Area Forecast Discussion
Issued by NWS Reno, NV

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FXUS65 KREV 260232 CCA
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
259 PM PST SUN JAN 25 2015

.SYNOPSIS...
HIGH PRESSURE OVER THE WEST WILL BRING MILD AFTERNOON TEMPERATURES
THROUGH MONDAY. PERIODS OF LIGHT VALLEY RAIN AND MOUNTAIN SNOW
SHOWERS ARE EXPECTED TUESDAY. COOLER TEMPERATURES RETURN TUESDAY
THROUGH THE END OF THE WEEK, WITH A FEW SHOWERS AGAIN POSSIBLE
SOUTH OF HIGHWAY 50 LATE IN THE WEEK.

&&

.SHORT TERM...
UPPER RIDGE AXIS OVERHEAD TODAY WILL SHIFT TO THE NORTHERN ROCKIES
AND FOUR CORNERS ON MONDAY. MEANWHILE, AN UPPER LOW WEST OF PUNTA
EUGENIA (BAJA CALIFORNIA) WILL BEGIN MOVING NORTH AS IT INTERACTS
WITH A TROUGH ABOUT 1000 MILES WEST OF LOS ANGELES. FOR WESTERN
NEVADA AND NORTHEAST CALIFORNIA MONDAY THIS WILL JUST BRING AN
INCREASE IN HIGH CLOUDS LATE IN THE AFTERNOON AND INTO THE EVENING.
OTHERWISE, IT WILL BE ANOTHER VERY MILD DAY WITH HIGHS IN THE MID
50S TO LOWER 60S FOR MOST LOCATIONS BELOW ABOUT 7000 FEET.

LATE MONDAY NIGHT AND TUESDAY, LOW PRESSURE WILL PROGRESS NORTH
INTO CALIFORNIA AND NEVADA. TO ITS DETRIMENT, THE LOW WILL BE
SQUEEZING BETWEEN ZONAL FLOW OVER THE PACIFIC NORTHWEST/SOUTHERN
CANADA AND THE UPPER RIDGE OVER THE INTERMOUNTAIN WEST. THIS WILL
SHEAR OUT AND WEAKEN THE LOW AS IT MOVES OVER THE SIERRA AND WESTERN
NEVADA ON TUESDAY. HOWEVER, DESPITE WEAKENED FORCING THERE WILL BE
PLENTY OF MOISTURE AND SOME DEFORMATION IN THE MID LEVELS AS THE
TROUGH MOVES OVERHEAD. WITH THIS IN MIND, PERIODS OF LIGHT RAIN AND
HIGHER ELEVATION SNOW ARE ON TAP FOR TUESDAY ESPECIALLY SOUTH OF
SUSANVILLE AND GERLACH.

IMPACTS FROM TUESDAY`S LIGHT SNOW IN THE HIGHER ELEVATIONS SHOULD
BE LOW END WITH ONLY UP TO A FEW INCHES EXPECTED ABOVE 7000 FEET.
THIS COULD CAUSE SLICK CONDITIONS FOR PASSES TUESDAY MORNING WITH
SOME DELAYS IF CHAIN CONTROLS ARE ENACTED. HOWEVER, THIS SYSTEM IS
NOT PARTICULARLY COLD SO AFTERNOON GROUND/ROAD HEATING SHOULD ALLOW
FOR MELTING OF ANY LIGHT SNOWFALL, ESPECIALLY BELOW 8000-8500 FEET.

