872
FXUS65 KREV 280944
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
244 AM PDT FRI AUG 28 2026
KEY MESSAGES
* WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED
WITHIN THE REGION TODAY, ALONG WITH MUCH COOLER TEMPERATURES.
* DRIER WEATHER WITH MILD TEMPERATURES ARE FORECAST THROUGH THE
WEEKEND.
* BREEZIER WINDS ARE ON TAP FOR EARLY NEXT WEEK WITH BELOW-
AVERAGE TEMPERATURES THROUGH THE WEEK.
DISCUSSION
ACCORDING TO THE LATEST RAP UPPER AIR ANALYSIS, A SOUTHWESTERLY
FLOW CONTINUES OVER THE CWA BEING BETWEEN A RIDGE OVER THE SW
CONUS AND A PACIFIC TROUGH. THERE IS ALSO AN UPPER LOW FEATURE
OVER THE SW CANADIAN COAST THAT MODELS PROJECT MOVING CLOSER TO
THE CANADA-U.S. BORDER THROUGH THE DAY. WITH THIS SETUP ALOFT, A
COOLER SYSTEM MOVES THROUGH THE REGION TODAY, GIVING THE CWA
WIDESPREAD SHOWER CHANCES OF AROUND 30-80%. WHEN LOOKING AT THE
06Z RUN OF THE HRRR, CHANCES FOR PRECIPITATION BEGIN TO INCREASE THE
WINDOW FOR THE MAIN BULK OF THE PRECIPITATION OPENS AROUND 9-10
AM AND ENDS AROUND 7 PM, THOUGH THERE IS A 10-40% CHANCE FOR LIGHT
SHOWERS ALONG I-80 PRIOR THIS WINDOW OPENING. PRECIPITATION
CHANCES FROM THIS SYSTEM EXPECT TO TAPER OFF COMPLETELY EARLY
SATURDAY MORNING. THE LATEST QPF VALUES LOOK TO RANGE FROM A TRACE
TO AROUND 0.3-0.4 INCHES IN THE SIERRA CREST. WITH INCREASED
CLOUD COVER EXPECTED TODAY, THE FORECAST ALSO SHOWS DAYTIME HIGHS
THAT WILL BE AROUND 5-15 DEGREES BELOW SEASONAL NORMALS TODAY. NE
CA AND W NV VALLEYS WILL SEE HIGH TEMPERATURES IN THE MIDDLE 70S
TO LOWER 80S RANGE WHILE THE SIERRA COMMUNITIES WILL HAVE HIGHS IN
THE MIDDLE 60S TO AROUND THE 70 DEGREE MARK.
AS FOR THUNDERSTORM CHANCES, THE LATEST NBM PROBABILITIES SHOW
AROUND A 10-40% CHANCE TODAY WITH PORTIONS OF THE REGION ALONG AND
SOUTH OF US-50 HAVING THE HIGHER END CHANCES. WHEN LOOKING AT
CONVECTIVE PARAMETERS FOR LATER TODAY, THERE IS AROUND 100-500 J/KG
IN THE AFOREMENTIONED HIGHER CHANCE AREAS, WITH POCKETS OF CAPE
VALUES OVER 1000 J/KG IN THE NV BASIN AND RANGE TODAY. FORECAST
SOUNDINGS DO LOOK TO BE PRETTY MOIST TODAY AS MORE TROPICAL MOISTURE
IS PUMPED INTO THE AREA WITH THE UPPER AIR SETUP. STRONGER
THUNDERSTORMS WILL BE CAPABLE OF FREQUENT LIGHTNING AND OUTFLOW WIND
GUSTS UP TO 50 MPH. STORMS CAN PRODUCE PERIODS OF HEAVY RAINFALL
TODAY TOO WITH PW VALUES OF 0.8-1.2 INCHES, THOUGH THE HIGHER PW
VALUES COULD JUST TRANSLATE INTO THE INCREASED CLOUD COVER TODAY.
EXPECTED STORM MOTIONS LOOK TO BE QUICK TODAY, BUT FLASH FLOODING
WILL STILL BE POSSIBLE WHERE STORMS TRAIN, ESPECIALLY IF THEY DO SO
OVER VULNERABLE BURN SCARS AND/OR STEEP TERRAIN. THE WPC CURRENTLY
HAS A MARGINAL RISK (5%) FOR EXCESSIVE RAINFALL GENERALLY ALONG AND
SOUTH OF A LINE FROM WINNEMUCCA TO PORTOLA TODAY. PLEASE BE WEATHER
AWARE TODAY AND HAVE A WAY TO RECEIVE THE LATEST WEATHER UPDATES!
