339  
FXUS65 KREV 260505 AAA  
AFDREV  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE RENO NV  
1005 PM PDT SUN JUN 25 2017  
   
UPDATE
 
 
CONVECTION IS FINALLY DYING OFF THIS EVENING WITH THE LAST REMNANT  
SOUTHWEST OF FALLON. THE HRRR IS TRYING TO SHOW ANOTHER ROUND OF  
CONVECTION IN MONO COUNTY DEVELOPING IN THE NEXT 2-3 HOURS, BUT  
THIS LOOKS UNLIKELY. CURRENT IR/WV IMAGERY SHOWS NO CLOUD  
DEVELOPMENT THERE WHERE IT SHOULD ALREADY BE OCCURRING (IF YOU  
BELIEVE THE HRRR). THE BEST FORCING WILL BE NORTH OF I-80 TONIGHT,  
SO THINK IT IS A VERY LOW PROBABILITY OF HAPPENING. WILL REMOVE  
THE MENTION OF SHOWERS AND STORMS FOR THE REMAINDER OF THE NIGHT.  
OTHERWISE, GOING FORECAST ON TRACK WITH GUSTY WINDS TOMORROW.  
WALLMANN  
 

 
   
PREVIOUS DISCUSSION
 
/ISSUED 159 PM PDT SUN JUN 25 2017/  
 
SYNOPSIS...  
 
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE POSSIBLE THIS  
EVENING WITH THE BEST COVERAGE LIKELY OVER NORTHEAST CALIFORNIA.  
CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY MONDAY AS VERY DRY  
AIR COMBINES WITH GUSTY WINDS. CHOPPY LAKE CONDITIONS ARE ALSO  
LIKELY MONDAY. TEMPERATURES WILL COOL DOWN TO NEAR SEASONAL  
AVERAGES THROUGH MIDWEEK, THEN SLOWLY WARM UP AGAIN LATE IN THE  
WEEK WITH MAINLY DRY WEATHER PREVAILING.  
 
DISCUSSION...  
 
ISOLATED THUNDERSTORMS TRYING TO DEVELOP IN THE LEE OF THE SIERRA  
DUE TO DIFFERENTIAL HEATING SHOULD BE RELATIVELY SHORT LIVED THIS  
EVENING. STORMS MAY LAST A LITTLE LONGER EAST OF THE SIERRA WHERE  
A WEAK ZEPHYR MAY FOCUS DEVELOPMENT, ALONG THE PINE NUTS, AND THE  
VIRGINIA RANGE...BUT ARE NOT EXPECTED TO TAKE ON ANY ORGANIZED  
CHARACTERISTICS. TO THE NORTH THERE IS GREATER POTENTIAL FOR  
LOOSELY ORGANIZED, LONGER-LIVED CONVECTION DUE TO THE PRESENCE OF  
UPPER LEVEL SUPPORT IN THE FORM OF POTENTIAL VORTICITY ADVECTION.  
AREAS NORTH OF A LINE FROM SUSANVILLE TO GERLACH SHOW THE BEST  
POTENTIAL FOR ANY ORGANIZATION. EVEN SO...STORMS WILL STILL BE NO  
MORE THAN WIDELY SCATTERED AND THE SUPPORT DOES NOT LAST LONG.  
CELLS SHOULD BE MOVING FAST ENOUGH TO LIMIT THE AMOUNT OF  
PRECIPITATION...BUT THAT INCREASES THE CHANCE FOR DRY LIGHTNING  
STRIKES.  
 
