Area Forecast Discussion
Issued by NWS Reno, NV

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FXUS65 KREV 220302 AAA
AFDREV

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE RENO NV
802 PM PDT SUN SEP 21 2014

.UPDATE...

SATELLITE IMAGERY SHOWS UPPER LOW OVER WEST CENTRAL NV LIFTING NE
TOWARD THE NORTH CENTRAL PART OF THE STATE. THIS IS IN LINE WITH
CURRENT MODEL GUIDANCE. CONVECTION OVER THE FAR EASTERN PARTS OF
THE CWA IS DISSIPATING...BUT THIS CONVECTION DID PRODUCE SOME
HEAVIER RAINS OVER ISOLATED AREAS TODAY RESULTING IN TWO REPORTS
OF WATER AND DEBRIS OVER STATE HIGHWAYS IN SOUTHEAST CHURCHILL
COUNTY. THE HRRR STILL SHOWS CONVECTION DEVELOPING OVER THE FAR
NRN CWA LATER THIS EVENING ASSOCIATED WITH A WEAK VORTICITY LOBE
ROTATING AROUND THE UPPER LOW AND A LITTLE LINGERING CONVECTION
OVER THE FAR EASTERN CWA. WITH THIS IN MIND HAVE DECREASED POPS
FOR THE FAR WEST AND SOUTH BUT LEFT SOME SMALL POPS IN OVER THE
FAR NORTH AND EAST THROUGH LATE EVENING. AS UPPER LOW EXITS LATE
TONIGHT DRIER CONDITIONS SHOULD RETURN FOR MONDAY.

ATTENTION TURNS TO THE SMOKE FROM THE KING FIRE THAT HAS MOVED
BACK INTO THE WESTERN PART OF NEVADA AND NORTHEAST CALIFORNIA. THE
SMOKE WAS A LITTLE THICKER LATE THIS AFTERNOON. THE THINNING OF
THE SMOKE IS LIKELY A RESPONSE TO LESS FIRE ACTIVITY AND LIGHTER
WINDS THIS EVENING. SMOKE FORECASTING CAN BE SOMEWHAT DIFFICULT AS
IT RELIES LARGELY ON THE INTENSITY OF THE FIRE. EVEN THOUGH THE
SMOKE HAS THINNED WE COULD SEE A RESURGENCE LATE TONIGHT AS THE
ATMOSPHERE BECOMES MORE STABLE...OR IT COULD THIN MORE. WILL LEAVE
THE DENSE SMOKE ADVISORY IN PLACE AS WINDS MONDAY SHOULD BECOME
MORE WESTERLY THROUGH THE DAY AND DRIVE ANY SMOKE GENERATED BACK
THIS DIRECTION. IT IS POSSIBLE THAT STRONGER WINDS LATER IN THE
WEEK WILL RESULT IN EVEN MORE SMOKE IN THE TAHOE BASIN AND WRN
NEVADA...BUT THIS REMAINS A BIT UNCERTAIN AT THIS TIME. 20

&&

.PREVIOUS DISCUSSION... /ISSUED 306 PM PDT SUN SEP 21 2014/

SYNOPSIS...

SOUTHWEST FLOW AND BUILDING HIGH PRESSURE WILL THEN BRING WARMER AND
DRIER CONDITIONS TO THE REGION THROUGH THE MIDDLE OF THE WEEK, ALONG
WITH SMOKE TO THE REGION FROM THE ONGOING KING FIRE. STRONGER
LOW PRESSURE BRINGS INCREASING WINDS AND COOLER TEMPERATURES WITH
POSSIBLE RAIN LATER IN THE WEEK.

SHORT TERM...

LIGHT RAINFALL TODAY THROUGH THE SIERRA AND UP THROUGH FAR NORTHWEST
NEVADA AS THE LOW PRESSURE PIVOTED THROUGH THE AREA. THE AREA THAT
RECEIVED THE HIGHEST RAINFALL WAS IN EASTERN PERSHING AND CHURCHILL
COUNTIES LAST NIGHT WHERE UP TO 0.50" FELL. OTHERWISE, ONLY LIGHT
RAIN WAS REPORTED FOR OTHER AREAS.

A FEW ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED IN WESTERN
NEVADA THIS AFTERNOON. ONE SHOWER THAT MOVED INTO FERNLEY EARLIER
PRODUCED BRIEF, BUT HEAVY RAINFALL IN THE AREA. THIS GOES TO SHOW
THAT THE MOISTURE CONTENT IN THE AIR IS VERY HIGH, WITH EFFICIENT
PRECIPITATION. ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH
THE EVENING HOURS, THEN TAPER OFF AS LOW PRESSURE MOVES OUT OF THE
REGION.

ABUNDANT CLOUD COVER HAS REMAINED OVER THE REGION ALL DAY, KEEPING
TEMPERATURES A BIT COOLER AND KEEPING THE AIR FROM MIXING. THIS WAS
A BIG FACTOR IN THE SMOKE IN THE TRUCKEE AREA NOT BEING ABLE TO MIX
OUT DUE TO THE LACK OF HEATING. WINDS AT RIDGE LEVEL HOWEVER ARE
SHIFTING TO THE SOUTHWEST AND WILL BRING ADDITIONAL SMOKE INTO TAHOE
BASIN AND RENO-CARSON-MINDEN AREAS AS WELL. A DENSE SMOKE ADVISORY
HAS BEEN ISSUED THROUGH MONDAY AFTERNOON IN ANTICIPATION THAT SMOKE
WILL BECOME WORSE OVER THE NEXT 24 HOURS. SMOKE DENSITY WILL ALSO
DEPEND HIGHLY ON FIRE ACTIVITY OVER THE NEXT FEW DAYS, SO THE DENSE
SMOKE ADVISORY WILL NEED TO BE REEVALUATED EACH AFTERNOON. BUT, WITH
THE SOUTHWEST FLOW EXPECTED TO CONTINUE, SMOKE WILL REMAIN IN THE
FORECAST THROUGH AT LEAST WEDNESDAY.

