SBCAPE VALUES OF 500 TO 1000 J/KG WITH 40 KT OF 0-6
   KM SHEAR AND UNIDIRECTIONAL WIND PROFILES. THIS ENVIRONMENT COULD
   SUPPORT AN ISOLATED WIND DAMAGE THREAT BUT THE THREAT IS EXPECTED TO
   REMAIN MARGINAL DUE TO THE LOWER SFC DEWPOINTS.
   
   ...NE KS/NCNTRL MO/SCNTRL IL...
   WEST TO NORTHWEST FLOW WILL BE IN PLACE ACROSS THE UPPER MIDWEST
   TODAY AS AN UPPER-LEVEL LOW DEVELOPS ACROSS THE SRN PLAINS. AT THE
   SFC...A WARM FRONT WILL MOVE NWD ACROSS NERN KS...NCNTRL MO AND SRN
   IL TODAY WITH MODERATE DESTABILIZATION POSSIBLY TAKING PLACE ALONG
   AND SOUTH OF THE BOUNDARY. THE MODELS AGAIN APPEAR TO BE
   OVERESTIMATING BOUNDARY LAYER MOISTURE CONTENT BUT SFC DEWPOINTS
   STILL COULD REACH THE UPPER 50S TO NEAR 60 F IN NCNTRL MO THIS
   AFTERNOON. THIS COMBINED WITH STEEP LOW-LEVEL LAPSE RATES AND
   UNIDIRECTIONAL LOW-LEVEL WINDS MAY BE ENOUGH FOR A WIND DAMAGE
   THREAT WITH CELLS THAT CAN INITIATE ALONG THE BOUNDARY THIS
   AFTERNOON.
   
   ..BROYLES/LEITMAN.. 05/15/2013
   
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