550  
FXUS65 KVEF 172110  
AFDVEF  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LAS VEGAS NV  
210 PM PDT SUN OCT 17 2021  
   
SYNOPSIS
 
WINDS WILL INCREASE THIS EVENING, PEAK OVERNIGHT, AND  
DECREASE ON MONDAY AS A COLD FRONT MOVES THROUGH THE AREA, LEAVING  
COOLER TEMPERATURES IN ITS WAKE MONDAY AND TUESDAY. LESS WIND AND  
GRADUALLY WARMING TEMPERATURES ARE EXPECTED THROUGH THE LATTER PART  
OF THE WEEK.  

 
   
SHORT TERM
 
THROUGH MONDAY NIGHT. MIDDAY SATELLITE LOOP SHOWED  
HIGH CLOUDS STREAMING OVER OUR AREA AHEAD OF THE LONG-ADVERTISED  
UPPER LEVEL TROUGH WHICH WAS NEARING THE COAST OF FAR NORTHERN  
CALIFORNIA. SURFACE WINDS WERE BEGINNING TO RESPOND, WITH EXPOSED  
STATIONS SEEING SOUTHERLY WINDS GUSTING INTO THE 20S AND 30S. THE  
STRONGER WINDS AND BETTER MIXING HAD ALSO KICKED TEMPERATURES UP A  
FEW DEGREES FROM YESTERDAY, ALTHOUGH THIS WAS NOT YET BEING FELT IN  
MANY VALLEYS (SUCH AS THE OWENS, LAS VEGAS, AND COLORADO RIVER  
VALLEYS) WHERE THE WINDS HAD NOT YET MADE IT DOWN TO THE VALLEY  
FLOORS. THE MAIN FOCUS FOR THIS EVENING THROUGH TOMORROW MORNING IS  
STILL WIND. WAVE CLOUDS WERE BECOMING MORE PRONOUNCED IN THE LEE OF  
THE CENTRAL SIERRA, AND THESE WILL SPREAD SOUTH THROUGH THE DAY WITH  
THE BELT OF STRONGER CROSS-BARRIER WINDS. WIND ADVISORY FOR THE  
OWENS VALLEY AND EASTERN SLOPES OF THE SIERRA BEGINNING LATE THIS  
AFTERNOON STILL LOOKS GOOD. HIGH RESOLUTION MODELS ARE SUGGESTING  
THAT THE STRONGEST DOWNSLOPE WINDS WILL NOT PENETRATE AS FAR EAST AS  
HIGHWAY 395, BUT EVEN IF THIS VERIFIES, ROTOR CIRCULATIONS WILL  
RESULT IN SUDDEN WIND SHIFTS AND GUSTS ALONG THE HIGHWAY. WINDS WILL  
LIKELY PEAK IN THIS AREA IN THE WEE HOURS OF THE MORNING, BY WHICH  
TIME SOUTH TO SOUTHWEST WINDS IN THE SPRING MOUNTAINS WILL ALSO BE  
KICKING UP. THE WIND ADVISORY FOR THE MOUNTAINS THEMSELVES LOOKS  
GOOD, WITH LINGERING QUESTIONS ABOUT ANY DOWNSLOPING. HIGH RES  
MODELS ARE STILL PINPOINTING SOUTHERLY DOWNSLOPE COMING OFF THE  
NORTHWEST END OF THE MOUNTAIN RANGE, WITH A SHORT PERIOD OF GUSTS  
OVER 40 MPH REACHING HIGHWAY 95 NEAR MERCURY-DESERT ROCK BETWEEN  
ABOUT 3 AND 7 AM. IF THIS VERIFIES, IT WOULD AFFECT SUCH A SMALL  
PERCENTAGE OF THE FORECAST ZONE THAT IT WOULD BE BEST HANDLED  
THROUGH SOCIAL MEDIA AND DIRECT PARTNER INTERACTION RATHER THAN  
THROUGH EXPANDING THE ADVISORY. OTHER AREAS OF CONCERN INCLUDE THE  
BARSTOW AND KINGMAN AREAS. FOR THE BARSTOW AREA, THE HIGH RES MODELS  
HAVE BEEN CONSISTENT IN SHOWING THE STRONGEST WINDS REMAINING NORTH  
OF I-15 AND THE POPULATED AREAS, SO CHOSE NOT TO EXPAND THE ADVISORY  
INTO THIS ZONE. THE KINGMAN AREA IS A BIT TOUGHER, AS THE MODELS  
SHOW PEAK WINDS MONDAY HOVERING JUST UNDER 40 MPH FOR LARGE SWATHS  
OF THE ZONE, INCLUDING KINGMAN PROPER. RUN TO RUN TRENDS ARE NEARLY  
FLAT, SO THAT DOESN'T HELP MUCH. FOR NOW, WILL FORGO AN ADVISORY FOR  
THAT AREA AND MESSAGE IT VIA SOCIAL MEDIA AND DIRECT OUTREACH. HIGH  
TEMPERATURES MONDAY WILL COME DOWN 10 TO 15 DEGREES FROM TODAY IN  
THE WAKE OF THE COLD FRONT, WITH LITTLE TO NO IMPACT EXPECTED FROM  
POST-FRONTAL NORTHERLY WINDS. PRECIPITATION CHANCES WILL BE CONFINED  
TO THE SIERRA AND SOUTHERN GREAT BASIN, WITH A COUPLE OF INCHES OF  
SNOW ON THE HIGHER ELEVATIONS OF THE SIERRA AND VERY LIGHT RAIN AND  
SNOW FROM NORTHERN ESMERALDA COUNTY TO NORTHERN LINCOLN COUNTY.  
   
