Area Forecast Discussion
Issued by NWS Reno, NV

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000
FXUS65 KREV 170944
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
244 AM PDT THU APR 17 2014

.SYNOPSIS...

A WEAK SYSTEM DROPS INTO NORTHERN CALIFORNIA AND NEVADA TODAY
BRINGING CHANCES FOR SHOWERS TODAY THROUGH SATURDAY, AND EVEN A
FEW THUNDERSTORMS FRIDAY AND SATURDAY. A STRONGER SYSTEM IS
POSSIBLE THE EARLY PART OF NEXT WEEK BRINGING BELOW NORMAL
TEMPERATURES ALONG WITH RAIN AND SNOW SHOWERS TO THE REGION.

&&

.SHORT TERM...

VERY FEW CHANGES WERE MADE TO THE ONGOING FORECAST AS MODELS
REMAIN CONSISTENT IN THEIR SOLUTIONS DURING THE SHORT TERM PERIOD.
A FAST MOVING DISTURBANCE WILL SHIFT THROUGH NORTHERN
CALIFORNIA/NEVADA TODAY WITH A COOL FRONT FOLLOWING OVERNIGHT.
THIS SYSTEM WILL BRING CHANCES FOR SHOWERS NORTH OF A SUSANVILLE-
GERLACH LINE LATE THIS AFTERNOON/EARLY THIS EVENING, WITH
CONVECTIVELY DRIVEN SHOWERS POSSIBLE ACROSS SOUTHERN MONO/MINERAL
COUNTIES. SURFACE GRADIENT INCREASES THIS AFTERNOON AHEAD OF THE
FRONT LEADING TO ENHANCED WESTERLY AFTERNOON WINDS WITH GUSTS
UP TO 35 MPH. THIS MAY LEAD TO CHOPPY CONDITIONS ON AREA LAKES,
BUT WINDS ARE EXPECTED TO STAY JUST BELOW LAKE WIND ADVISORY
CRITERIA. THE INCREASED WINDS WILL HELP WITH MIXING LEADING TO
DAYTIME HIGHS TODAY ABOUT 10 TO 15 DEGREES ABOVE NORMAL.

THERE IS DECENT FRONTOGENESIS ALONG THE COOL FRONT OVERNIGHT,
HOWEVER IT DOES NOT APPEAR TO BE ENOUGH TO GENERATE NOCTURNAL
THUNDERSTORMS ALONG THE BOUNDARY. HAVE CONTINUED WITH ISOLATED TO
SCATTERED SHOWERS, THOUGH A STRIKE OR TWO OF LIGHTNING IS NOT OUT
OF THE QUESTION. BETTER CHANCES FOR THUNDERSTORM DEVELOPMENT EXIST
ON FRIDAY AS A WEAK UPPER LEVEL LOW THAT HAD BEEN SITTING OFF THE
SOUTHERN CALIFORNIA COAST BEGINS TO MOVE INLAND. UPPER LEVEL
DIFFLUENCE ALONG THE NORTH SIDE OF THE LOW SHOULD GENERATE THE
DEEPER CONVECTION NECESSARY FOR THUNDERSTORM DEVELOPMENT MAINLY
FROM INTERSTATE 80 SOUTH FRIDAY AFTERNOON. ONE DRAWBACK COULD BE
CLOUD COVER STIFLING DAYTIME HEATING AND LIMITING LOW LEVEL
INSTABILITY, BUT APPEARS THERE WILL BE ENOUGH FORCING TO OVERCOME
THIS.

TROUGH EXITS THE REGION BY SATURDAY WITH HIGH TEMPERATURES ONCE
AGAIN WARMING AFTER THE SLIGHT COOL DOWN ON FRIDAY. DRIER AIR
BEGINS TO WORK INTO THE REGION, BUT SOME LINGERING MOISTURE IN
MONO COUNTY ALONG WITH LOW LEVEL INSTABILITY GENERATED BY DAYTIME
HEATING MAY BE ENOUGH FOR ISOLATED THUNDERSTORMS TO DEVELOP,
HOWEVER CONFIDENCE REMAINS LOW AT THIS TIME. DJ

.LONG TERM...SUNDAY THROUGH WEDNESDAY...

