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000
FXUS65 KREV 172120
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
220 PM PDT MON JUN 17 2013

.SYNOPSIS...

INCREASED WINDS ARE EXPECTED THROUGH WEDNESDAY AS LOW PRESSURE OFF
THE WEST COAST MOVES INTO THE PACIFIC NORTHWEST. THE STRONGEST
AND MOST WIDESPREAD WINDS WILL BE TUESDAY WITH GUSTS UP TO 45 MPH.
THIS WILL COINCIDE WITH VERY DRY AIR, MAKING FOR CRITICAL FIRE
WEATHER CONDITIONS. TEMPERATURES WILL FALL TO BELOW AVERAGE
THROUGH THURSDAY BEFORE WARMING TO ABOVE AVERAGE BY NEXT WEEKEND.

&&

.SHORT TERM...

ONGOING FORECAST REMAINS ON TRACK WITH FEW CHANGES MADE. THE UPPER
LEVEL LOW OFF THE NORTHWEST COAST WILL MOVE ONSHORE TUESDAY,
SENDING A COLD FRONT THROUGH NORTHWEST CALIFORNIA AND NORTHEAST
NEVADA. THE THERMAL AND PRESSURE GRADIENTS INCREASE AHEAD OF THE
FRONT BRINGING STRONG AND GUSTY WINDS TO THE REGION. WIDESPREAD
WIND GUSTS UP TO 45 MPH ARE EXPECTED, WITH WIND PRONE LOCATIONS
POTENTIALLY GUSTING AS HIGH AS 55 MPH. THESE WINDS WILL COINCIDE
WITH A VERY DRY AIR MASS, CREATING CRITICAL FIRE WEATHER
CONDITIONS THROUGHOUT NORTHEAST CALIFORNIA, NORTHWEST NEVADA, AND
THE SIERRA. BEHIND THE FRONT, THE AIRMASS WILL BEGIN TO MOISTEN,
SO AREAS NORTH OF A SUSANVILLE-GERLACH LINE, WHILE WINDY, WILL NOT
BE AS CRITICAL. FOR MORE DETAILS ON FIRE WEATHER IMPACTS, PLEASE
SEE THE FIRE WEATHER SECTION BELOW. WINDS WILL ALSO CREATE ROUGH
AND CHOPPY WATERS ON LAKES SO LAKE WIND ADVISORIES ARE BEING ISSUED
TOMORROW FOR ALL AREA LAKES FOR THE AFTERNOON AND EVENING. POST-
FRONTAL BREEZY CONDITIONS WILL LINGER INTO WEDNESDAY, BUT WILL NOT
BE NEARLY AS STRONG AS ON TUESDAY.

AS THE UPPER LOW SWINGS INLAND THROUGH THE PACIFIC NORTHWEST,
MOISTURE ALONG THE SOUTHERN PERIPHERY COMBINED WITH A JET STREAK
WILL GENERATE SHOWERS TUESDAY EVENING THROUGH WEDNESDAY MAINLY
NORTH OF A SUSANVILLE-GERLACH LINE. MOISTURE IS NOT VERY DEEP, SO
QPF AMOUNTS SHOULD BE LIMITED TO UNDER A TENTH OF AN INCH.
INSTABILITY REMAINS BEST FURTHER NORTH INTO OREGON AND IDAHO,
CLOSER TO THE CORE OF THE LOW, SO WILL LEAVE MENTION OF THUNDER
OUT OF THE FORECAST AT THIS TIME. THE LOW WILL ALSO USHER IN A
COOLER AIRMASS, WITH TEMPERATURES FALLING BELOW NORMAL TUESDAY
THROUGH THURSDAY. DF


.LONG TERM...THURSDAY THROUGH MONDAY...

DRY WEATHER WITH LIMITED CLOUD COVER WILL PREVAIL FROM THURSDAY THRU
EARLY NEXT WEEK. ALTHOUGH UPPER TROUGH REMAINS OVER THE NORTHWEST US
THRU FRIDAY, ITS INFLUENCE OVER CA-NV WILL WEAKEN AS WEST FLOW ALOFT
DECREASES. WHILE A WARMING TREND BEGINS THURSDAY, MAX TEMPS WILL
STILL BE SLIGHTLY BELOW NORMAL WITH HIGHS NEAR 80 IN WESTERN NV. BY
FRIDAY, 5-8 DEGREES OF WARMING WILL LEAD TO TEMPS REACHING THE
MID-UPR 80S FOR MOST VALLEYS.

