FXUS66 KHNX 262238
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
238 PM PST THU NOV 26 2009
.SYNOPSIS...
AN APPROACHING STORM SYSTEM WILL BRING A CHANCE OF RAIN AND
MOUNTAIN SNOW ACROSS CENTRAL CALIFORNIA LATE FRIDAY AFTERNOON
THROUGH SATURDAY. POSSIBLE MONO WIND CONDITIONS SATURDAY NIGHT AND
SUNDAY OVER THE SIERRA NEVADA AND FOOTHILLS NORTH OF KINGS CANYON.
&&
.DISCUSSION...UPPER RIDGE SHIFTING EAST TOWARD THE ROCKIES WITH AN
UPPER LOW OVER THE PACIFIC NORTHWEST COAST POISED TO DROP SOUTH
INTO CALIFORNIA FRIDAY. HIGH CLOUDS WILL BEGIN TO MOVE INTO
CENTRAL CALIFORNIA TONIGHT WITH INCREASING CLOUDS FRIDAY AS THE
TROUGH DROPS TOWARD THE BAY AREA. THE NAM DROPS THE LOW SOUTHWARD
ALONG THE COAST WHILE THE ECMWF AND GFS HAVE BEEN CONSISTENT IN
TRACKING THE LOW FARTHER INLAND OVER COASTAL MOUNTAINS AND SAN
JOAQUIN VALLEY. THIS FURTHER INLAND TRACK IS THE FAVORED SOLUTION.
PRECIPITATION IS EXPECTED TO BEGIN SPREADING INTO THE NORTHERN
PART OF THE CWFA FRIDAY AFTERNOON...THEN OVER THE ENTIRE AREA
EXCEPT THE KERN DESERT FRIDAY NIGHT AND INTO SATURDAY. THIS DOES
NOT LOOK LIKE A MAJOR STORM AT THIS TIME BUT RATHER A LOW QPF
EVENT WITH A SHOT OF MUCH COOLER AIR. THE KERN COUNTY MOUNTAINS
COULD GET A LITTLE SNOW ON FRIDAY NIGHT AND EARLY SATURDAY MORNING
AS THE COLDER AIR ARRIVES AND SNOW LEVELS FALL TO AROUND 4500
FEET. WILL NEED TO WATCH THIS SCENARIO FOR TRAVEL DIFFICULTIES FOR
THOSE TRAVELERS HEADING HOME A DAY EARLY.
AS FAR AS THE THREAT OF THUNDERSTORMS FOR THE VALLEY FRIDAY
EVENING...THE CHANCES LOOK MINIMAL. HOWEVER...WITH 500 MB
TEMPERATURES OF -25C WITH THE CORE OF THE LOW...HAVE MAINTAINED
THE SLIGHT CHANCE FOR NOW.
TEMPERATURES WILL DROP SHARPLY ON SATURDAY AS THE COLDER AIR
SETTLES INTO THE AREA. AS THE LOW PRESSURE SYSTEM EXITS LATER
SATURDAY...SKIES WILL CLEAR AND OVERNIGHT TEMPERATURES MAY DROP
INTO THE LOWER 30S IN THE SAN JOAQUIN VALLEY EARLY SUNDAY
MORNING. THIS WILL GIVE THE POTENTIAL FOR FROST AS WELL AS PATCHY
FOG SATURDAY NIGHT AND SUNDAY MORNING. ANOTHER PROBLEM AS THIS
SYSTEM EXITS THE REGION IS THE POTENTIAL FOR MONO WINDS OVER THE
SIERRA NEVADA AND FOOTHILLS. FORECAST MODELS ARE IN PRETTY GOOD
AGREEMENT IN PROJECTING THE INGREDIENTS FOR A MONO WIND EVENT
SATURDAY NIGHT AND EARLY SUNDAY MORNING WILL A 100KT NORTHEAST JET
AND STRONG OFFSHORE SURFACE PRESSURE GRADIENT OVER THE SIERRA
NEAR YOSEMITE. A HIGH WIND WATCH REMAINS IN EFFECT FOR MONO WINDS
DURING THIS TIME PERIOD FOR THE SIERRA NEVADA AND FOOTHILLS.
THE UPPER RIDGE REBUILDS ALONG THE WEST COAST FOR THE EARLY PART
OF THE WEEK FOR DRY WEATHER. THE ECMWF DROPS ANOTHER SYSTEM INTO
THE INTER-MOUNTAIN WEST...CREATING A NORTHERLY FLOW ALOFT OVER
CALIFORNIA WITH ONLY SMALL DAY TO DAY CHANGES IN TEMPERATURES
THROUGH MID WEEK.
&&
.AVIATION...
MVFR VISIBILITIES DUE TO HAZE WILL CONTINUE IN THE SAN JOAQUIN
VALLEY THROUGH 18Z FRIDAY WITH LOCAL IFR/LIFR IN FOG FROM 08Z-16Z
FRIDAY. INCREASING CLOUDS WITH PRECIPITATION MOVING IN FROM THE
NORTH AFTER 20Z FRIDAY RESULTING IN AREAS MVFR CIGS AND VSBYS ALONG
WITH MOUNTAIN OBSCURATIONS. OTHERWISE...VFR CONDITIONS WILL PREVAIL
ELSEWHERE ACROSS THE CENTRAL CA INTERIOR THROUGH 00Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY NOVEMBER 27 2009... FIREPLACE/WOOD STOVE BURNING IS
PROHIBITED IN KERN AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM SATURDAY EVENING THROUGH SUNDAY MORNING FOR
CAZ093-096.
&&
$$
PUBLIC...BEAN
AVN/FW...DCH
WEATHER.GOV/HANFORD
