545  
FXUS65 KREV 091951  
AFDREV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RENO NV  
1251 PM PDT TUE AUG 9 2022  
   
SYNOPSIS
 
 
AN ACTIVE THUNDERSTORM PATTERN WILL CONTINUE TODAY WITH PLENTY OF  
MOISTURE FOR THUNDERSTORMS, SOME WITH HEAVY RAIN, STRONG GUSTY  
WINDS AND SMALL HAIL. LOW PRESSURE OFF THE NORTHERN CALIFORNIA  
COAST THEN LIFTS NORTHEAST WITH A DRIER, MORE STABLE AIRMASS  
DECREASING STORM POTENTIAL THE REMAINDER OF THE WEEK. SEASONAL  
TEMPERATURES AND TYPICAL AFTERNOON BREEZES WILL ALSO RETURN.  
 

 
   
SHORT TERM (THROUGH WEDNESDAY NIGHT)
 
 
CONVECTION GOT OFF TO AN EARLY START THIS MORNING WITH SHOWERS  
AND A COUPLE RUMBLES OF THUNDER QUICKLY MOVING NORTH NEAR 30  
KNOTS. THUNDERSTORM COVERAGE WILL CONTINUE TO SPREAD THROUGH THE  
AFTERNOON HOURS THANKS TO BROAD SYNOPTIC FORCING AS OUR AREA  
RESIDES UNDER THE RIGHT ENTRANCE REGION OF AN UPPER-LEVEL JET  
STREAK. THE 12Z RAOB FROM OUR OFFICE IN RENO SAMPLED 0.99 PWAT,  
AND 06Z ECMWF ENSEMBLES TEND TO AGREE THAT FALLON'S PWATS ARE  
RIGHT AROUND 1.25 +/- 0.05 INCHES. STORMS, THEREFORE, WILL BE  
RATHER JUICY WITH HIGH RAIN RATES TODAY AND WILL BE CAPABLE OF  
LOCALIZED FLASH FLOODING IF THEY HAPPEN TO TRAIN OVER ONE AREA FOR  
A PERIOD OF TIME. IN OUR FAR NORTHERN AREAS (N LASSEN, E MODOC, N  
WASHOE), THERE IS A MARGINAL SEVERE RISK THIS AFTERNOON,  
PRIMARILY DUE TO DAMAGING WIND GUSTS AS 0-6KM BULK SHEAR OF  
35-45 KT AND DCAPE 1200-1600 J/KG WILL SUPPORT A FEW DISCRETE  
CELLS CAPABLE OF PRODUCING STRONG/DAMAGING WIND AND PERHAPS SOME  
SMALL HAIL. WITH THE QUICK STORM MOTION, SOME STORMS MAY NOT  
PRODUCE ENOUGH PRECIP QUICK ENOUGH TO COMPENSATE BURSTS OF CG  
LIGHTNING. THEREFORE THERE IS AN ELEVATED RISK OF NEW FIRE STARTS  
IN THESE AREAS. AS FOR HIGH TEMPERATURES TODAY, WE'RE LOOKING  
RIGHT AROUND 80 IN SIERRA VALLEYS AND UPPER 80S TO LOW 90S IN  
WESTERN NEVADA; ULTIMATELY, HIGHS WILL BE CONTINGENT ON SHOWER AND  
STORM ACTIVITY THROUGH THE DAY...  
 
BY WEDNESDAY, THE AREA OF LOW PRESSURE THAT HAS BEEN PESTERING US  
FOR SOME TIME WILL FINALLY BEGIN PULLING OFF TO THE NORTH,  
PARALLELING THE PACIFIC COASTLINE. WHILE THE MAIN FORCING THAT WE  
HAVE BEEN EXPERIENCING IN RECENT DAYS WILL BE SUBSIDING AS THE LOW  
PULLS AWAY, UPPER LEVEL DIVERGENCE ON THE SOUTHEASTERN SIDE OF  
THE JET COMBINED WITH ABUNDANT DAYTIME HEATING (HIGHS IN THE MID-  
90S ACROSS WESTERN NV) WILL SUPPORT AT LEAST ISOLATED  
THUNDERSTORMS. BULK SHEAR OF 25-30 KT HANGING AROUND WILL SUPPORT  
QUICKER STORM MOTIONS AND DCAPE OF 1500-2000 J/KG WILL SUPPORT  
STRONGER DOWNDRAFTS AND GUSTY WINDS. WITH THE DRIER AIR INTRUDING  
INTO THE AREA ON THE BACKSIDE OF THE LOW, ISOLATED TO SCATTERED  
STORM CHANCES WILL MAINLY BE CONFINED ALONG AND EAST OF US-95.  
-DUSTIN  
   
