759
FXUS65 KREV 271018
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
218 AM PST TUE JAN 27 2026
KEY MESSAGES
* A WEAK WEATHER SYSTEM MAY BRING CHANCES FOR LIGHT SNOW SHOWERS,
MAINLY ALONG THE SIERRA CREST TONIGHT INTO WEDNESDAY MORNING.
* DRY CONDITIONS CONTINUE WEDNESDAY ONWARD WITH HIGH PRESSURE
RETURNING TO THE AREA.
* A SLOW, GRADUAL WARMING TREND INTO THIS WEEKEND WILL BRING ABOVE
AVERAGE TEMPERATURES BY SATURDAY.
DISCUSSION
THE LATEST RAP UPPER AIR ANALYSIS SHOWS AN UPPER RIDGE OVER THE CWA
WITH A TRAILING TROUGH OVER THE PACIFIC THIS MORNING. ENSEMBLE
GUIDANCE IS PROJECTING THE AFOREMENTIONED TROUGH TO EVOLVE MORE INTO
A SHORTWAVE EMBEDDED WITHIN THE RIDGE AND PASS THROUGH THE NW
CONUS LATE TONIGHT INTO WEDNESDAY MORNING. AFTER THE SHORTWAVE
PASSES, THE RIDGE LOOKS TO BUILD ITSELF BACK UP AGAIN THROUGH THE
REST OF THE WEEK BEFORE ANOTHER WEAK TROUGH PUSHES THROUGH THE
REGION AT THE START OF NEXT WEEK.
WITH THIS PATTERN ALOFT, THE REGION WILL SEE DRY CONDITIONS AND
LIGHT WINDS TO BEGIN THE DAY. HOWEVER, WINDS START TO PICK UP
SLIGHTLY IN THE AFTERNOON AHEAD OF AN APPROACHING WINTRY SYSTEM.
BY TONIGHT WHEN THE SYSTEM ARRIVES, RIDGE WINDS GUSTING UP TO
AROUND 70 MPH ARE IN THE FORECAST GOING THROUGH WEDNESDAY MORNING.
THE WINDOW FOR LIGHT SNOW SHOWERS LOOKS TO OPEN IN NE CA AND THE
NORTHERN SIERRA AROUND 6-7 PM TONIGHT WITH THE CHANCES SPREADING
INTO THE TAHOE BASIN AND W NV A FEW HOURS LATER. ACCORDING TO THE
06Z RRFS MODEL, MOST OF THE PRECIPITATION CHANCES IN THE REGION
TAPER OFF BY 6 AM THOUGH THERE COULD BE SOME LINGERING SHOWERS AT
THE SIERRA CREST THROUGH THE LATE MORNING. SNOW LEVELS ARE
FORECAST TO GENERALLY BE BETWEEN 4500-5000 FEET AND RISE SLIGHTLY
IN SOME AREAS TO AROUND 5500 FEET ON WEDNESDAY MORNING, SO P-TYPE
FOR THE SHOWERS LOOKS TO BE MOSTLY LIGHT SNOW THOUGH THERE COULD
BE LIGHT RAIN MIXED IN FOR SOME AREAS. LATEST NBM SNOW
PROBABILITIES HAVE COME UP SLIGHTLY WITH DONNER PASS SEEING AROUND
A 30-40% CHANCE OF 1 INCH OF SNOW OR MORE BY THE END OF THE
SYSTEM. IN THE TAHOE BASIN, THERE LOOKS TO BE AROUND A 30% CHANCE
FOR 0.1 INCHES OF SNOW OR MORE AT LAKE LEVEL. WHILE SOME MODELS
ARE SHOWING SOME SPILLOVER POTENTIAL INTO THE SIERRA FRONT (10-20%
OF A STRAY SHOWER OR TWO JUST AFTER MIDNIGHT TONIGHT), NOT MUCH
ACCUMULATION ARE EXPECTED IN THOSE AREAS IF ANY AT ALL. CURRENTLY,
THE HIGHEST ELEVATIONS IN WESTERN LASSEN COUNTY SEE AMOUNTS UP TO
AROUND 3 INCHES WITH THIS SYSTEM (WITH A 20% PROBABILITY). IF YOU
ARE TRAVELING OVER THE SIERRA TONIGHT INTO TOMORROW MORNING,
PLEASE USE CAUTION AS ROADS AND SURFACES MAY BE SLICK WITH THIS
SNOWFALL DUE TO THE PROJECTED SNOWFALL AND COLD OVERNIGHT
TEMPERATURES.
