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
000
FXUS65 KREV 230902
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
202 AM PDT SAT AUG 23 2014

.SYNOPSIS...
COOLER TEMPERATURES WITH LIGHT WINDS AND DRY CONDITIONS WILL
CONTINUE INTO EARLY NEXT WEEK. A WARMING TREND IS EXPECTED
BEGINNING TUESDAY WITH HIGH PRESSURE BUILDING OVER THE WEST.

&&

.SHORT TERM...
FEW CHANGES IN THE SHORT TERM FORECAST WITH COOLER TEMPERATURES THIS
WEEKEND AND INTO THE START OF NEXT WEEK. SURFACE HIGH PRESSURE WILL
BUILD BEHIND THE UPPER LOW THAT PROVIDED OUR WINDS ON FRIDAY. THIS
WILL PRODUCE LIGHT NORTHERLY FLOW ACROSS THE REGION TODAY WITH HIGH
TEMPERATURES STAYING IN THE LOWER TO MID 80S ACROSS WESTERN NEVADA
AND MID 70S ACROSS SIERRA VALLEYS. CLEAR SKIES AND DRIER AIR WILL
ALLOW COLDER SIERRA VALLEYS LOW TEMPS TO DIP NEAR THE FREEZING MARK
TONIGHT THROUGH EARLY NEXT WEEK WITH LOWS IN THE 40S ACROSS COLDER
WESTERN NEVADA VALLEYS.

TEMPERATURES WILL REBOUND BACK INTO THE MID 80S FOR WESTERN NEVADA
AND UPPER 70S FOR THE SIERRA ON SUNDAY WITH CLEAR SKIES AND LIGHT
AFTERNOON BREEZES. BY MONDAY, ANOTHER UPPER LEVEL LOW DROPS ACROSS
THE PACIFIC NORTHWEST AND INTO NORTHERN NEVADA. LATEST MODEL RUNS
HAVE BEEN DIGGING THE TROUGH FURTHER TOWARDS THE SOUTHWEST WITH THE
NAM BEING THE MOST AGGRESSIVE BY DIGGING THE CENTER OF THE LOW ACROSS
FAR NORTHEAST CALIFORNIA. ENSEMBLES SEEM TO SUPPORT THIS SCENARIO
AND HAVE COOLED TEMPERATURES AND INCREASED CLOUD COVER AND WINDS A
BIT AS A RESULT. SOME HINT AT THE POSSIBILITY OF ISOLATED SHOWERS
MAINLY ACROSS THE WESTERN NEVADA BASIN AND RANGE AREA BUT HAVE LEFT
MENTION OF PRECIPITATION OUT OF THE FORECAST AT THIS TIME UNTIL
BETTER AGREEMENT ARISES WITH THE DETERMINISTIC RUNS. FUENTES


.LONG TERM...TUESDAY THROUGH FRIDAY...
ONLY MINOR TWEAKS WERE MADE TO THE INHERITED EXTENDED FORECAST THIS
CYCLE. MEDIUM RANGE OPERATIONAL MODELS ARE IN GENERAL AGREEMENT
THROUGH MOST OF THE PERIOD. THE GEM IS A BIT SLOWER LIFTING THE
UPPER TROUGH OUT OF THE REGION EARLY ON...BUT THEN CATCHES UP TO THE
GFS AND ECMWF. THE GFS REMAINS THE FASTEST WITH BUILDING THE RIDGE
INTO THE REGION.

A WARMING TREND ACCOMPANIES THE BUILDING RIDGE OVER THE REGION
THROUGH THURSDAY WITH ABOVE NORMAL HIGHS AND LOWS EACH DAY. BY LATE
THURSDAY THE ECMWF IS STARTING THE PROCESS OF FLATTENING THE RIDGE A
BIT FASTER THAN THE OTHER MODELS. THE GEFS ENSEMBLE MEMBERS SHOW A
VARYING RANGE OF MODEL SUPPORT BY THIS TIME AS WELL. SOME FLATTEN
THE RIDGE FASTER WHILE OTHERS HOLD ON TO IT INTO FRIDAY.

ALL OF THE OPERATIONAL MODELS ARE SHOWING A REMNANT TROPICAL LOW
LIFTING NORTH IN THE VICINITY OF 30N 130W BY LATE IN THE FORECAST
PERIOD. THE GFS IS THE MOST AGGRESSIVE WITH THIS LOW AND HOLDS IT
TOGETHER THE BEST. THE GFS AND GEM ALSO START TO DIG A LONG WAVE
TROUGH TOWARD THE COAST BY LATE FRIDAY HELPING TO DRAW THIS TROPICAL
SYSTEM NORTH. THE ECMWF IS LESS AGGRESSIVE...KEEPING THE TROUGH AXIS
WELL NORTHWEST OF THE REGION AND THE TROPICAL SYSTEM FARTHER OFF
SHORE. THE GEFS ENSEMBLE MEMBERS SHOW QUITE A SPREAD WITH THIS
SOLUTION.

IF THE GFS IS CORRECT FRIDAY WOULD BE WELL ABOVE NORMAL FOR TEMPS
MOST AREAS BUT ALSO WOULD SEE AN INCREASE IN CLOUD COVER. THE ECMWF
WOULD BE COOLER WITH SLIGHTLY LESS CLOUDS BUT POSSIBLY STRONGER
WINDS. EITHER WAY...CONFIDENCE IN THE LAST DAY OF THE FORECAST AND
BEYOND IS QUITE LOW AT THIS TIME. 20
&&

.AVIATION...
LOW LVL WINDS BECOME MORE NORTHEAST AND LIGHT FOR MOST OF THE AREA
TODAY IN THE WAKE OF A DRY SURFACE FRONT THAT MOVED THROUGH ALL
BUT THE FAR WESTERN AND SOUTHWEST PARTS OF THE AREA LAST NIGHT.
NEAR THE SIERRA WINDS ARE LIKELY TO BE VARIABLE TODAY BUT
STRENGTHEN OVERNIGHT FROM THE EAST.

VFR CONDITIONS THROUGH THE NEXT FEW DAYS WITH CONTINUED LIGHT WINDS.
THE WINDS WILL TURN AROUND TO THE WEST LATE SUNDAY...BUT REMAIN LESS
THAN 15 KTS MOST AREAS. 20
&&


.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.