766
FXUS65 KREV 222148
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
248 PM PDT THU OCT 22 2026
KEY MESSAGES
* PERSISTENT RAIN THIS AFTERNOON AND TONIGHT MAY CAUSE LOCALIZED
FLOODING IN NORTHEASTERN LASSEN COUNTY, SURPRISE VALLEY, NORTHERN
WASHOE COUNTY AND NORTHWESTERN PERSHING COUNTY, ESPECIALLY NEAR
BURN SCARS.
* SHOWERS AND ISOLATED THUNDERSTORMS MAY PRODUCE SMALL HAIL, GUSTY
OUTFLOWS AND BRIEF DOWNPOURS THIS AFTERNOON AND EVENING. SNOW
BURSTS ABOVE 8000 FEET MAY MAKE MONO COUNTY PASSES SLICK.
* NORTHEAST TO EAST WIND FRIDAY NIGHT INTO SATURDAY BRING ROUGH
CONDITIONS ON LAKE TAHOE AND LOW WIND CHILLS ON EXPOSED SIERRA
PEAKS. DRY WEATHER AND COLD NIGHTS PREVAIL THIS WEEKEND.
DISCUSSION
STORM PRECIPITATION SO FAR:
* 36-HOUR QUANTITATIVE PRECIPITATION ESTIMATES ENDING 11 AM PDT
SHOWS 0.25-0.75 INCH AROUND TAHOE/TRUCKEE, ALPINE COUNTY, CARSON
VALLEY AND LOVELOCK/FALLON, LOCALLY OVER 1 INCH EAST OF FALLON.
ESTIMATES ARE GENERALLY UNDER 0.25 INCH ACROSS EASTERN
PLUMAS/LASSEN COUNTIES, SURPRISE VALLEY AND NORTHERN WASHOE
COUNTY; ELSEWHERE, MOSTLY 0.05-0.50 INCH, INCLUDING SIERRA
VALLEY, RENO-SPARKS, AND LYON, MINERAL AND MONO COUNTIES.
SNOWFALL REPORTS REACHED 3-5 INCHES IN THE HIGH TERRAIN WEST OF
MAMMOTH LAKES.
THIS AFTERNOON THROUGH FRIDAY MORNING:
* SATELLITE SHOWS THE CLOSED LOW LIFTING NORTHEAST ACROSS
CALIFORNIA, WITH RAIN BANDS FROM TAHOE/RENO TO LOVELOCK AND THE
BLACK ROCK DESERT. COLD AIR ALOFT SUPPORTS 700-500-MB LAPSE
RATES NEAR 6.5-7.5C/KM. RESIDUAL BOUNDARY-LAYER MOISTURE AND
ANY HEATING BENEATH CLOUD BREAKS FAVOR WEAK INSTABILITY AND A
20% THUNDERSTORM CHANCE, WITH SMALL HAIL, DOWNPOURS AND GUSTY
OUTFLOWS.
* MONO COUNTY SNOW LEVELS LOWER FROM 8000 TO AROUND 7500 FEET THIS
EVENING. CONVECTIVE SNOW BURSTS SUPPORT KEEPING THE WINTER WEATHER
ADVISORY ABOVE 8000 FEET THROUGH 5 PM, WITH LIGHTER ACCUMULATIONS
THEREAFTER.
* UPPER-LEVEL DIVERGENCE AHEAD OF A 90-110 KT JET AND CONVERGENCE
ALONG THE COLD FRONT/OUTFLOW BOUNDARIES WILL MAKE RAIN MORE
WIDESPREAD AND PERSISTENT THIS AFTERNOON AND TONIGHT.
THUNDERSTORM CHANCES DIMINISH THIS EVENING, BUT CONTINUED ASCENT
THROUGH MOIST AIR SUSTAINS STEADIER, LOCALLY HEAVY RAIN.
* ADDITIONAL PRECIPITATION THROUGH FRIDAY MORNING: 0.5-1.5 INCHES
ACROSS NORTHEASTERN LASSEN COUNTY, SURPRISE VALLEY, NORTHERN
WASHOE COUNTY AND NORTHWESTERN PERSHING COUNTY, LOCALLY OVER 2
INCHES POSSIBLE. EXPECT 0.10-0.40 INCH ACROSS EASTERN
PLUMAS/SOUTHWESTERN LASSEN COUNTIES, TAHOE/TRUCKEE, ALPINE
COUNTY, LOVELOCK/FALLON AND MINERAL COUNTY; A FEW HUNDREDTHS TO
0.25 INCH AROUND RENO-CARSON CITY-MINDEN AND IN LYON/MONO
COUNTIES. LOCALLY HIGHER TOTALS REMAIN POSSIBLE BENEATH HEAVIER
SHOWERS.