GOING BEYOND THIS SYSTEM, A DRY PERIOD LOOKS TO RESUME LATER
WEDNESDAY THAT CONTINUES THROUGH THE REST OF THE WEEK. CHANCES FOR
PRECIPITATION DO NOT LOOK TO APPEAR AGAIN UNTIL THE BEGINNING OF
FEBRUARY ON SUNDAY AND MONDAY WITH A 15-25% CHANCE FOR SOME LIGHT
PRECIPITATION THOUGH CONFIDENCE IS LOW THIS FAR OUT. LIGHT WINDS ARE
TO BE EXPECTED WITH HIGH PRESSURE BUILDING IN THE REGION ALLOWING
FOR VALLEY INVERSIONS TO MAKE A COMEBACK THROUGH THE REST OF THE
WEEK. THOSE SENSITIVE TO REDUCED AIR QUALITY MAY WANT TO MONITOR
AIRNOW.GOV SO THE LATEST AIR QUALITY DATA. ALSO, AREA TEMPERATURES
CONTINUE A SLOW WARMING TREND THAT THEY WILL BE ~5-10 DEGREES
ABOVE NORMALS BY THE WEEKEND. PORTIONS OF W NV SEE POTENTIAL TO BE
AT OR NEAR THE 60 DEGREE MARK BEGINNING ON FRIDAY THAT CONTINUE
THROUGH THE WEEKEND. THE RENO-SPARKS METRO AREA SEES A 40-60%
CHANCE OF 60 DEGREES OR HIGHER ON SATURDAY AND SUNDAY. FOR YOUR
LOCAL TEMPERATURE FORECAST, PLEASE VISIT WEATHER.GOV/REV. -078
AVIATION
VFR CONDITIONS ARE EXPECTED FOR ALL AREA TAF SITES THROUGH MOST OF
THE DAY TODAY. WHILE WINDS START LIGHT AND VARIABLE, THE WINDS PICK
UP SLIGHTLY AROUND 27/20Z FOR SIERRA TERMINALS WITH W NV TERMINALS
FOLLOWING SUIT AROUND 28/00Z AS A WINTRY SYSTEM APPROACHES THE
REGION. NE CA AND THE SIERRA WILL ALSO EXPERIENCE INCREASED RIDGE
WIND GUSTING UP TO AROUND 60 KTS LATER TONIGHT INTO WEDNESDAY WITH
THIS SYSTEM. LLWS AND TURBULENCE ARE EXPECTED WITHIN THE REGION
TODAY THROUGH WEDNESDAY MORNING AS WELL.
LIGHT SNOW SHOWER CHANCES WITH THIS SYSTEM BEGIN IN NE CA AND THE
NORTHERN SIERRA AROUND 28/02-03Z THAT SPREAD INTO THE TAHOE BASIN
AND NW NV BY 28/06Z. PRECIPITATION CHANCES MOSTLY END BY 28/12Z
THOUGH THERE MAY BE SOME LINGERING SHOWERS AT THE SIERRA CREST FOR A
FEW HOURS. NOT ANTICIPATING SUB-VFR CONDITIONS AT THIS TIME WITH THE
PRECIPITATION, BUT VISIBILITY COULD POSSIBLY DROP A BIT SHOULD A
SHOWER LINGER OVER AN AREA LONG ENOUGH WITH INCREASED INTENSITY (LOW
CONFIDENCE IN THIS HAPPENING). -078
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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