Area Forecast Discussion
Issued by NWS Las Vegas, NV

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS65 KVEF 300958 AFDVEF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 258 AM PDT WED JUL 30 2014 .SYNOPSIS...LIMITED SHOWER AND THUNDERSTORM DEVELOPMENT WILL BE CONFINED PRIMARILY TO NORTHERN INYO COUNTY AND SOUTHERN GREAT BASIN UNDER A DRIER AND MORE STABLE WEST TO SOUTHWEST FLOW ALOFT THROUGH FRIDAY. ANOTHER PUSH OF MOISTURE IS EXPECTED TO SPREAD UP ACROSS THE REGION OVER THE WEEKEND FOR AN UPSWING IN SHOWERS AND THUNDERSTORMS. && .SHORT TERM...THROUGH FRIDAY NIGHT...MOSTLY CLOUDY OVER THE SOUTHERN SIERRA/WRN INYO COUNTY THIS MORNING WITH ISOLATED SHOWERS/THUNDERSTORMS ALONG THE WESTERN FOOTHILLS. ELSEWHERE, SATELLITE SHOWS MOSTLY CLEAR TO PARTLY CLOUDY SKIES. THE SUBTROPICAL RIDGE AXIS WILL EXTEND FROM SOUTHERN CALIFORNIA SOUTHEAST INTO SOUTH TEXAS TODAY AND THURSDAY. AREA OF INTEREST THE COMING DAYS WILL BE AREA OF MOISTURE AND EMBEDDED WEAK DISTURBANCES PROGGED TO STREAM THROUGH CENTRAL CALIFORNIA TODAY, THEN SPREAD NORTHEAST ACROSS THE SOUTHERN SIERRA AND INTO CENTRAL NEVADA TONIGHT AND THURSDAY. REMNANTS FROM HERNAN WILL ALSO INJECT SOME ADDITIONAL MOISTURE INTO THE MIX. DID INCREASE POPS A BIT MORE OVER NORTHERN INYO, ESMERALDA AND CENTRAL NYE COUNTIES TODAY BASED ON THE LATEST HRRR. STILL LOOKS LIKE A FEW SHOWERS OR THUNDERSTORMS WILL CONTINUE ACROSS CENTRAL NEVADA TONIGHT AND FRIDAY WITH UPPER LEVEL DISTURBANCE. BY FRIDAY, RIDGE EXPANDS NORTH INTO THE NORTHERN ROCKIES. RESIDUAL MOISTURE AND LIMITED INSTABILITY OVER THE AREA SHOULD BE ENOUGH TO GENERATE A FEW THUNDERSTORMS OVER THE HIGHER TERRAIN OF THE SOUTHERN GREAT BASIN AND NORTHWEST ARIZONA. DAYTIME HIGHS WILL BE NEAR NORMAL THROUGH FRIDAY WHILE NO SIGNIFICANT WINDS ARE EXPECTED. .LONG TERM...SATURDAY THROUGH WEDNESDAY. WELL GET READY FOR ANOTHER PUSH OF JUICIER MOISTURE THIS WEEKEND, ESPECIALLY OVER THE EASTERN HALF OF THE AREA, AS THE FLOW ALOFT TRANSITIONS TO THE SOUTHEAST BY SATURDAY MORNING ACROSS OUR AREA AS THE CLASSIC SUMMERTIME FOUR CORNERS HIGH SETS BACK UP. AT LEAST INITIALLY, IT APPEARS THAT WHATEVER SHOWER AND THUNDERSTORM ACTIVITY THAT DEVELOPS ON SATURDAY AFTERNOON AND EVENING SHOULD DEVELOP COURTESY OF ANY DIFFERENTIAL HEATING BOUNDARIES OR BE TERRAIN INDUCED. THE LATEST ECMWF AND GFS ARE MORE STABLE OVER THE WESTERN CWFA AND THUS IF THIS TREND CONTINUES WE MAY NEED TO TRIM POPS THERE DOWN. PWAT VALUES PUSHING 1.50 INCHES WILL MEAN THE ATMOSPHERE WILL HAVE A LOT OF JUICE AND THUS FLASH FLOODING WILL BE THE PRIMARY THREAT IN STRONGER OR