* A FLOOD WATCH IS IN EFFECT THROUGH 5 AM FRIDAY FOR THE HEAVIER-
RAINFALL CORRIDOR FROM NORTHEASTERN LASSEN COUNTY AND SURPRISE
VALLEY INTO NORTHERN WASHOE AND NORTHWESTERN PERSHING COUNTIES,
INCLUDING THE BISCAR AND S1-VYA BURN SCARS. PROLONGED RUNOFF
THREATENS BURN SCARS, RURAL ROADS AND CULVERTS.
FRIDAY THROUGH SUNDAY:
* COOLER, DRIER AIR SETTLES IN FRIDAY AS POST-FRONTAL WINDS
DIMINISH. NORTH-NORTHWEST WINDS WILL GENERALLY BE 10-15 MPH,
WITH GUSTS TO 30 MPH MAINLY IN THE MORNING, LOCALLY 35 MPH NEAR
PYRAMID LAKE, FERNLEY, FALLON AND LOVELOCK. WINDS REMAIN LIGHT
AROUND TAHOE/TRUCKEE DURING THE DAY FRIDAY, WITH NORTHERLY WINDS
NEAR 10 MPH IN MONO COUNTY BY AFTERNOON. MORNING LOWS RANGE
FROM THE 20S IN SIERRA VALLEYS TO THE 30S ACROSS MUCH OF WESTERN
NEVADA. HIGHS REACH THE UPPER 40S/LOWER 50S IN SIERRA VALLEYS
AND MID 50S/LOWER 60S IN LOWER WESTERN NEVADA VALLEYS.
* SIERRA CREST WINDS TURN NORTHEAST-EAST FRIDAY NIGHT INTO
SATURDAY, COMBINING WITH COLD TEMPERATURES TO PRODUCE LOW WIND
CHILLS ON EXPOSED HIGH HIGHER PEAKS. THESE WINDS WILL ALSO REACH
LAKE LEVEL, PRODUCING ROUGH WATERS ON LAKE TAHOE. A LAKE WIND
ADVISORY HAS BEEN ISSUED FROM 8 PM FRIDAY TO 8 AM SATURDAY PDT.
CLEARING AND LIGHTER WINDS IN SHELTERED VALLEYS FAVOR FRIDAY
NIGHT LOWS IN THE TEENS/LOWER 20S IN SIERRA VALLEYS AND 20S TO
NEAR 30 FROM RENO-CARSON CITY THROUGH LOVELOCK/FALLON. RIDGING
KEEPS THE WEEKEND DRY.
MONDAY THROUGH NEXT FRIDAY MORNING:
* AN EARLY-WEEK SHORTWAVE MAY BRUSH THE OREGON BORDER, WHILE MOST
OF NORTHEASTERN CALIFORNIA, THE EASTERN SIERRA AND WESTERN
NEVADA REMAIN DRY THROUGH NEXT FRIDAY MORNING, OCTOBER 30. CPC
FAVORS ABOVE-NORMAL PRECIPITATION OCTOBER 29-NOVEMBER 4, BUT
CONFIDENCE REMAINS LOW IN PRECIPITATION ARRIVING BEFORE FRIDAY
MORNING.
-JOHNSTON
AVIATION
KRNO... MAINLY VFR; 30% CHANCE OF TSRA THROUGH 23Z WITH BRIEF MVFR
VISIBILITY AND GUSTS TO 35 KT. WEST GUSTS TO 20 KT 23-03Z, THEN
NORTH WINDS OVERNIGHT. SHOWERS RETURN 07-15Z WITH CEILINGS NEAR
3500 FT AGL.
REGIONAL... SHRA/ISOLATED TS THROUGH 00Z BRING MOUNTAIN OBSCURATION,
BRIEF MVFR/IFR AND OUTFLOW GUSTS TO 35 KT. WET GROUND/LIGHT WINDS
FAVOR KTRK IFR VISIBILITY AFTER 07Z. FOR 12-15Z, 18Z LAMP GIVES A
40-55% CHANCE OF VISIBILITY BELOW 1 SM IF SHOWERS PERSIST. KTVL
TRENDS MVFR AFTER 09Z; MVFR CEILINGS MAY LINGER AT BOTH THROUGH
LATE FRIDAY MORNING. WEEKEND CONCERNS: KTRK FOG/FREEZING FOG AND
SIERRA CREST TURBULENCE FRIDAY NIGHT/SATURDAY.
-JOHNSTON
REV WATCHES/WARNINGS/ADVISORIES
NV...FLOOD WATCH THROUGH LATE TONIGHT NVZ004-005.
LAKE WIND ADVISORY FROM 8 PM FRIDAY TO 8 AM PDT SATURDAY NVZ002.
CA...FLOOD WATCH THROUGH LATE TONIGHT CAZ070-071.
LAKE WIND ADVISORY FROM 8 PM FRIDAY TO 8 AM PDT SATURDAY CAZ072.
WINTER WEATHER ADVISORY UNTIL 5 PM PDT THIS AFTERNOON CAZ073.
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