FOR THIS WEEKEND, FLAT RIDGE OFF THE WEST COAST WILL MOVE EAST
ACROSS THE GREAT BASIN AND CONTINUE THE WARMING TREND, WITH HIGHS
REACHING THE LOWER-MID 90S IN WESTERN NV AND LOWER 80S IN THE TAHOE
BASIN BY SUNDAY. LIGHT WINDS ARE EXPECTED SATURDAY, FOLLOWED BY A
WEAK LATE DAY ZEPHYR BREEZE SUNDAY AS THE THERMAL TROUGH SHIFTS INTO
WEST CENTRAL NV. THE COMBINATION OF GENERALLY LIGHT WINDS AND
INCREASED HEATING WILL LEAD TO FLAT CUMULUS NEAR THE SIERRA EACH
AFTERNOON, BUT WARM TEMPS ALOFT AND LACK OF FORCING WILL INHIBIT
CONVECTIVE ACTIVITY.

BY MONDAY, MEDIUM RANGE GUIDANCE IS IN GENERAL AGREEMENT WITH TROUGH
APPROACHING THE WEST COAST AND DISPLACING THE RIDGE FARTHER EAST.
THIS WILL RESULT IN INCREASING WINDS OVER MOST OF THE REGION. THE
MAIN UPPER JET IS STILL WELL NORTH OF CALIFORNIA AND 700 MB FLOW
ONLY INCREASES TO 20-25 KT, SO AFTERNOON WIND GUSTS WOULD PROBABLY
RANGE FROM 30-35 MPH MAINLY NORTH OF HIGHWAY 50. MJD

&&

.AVIATION...

BREEZY CONDITIONS THIS AFTERNOON WITH GUSTS OF 20 TO 30 KTS AT
AREA TERMINALS. WINDS TO FURTHER INCREASE TUESDAY BECOMING STRONG
AND GUSTY FROM AROUND 18Z THROUGH 04Z. SUSTAINED SOUTHWEST WINDS
OF 15 TO 25 KTS WITH GUSTS TO 40 KTS CAN BE EXPECTED, WITH
TURBULENCE LIKELY DOWNWIND OF THE SIERRA. WINDS MAY CAUSE AREAS
OF BLOWING DUST PRIMARILY THROUGH THE BASIN AND RANGE. SHOWERS ARE
POSSIBLE TUESDAY NIGHT INTO WEDNESDAY NORTH OF A SUSANVILLE-
GERLACH LINE, BUT CONDITIONS SHOULD REMAIN VFR. DF

&&

.FIRE WEATHER...

A LOW PRESSURE SYSTEM APPROACHING THE NORTHERN CALIFORNIA COAST
THROUGH TUESDAY WILL BRING GUSTY AFTERNOON/EVENING WINDS ACROSS
THE SIERRA AND WESTERN NEVADA. PERSISTENT DRY CONDITIONS COMBINED
WITH GUSTY WINDS WILL PRODUCE CRITICAL CONDITIONS.

