

236 

WWUS20 KWNS 112045

SEL5

SPC WW 112045

COZ000-KSZ000-OKZ000-TXZ000-120200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 55

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT SAT APR 11 2015



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  EXTREME SOUTHEAST COLORADO

  EXTREME SOUTHWEST KANSAS

  TJE WESTERN OKLAHOMA PANHANDLE

  THE WESTERN HALF OF THE TEXAS PANHANDLE



* EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

  900 PM CDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF

SPRINGFIELD COLORADO TO 45 MILES SOUTHWEST OF AMARILLO TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



&&



DISCUSSION...THUNDERSTORM DEVELOPMENT IS UNDERWAY IN SMALL CLUSTERS

ACROSS SE CO AND ALONG I-40 W OF AMA.  THESE AREAS AGREE WELL WITH

SHORT-TERM MODEL FORECASTS...AND THE DOWNSTREAM ENVIRONMENT HAS

SUFFICIENT BUOYANCY /MLCAPE NEAR 1500 J PER KG/ AND VERTICAL SHEAR

/EFFECTIVE SHEAR AOA 40 KT/ FOR SUPERCELLS.  LARGE HAIL WILL BE THE

MAIN CONCERN THROUGH THIS EVENING GIVEN THE MODERATE BUOYANCY AND

STEEP LAPSE RATES.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 27020.





...THOMPSON



288 

WWUS20 KWNS 112045

SEL5

SPC WW 112045

COZ000-KSZ000-OKZ000-TXZ000-120200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 55

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT SAT APR 11 2015



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  EXTREME SOUTHEAST COLORADO

  EXTREME SOUTHWEST KANSAS

  TJE WESTERN OKLAHOMA PANHANDLE

  THE WESTERN HALF OF THE TEXAS PANHANDLE



* EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

  900 PM CDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF

SPRINGFIELD COLORADO TO 45 MILES SOUTHWEST OF AMARILLO TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



&&



DISCUSSION...THUNDERSTORM DEVELOPMENT IS UNDERWAY IN SMALL CLUSTERS

ACROSS SE CO AND ALONG I-40 W OF AMA.  THESE AREAS AGREE WELL WITH

SHORT-TERM MODEL FORECASTS...AND THE DOWNSTREAM ENVIRONMENT HAS

SUFFICIENT BUOYANCY /MLCAPE NEAR 1500 J PER KG/ AND VERTICAL SHEAR

/EFFECTIVE SHEAR AOA 40 KT/ FOR SUPERCELLS.  LARGE HAIL WILL BE THE

MAIN CONCERN THROUGH THIS EVENING GIVEN THE MODERATE BUOYANCY AND

STEEP LAPSE RATES.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 27020.





...THOMPSON

