247  
FXUS65 KVEF 210236 AAA  
AFDVEF  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LAS VEGAS NV  
735 PM PDT THU JUL 20 2017  
   
SYNOPSIS
 
 
MONSOON MOISTURE WILL RETREAT AS TEMPERATURES WARM THROUGH THE  
WEEKEND. MOISTURE LOOKS TO WORK BACK INTO THE AREA NEXT WEEK,  
BRINGING ADDITIONAL THUNDERSTORM CHANCES TO THE REGION.  

 
   
UPDATE
 
SHOWERS AND THUNDERSTORMS OVER MOHAVE COUNTY DISSIPATING  
QUICKLY THIS EVENING SO TRIMMED BACK ON POPS AS SMALL AREA PRESENTLY  
NEAR MOUNT TRUMBULL DISSIPATES IN THE NEXT HOUR. ELSEWHERE, INCLUDED  
THE MENTION OF SMOKE TO PARTS OF INYO AND ESMERALDA COUNTIES TONIGHT  
THROUGH TOMORROW NIGHT. FLOW LOOKS FAVORABLE TO BRING SMOKE FROM THE  
DETWILER WILDFIRE TO THAT AREA OVER THE COMING DAYS.  

 
   
PREV DISCUSSION
 
231 PM PDT THU JUL 20 2017   
SHORT TERM
 
THROUGH SATURDAY.  
 
DRYING NOTED BEGINNING IN WESTERN PORTIONS OF THE AREA AS PROGGED  
BY MODELS, WITH DEWPOINTS FALLING SHARPLY IN AREAS OF SAN  
BERNARDINO, INYO, AND NYE COUNTIES. EXPECT THIS TREND TO CONTINUE  
FOR THE NEXT FEW DAYS, THOUGH MCVS MAY SLOW THE TREND IN SOME  
PLACES ON ANY GIVEN DAY. THUNDERSTORMS WILL REMAIN CONFINED TO  
LINCOLN AND MOHAVE COUNTIES AS SUBSIDENCE TAKES OVER, WARMING AND  
DRYING THE REGION.  
   
LONG TERM
 
SATURDAY THROUGH THURSDAY.  
 
THE POTENTIAL FOR ISOLATED THUNDERSTORMS AROUND SOUTHERN NEVADA AND  
NORTHWEST ARIZONA WILL NOT BE COMPLETELY ELIMINATED SATURDAY AND  
SUNDAY AS SUFFICIENT MOISTURE AND INSTABILITY SHOULD REMAIN FOR A  
SLIGHT CHANCE OVER THE MOUNTAINS. THE DOOR FOR MONSOONAL FLOW THEN  
OPENS WIDE MONDAY AND TUESDAY AS HIGH PRESSURE OVER NEVADA DURING  
THE WEEKEND HEADS OVER THE FOUR CORNERS ALLOWING SOUTHEAST TO  
SOUTHERLY FLOW TO DRAW ADDITIONAL MOISTURE INTO MOST OF OUR REGION.  
IT APPEARS SUFFICIENT MOISTURE WILL BE PULLED FAR ENOUGH WESTWARD  
FOR A CHANCE OF THUNDERSTORMS OVER THE SIERRA, ESPECIALLY MONDAY  
INTO TUESDAY. THE ECMWF AND GFS INDICATE A BROAD TROUGH APPROACHING  
THE WEST COAST WEDNESDAY INTO THURSDAY WHICH WOULD LEAD TO DRY  
SOUTHWEST FLOW WORKING INTO OUR REGION. THE GFS INDICATES MORE OF A  
DRYING TREND THAN THE ECMWF. THE GRIDDED FORECAST REFLECTS A SLIGHT  
DOWNWARD TREND IN THUNDERSTORM POTENTIAL WEDNESDAY INTO THURSDAY  
BASED ON THE GFS. TEMPERATURES WILL REMAIN NEAR NORMAL THOUGH  
SIGNIFICANT VARIATIONS COULD OCCUR DUE TO SHOWERS AND THUNDERSTORMS  
FOR ANY GIVEN LOCATION.  

 
   
FIRE WEATHER
 
 
RETREATING MONSOON MOISTURE WILL LEAD TO DRYING CONDITION,  
ESPECIALLY FOR THE WESTERN HALF OF THE AREA, WHILE THUNDERSTORMS  
BECOMING INCREASING ISOLATED IN MOHAVE AND LINCOLN COUNTIES.  
AFTERNOON HUMIDITIES WILL DECREASE TO AROUND 10 PERCENT IN  
CALIFORNIA UP TO 30 PERCENT IN NW ARIZONA. NO SIGNIFICANT WINDS  
ARE FORECAST, KEEPING EXTREME FIRE DANGER OUT OF THE FORECAST FOR  
NOW. MOISTURE WILL BE ON THE INCREASE NEXT WEEK WITH ADDITIONAL  
CHANCES OF THUNDERSTORMS.  

 
   
AVIATION...FOR MCCARRAN
 
WINDS WILL FAVOR A SOUTHERLY DIRECTION  
WITH SPEEDS NEAR 10 KNOTS THROUGH EARLY THIS EVENING. WINDS THIS  
EVENING AND OVERNIGHT WILL GENERALLY BE FROM THE SOUTHWEST UP TO 10  
KNOTS. MAINLY SOUTHEAST WINDS EXPECTED FRIDAY UP TO 10 KNOTS. BKN  
MID TO HIGH CLOUDS WILL BE PRESENT THROUGH EARLY THIS EVENING THEN  
SCATTERED OVERNIGHT AND FRIDAY. IT APPEARS UNLIKELY THAT THERE WILL  
BE ANY STORMS IN OR NEAR THE LAS VEGAS VALLEY THROUGH FRIDAY.  
 
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA AND SOUTHEAST  
CALIFORNIA...MAINLY SOUTHERLY WINDS ACROSS THE AREA THROUGH EARLY  
THIS EVENING THEN MAINLY DIURNAL WINDS TONIGHT AND FRIDAY MORNING  
WITH SOUTH WINDS 5-15 KNOTS DEVELOPING AGAIN FRIDAY AFTERNOON.  
THUNDERSTORM CHANCES WILL BE LIMITED TO MAINLY MOHAVE AND EASTERN  
LINCOLN COUNTIES THROUGH EARLY THIS EVENING AND AGAIN FRIDAY  
AFTERNOON.  

 
   
SPOTTER INFORMATION STATEMENT
 
THUNDERSTORMS WILL BE INCREASING  
ISOLATED TO MOHAVE COUNTY, AZ AND LINCOLN COUNTY, NV AS MONSOON  
MOISTURE RETREATS OVER THE WEEKEND. THEREFORE, SPOTTER ACTIVATION  
IS NOT ANTICIPATED AT THIS TIME.  

 
 

 
 
UPDATE...PIERCE  
 
SHORT TERM/FIRE...STEELE  
AVIATION..........HARRISON  
LONG TERM.........ADAIR  
 
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:  
 
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER  
 
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