259
FXUS65 KREV 280840
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
140 AM PDT TUE APR 28 2026
KEY MESSAGES
* LINGERING SHOWER AND ISOLATED THUNDERSTORM CHANCES WILL CONTINUE
EACH AFTERNOON THROUGH WEDNESDAY MAINLY NEAR THE EASTERN SIERRA.
* EXPECT DRIER WEATHER WITH TEMPERATURES WARMING TO AROUND 10
DEGREES ABOVE AVERAGE BY FRIDAY AND SATURDAY.
* SHOWER AND THUNDER CHANCES MAY RETURN FOR THE UPCOMING WEEKEND,
MAINLY ON SUNDAY AND CONTINUE THROUGH EARLY NEXT WEEK.
DISCUSSION
WHILE THE LOW PRESSURE TROUGH THAT TRIGGERED MONDAY'S SHOWER
ACTIVITY HAS EXITED TO THE EAST, A SECONDARY WAVE DROPPING
SOUTHWARD ALONG THE CA COAST IS TRACKING A BIT CLOSER TO THE
SIERRA. UPPER LEVEL FORCING AND DIVERGENCE ASSOCIATED WITH THIS
WAVE IS PROJECTED TO LINE UP ALONG THE SIERRA CREST AND ADJACENT
PORTIONS OF NORTHEAST CA, COMBINED WITH TERRAIN-DRIVEN
CONVERGENCE AND A BIT MORE DAYTIME HEATING, RESULTING IN ANOTHER
ROUND OF SHOWERS WITH ISOLATED THUNDER. MOST UNSTABLE CAPE VALUES
ON HIGH RESOLUTION GUIDANCE INCREASE TO BETWEEN 200-600 J/KG IN
CLOSE PROXIMITY TO THE CREST THIS AFTERNOON, INCREASING THE
POTENTIAL FOR LIGHTNING (15-25% CHANCE) COMPARED TO YESTERDAY.
WHILE MOST ACTIVITY WILL REMAIN IN THE HIGHER TERRAIN OR PUSH WEST
OF THE CREST WHERE INSTABILITY IS GREATER, A FEW SHOWERS COULD
DEVELOP CLOSER TO US-395 IN FAR WESTERN NV AND SOUTHWARD NEAR THE
CA-NV BORDER IN LYON/MINERAL COUNTIES, AND NEAR FAVORED
CONVERGENCE ZONES IN NORTHERN PARTS OF LASSEN/WASHOE COUNTIES.
THE MOST FAVORED HOURS FOR SHOWERS/THUNDER ARE BETWEEN 2-6 PM,
WITH MOST ACTIVITY WINDING DOWN BY 9 PM. ALTHOUGH SNOW LEVELS WILL
CLIMB TO NEAR 8000 FT, A WELL-PLACED SLOW MOVING CELL COULD STILL
PRODUCE SLICK SIERRA TRAVEL WITH MINOR ACCUMULATION OF PELLETS OR
SMALL HAIL.
FOR WEDNESDAY, A SIMILAR SETUP IS AGAIN PROJECTED FOR AFTERNOON
SHOWERS NEAR THE SIERRA CREST, ALTHOUGH DECREASED FORCING AND
INSTABILITY WILL LIMIT CELL DEVELOPMENT, WITH THUNDER CHANCES
DROPPING BELOW 10%. EVEN ON THURSDAY SOME CUMULUS BUILDUPS ARE
AGAIN PROJECTED NEAR THE SIERRA CREST, BUT SHOWER CHANCES DROP
BELOW 10%.
ALTHOUGH A PREVAILING NORTH-NORTHEAST FLOW IS EXPECTED FOR MUCH OF
THIS WEEK, TEMPERATURES WILL WARM UP EACH DAY, CLIMBING TO NEAR
SEASONAL AVERAGES TODAY (MID-UPPER 60S LOWER ELEVATIONS AND MID
50S FOR SIERRA COMMUNITIES) AND PEAK NEAR 80 AND 70 DEGREES IN
THESE RESPECTIVE AREAS BY FRIDAY-SATURDAY, ABOUT 10-15 DEGREES
ABOVE EARLY MAY AVERAGES. A MODEST BACK DOOR FRONT PASSAGE ACROSS
CENTRAL NV IS STILL PROJECTED TO BRING INCREASED NORTH WIND GUSTS
25-35 MPH THURSDAY AFTERNOON ALONG THE US-95 AND US-6 CORRIDORS OF
MINERAL/SOUTHEAST MONO COUNTIES.
FOR THE UPCOMING WEEKEND THROUGH EARLY NEXT WEEK, A CLOSED LOW
APPROACHING THE WEST COAST BRINGS INCREASED SOUTH TO SOUTHWEST
WINDS BY SATURDAY. SHOWERS MAY BEGIN LATE SATURDAY IN FAR
NORTHEAST CALIFORNIA AND NEAR THE SIERRA CREST. THEN SHOWER AND
ISOLATED THUNDER CHANCES INCREASE AND EXPAND TO THE EASTERN
SIERRA-WESTERN NV SUNDAY, POTENTIALLY EXTENDING THROUGH NEXT
MONDAY-TUESDAY, ALONG WITH DAYTIME HIGHS DIPPING TO NEAR EARLY
MAY AVERAGES. CONFIDENCE REMAINS LOW REGARDING THE SYSTEM’S TIMING
AND TRACK, WHICH IS TYPICAL FOR SLOW-MOVING SPRING CUT-OFF LOWS.
MJD
AVIATION
FOR THIS AFTERNOON, ISOLATED SHOWERS WITH ABOUT 20% CHANCE FOR
THUNDER WILL BE CAPABLE OF PRODUCING SHORT PERIODS OF MVFR
CONDITIONS FOR THE SIERRA/TAHOE AREA TERMINALS, MAINLY BETWEEN
21-02Z. FOR WESTERN NV TERMINALS, SHOWER CHANCES DECREASE TO
AROUND 15% WITH VFR CONDITIONS PREVAILING. FOR WEDNESDAY, SHOWER
CHANCES DECREASE TO 10-15% AT KTVL/KMMH AND BELOW 10% ELSEWHERE
WITH VFR CONDITIONS PREVAILING AT ALL TERMINALS.
OVERALL WINDS WILL BE LIGHT TODAY AND WEDNESDAY WITH GUSTS BELOW
20 KT, BUT BRIEF GUSTS TO 30 KT COULD OCCUR NEAR SHOWER/T-STORM
ACTIVITY.
DECREASING CLOUD COVER EACH NIGHT WILL SET UP FAVORABLE CHANCES
(50-70%) FOR FZFG AT KTRK WITH LIFR CONDITIONS THIS MORNING AND
AGAIN EARLY WEDNESDAY, MAINLY BETWEEN 08-15Z. AN EAST FLOW OVER
THE SIERRA MAY MAKE THE FOG MORE PATCHY OR INTERMITTENT EACH
MORNING, BUT FOG POTENTIAL INCREASES LATE TONIGHT IF PRECIP OCCURS
AT KTRK TODAY. MJD
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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