SLOWER MOVING STORMS. THINGS GET MORE INTERESTING SATURDAY NIGHT THROUGH MONDAY AS AN INVERTED TROUGH OR SOME SORT OF VORTICITY MAXIMUM OR LOBE HEADS NORTHWEST FROM CENTRAL ARIZONA AND CROSSES THE AREA. THIS FEATURE SHOULD LIFT SLOWLY NORTHEAST ON MONDAY BUT CONTINUES TO TREND TOWARD A SLOWER EXIT ON THE MODELS. THE PRESENCE OF THIS FEATURE IS SHOWN ON THE BIG 4 MEDIUM RANGE OPERATIONAL MODELS (GFS, ECMWF, GEM AND DGEX) AND THIS TRIGGER FEATURE COMBINED WITH THE HIGH MOISTURE CONTENT AVAILABLE SHOULD RESULT IN AN EVEN BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS EVEN AT NIGHT. POPS WERE RAISED AGAIN TO SHOW A BETTER UPTICK IN ACTIVITY FOR SUNDAY THROUGH MONDAY. THE MAIN CONCERN CONTINUES TO BE HOW MUCH CLOUD COVER EXISTS AS THIS WOULD LIMIT HEATING AND RESULT IN MORE SHOWERS AND LOW-GRADE THUNDERSTORMS. HOWEVER, IF WE GET ENOUGH HEATING SUNDAY, ACTIVITY WOULD SUPPORT THE POTENTIAL FOR STRONGER THUNDERSTORMS WITH 0-6 KM BULK SHEAR VALUES SHOWN BY THE GFS TO EXCEED 20 KTS ACROSS THE EASTERN CWFA. HEAVY RAIN PRODUCING THUNDERSTORMS WILL BE THE MAIN THREAT ALONG WITH THE RISK FOR FLASH FLOODING. HIGH TEMPS WILL BE VERY TRICKY ESPECIALLY ON SUNDAY AS CLOUDS COULD EASILY HOLD TEMPS DOWN ANOTHER 6-8 DEGREES FROM WHAT IS FORECAST. THE LATEST MODELS NOW SHOW A SLOWER EXIT TO THIS FEATURE KEEPING IT OVER THE NORTHEAST CWFA THROUGH TUESDAY BEFORE FINALLY GIVING IT THE BOOT. THUS POPS WERE RAISED MONDAY THROUGH TUESDAY ESPECIALLY IN LINCOLN COUNTY. DRIER AIR SHOULD FINALLY WORK IN FROM THE SOUTHWEST AS THE FLOW ALOFT TURNS IN THAT DIRECTION AND THIS SHOULD CUT BACK ON THE COVERAGE OF STORMS OUT THAT WAY. WITH LESS CLOUDS, TEMPS SHOULD TREND BACK CLOSER TO NORMAL. && .AVIATION...FOR MCCARRAN...PREVAILING SOUTHWEST WINDS AROUND 10 KNOTS WILL PERSIST INTO THE MORNING THEN A LIGHT EASTERLY WIND COMPONENT SHOULD DEVELOP LATE MORNING AND PERSIST INTO THE EVENING BEFORE WINDS SHIFT BACK MORE SOUTHWESTERLY. SCT-BKN CLOUD BASES ABOVE 15 KFT CAN BE EXPECTED. ISOLATED THUNDERSTORMS WILL BE POSSIBLE IN THE BEATTY AND MORMON MESA CORRIDORS THIS AFTERNOON/EARLY EVENING. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR MAINLY IN NORTHERN INYO...ESMERALDA AND CENTRAL NYE COUNTIES TODAY AND TONIGHT. ISOLATED THUNDERSTORM DEVELOPMENT CAN BE EXPECTED ELSEWHERE ACROSS THE SOUTHERN GREAT BASIN AND NORTHWEST ARIZONA. THE REST OF THE REGION WILL SEE WINDS GENERALLY LESS THAN 15 KTS AND SCT-BKN MID TO HIGH LEVEL CLOUDS. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && PIERCE/STACHELSKI FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.