LONG TERM (THURSDAY THROUGH NEXT WEEKEND)
 
 
A NEARLY STATIONARY UPPER LEVEL DISTURBANCE SPINNING OVER THE GULF  
OF ALASKA AND STRONG UPPER RIDGE WITH A 5960 HPA CENTRAL HIGH  
ANCHORED OVER THE CENTRAL ROCKIES/UPPER PLAINS WILL MAINTAIN A  
DRIER SOUTHWEST UPPER FLOW OVER THE REGION FRIDAY. THIS PATTERN  
EFFECTIVELY SHUTS OFF THE FLUX OF MONSOONAL MOISTURE OVER THE  
SIERRA AND FAR WESTERN NV FOR THE TIME BEING THROUGH THIS WEEKEND.  
SOME RESIDUAL MOISTURE COUPLED WITH SFC HEATING WILL STILL AN  
INCREASED RISK OF AN ISOLATED SHOWER OR T-STORM (15-20%) OVER THE  
MONO-MINERAL CONVERGENCE ZONE THAT COULD MEANDER INTO SOUTHEAST  
CHURCHILL COUNTY BRINGING GUSTY OUTFLOWS TO 45 MPH AND BRIEF  
VISIBILITY REDUCTIONS IN BLOWING DUST. THE WEEKEND SHOULD SEE A  
BRIEF RETURN OF THE AFTERNOON ZEPHYR BREEZES TO 25 MPH AND MORE  
SEASONAL SUMMER TEMPERATURES IN THE MID 90S IN LOWER VALLEYS AND  
80S FOR SIERRA LOCATIONS.  
 
BUT THIS CURRENT BREAK FROM THE HIGHER HUMIDITY AND AFTERNOON  
STORMS WILL BE SHORT-LIVED. THE UPPER LOW HANGING JUST OFF-SHORE  
THE PACIFIC NORTHWEST WILL GET A JET-STREAM BOOST AND LIFT  
NORTHEAST INTO SOUTHWEST BC SATURDAY, DRAGGING A NEGATIVE TILTED  
UPPER TROUGH EAST AND SOUTHEAST ACROSS WA/OR AS WELL AD NORTHERN  
CA. ENSEMBLE CLUSTER GUIDANCE DOES FOCUS SOME UNCERTAINTY AS TO  
THE EXTENT THE UPPER TROUGH INFLUENCES NORTHERN NV WITH EUROPEAN  
EPS SIMULATIONS WEIGHING HEAVILY TOWARDS THAT SOLUTION.  
 
AS THIS UPPER WAVE CONTINUES EAST, IT WILL FLATTEN THEN SHIFT THE  
RIDGE AXIS MORE WEST BACK OVER THE FOUR-CORNERS AND GREAT BASIN BY  
EARLY NEXT WEEK. ONCE AGAIN THE TAP OF MONSOONAL MOISTURE IS TWISTED  
OPEN TO SWEEP NORTH IN THE SIERRA AND WESTERN NV. ENSEMBLE METEOGRAM  
GUIDANCE FORESEES MOISTURE INCREASING OVER THE REGION WITH THE  
MAJORITY OF SIMULATIONS BRING PWATS VALUES CLOSE TO A 0.6” TO 0.9”  
RANGE. AS PER ENSEMBLE BLENDED GUIDANCE, AN INCREASED CHANCE OF  
AFTERNOON/EVENING SHOWERS AND/OR HYBRID TYPE THUNDERSTORMS (15-20%)  
WILL ONCE AGAIN DOT THE REGION WITH GUSTY OUTFLOW WINDS, LOCALIZED  
BLOWING DUST, LIGHTNING (NOT NECESSARILY DRY), AND HEAVY RAINFALL  
CORES. -AMANDA  
 

