Weather Service Report


403 
FXUS65 KREV 300343 AAA
AFDREV

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE RENO NV
743 PM PST THU JAN 29 2015

.UPDATE...
CLOUD COVER BECOMING MORE EXTENSIVE ACROSS THE EASTERN SIERRA AND
WESTERN NEVADA THIS EVENING IN A WEAK AREA OF DEFORMATION NORTH OF
THE UPPER LOW OFF BAJA. SOME LIGHT SHOWERS WERE SEEN WEST OF THE
SIERRA CREST EARLIER, BUT NOW SOME HAVE MOVED ACROSS WITH SOME
LIGHT RETURNS NEAR PORTOLA. ALSO HAVE GOTTEN REPORTS OF LIGHT TO
MODERATE SHOWERS AROUND MONO LAKE. WILL UPDATE TO ADD SHOWERS IN
THE SIERRA FROM HIGHWAY 70 SOUTH THROUGH MONO COUNTY. HAVE ALSO
UPDATED TO INCREASE CLOUD COVER AND RAISE OVERNIGHT LOWS. CLOUD
COVER SHOULD KEEP TEMPS SOMEWHAT MILD TONIGHT SOUTH OF I-80.
WALLMANN 

&&

.PREVIOUS DISCUSSION... /ISSUED 233 PM PST THU JAN 29 2015/ 

SYNOPSIS...

A LOW PRESSURE CENTER OFF THE BAJA PENINSULA WILL PROVIDE PARTLY
CLOUDY CONDITIONS FRIDAY WITH CLEARING ON SATURDAY AS HIGH
PRESSURE BUILDS. GUSTY RIDGE WINDS ARE EXPECTED ON FRIDAY WITH
CHOPPY CONDITIONS POSSIBLE ON LAKE TAHOE. HIGH PRESSURE WILL BRING
DRY AND MILD CONDITIONS THIS WEEKEND WITH THE STORM TRACK
REMAINING TO OUR NORTH THROUGH NEXT WEEK.

SHORT TERM...

PARTLY TO MOSTLY CLOUDY SKIES ARE SPREAD ACROSS MUCH OF NEVADA AND 
THE SIERRA AS MOISTURE STREAMS NORTH FROM AN UPPER LOW OFF THE BAJA 
PENINSULA. THERE IS A NARROW BAND OF LOW LEVEL MOISTURE PUSHING 
NORTH OF PYRAMID LAKE WHICH IS CREATING AN OVERCAST DECK NEAR 
10,000' MSL BUT OTHERWISE JUST SHALLOW CUMULUS AND HIGH CLOUDS 
ACROSS OTHER AREAS. EXPECTING HIGH CLOUDS TO CONTINUE INTO FRIDAY 
WITH CLEARING BEGINNING INTO SATURDAY AS A RIDGE BUILDS ACROSS THE 
PACIFIC NORTHWEST AND DISPLACES THE UPPER LOW ACROSS FAR SOUTHERN 
CALIFORNIA. EAST WINDS WILL ALSO REMAIN IN THE WAKE OF THE LOW WITH 
A MODEST UPPER LEVEL JET DROPPING SOUTH ACROSS THE SIERRA BEGINNING 
FRIDAY NIGHT INTO SATURDAY MORNING. GUSTY WINDS FROM THE EAST COULD 
CREATE SOME CHOPPY CONDITIONS ACROSS LAKE TAHOE LATE FRIDAY 
AFTERNOON WITH GUSTS OVER THE SIERRA RIDGES REACHING NEAR 75 MPH
INTO SATURDAY MORNING.

A DRY SLOT THEN FILTERS ACROSS THE REGION SATURDAY INTO SUNDAY AS 
THE RIDGE BUILDS, RESULTING IN CLEARING AND TEMPERATURES REMAINING 
ABOVE SEASONAL AVERAGES THROUGH THE WEEKEND. HIGHS IN THE MID TO 
UPPER 50S ACROSS WESTERN NEVADA COULD SEE HIGHS BACK IN THE LOWER 
60S BY SUNDAY. LOW 50S IN THE SIERRA WILL INCREASE INTO THE UPPER 
50S BY SUNDAY WITH SOME INCREASE IN HIGH CLOUDS AS MOISTURE STREAMS 
ACROSS THE PERIPHERY OF THE RIDGE. FUENTES

LONG TERM...MONDAY THROUGH THURSDAY...

THE FORECAST IS ON TRACK FOR A WEAK SYSTEM TO SPREAD MOISTURE MAINLY 
ACROSS THE PACIFIC NORTHWEST MONDAY, WITH A SLIGHT CHANCE FOR 
SHOWERS NORTH OF A SUSANVILLE-GERLACH LINE. TUESDAY-WEDNESDAY A 
RIDGE OF HIGH PRESSURE WILL PROVIDE A DRY AND WARMING AIR MASS OVER THE 
SIERRA AND WESTERN NV. THE RIDGE AXIS IS EXPECTED TO PROGRESS 
EASTWARD TO OVER THE SIERRA BY WEDNESDAY, LEADING TO WINDS ALOFT 
TRANSITIONING FROM NORTHWEST TUESDAY TO SOUTHWEST-WEST BY WEDNESDAY. 
WINDS SHOULD BE LIGHT AND EVEN ACROSS SIERRA RIDGES GUSTS LESS THAN 
20 MPH ARE EXPECTED. MODERATE VALLEY TEMPERATURE INVERSIONS WILL 
OCCUR EACH NIGHT, BUT SURFACE HEATING SHOULD PROVIDE ENOUGH 
AFTERNOON MIXING TO LIMIT THE TYPICAL INCREASE OF HAZE AND STAGNANT 
AIR.

THE RIDGE AXIS IS EXPECTED TO SHIFT OVER THE GREAT BASIN BY THURSDAY 
AS A LOW PRESSURE SYSTEM APPROACHES THE WEST COAST. TIMING IS 
UNCERTAIN, BUT STRONGER SOUTHWEST WINDS (SIERRA RIDGE GUSTS POSSIBLY 
AROUND 60 MPH) COULD INCREASE AFTERNOON MIXING AND MAKE THURSDAY THE 
WARMEST DAY OF THE WEEK. JCM

 
AVIATION...EXPECT LIGHT EAST WINDS THROUGH 03Z THURSDAY AND THEN 
CALM WINDS OVERNIGHT. THE TYPICAL ENHANCEMENT OF THE EAST WINDS AT 
KCXP, WITH SPEEDS IN THE 10-15 KT RANGE SHOULD ALSO CONTINUE UNTIL 
AROUND 03Z. ON FRIDAY, SFC FLOW BECOMES NORTHEAST DURING THE 
AFTERNOON WITH PREVAILING SPEEDS AROUND 10 KT. STRONGER NORTHEAST 
WINDS AT RIDGE LEVEL WILL LIKELY PRODUCE AREAS OF TURBULENCE FROM 
LATE FRIDAY THROUGH SATURDAY NEAR THE SIERRA. VFR CONDITIONS AT ALL 
TERMINALS WITH THE EXCEPTION OF FOG AT KTRK AFTER 12Z FRIDAY 
MORNING. JCM

&&

.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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