DRY AND WARM CONDITIONS WILL RETURN TO THE REGION MONDAY AND TUESDAY
AS HIGH PRESSURE BUILDS OVER THE REGION AND SOUTHWEST FLOW RETURNS
ALOFT. EXPECT TEMPERATURES TO INCREASE TO ABOVE NORMAL AGAIN WITH
MID TO UPPER 80S IN WESTERN NEVADA AND 70S IN THE SIERRA. HOON

LONG TERM...WEDNESDAY THROUGH SUNDAY...

A TROUGH OVER THE EAST PACIFIC WILL PROVIDE BREEZY SOUTHWEST WINDS
BY MIDWEEK AHEAD OF A COLD FRONT WHICH WILL PROVIDE COOLER
CONDITIONS AND CHANCES FOR SHOWERS THE SECOND HALF OF THE WEEK. THE
FORECAST CONFIDENCE IN THE EXTENDED IS GOOD FOR WEDNESDAY AND
THURSDAY BEFORE DEGRADING SIGNIFICANTLY OVERNIGHT THURSDAY INTO
FRIDAY DUE TO LARGE DISCREPANCIES IN TIMING THE EJECTION OF THE
UPPER LOW.

FOR WED-THU, AXIS OF THE UPPER TROUGH WILL REMAIN JUST OFF THE WEST
COAST WITH GUSTY WINDS MAINLY CONCENTRATED NORTH OF INTERSTATE 80 AS
THE UPPER LEVEL JET BEGINS TO DROP ACROSS NE CALIFORNIA. STRONGER
WINDS LOOK TO BECOME MORE WIDESPREAD BY THURSDAY AHEAD OF A FRONT AS
THE SURFACE PRESSURE GRADIENT INTENSIFIES AND THE CORE OF 105+ KT
JET CROSSES THE SIERRA. SUSTAINED SW-W WINDS IN THE 15-25 MPH RANGE
ARE POSSIBLE THURSDAY BEFORE SHIFTING NORTHWEST BEHIND THE FRONT
WITH MODELS PUSHING THE FRONT THROUGH OVERNIGHT THURSDAY INTO EARLY
FRIDAY.

COOLER CONDITIONS ARE EXPECTED BEHIND THE FRONT WITH POSSIBLE HIGH
TEMPERATURES ACROSS WESTERN NEVADA ONLY IN THE UPPER 60S TO LOWER
70S AND LOWER 60S ACROSS SIERRA VALLEYS. CONSIDERABLE UNCERTAINTY
EXISTS WITH HOW QUICKLY THE LOW DEPARTS WITH THE GFS BEING MUCH
QUICKER THAN THE EC WHICH LINGERS THE LOW OVER THE REGION THROUGH
NEXT WEEKEND. THE EC WOULD PROVIDE US WITH A COOLER AND WETTER
FORECAST THAN THE WARMER AND DRIER SOLUTION OF THE GFS. LITTLE
CHANGE MADE IN THE FORECAST FOR NEXT WEEKEND AS TRENDS AND ENSEMBLE
RUNS OFFER LITTLE CONFIDENCE TO MAKE MANY ADJUSTMENTS. WILL MAINTAIN
SLIGHT CHANCES FOR SHOWERS AND A SLOWER WARMUP IN THE FORECAST
BEYOND FRIDAY. FUENTES

AVIATION...

THE KING WILDFIRE ALONG THE WEST SLOPES OF THE SIERRA WILL CONTINUE
TO PUSH SMOKE AND HAZE ACROSS THE TERMINALS WITH SURFACE VIS AS LOW
AS 1SM POSSIBLE AT KTVL/KTRK AND LESS THAN 3SM POSSIBLE AT
KCXP/KRNO. OTHERWISE, BRIEF PERIODS OF MVFR CIGS/VIS IN -SHRA ARE
POSSIBLE THROUGH 06Z THIS EVENING BUT CHANCES WILL REMAIN GENERALLY
BELOW 15% ACROSS ALL TERMINALS BEFORE DIMINISHING OVERNIGHT.

THE MAIN STORY INTO MIDWEEK WILL BE ANOTHER APPROACHING LOW PRESSURE
SYSTEM THAT WILL INCREASE SOUTHWESTERLY WINDS AND SMOKE TRANSPORT
INTO KTVL/KTRK/KCXP/KRNO. MOUNTAIN OBSCURATION AND DECREASED SURFACE
VIS WILL BE AN ISSUE AND WILL LIKELY CONTINUE EACH DAY THROUGH AT
LEAST THURSDAY ASSUMING THE KING FIRE REMAINS ACTIVE. FUENTES

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...DENSE SMOKE ADVISORY UNTIL 5 PM PDT MONDAY NVZ002-003.

CA...DENSE SMOKE ADVISORY UNTIL 5 PM PDT MONDAY CAZ072.

&&

$$

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







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