SLIGHT INCREASE IN POP TUESDAY AND WEDNESDAY, OTHERWISE NO
SIGNIFICANT CHANGES TO THE LONG TERM FORECAST.

SUNDAY WILL BRING LIGHT WINDS AND WELL ABOVE AVERAGE TEMPERATURES
WITH A FLAT UPPER RIDGE OVERHEAD. ON MONDAY, MID AND HIGH LEVEL
CLOUDS WILL BE ON THE INCREASE AS THE RIDGE PUSHES OFF INTO THE
NORTHERN ROCKIES WITH A COLD UPPER TROUGH APPROACHING FROM THE
NORTHEAST PACIFIC. ALSO, WINDS WILL BE ON THE INCREASE MONDAY
AFTERNOON AND EVENING AS A GOOD THERMAL GRADIENT DEVELOPS BETWEEN
COLDER AIR FILTERING INTO NORTHERN CALIFORNIA AND MUCH WARMER AIR
OVER CENTRAL NEVADA. HOWEVER, WHILE THE THERMAL GRADIENT ALONE WILL
MAKE FOR BREEZY CONDITIONS, SOUTHERLY FLOW ALOFT IN THE MODELS MAY
SERVE TO LIMIT THE STRENGTH OF DOWNSLOPING IN THE LEE OF THE
SIERRA.

MONDAY NIGHT AND TUESDAY, CHANCES FOR RAIN AND SNOW ARE INCREASING
WITH GOOD AGREEMENT FOR BRINGING IN THE PACIFIC TROUGH ALONG WITH A
FAIRLY STRONG COLD FRONT. IF MODELS HOLD TO THE CURRENT TIMING AND
STRENGTH OF THE COLD FRONT, POP MAY NEED TO BE RAISED SIGNIFICANTLY
MORE IN THE NEXT DAY ESPECIALLY IN THE SIERRA AND NORTH OF HIGHWAY
50. AS FAR AS SNOWFALL POTENTIAL/IMPACTS, IT CURRENTLY LOOKS TO
REMAIN WELL ABOVE LOWER VALLEYS EARLY TUESDAY BUT SOME IMPACT IS
CERTAINLY ON THE TABLE FOR THE SIERRA ESPECIALLY IF THE HEAVIEST
SNOW FALLS OVERNIGHT OR BEFORE MID MORNING TUESDAY.

WEDNESDAY, MODEL DISCREPANCIES BEGIN TO APPEAR AS THE GFS BRINGS IN
ONE MORE DISTURBANCE WITH THE UPPER TROUGH WHILE THE ECMWF AND GEM
ARE QUICKER TO PUSH THE MAIN TROUGH OFF TO THE EAST. WITH SOME
CHANCE FOR AN ADDITIONAL DISTURBANCE, I HAVE KEPT SLIGHT CHANCE TO
CHANCE POP GOING FOR MOST OF THE SIERRA AND WESTERN NEVADA THROUGH
WEDNESDAY AFTERNOON. IF THE GFS IS RIGHT, SNOW IS POSSIBLE ALL THE
WAY TO LOWER VALLEY FLOORS WEDNESDAY MORNING WITH AN OUTSIDE SHOT AT
BRIEF TRAVEL IMPACTS IF SNOW FALLS BEFORE TO JUST AFTER SUNRISE.
SNYDER

&&

.AVIATION...

SOUTHWEST TO WEST WINDS TO INCREASE FOR NORTHEAST CALIFORNIA AND
WESTERN NEVADA THIS AFTERNOON AND EVENING WITH GUSTS TO AROUND 25
KTS (LOCALLY 30). ALSO, A FEW SHOWERS ARE EXPECTED THIS AFTERNOON
AND TONIGHT MAINLY WELL NORTH OF INTERSTATE 80. SNOW LEVELS REMAIN
HIGH SO ONLY IMPACTS EXPECTED TO BE HIGHER TERRAIN OBSCURATION WITH
OCCASIONAL HIGH MVFR CIGS NORTH OF SUSANVILLE/GERLACH.

FRIDAY AFTERNOON, SCATTERED SHOWERS ARE EXPECTED NEAR AND SOUTH OF
INTERSTATE 80. THERE IS ALSO A LOW (5-10%) CHANCE FOR THUNDERSTORMS.
SNYDER


&&

.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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