THAT BRINGS US TO MONDAY WHEN DRIER AIR MOVES INTO ALL BUT THE  
VERY FAR NORTHERN PARTS OF THE FORECAST AREA...HEIGHTS AND  
TEMPERATURES DECREASE AND BREEZES INCREASE. THE COMBINATION OF  
BREEZY WINDS AND DRIER AIR WILL CREATE CRITICAL FIRE WEATHER  
CONDITIONS IN AREAS WHERE FUELS ARE RECEPTIVE. WE ARE ALSO  
CONCERNED WITH HOLDOVERS FROM LIGHTNING STRIKES THIS EVENING.  
MORE DETAILS ARE IN THE FIRE WEATHER SECTION. WE HAVE ISSUED LAKE  
WIND ADVISORIES FOR AREAS EAST OF THE SIERRA FRONT INTO PARTS OF  
THE BASIN AND RANGE TO ACCOUNT FOR GUSTY WINDS MONDAY AS WELL.  
FORECAST GUIDANCE DOES SHOW A LITTLE RESIDUAL MOISTURE INTERACTING  
WITH A SECONDARY VORTICITY LOBE OVER THE FAR NORTHERN FORECAST  
AREA MONDAY EVENING...SO A SLIGHT CHANCE OF THUNDERSTORMS WAS  
ADDED THERE.  
 
BEYOND MONDAY THE WEATHER TURNS GENERALLY BENIGN WITH DRY  
WESTERLY FLOW OVER MUCH OF THE REGION. HIGH TEMPERATURES SHOULD BE  
CLOSER TO NORMAL OR JUST A LITTLE ABOVE THROUGH THURSDAY.  
 
THE GFS PERSISTS IN BRINGING A WEAK UPPER LEVEL LOW INTO THE  
REGION LATE FRIDAY. THE ECMWF HAS A SIMILAR FEATURE...BUT IS NOT  
AS AGGRESSIVE. THERE IS A LACK OF MOISTURE...BUT THE MERE  
PRESENCE OF THE FEATURE ALONG WITH INCREASING INSTABILITY DUE TO  
WARMING TEMPERATURES COULD DEVELOP AFTERNOON TOWERING CUMULUS.  
RIGHT NOW WE WILL LEAVE MENTION OF THUNDERSTORMS OUT OF THE  
FORECAST.  
 
THE MODELS DIVERGE MORE FOR SATURDAY WITH THE ECMWF MORE  
AGGRESSIVE WITH A DEEPER TROUGH BY THEN. THE GFS IS TRYING TO  
START BUILDING A RIDGE AGAIN. BOTH ARE BACK TO WESTERLY FLOW FOR  
SUNDAY. GIVEN THE DIFFERENCES BETWEEN THE MODELS AND SOME RUN-TO-  
RUN DIFFERENCES CROPPING UP IN EACH MODEL...WE WILL KEEP THE  
EXPLICIT MENTION OF STORMS OUT OF THE FORECAST FOR NEXT  
WEEKEND...BUT THEY ARE NOT OUT OF THE QUESTION FOR SATURDAY.  
TEMPERATURES WARM A BIT MORE FOR SATURDAY AND SUNDAY...BACK TO  
WELL ABOVE AVERAGE.  
 
AVIATION...  
 
CONVECTION ACROSS WESTERN NEVADA AND THE EASTERN SIERRA SHOULD  
DECREASE THROUGH THE EVENING. OVER NORTHEAST CALIFORNIA AND FAR  
NORTHWEST NEVADA THE CONVECTION IS LIKELY TO CONTINUE INTO THE  
LATER EVENING HOURS. THE ONLY TERMINALS LIKELY TO SEE ANY  
THUNDERSTORM ACTIVITY THIS EVENING ARE KMMH AND KSVE.  
 
BY MONDAY...BREEZY WINDS DEVELOP ACROSS THE FORECAST AREA WITH  
SURFACE GUSTS EAST OF THE SIERRA AND THROUGH WESTERN NEVADA  
REACHING 30-35 KTS AT TIMES. ANOTHER BREEZY DAY IS LIKELY TUESDAY  
WITH SURFACE GUSTS APPROACHING 25-30 KTS.  
 
WINDS SHOULD DECREASE INTO WEDNESDAY AND THURSDAY. FRIDAY INTO  
NEXT WEEKEND MAY SEE A RETURN TO ISOLATED CONVECTION ALONG AND  
JUST EAST OF THE SIERRA EACH AFTERNOON AND EVENING...BUT RIGHT NOW  
THE CHANCES ARE LESS THAN 15%.  
 