TONIGHT...TIGHTENING SURFACE PRESSURE AND SURFACE THERMAL GRADIENTS
ALONG THE NORTHERN PORTION OF THE FORECAST AREA HAS RESULTED IN
INCREASED WEST TO SOUTHWEST WINDS. CATNIP MOUNTAIN RAWS IN
NORTHERN WASHOE COUNTY HAS A RELATIVE HUMIDITY AROUND 12% WITH
WIND GUSTS AROUND 30 MPH AND EXPECT OTHER RAWS STATIONS TO
STARTING HITTING CRITERIA AS WELL. WINDS WILL CONTINUE TO INCREASE
TO 15 TO 25 MPH WITH GUSTS 30 TO 35 MPH NORTH OF SUSANVILLE AND
GERLACH THROUGH THIS EVENING. CONDITIONS WILL BE CLOSE FOR A FEW
HOURS ALONG THE SIERRA FRONT, ESPECIALLY LOCATIONS NORTH OF
INTERSTATE 80 WHERE GUSTS AROUND 30 TO 35 MPH WILL BE POSSIBLE FOR
A COUPLE OF HOURS. FOR TONIGHT INTO TUESDAY MORNING, A DRY SLOT
WILL PUSH INTO THE SIERRA AND WESTERN NEVADA LIMITING MID SLOPE
RECOVERIES FURTHER WITH SOME LOCATIONS STAYING AROUND 20%
OVERNIGHT. A RED FLAG WARNING REMAINS IN EFFECT THROUGH 10 PM THIS
EVENING FOR ZONES 278-458.

FORECASTER CONFIDENCE REMAINS HIGH FOR THE RED FLAG WARNING EVENT
FOR TUESDAY AFTERNOON/EVENING. ON TUESDAY, A STRONG JET ASSOCIATED
WITH THE LOW PRESSURE SYSTEM MOVES ACROSS THE SIERRA AND WESTERN
NEVADA FURTHER INCREASING SOUTHWEST FLOW ALOFT. TIGHTENING SURFACE
PRESSURE/THERMAL GRADIENTS ON TUESDAY AFTERNOON WILL BE ENHANCED
BY THE STRENGTHENING UPPER LEVEL FLOW ALLOWING FIERCE GUSTY WINDS
TO DEVELOP. WIDESPREAD SUSTAINED WINDS 15 TO 30 MPH WITH WIND
GUSTS BETWEEN 40 TO 45 MPH WILL DEVELOP TUESDAY AFTERNOON. WITH
CONTINUED DRY CONDITIONS FORECAST ACROSS AREAS SOUTH OF SUSANVILLE
AND GERLACH, A RED FLAG WARNING IS IN EFFECT FROM NOON THROUGH 11
PM ON TUESDAY.

WITH RELATIVE HUMIDITY VALUES ON THE INCREASE NORTH OF SUSANVILLE
AND GERLACH ON TUESDAY, CRITICAL FIRE WEATHER CONDITIONS ARE NOT
EXPECTED. SUFFICIENT MOISTURE AND LIMITED INSTABILITY ACROSS THOSE
AREAS MAY RESULT IN A SLIGHT CHANCE FOR SHOWERS TUESDAY EVENING AND
EARLY WEDNESDAY. AS FLOW GRADUALLY TRANSITIONS FROM WEST TO
NORTHWEST, WINDS ARE EXPECTED TO REMAIN BREEZY, AROUND 10 TO 15 MPH,
ACROSS MOST OF THE SIERRA AND WESTERN NEVADA TUESDAY NIGHT INTO
WEDNESDAY. WIND PRONE LOCATIONS IN MINERAL AND MONO COUNTY MAY
REMAIN GUSTY OVERNIGHT WITH GUSTS UP TO 25 MPH POSSIBLE. LINDAMAN


&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...RED FLAG WARNING UNTIL 10 PM PDT THIS EVENING NVZ458.

     RED FLAG WARNING FROM NOON TO 11 PM PDT TUESDAY
     NVZ450-453-458-459.

     LAKE WIND ADVISORY FROM NOON TO 9 PM PDT TUESDAY NVZ002.

     LAKE WIND ADVISORY FROM 2 PM TO 11 PM PDT TUESDAY NVZ001.

     LAKE WIND ADVISORY FROM NOON TO 9 PM PDT TUESDAY NVZ004.

CA...RED FLAG WARNING UNTIL 10 PM PDT THIS EVENING CAZ270-278.

     RED FLAG WARNING FROM NOON TO 11 PM PDT TUESDAY CAZ271>273-278.

     LAKE WIND ADVISORY FROM NOON TO 9 PM PDT TUESDAY CAZ071.

     LAKE WIND ADVISORY FROM 2 PM TO 11 PM PDT TUESDAY CAZ073.

     LAKE WIND ADVISORY FROM NOON TO 9 PM PDT TUESDAY CAZ072.

&&

$$

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