Area Forecast Discussion
Issued by NWS Reno, NV

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
000
FXUS65 KREV 142351
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
451 PM PDT SUN SEP 14 2014

.DISCUSSION...SMOKE FROM THE KING WILDFIRE NEAR POLLOCK PINES (NEAR
HIGHWAY 50 ON THE WEST SIDE OF THE SIERRA CREST) IS REDUCING
VISIBILITIES IN THE TAHOE BASIN TO 1 MILE IN SOME AREAS AND SMOKE
IS ALSO CURRENTLY MOVING INTO THE RENO AREA. ASH FALLING TO THE
GROUND HAS BEEN REPORTED IN TRUCKEE. THE FORECAST FOR TONIGHT WAS
UPDATED FOR THESE CONDITIONS. THE SMOKE SHOULD CONTINUE TO MOVE
NORTHEAST THIS EVENING CREATING HAZE AT LEAST AS FAR EAST AS
FERNLEY, NV. WINDS WILL LESSEN OVERNIGHT TONIGHT, REDUCING THE
AMOUNT OF SMOKE TRANSPORTED EAST OF THE SIERRA. HOWEVER, SMOKE
WILL SETTLE INTO THE TAHOE BASIN AND PROBABLY INTO THE RENO AREA
AS WELL. PERSONS SENSITIVE TO SMOKE SHOULD REDUCE THEIR ACTIVITY
AND STAY INDOORS IF POSSIBLE. JCM

&&

.PREVIOUS DISCUSSION... /ISSUED 316 PM PDT SUN SEP 14 2014/

SYNOPSIS...

A FEW THUNDERSTORMS MAY DEVELOP IN NORTHEAST CALIFORNIA MONDAY
AFTERNOON AS WEAK LOW PRESSURE MOVES NEAR THE PACIFIC NORTHWEST
COAST. OTHERWISE WARM AND DRY CONDITIONS WILL PREVAIL THROUGH
TUESDAY WITH TYPICAL AFTERNOON BREEZES. A STRONGER LOW PRESSURE
APPROACHING THE WEST COAST WILL BRING GUSTY WINDS WEDNESDAY,
FOLLOWED BY COOLER TEMPERATURES AND POSSIBLE SHOWERS BY THURSDAY.

SHORT TERM...

THE RIDGE THAT HAS PRODUCED VERY WARM AND DRY WEATHER FOR THE PAST
SEVERAL DAYS WILL BECOME CENTERED OVER THE SOUTHWEST US BY MONDAY.
THIS WILL LEAD TO SOUTHWEST FLOW ALOFT OVER THE SIERRA AS A SERIES
OF SHORTWAVES APPROACH THE WEST COAST.

THE FIRST SHORTWAVE WILL MOVE QUICKLY NORTH ALONG THE PACIFIC
NORTHWEST MONDAY. THE NEGATIVE TILT ORIENTATION OF THIS SYSTEM
WILL PRODUCE AN AREA OF INSTABILITY MONDAY AFTERNOON AND EARLY
EVENING EXTENDING FROM NORTHERN CALIFORNIA TO SOUTHERN OREGON.
WHILE THE BEST FORCING SHOULD REMAIN NORTH AND WEST OF THE
FORECAST AREA, LATEST GUIDANCE HAS TRENDED TOWARD A BETTER
POSSIBILITY OF ISOLATED CONVECTION IN NORTHEAST CA-NORTHWEST NV,
SO WE WILL ADD SLIGHT CHANCE OF THUNDER FOR MONDAY AFTERNOON AND
EARLY EVENING NORTH OF A PORTOLA-SUSANVILLE-GERLACH LINE. SLIGHT
INSTABILITY IS ALSO SHOWING UP EAST OF THE SIERRA CREST FROM TAHOE
TO MONO COUNTY AND FAR WESTERN NV, BUT THE POTENTIAL FOR THUNDER
IS LOWER IN THESE AREAS AS MID LEVEL CAPPING WILL BE MORE
DIFFICULT TO OVERCOME. A TYPICAL ZEPHYR WIND IS EXPECTED MONDAY
AFTERNOON AND EVENING WITH GUSTS GENERALLY AROUND 25 MPH.

TUESDAY SHOULD BE DRY AS EASTERN CA-WESTERN NV WILL BE IN BETWEEN
WEATHER SYSTEMS, ALTHOUGH MORE CUMULUS BUILDUPS ARE LIKELY SOUTH
OF HIGHWAY 50. AFTERNOON WINDS WILL EDGE UP A BIT HIGHER WITH
GUSTS UP TO 30 MPH AS THE MID LEVEL SOUTHWEST FLOW INCREASES A BIT
COMPARED TO MONDAY.

