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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
204 PM PDT THU AUG 21 2014

.SYNOPSIS...
LOW PRESSURE WILL MOVE INTO THE PACIFIC NORTHWEST AND BRING
INCREASING WINDS AND CRITICAL FIRE WEATHER CONDITIONS ON FRIDAY.
COOLER TEMPERATURES WILL REACH THE AREA SATURDAY WITH DRY AND WARM
CONDITIONS NEXT WEEK.

&&

.SHORT TERM...

FORECAST REMAINS ON TRACK FOR THE START OF THE WEEKEND. UPPER LOW
WILL DROP INTO THE PACIFIC NORTHWEST TONIGHT, REACHING SOUTHERN
IDAHO SATURDAY MORNING. A JET SEGMENT ROUNDING THE BASE OF THE LOW
WILL PASS OVER NORTHEAST CALIFORNIA AND NORTHWEST NEVADA FRIDAY
AFTERNOON BRINGING AN INCREASE IN WINDS.

FOR TONIGHT, DRY CONDITIONS WITH THE TYPICAL AFTERNOON AND EVENING
BREEZES OFF THE SIERRA. WINDS MAY NOT DECREASE MUCH NORTH OF
PORTOLA-GERLACH AS THE LOW AND JET APPROACH NORTHWEST NEVADA.

WITH THE JET OVERHEAD FRIDAY AFTERNOON, PEAK GUSTS WILL REACH
30-40 MPH WITH A FEW GUSTS AS HIGH AS 45 MPH IN WIND PRONE
LOCATIONS ALONG THE SIERRA FRONT. SOUTH OF HIGHWAY 50 AND FOR THE
EASTERN SIERRA, WINDS WILL INCREASE BY MID AFTERNOON WITH PEAK
GUSTS NEAR 30 MPH, WITH A FEW WIND PRONE LOCATIONS ALONG HIGHWAYS
95 AND 395 GUSTING TO 35 MPH. HAZARDOUS BOATING CONDITIONS WILL
START ON TAHOE AND PYRAMID BY LATE FRIDAY MORNING OR EARLY FRIDAY
AFTERNOON PERSISTING INTO FRIDAY EVENING. THE WEST TO NORTHWEST
FLOW WITH THE JET MAY TRANSPORT A BIT MORE SMOKE AND HAZE FROM
WILDFIRES OVER SOUTHERN OREGON AND NORTHWEST CALIFORNIA INTO AREAS
NORTH OF HIGHWAY 50, THOUGH WITH ONLY MINIMAL REDUCTIONS TO
VISIBILITY AND AIR QUALITY.

CRITICAL FIRE WEATHER CONDITIONS
WILL ALSO OCCUR ROUGHLY FROM RENO TO DOUGLAS COUNTY EASTWARD TO
LOVELOCK AND FALLON.

THE TAIL END OF A COLD FRONT WILL SKIM NORTHERN NEVADA FRIDAY
EVENING WHICH COULD PRODUCE A FEW LIGHT RAIN SHOWERS NORTH OF
GERLACH TO LOVELOCK.

FOR SATURDAY COOLER AIR WILL MOVE INTO THE REGION BEHIND THE LOW.
THIS WILL DROP AFTERNOON HIGHS FROM THE UPPER 70S TO MID 80S
ACROSS THE VALLEYS WITH 70S FOR THE SIERRA. OVERNIGHT LOWS
SATURDAY NIGHT/SUNDAY MORNING MAY COOL QUITE A BIT WITH OUTLYING
VALLEYS FALLING TO NEAR 40 WITH A FEW SIERRA VALLEYS DROPPING OFF
TO NEAR FREEZING. BRONG

.LONG TERM...SUNDAY THROUGH THURSDAY...

THE GEM MODEL AND A PREVIOUS RUN OF THE ECMWF MODEL ADVERTISED A LOW 
PRESSURE WEATHER SYSTEM MON NIGHT-TUE, BUT THE LATEST (12Z) ECMWF IS 
ADVERTISING A RIDGE INSTEAD. THIS BRINGS THE EC MORE IN LINE WITH 
THE GFS. FURTHERMORE, THE LATEST (12Z) GFS ENSEMBLE HAS ONLY ONE 
MEMBER SHOWING A LOW OVER WESTERN NV TUE.  THE BOTTOM LINE 
THEREFORE, IS INCREASING CONFIDENCE FOR A DRY NORTHWEST FLOW FOR THE 
EARLY PART OF THE WEEK FOLLOWED BY A HIGH PRESSURE RIDGE OVER CA AND 
WESTERN NV BY MIDWEEK. LITTLE CHANGE TO THE ONGOING FORECAST WHICH 
CALLS FOR DRY CONDITIONS, TYPICAL AFTERNOON BREEZES AND MOSTLY CLEAR 
SKIES. AFTERNOON TEMPERATURES ARE FORECAST TO BE SLIGHTLY BELOW 
NORMAL SUNDAY WITH A SLOW WARMING TREND THROUGH MIDWEEK. JCM 