FIRE WEATHER...  
 
THUNDERSTORMS ARE LOOKING LESS LIKELY ALONG THE SIERRA FRONT FROM  
AROUND SUSANVILLE THROUGH NORTHERN MONO COUNTY THIS AFTERNOON AND  
EVENING. CLOUDS ARE FORMING, BUT ELEMENTS ARE RELATIVELY FLAT.  
STILL, A LATE AFTERNOON THUNDERSTORM IS POSSIBLE (ABOUT A 10%  
CHANCE) OVER THE VIRGINIA RANGE. SLIGHT CHANCES OF GENERAL  
THUNDERSTORMS REMAIN POSSIBLE MAINLY FOR EASTERN MONO AND WESTERN  
MINERAL COUNTIES WHERE SURFACE CONVERGENCE IS EXPECTED TO BE  
STRONGER. ALSO, THE BEST CHANCES OF DRY VARIETY THUNDERSTORMS  
REMAIN IN NORTHERN LASSEN COUNTY WITH SLIGHT CHANCES FOR FAR  
NORTHERN WASHOE/MODOC COUNTIES. HOLDOVERS FROM DRY STRIKES WILL BE  
A CONCERN HEADING INTO MONDAY. OVERALL, OVERNIGHT RECOVERIES WILL  
BE POOR TO MODERATE FOR MOST VALLEYS.  
 
THE UPPER CIRCULATION SHIFTS TOWARDS THE WEST COAST TONIGHT RESULTING  
IN A STRONGER PRESSURE GRADIENT OVER THE REGION FOR MONDAY IN THE  
AFTERNOON AND EVENING. IT IS EXPECTED THAT WINDS WILL INCREASE  
ACROSS NORTHERN NEVADA AND FAR NORTHEASTERN CALIFORNIA, SUSTAINED 15  
TO 20 MPH WITH GUSTS AROUND 35 MPH. COUPLED WITH LOW RH IN THE  
SINGLE DIGITS TO 14%, CRITICAL FIRE WEATHER CONDITIONS WILL BE  
LIKELY. AS SUCH, THE FIRE WEATHER WATCHES FOR THE SIERRA FRONT AND  
NEVADA INTERIOR, INCLUDING NORTHERN MINERAL COUNTY, HAVE BEEN  
UPGRADED TO A RED FLAG WARNING. ALSO, FINE FUELS HAVE BEEN DEEMED  
READY FOR EASTERN LASSEN COUNTY AND A PORTION OF ZONE 458 WHICH  
INCLUDES GERLACH AND THE SMOKE CREEK DESERT. RED FLAG WARNINGS  
HAVE BEEN ISSUED FOR THESE AREAS AS WELL. RECOVERIES WILL  
CONTINUE TO BE POOR TO MODERATE FOR MOST VALLEYS.  
 
WINDS REMAIN BREEZY TUESDAY AFTERNOON, BUT BELOW CRITERIA. STILL,  
WINDS WILL BE SUFFICIENT TO DRIVE ANY EXISTING FIRES THAT MAY BE  
OCCURRING IN VALLEY LOCATIONS MAINLY THROUGH NEARLY CONTINUOUS  
GRASSES AND BRUSH. AFTERNOON WINDS BECOME LIGHTER BY WEDNESDAY WITH  
SLIGHTLY COOLER TEMPERATURES. BOYD  
 

 
   
REV WATCHES/WARNINGS/ADVISORIES
 
 
NV...RED FLAG WARNING FROM 1 PM TO 11 PM PDT MONDAY  
NVZ450-453-458-459.  
 
LAKE WIND ADVISORY FROM 1 PM TO 11 PM PDT MONDAY FOR WASHOE LAKE  
IN NVZ003.  
 
LAKE WIND ADVISORY FROM 1 PM TO 11 PM PDT MONDAY NVZ004.  
 
CA...RED FLAG WARNING FROM 1 PM TO 11 PM PDT MONDAY CAZ278.  
 

 
 

 
 
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