MAX TEMPS WILL REMAIN ABOVE NORMAL THRU TUESDAY WITH HIGHS MAINLY
IN THE LOWER 90S FOR MOST OF WESTERN NV AND 80S FOR THE SIERRA
VALLEYS. MJD

LONG TERM...WEDNESDAY THROUGH SATURDAY...

MADE SOME SLIGHT ADJUSTMENTS TO THE PREVIOUS FORECAST BASED ON MODEL
TRENDS OVER THE LAST COUPLE OF DAYS. LONG TERM MODELS REMAIN IN
FAIRLY GOOD AGREEMENT THROUGH THURSDAY BEFORE THE GFS AND ECMWF
DIVERGE. BOTH GFS AND THE EC DEPICT AN INCREASINGLY SPLIT ENERGY
TROUGH PUSHING INTO NORTHERN CALIFORNIA LATE WEDNESDAY WHICH
PROGRESSES INTO SOUTHWESTERN NEVADA BY FRIDAY NIGHT. THE MAIN ENERGY
HAS SHIFTED NORTHWARD INTO THE PACIFIC NORTHWEST WITH THIS FEATURE
REDUCING THE SOUTHERN PORTION OF THE TROUGH`S POTENCY. THIS WILL
RESULT IN WIND SPEEDS NOT INCREASING AS MUCH FOR WEDNESDAY AND AN
EASTWARD SHIFT IN THE TRACK OF THE MONSOONAL MOISTURE SURGE
THURSDAY AND FRIDAY. THEREFORE, LOWERED WINDS A LITTLE WEDNESDAY
(GUSTS GENERALLY UP TO 35 MPH) FROM THE PREVIOUS FORECAST AND
REMOVED PRECIPITATION CHANCES FOR MOST OF CHURCHILL AND PERSHING
COUNTIES ON THURSDAY.

FORECASTER CONFIDENCE LOWERS SIGNIFICANTLY FOR FRIDAY INTO THE
WEEKEND AS THE GFS AND EC PRESENT DIFFERING SOLUTIONS. THE EC
CONTINUES TO DEPICT A CUT-OFF LOW WHILE THE GFS SHOWS A MORE
PROGRESSIVE TROUGH STILL ATTACHED TO UPPER LEVEL FLOW. HOWEVER, THE
GFS IS SLOWING ITS PROGRESSION AND BEGINNING TO PINCH UPPER LEVEL
CONTOURS SUGGESTING THAT A CUT-OFF LOW MAY NOT BE OUT OF THE
QUESTION. WITH THE SLOWER GFS AND MEANDERING CUT-OFF LOW IN THE EC,
HAVE ADDED SOME SLIGHT CHANCES OF A THUNDERSTORM FOR MONO COUNTY ON
FRIDAY PRIMARILY OVER HIGHER TERRAIN. IF THE GFS CONTINUES TO TREND
TOWARDS THE EC, WE MAY NEED TO EXPAND SHOWER AND THUNDERSTORM
COVERAGE ON FRIDAY. BOYD

AVIATION...

WINDS AND MECHANICAL TURBULENCE WILL BE THE PRIMARY THREATS OVER THE
NEXT COUPLE OF DAYS AS SOUTHWESTERLY FLOW STRENGTHENS AHEAD OF AN
APPROACHING TROUGH. STILL VALLEY GUSTS SHOULD ONLY BE IN THE 25 TO
30 KT RANGE AT SIERRA AND WESTERN NEVADA TERMINALS. RIDGE WINDS
WILL BE HIGHER WITH GUSTS AROUND 50 KTS CREATING A FAVORABLE
ENVIRONMENT FOR MECHANICAL TURBULENCE ESPECIALLY ALONG THE EASTERN
SLOPES OF THE SIERRA. ALSO, SHOWERS WILL BE POSSIBLE WITH A
PASSING IMPULSE MONDAY AFTERNOON MAINLY IN THE NORTHERN SIERRA
NORTH OF INTERSTATE 80.

THE NEXT CHANCES OF PRECIPITATION OCCUR LATE IN THE WEEK ON THURSDAY
WHEN A TROUGH PUSHES INTO NORTHERN CALIFORNIA. CONDITIONS WILL BE
UNSTABLE ENOUGH FOR A FEW THUNDERSTORMS ACROSS THE SIERRA INTO
WESTERN NEVADA. MOST OF THE MOISTURE, HOWEVER, WILL BE DISPLACED
INTO SOUTHERN AND EASTERN NEVADA AS MONSOONAL MOISTURE SURGES
NORTHWARD ON THURSDAY. BOYD

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&

$$

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






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.