WEDNESDAY, A VERY WEAK IMPULSE/TROUGH OFF THE CALIFORNIA COAST
WILL NEAR THE COAST. PRECIPITATION IS NOT EXPECTED FROM THIS WEAK
DISTURBANCE, ALTHOUGH PLENTY OF CLOUD COVER IS LIKELY WITH LEFTOVER
MOISTURE PERSISTING FROM TUESDAY`S LOW. TEMPERATURES WEDNESDAY WILL
BE GENERALLY WITHIN A FEW DEGREES OF AVERAGE. SNYDER

.LONG TERM...THURSDAY THROUGH SUNDAY...
FEW CHANGES NEEDED TO ONGOING FORECAST AS MEDIUM RANGE MODELS REMAIN
IN DECENT RUN TO RUN AGREEMENT. THE PERIOD STARTS OUT WITH A TROUGH
AXIS CENTERED AROUND 125W/25N, AND A POSITIVELY TILTED RIDGE SLIDING
OVER THE TOP OF THE TROUGH INTO THE PACIFIC NORTHWEST COAST. THIS
TROUGH WILL BEGIN TO SHIFT INLAND THURSDAY INTO FRIDAY, DEEPENING
INTO A CLOSED LOW OVER THE WEEKEND. A DEFORMATION BAND WRAPS AROUND
THE NORTH AND EAST SIDE OF THE LOW BRINGING A SLIGHT CHANCE FOR
SHOWERS TO AREAS SOUTH OF HIGHWAY 50 LATE THURSDAY INTO FRIDAY.

ONCE AGAIN THE RIDGE WINS OUT AND EXPANDS WESTWARD SATURDAY INTO
SUNDAY, WHICH PUSHES THE CLOSED LOW SOUTH OVER BAJA/NORTHERN MEXICO,
TAKING ALL CHANCES OF PRECIPITATION WITH IT. THERE ARE MINOR
DIFFERENCES AMONG OPERATIONAL MODELS AND ENSEMBLES IN HOW FAR SOUTH
THE LOW WILL DROP, BUT EITHER WAY THE SIERRA AND NORTHWEST NEVADA
LOOK TO REMAIN DRY SATURDAY AND SUNDAY WITH SKIES CLEARING FROM THE
NORTH TO THE SOUTH.

IT STILL APPEARS GUSTY EAST WINDS WILL DEVELOP FRIDAY NIGHT INTO
SATURDAY BETWEEN THE BUILDING HIGH AND THE EXITING LOW WITH GUSTS
POSSIBLY REACHING 60 TO 80 MPH ACROSS SIERRA RIDGES. TEMPERATURES
WILL BE LIMITED BY CLOUD COVER THURSDAY AND FRIDAY, BUT STILL ABOUT
5 DEGREES ABOVE NORMAL. HIGHS WILL CONTINUE TO WARM INTO THE WEEKEND,
REACHING ABOUT 10 DEGREES ABOVE AVERAGE WITH LOWS NEAR NORMAL AS
CLEARING SKIES HELPS WITH RADIATIONAL COOLING. DJ

&&

.AVIATION...
VFR CONDITIONS WILL CONTINUE INTO MONDAY WITH MID AND HIGH LEVEL
CLOUDS BEGINNING TO INCREASE FROM THE SOUTH TO THE NORTH MONDAY
AHEAD OF AN INCOMING AREA OF LOW PRESSURE. THIS SYSTEM WILL BRING
CHANCES FOR SHOWERS ACROSS THE SIERRA AND WESTERN NEVADA MONDAY
NIGHT INTO TUESDAY. WITH SNOW LEVELS AROUND 6000-6500 FEET, A
RAIN/SNOW MIX IS POSSIBLE FOR KTRK, KTVL, AND KMMH, BUT RUNWAY
ACCUMULATION IS UNLIKELY DUE TO THE WARMER TEMPERATURES. PERIODS
OF IFR CIGS/VIS AND MOUNTAIN OBSCURATION ARE LIKELY IN THE SIERRA.
FOR WESTERN NEVADA, LIGHT RAIN IS EXPECTED WITH PERIODS OF MVFR
CONDITIONS.

THE EASTERLY WINDS WILL WEAKEN THROUGH THE DAY, BECOMING MORE
SOUTHEASTERLY OVERNIGHT AND THEN SOUTHWEST MONDAY. THERE IS ONLY A
10 PERCENT CHANCE OF FOG DEVELOPING AROUND KTRK TONIGHT DUE TO THE
DRY LOW LEVEL AIR MASS AND SOUTHEAST FLOW. DJ

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&

$$

FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)





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