 
   
AVIATION
 
 
THUNDERSTORMS WILL ONCE AGAIN DEVELOP THIS AFTERNOON STARTING  
AROUND 20-21Z AND CONTINUING UNTIL ABOUT 03Z. THE GREATEST RISK  
AND COVERAGE IS EXPECTED IN WEST CENTRAL NV INCLUDING  
KHTH/KNFL/KLOL, WITH FAST MOVING STORMS POTENTIALLY BRINGING SHORT  
BURSTS OF HEAVY RAIN AND SMALL HAIL, GUSTY OUTFLOW WINDS 40-50  
KTS, LOW-LEVEL TURBULENCE, AND REDUCED VISIBILITY IN BLOWING DUST.  
FOR THE MAIN TERMINALS IN FAR WESTERN NV SOUTHWARD TO KMMH, THE  
THUNDERSTORM THREAT IS LOWER, WITH OCCASIONAL THUNDER, BRIEF LIGHT  
RAIN AND OUTFLOW GUSTS TO 30 KT POSSIBLE GENERALLY BETWEEN 20Z-  
00Z. FOR THE TAHOE AREA TERMINALS, THE RISK FOR THUNDER IS QUITE  
LOW TODAY AS DRIER SW FLOW SETS UP ACROSS THE SIERRA.  
 
FOR WEDNESDAY, THUNDERSTORM ACTIVITY IS EXPECTED TO DECREASE WITH  
ISOLATED PM STORMS LIMITED TO AREAS EAST OF US-95. ELSEWHERE,  
DRIER AND MORE STABLE CONDITIONS RETURN WITH AFTERNOON ZEPHYR  
GUSTS OF 20-25 KT, WITH THESE DRIER CONDITIONS ALSO EXTENDING TO  
WEST CENTRAL NV BY THURSDAY. MJD  
 

 
   
FIRE WEATHER
 
 
* SCATTERED THUNDERSTORMS WILL BRING INCREASED RISK OF NEW  
LIGHTNING FIRE STARTS IN NORTHWEST AND WEST CENTRAL NV THIS  
AFTERNOON AND INTO THE EVENING. ALTHOUGH MOST OF THESE STORMS  
WILL CONTAIN SUBSTANTIAL MOISTURE AND PRODUCE BURSTS OF HEAVIER  
RAIN, THEY'LL MOVE QUICKLY WITH POTENTIAL FOR LIGHTNING STRIKES  
OUTSIDE THE PRECIP CORES, ALONG WITH STRONG OUTFLOW GUSTS OF  
40-60 MPH.  
 
* MOST STORM ACTIVITY IS EXPECTED TO REMAIN EAST OF THE HIGHER  
RISK BURN SCARS IN EASTERN CA AND FAR WESTERN NV. ISOLATED BRIEF  
RAIN SHOWERS ARE POSSIBLE BUT RAINFALL AMOUNTS WILL BE SPARSE.  
THE POODLE FIRE BURN SCAR IN NORTHWEST NV HAS A BIT MORE RISK,  
WITH ABOUT A 20% PROBABILITY OF A STRONGER CELL MOVING THROUGH  
THIS AREA LATER THIS AFTERNOON.  
 
* FROM WEDNESDAY THROUGH THE REST OF THIS WEEK, WE'RE LOOKING AT A  
RETURN TO A DRIER WEATHER PATTERN WITH TYPICAL ZEPHYR BREEZES  
20-30 MPH EACH AFTERNOON, WHICH COULD BRING THE EMERGENCE OF  
HOLDOVER LIGHTNING FIRE STARTS FROM RECENT THUNDERSTORM  
ACTIVITY. MJD  
 

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

 
 

 
 
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...  
HTTP://WEATHER.GOV/RENO  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab NV Page
The Nexlab CA Page Main Text Page