GOING THROUGH THE WEEKEND, FORECAST GUIDANCE SHOWS THE UPPER LOW
MOVING EASTWARD ALONG THE INTERNATIONAL BORDER WITH THE PACIFIC
TROUGH PROGRESSING OVER THE CWA. SKIES OVER THE WEEKEND WILL CLEAR
UP QUITE A BIT FOLLOWING THE DEPARTURE OF TODAY'S SYSTEM, WHICH WILL
ALLOW FOR AREA TEMPERATURES TO REBOUND SLIGHTLY. NE CA AND W NV
VALLEYS WILL SEE HIGH TEMPERATURES IN THE LOWER TO MIDDLE 80S
WITH SIERRA HIGH TEMPERATURES IN THE UPPER 60S TO MIDDLE 70S.
WHILE MOSTLY DRY CONDITIONS PREVAIL THROUGH THE WEEKEND, THERE IS
A 10-20% CHANCE FOR A DIURNAL SHOWER OR TWO DURING THE AFTERNOON
HOURS IN THE NV BASIN & RANGE AND MONO COUNTY.
FOR NEXT WEEK, ENSEMBLE GUIDANCE BEGINS TO SHOW ANOTHER PACIFIC
TROUGH ENTERING THE PICTURE. THIS PATTERN LOOKS TO POSSIBLY CAUSE
WINDS ON MONDAY AND TUESDAY AFTERNOONS TO INCREASE WITH GUSTS UP TO
AROUND 25-35 MPH AGAIN, THOUGH CONFIDENCE IS LOW AT THIS TIME. WIND
GUSTS OF THIS MAGNITUDE COULD CAUSE FIRE WEATHER CONCERNS TO RETURN
TO THE REGION WITH CONDITIONS MOSTLY DRYING OUT AFTER TODAY. WILL
CONTINUE TO MONITOR THIS AS WELL AS SOME POSSIBLE PRECIPITATION
CHANCES FOR THE MIDDLE OF NEXT WEEK. THE FORECAST IS ALSO SHOWING
HIGH TEMPERATURES BEGINNING THE MONTH OF SEPTEMBER THAT WILL BE
MILD, YET STILL 5-10 DEGREES COOLER THAN NORMAL HIGHS FOR THIS
TIME. -078
AVIATION
A COOLER SYSTEM MOVES THROUGH THE REGION TODAY, BRINGING WIDESPREAD
SHOWER CHANCES (30-80%) ALONG WITH ISOLATED THUNDERSTORM CHANCES (10-
40%). WHILE ISOLATED SHOWERS ARE POSSIBLE EARLY THIS MORNING, THE
06Z HRRR MODEL SHOWS THE WINDOW FOR THE BULK OF THE SHOWERS AND
STORMS TO BE 28/16Z-29/03Z. THERE MAY BE SOME LINGERING SHOWERS IN
THE NV BASIN AND RANGE THROUGH 29/06Z WITH THE SYSTEM EXITING
OVERNIGHT. THE HIGHER END CHANCES FOR THUNDERSTORMS TODAY
GENERALLY LOOK TO BE ALONG AND SOUTH OF US-50. THUNDERSTORMS NEAR
TERMINALS TODAY WILL HAVE THE CAPABILITY OF PRODUCING ERRATIC
OUTFLOW WINDS GUSTING UP TO AROUND 30+ KTS. WHILE NOT CURRENTLY
ANTICIPATING SUB-VFR CONDITIONS AT AREA TAF SITES, WILL BE
MONITORING FOR STRONGER THUNDERSTORM TODAY AS PERIODS OF HEAVIER
RAINFALL ARE POSSIBLE WHICH WILL REDUCE VISIBILITY. ALSO, SIERRA
RIDGE WINDS WILL GUST UP TO AROUND 40 KTS THIS AFTERNOON.
DRIER CONDITIONS ARE IN THE FORECAST THROUGH THE WEEKEND, WITH
DECREASED CHANCES (10-20%) FOR AN ISOLATED SHOWER OR TWO DURING THE
AFTERNOON HOURS IN THE NV BASIN AND RANGE AND S. MONO COUNTY. SATURDAY
AFTERNOON WINDS GUSTING UP TO AROUND 20-30 KTS ARE IN THE FORECAST,
FOLLOWED BY TYPICAL AFTERNOON ZEPHYR BREEZES ON SUNDAY. -078
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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