261
FXUS65 KREV 072235
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
235 PM PST SAT NOV 7 2009
SHORT TERM
UPPER LOW IN THE GULF OF ALASKA WILL KEEP THE JET DIRECTED INTO
THE WEST COAST THROUGH EARLY NEXT WEEK. MODELS REMAIN IN GOOD
AGREEMENT THAT BULK OF THE MOISTURE AND LIFT REMAINS NORTH OF THE
FORECAST AREA. MODELS HAVE SLOWED THE PROGRESSION OF THE STRONGEST
PIECE ENERGY UNTIL MID WEEK. OVERALL CONDITIONS WILL BE DRY WITH
A SLOW WARMING TREND AND THE POTENTIAL FOR BREEZY CONDITIONS
TUESDAY.
LOW THE NEXT COUPLE NIGHTS WILL BE COLD AS LIGHT WINDS...NEARLY
CLEAR SKIES...AND DRY AIR MOVING INTO THE AREA ALLOW FOR GOOD
RADIATIONAL COOLING. SOME POTENTIAL FOR FOG IN THE SIERRA VALLEYS
FROM TRUCKEE NORTHWARD DUE TO RECENT RAINS. THERE WILL BE A DRY
NORTHEAST FLOW SETTING UP OVER THE SIERRA LATE TONIGHT THAT SHOULD
PREVENT FOG FROM DEVELOPING.
SINCE THE MODELS KEEP THE ENERGY NORTH OF THE AREA REDUCED
RAIN/SNOW CHANCES MONDAY NIGHT THROUGH TUESDAY NIGHT. THERE IS LOW
CHANCE SHOWERS FOR THE NORTHERN AREAS WITH THE JET AND POCKETS OF
MOISTURE PASSING OVER THE NORTHERN AREAS. LACK OF A LIFTING
MECHANISM AND DRY SURFACE LAYERS WILL LIMIT SHOWER DEVELOPMENT AND
RAIN REACHING THE GROUND.
DID INCREASE WINDS WITH THE STRONGER FLOW ALOFT FOR MONDAY AND
TUESDAY. GFS/NAM SHOWING PERIODS OF 30-40KT 700MB FLOW MONDAY
INTO TUESDAY NORTH OF I-80...SO THERE IS POTENTIAL FOR BREEZY
CONDITIONS. SURFACE GRADIENTS INCREASE TUESDAY...WHICH LOOKS LIKE
THE WINDIER DAY.
TEMPERATURES SHOULD BE SLOW TO INCREASE DUE TO LIGHT SURFACE
SUNDAY SURFACE WINDS SHOULD INCREASE OR AT LEAST BE FROM THE SOUTH
ON MONDAY AND TUESDAY...WHEN THE APPROACHING WAVE TURNS THE FLOW
TO THE SOUTHWEST AND HELPS TO MIX OUT THE LOWER VALLEYS. BRONG
LONG TERM...WEDNESDAY THROUGH SATURDAY
NO MAJOR CHANGES TO LONG TERM. SECOND HALF OF NEXT WEEK STILL
UNCERTAIN...ALTHOUGH GOOD CONFIDENCE OVERALL IN THE TROUGHING OVER
THE WESTERN STATES. A PAIR OF SHORTWAVES WILL MOVE THROUGH THE
MEAN TROUGH...WITH MODELS REALLY HAVING A HARD TIME RESOLVING THE
DETAILS OF THE PATTERN. TEMPERATURES WILL BE BELOW NORMAL AFTER
WEDNESDAY...WITH SOME CHANCE FOR LIGHT PRECIP IN THE EASTERN
SIERRA AND SIERRA FRONT THROUGH MUCH OF THE LONG TERM.
THE FIRST WAVE LOOKS TO BE COMING THROUGH ON WED TO WED NIGHT.
INCREASED POPS TO REFLECT A BETTER CHANCE OF RAIN-SNOW IN THE
SIERRA. THIS WAVE HAS BEEN TRENDING SLOWER EACH DAY IN THE
MODELS...SO DON'T REALLY HAVE MUCH STOCK IN IT...BUT BOTH GFS AND
ECMWF IN BETTER AGREEMENT NOW WITH THE TIMING OF THE FIRST WAVE. DID
INCREASE TEMPS FOR WEDNESDAY...AS THE SLOWER TIMING OF THE TROUGH
WILL ALLOW FOR CONTINUED SOUTHWEST WARM FLOW. LOWERED TEMPS FOR
THU-FRI...NORTHEASTERLY POST-FRONTAL FLOW SHOULD KEEP US COOL. WE
MAY NEED TO LOWER TEMPS EVEN FURTHER IF THE GFS PANS OUT. AFTER
THIS SHORTWAVE MOVES THROUGH THE SECOND WAVE WILL MOVE ACROSS
NORTHERN CA/NV ON BY FRIDAY..GIVING US ANOTHER SHOT AT LIGHT
PRECIP. HOON
AVIATION
VFR THROUGH SUNDAY...WITH GUSTS OUT OF THE WEST UP TO 18 KTS
BECOMING LIGHT VARIABLE. 50-50 CHANCE OF FREEZING FOG AT KTRK
TONIGHT AND EARLY SUNDAY MORNING. WILL LEAVE IT OUT OF THE FORECAST
FOR NOW...DUE TO LIGHT EAST FLOW AND DRYING CONDITIONS TONIGHT...BUT
STILL HAVE A CHANCE OF A FEW HOURS OF IFR CONDS SUNDAY MORNING. HOON
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
HTTP://WEATHER.GOV/RENO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page