249  
FXUS65 KREV 092004  
AFDREV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RENO NV  
104 PM PDT THU MAY 9 2024  
 
   
SYNOPSIS
 
 
A WARMING TREND FINALLY SETTLES IN ACROSS THE SIERRA AND WESTERN  
NEVADA WITH ABOVE AVERAGE TEMPERATURES EXPECTED BY THIS WEEKEND. THE  
POTENTIAL FOR SHOWERS AND THUNDERSTORMS ALSO RETURN TO THE SIERRA BY  
FRIDAY AFTERNOON WITH ONGOING LOW CHANCES EACH DAY THROUGH EARLY  
NEXT WEEK.  
 

 
   
DISCUSSION
 
 
PLAN ON AT LEAST A COUPLE MORE DAYS OF THE PESKY NORTHEAST TO  
EASTERLY FLOW FOR THE SIERRA AND WESTERN NEVADA. THE EASTERLY FLOW  
HAS LIMITED THE WARMING POTENTIAL AND ALSO KEPT THE REGION FAIRLY  
DRY FOR MUCH OF THE WEEK. THE BROAD UPPER LEVEL LOW CENTERED OVER  
THE FOUR-CORNERS REGION IS PROJECTED TO RETROGRADE WESTWARD  
SLIGHTLY, RESULTING IN ONE LAST PUSH OF EASTERLY WINDS FROM THE  
TAHOE BASIN SOUTHWARD. THIS WAVE WILL ALSO BRING LOW CHANCES (10-  
15%) FOR LIGHT SHOWERS (LIGHT SNOW FOR HIGHEST MOUNTAIN PEAKS) FOR  
AREAS FROM MONO LAKE SOUTHWARD IN MONO COUNTY AND MINERAL COUNTY TOO  
THIS EVENING THROUGH EARLY FRIDAY MORNING. RESIDUAL MOISTURE FROM  
THE EXITING UPPER LEVEL WAVE ALONG WITH AFTERNOON HEATING MAY BE  
ENOUGH TO KICK OFF A HANDFUL OF SHOWERS AND STORMS ALONG THE SIERRA,  
BUT WITH EASTERLY STEERING FLOW ANYTHING THAT POPS UP WILL MEANDER  
TOWARD INTERIOR CA.  
 
THE BROAD UPPER LOW FINALLY MIGRATES EASTWARD AS WEAK HIGH PRESSURE  
BUILDS ACROSS CA AND NV IN ITS WAKE. THE FLY IN THE OINTMENT FOR A  
TRUE RIDGE PATTERN (WARMER/DRIER CONDITIONS) APPEARS TO BE A WEAK  
TROUGH IN THE VICINITY OF THE WEST COAST SATURDAY INTO SUNDAY.  
SURFACE TEMPERATURES WILL STILL WARM THROUGH THE WEEKEND, BUT THE  
LOW WILL INTRODUCE VARYING CHANCES FOR SHOWERS AND THUNDERSTORMS AS  
IT NEARS THE REGION. FOR NOW, SIMULATIONS HIGHLIGHT A 10-15% CHANCE  
FOR ISOLATED SHOWERS AND THUNDERSTORMS FOR THE SIERRA ON SUNDAY  
AFTERNOON WITH LESS THAN A 10% CHANCE ON SATURDAY. THE POTENTIAL  
WILL CONTINUE THROUGH EARLY NEXT WEEK AS THE WEAK TROUGH SAGS  
THROUGH THE SOCAL.  
 
BEYOND WEDNESDAY, ENSEMBLE CLUSTERS ARE SHOWING HINTS OF A STRONGER  
RIDGE SIGNAL TO WRAP UP THE LATTER HALF OF THE WEEK. THERE MAY BE A  
BIT OF A WEATHER PATTERN SHIFT BATTLE BETWEEN THE BUILDING EASTERN  
PACIFIC RIDGE AND THE UPPER LEVEL TROUGH DEEPENING ACROSS THE  
ROCKIES. WARMING TREND SHOULD REMAIN ON TRACK THROUGH THE EARLY HALF  
OF NEXT WEEK, BUT THE BLENDED GUIDANCE IS SHOWING A BIT MORE SPREAD  
IN THE FORECAST HIGHS BY THURSDAY, WHICH WOULD LINE UP WITH THE  
PATTERN SHIFT INDECISION BY MOTHER NATURE.  
 
-EDAN  
 

 
   
AVIATION
 
 
* VFR CONDITIONS WILL PERSIST AT ALL TAF SITES TO END THE WEEK. KMMH  
WILL BE THE EXCEPTION OVERNIGHT WHERE SOME MID TO HIGH LEVEL CLOUD  
COVER ARRIVES BETWEEN 0Z-6Z FRIDAY.  
 
* WINDS: BREEZY EASTERLY AFTERNOON WINDS WILL DEVELOP TODAY AND  
FRIDAY AFTERNOON BEFORE SHIFTING TO LIGHTER FLOW ON SATURDAY. THE  
MORE TYPICAL WEST WINDS ARE SLATED TO RETURN ON SUNDAY AFTERNOON.  
BREEZES WILL REMAIN IN THE 20-25 KT RANGE EACH AFTERNOON THROUGH  
THE WEEKEND, WITH THE LIGHTEST WINDS ON SATURDAY.  
 
* PRECIPITATION: A FEW CUMULUS BUILDUPS WILL DEVELOP LATE THIS  
AFTERNOON, BUT LESS THAN A 5% CHANCE FOR SHOWERS OR THUNDERSTORMS  
THROUGH 0Z FRI. BETWEEN 0-6Z KMMH MAY HAVE A FEW SHOWERS DEVELOP  
AS THE UPPER LOW RETROGRADES WESTWARD TOWARDS THE SIERRA. LIGHT  
SHOWERS, AND EVEN VERY HIGH ELEVATION SNOW, MAY CONTINUE THROUGH  
FRIDAY 18Z. ANY ADDITIONAL SHOWERS OR THUNDERSTORMS POTENTIAL WILL  
FORM ALONG THE CREST WITH THE EASTERLY STEERING FLOW PUSHING THEM  
TOWARD INTERIOR CA.  
 
-EDAN  
 

 
 
   
REV WATCHES/WARNINGS/ADVISORIES
 
 
NV...NONE.  
CA...NONE.  

 
 

 
 
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