Apr 11, 2015 2000 UTC Day 1 Convective Outlook
Updated: Sat Apr 11 19:58:45 UTC 2015 (20150411 2000Z Day 1 shapefile | 20150411 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150411 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 25,318 464,114 Amarillo, TX...Plainview, TX...Hereford, TX...Dumas, TX...Borger, TX...
MARGINAL 57,711 608,304 Lubbock, TX...Garden City, KS...Dodge City, KS...Liberal, KS...Pampa, TX...
Probabilistic Tornado Graphic
20150411 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.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 14,662 345,222 Amarillo, TX...Dumas, TX...Borger, TX...Canyon, TX...Guymon, OK...
Probabilistic Damaging Wind Graphic
20150411 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.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 65,860 981,620 Lubbock, TX...Amarillo, TX...Garden City, KS...Plainview, TX...Liberal, KS...
Probabilistic Large Hail Graphic
20150411 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.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 25,318 464,114 Amarillo, TX...Plainview, TX...Hereford, TX...Dumas, TX...Borger, TX...
5 % 57,589 608,226 Lubbock, TX...Garden City, KS...Dodge City, KS...Liberal, KS...Pampa, TX...
   SPC AC 111958

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0258 PM CDT SAT APR 11 2015

   VALID 112000Z - 121200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON INTO EARLY
   TONIGHT FOR PARTS OF THE TX PANHANDLE INTO SW KS/SE CO...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE CENTRAL/SRN HIGH
   PLAINS...

   ...SUMMARY...
   ISOLATED SEVERE STORMS ARE POSSIBLE OVER THE CENTRAL AND SOUTHERN
   HIGH PLAINS THIS AFTERNOON INTO EVENING.  LARGE HAIL WILL BE THE
   PRIMARY SEVERE WEATHER CONCERN.

   ...SRN HIGH PLAINS...
   NO CHANGES ARE NEEDED WITH THIS OUTLOOK ISSUANCE.  FORECAST SCENARIO
   FOR A SEVERE WEATHER THREAT REMAINS ON TRACK...AS LOW-LEVEL MOISTURE
   CONTINUES TO RETURN NWD ACROSS THIS REGION.  VISIBLE SATELLITE AND
   MOSAIC RADAR IMAGERY SHOWED CONVECTIVE DEVELOPMENT/DEEPER CU ACROSS
   EAST-CENTRAL NM AND NERN NM INTO FAR SERN CO.  THE 19Z AMA SPECIAL
   SOUNDING INDICATED A CAP REMAINS IN THIS PORTION OF THE TX
   PANHANDLE.  HOWEVER...THIS SOUNDING MODIFIED FOR WARMER SURFACE
   TEMPS/DEW POINTS...LOWER 70S AND LOWER 50S...RESPECTIVELY...TO THE
   WEST-SOUTHWEST OF AMA RESULTS IN SUFFICIENT WEAKENING OF THE CAP FOR
   SURFACE-BASED DEVELOPMENT.  THIS TREND FOR CONVECTIVE DEVELOPMENT
   AND EVENTUAL TSTMS IS ONGOING IN THE AFOREMENTIONED AREAS OF ERN NM
   TO FAR SERN CO AND IS CONSISTENT WITH THE LATEST HRRR RUN FOR THIS
   REGION...WITH ACTIVITY BECOMING STRONGER AS IT SPREADS EWD INTO A
   N-S CORRIDOR OF MODERATE INSTABILITY/STRONG BULK SHEAR.

   ..PETERS.. 04/11/2015

   .PREV DISCUSSION... /ISSUED 1130 AM CDT SAT APR 11 2015/

   ...SRN HIGH PLAINS THIS AFTERNOON INTO EARLY TONIGHT...
   LOW-LEVEL MOISTURE IS RETURNING NWD FROM SW TX TO THE TX
   PANHANDLE...WHERE BOUNDARY LAYER DEWPOINTS WILL INCREASE INTO THE
   LOW-MID 50S THIS AFTERNOON.  SURFACE HEATING W OF AN AREA OF ONGOING
   CONVECTION OVER THE ERN TX PANHANDLE/WRN OK IN ASSOCIATION WITH
   WAA...AND PERHAPS A DIFFUSE SPEED MAX ALOFT...WILL COMBINE WITH THE
   LOW-LEVEL MOISTENING TO SUPPORT AFTERNOON MLCAPE VALUES OF 1000-1500
   J/KG.  THE PRIMARY FOCUS FOR STORM INITIATION WILL BE DEEPER MIXING
   AND WEAK LOW-LEVEL CONVERGENCE ALONG THE W EDGE OF THE UPPER 40S TO
   LOWER 50S DEWPOINTS...FROM THE WRN TX PANHANDLE NWD INTO SE CO/SW KS
   BY LATE AFTERNOON/EVENING.  THUS...STORM COVERAGE THIS
   AFTERNOON/EVENING SHOULD REMAIN RATHER ISOLATED.

   DEEP-LAYER VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS WITH
   ISOLATED LARGE HAIL/DAMAGING WINDS ACROSS THIS CORRIDOR FROM THE TX
   PANHANDLE NWD TO SE CO/SW KS...GIVEN THE MODERATE BUOYANCY AND STEEP
   LOW-MIDLEVEL LAPSE RATES.  ANY TORNADO RISK WILL BE MORE MARGINAL
   AND CONFINED TO AREAS OF SOMEWHAT RICHER LOW-LEVEL MOISTURE.  LATER
   THIS EVENING AND INTO TONIGHT...SOME OF THE INITIAL HIGH PLAINS
   STORMS COULD PERSIST AS ELEVATED CONVECTION IN A STRENGTHENING WAA
   REGIME...WHERE GRADUAL MOISTURE INCREASES ABOVE THE SURFACE WILL
   MAINTAIN MUCAPE AOA 1000 J/KG. 

   ...LOWER RIO GRANDE VALLEY/S CENTRAL TX THIS AFTERNOON...
   LAPSE RATE PROFILES OVER S TX...AND UPSTREAM OVER NRN MEXICO...ARE
   RATHER POOR...AND WIDESPREAD CLOUDS WILL SLOW SURFACE HEATING. 
   ADDITIONALLY...LOW-LEVEL FLOW SHOULD REMAIN RATHER WEAK...LEAVING AN
   ENVIRONMENT THAT IS TOO MARGINAL TO WARRANT SEVERE HAIL OR WIND
   PROBABILITIES.

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