&&

.AVIATION...
TYPICAL WEST WINDS TODAY WITH LEE SIDE TERMINALS GUSTING TO AROUND 
25 KTS THIS AFTERNOON/EVENING. VFR CONDITIONS WITH FEW CLOUDS 
THROUGH TONIGHT.

STRONGER WINDS ARE LIKELY TOMORROW AS AN UPPER LOW STARTS TO DROP 
TOWARD THE REGION. COULD SEE GUSTS AS HIGH AS 35 KTS IN SOME AREAS 
FRIDAY AFTERNOON WITH BLOWING DUST REDUCING VISIBILITIES NEAR THE 
SFC IN AREAS EAST OF PRIMARY DUST SOURCES. 20/JCM

&&

.FIRE WEATHER...

A TROUGH OF LOW PRESSURE WILL SHIFT THROUGH THE NORTHWEST ON
FRIDAY BACKED BY A 90 MPH JET STREAM. RIDGE LEVEL WINDS BEGIN TO
INCREASE BY EARLY FRIDAY MORNING, BECOMING STRONGEST FRIDAY
AFTERNOON FROM HIGHWAY 50 NORTH. THESE MID LEVEL WINDS COINCIDE
WITH A STRENGTHENING SURFACE GRADIENT BRINGING GUSTS OF 30 TO 40
MPH ACROSS NORTHEAST CALIFORNIA AND NORTHWEST NEVADA FRIDAY
AFTERNOON. THE STRONGEST WINDS WILL LIKELY BE ALONG THE WESTERN
NEVADA SIERRA FRONT INTO THE CENTRAL BASIN AND RANGE. THERE IS A
DRY SLOT MOVING IN BEHIND THE LOW AND THIS DRIER AIR WILL LIKELY
MIX DOWN TO THE SURFACE BRINGING 10 TO 15 PERCENT RELATIVE
HUMIDITY VALUES TO SOME DESERTS OF NORTHWEST NEVADA. CRITICAL FIRE
WEATHER CONDITIONS ARE EXPECTED FRIDAY AFTERNOON FOR THE SIERRA
FRONT AND THE CENTRAL BASIN AND RANGE, MAINLY SOUTH OF A PYRAMID
LAKE-LOVELOCK LINE. THE FIRE WEATHER WATCH WAS UPGRADED TO A RED
FLAG WARNING FOR THESE AREAS FRIDAY AFTERNOON.

THE FIRE WEATHER WATCH WAS DROPPED FOR EASTERN LASSEN COUNTY, THE 
SURPRISE VALLEY, AND NORTHERN WASHOE COUNTY. RELATIVE HUMIDITY 
VALUES WILL STAY SLIGHTLY HIGHER THAN PREVIOUSLY THOUGHT AND WHILE 
WINDS WILL BE BREEZY, THEY WILL BE A LITTLE LESS STRONG THAN 
ANTICIPATED.

LIGHT NORTHEAST WINDS WILL RESULT AS THE LOW SHIFTS EASTWARD ON 
SATURDAY BEFORE BREEZY WEST WINDS RETURN SUNDAY INTO MONDAY AS A 
SECONDARY SHORTWAVE MOVES THROUGH THE NORTHWEST. WARMING AND DRYING 
CONDITIONS ARE EXPECTED HEADING INTO THE MIDDLE OF NEXT WEEK. DJ

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...RED FLAG WARNING FROM 11 AM TO 8 PM PDT FRIDAY NVZ450-453.

     LAKE WIND ADVISORY FROM 11 AM TO 11 PM PDT FRIDAY NVZ004.

     LAKE WIND ADVISORY FROM 11 AM TO 11 PM PDT FRIDAY NVZ002.

CA...LAKE WIND ADVISORY FROM 11 AM TO 11 PM PDT FRIDAY CAZ072.

&&

$$

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


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