LONG TERM
 
TUESDAY THROUGH SATURDAY.  
 
THE SYSTEM THAT WILL BRING WITH IT A GUSTY MONDAY MORNING WILL ALSO  
DROP TEMPERATURES SUBSTANTIALLY, WITH TUESDAY'S AFTERNOON HIGHS  
DROPPING TO 8-12 DEGREES BELOW SEASONAL AVERAGES. THAT SAID, IN THE  
SYSTEM'S WAKE, A RIDGE OF HIGH PRESSURE WILL SET UP ACROSS THE  
DESERT SOUTHWEST THAT WILL BRING DRY WEATHER AND WILL ALLOW  
TEMPERATURES TO SLOWLY CLIMB BACK TO NORMAL THROUGH THE WEEK AND  
INTO THE WEEKEND.  
 
THERE CONTINUES TO BE AN INDICATION OF A STRONG WEATHER SYSTEM  
IMPACTING OUR AREA AT THE END OF THE WORK WEEK AND THROUGH THE  
WEEKEND. THOUGH THERE REMAINS QUITE A BIT OF UNCERTAINTY REGARDING  
STRENGTH, TIMING, AND POSITION, THE NBM SEEMS SOLD ON IMPACTS ON THE  
NORTHERN PORTIONS OF OUR CWA, WITH AT LEAST "SLIGHT" POPS ACROSS THE  
HIGHER ELEVATIONS OF INYO COUNTY AND ACROSS THE SOUTHERN GREAT BASIN  
FOR THE WEEKEND AS WELL AS A DROP IN TEMPERATURES. WILL CONTINUE TO  
MONITOR TRENDS THROUGH THE WEEK.  

 
   
AVIATION...FOR MCCARRAN
 
EASTERLY WINDS UP TO 8 KNOTS ARE  
EXPECTED TO TRANSITION TO THE SOUTH AND SOUTHWEST THIS AFTERNOON.  
WIND SPEEDS ARE EXPECTED TO INCREASE AND BECOME GUSTY AS THE WINDS  
TRANSITION. THERE COULD VERY WELL BE A PERIOD OF TIME OF A SOUTHEAST  
COMPONENT TO THE WINDS PRIOR TO TURNING PREDOMINANTLY SOUTH TO  
SOUTHWEST. WINDS REMAIN GUSTY OVERNIGHT FROM THE SOUTHWEST THEN  
INCREASE MONDAY MORNING WITH WIND SPEEDS AROUND 20 KNOTS AND GUSTS  
AROUND 30 KNOTS. THE GUSTY WINDS WILL GRADUALLY SUBSIDE MONDAY  
AFTERNOON AND TURN MORE TO THE WEST OR NORTHWEST. HIGH CLOUDS WILL  
MOVE ACROSS THE AREA AT TIMES BUT NO OPERATIONAL IMPACTS ARE  
EXPECTED.  
 
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA, AND SOUTHEAST  
CALIFORNIA...GUSTY WEST TO SOUTHWEST WINDS WILL CONTINUE AT MOST  
SITES WITH THE EXCEPTION OF THE LOWER COLORADO RIVER SITES WHERE  
MORE SOUTHERLY WINDS ARE EXPECTED THIS AFTERNOON. THE WIND FORECAST  
FOR KBIH IS A DIFFICULT ONE AND REMAINS OF LOW CONFIDENCE.  
INITIALLY, SOUTHEAST WINDS AROUND 15 KTS AND GUSTY ARE EXPECTED BUT  
THEN THE FORECAST CALLS FOR WINDS TO TURN TO THE SOUTHWEST BEFORE  
TURNING BACK TO THE SOUTHEAST OVERNIGHT. SHOWER CHANCES INCREASE AT  
KBIH BETWEEN 09Z-12Z WHEN CIGS COULD FALL TO 5K FEET OR LOWER.  
SHORTLY AFTER THE SHOWER ACTIVITY ENDS, WINDS SHOULD TURN NORTHERLY.  
EXPECT STRONG TURBULENCE THROUGH TONIGHT IN THE LEE OF THE SIERRA.  
HIGH CLOUDS WILL MOVE ACROSS THE AREA AT TIMES BUT NO OPERATIONAL  
IMPACTS ARE EXPECTED.  

 
   
SPOTTER INFORMATION STATEMENT
 
SPOTTERS ARE ENCOURAGED TO REPORT  
ANY SIGNIFICANT WEATHER OR IMPACTS ACCORDING TO STANDARD OPERATING  
PROCEDURES.  

 
 

 
 
SHORT TERM...MORGAN  
LONG TERM...VARIAN  
AVIATION...SALMEN  
 
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:  
HTTPS://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER  
 
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