FXUS66 KHNX 270405
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
805 PM PST THU NOV 26 2009
.SYNOPSIS...
PATCHY MORNING FOG WILL CONTINUE TO BE A CONCERN FOR THE VALLEY LATE
TONIGHT AND EARLY MORNING HOURS FRIDAY. A CHANCE OF RAIN FRIDAY NIGHT
AND SATURDAY IS EXPECTED.
&&
.DISCUSSION...
AN UPPER-LEVEL RIDGE DOMINATED THE WEATHER ACROSS THE CENTRAL
CALIFORNIA INTERIOR TODAY...WITH A BROAD SURFACE HIGH EXTENDING FROM
THE EASTERN PACIFIC ACROSS CALIFORNIA INTO THE DESERT SOUTHWEST. IN
THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY...TODAY/S HIGHS AS OF 00Z
FRIDAY /1600 PST TODAY/ RANGED FROM 70 /AT MERCED MUNICIPAL AIRPORT/
TO 75 DEGREES /AT COALINGA/. THERE WAS A THREE-WAY TIE FOR THE
WARMEST SPOT IN THE HANFORD WARNING/FORECAST AREA...WITH COALINGA...
ISABELLA DAM AND THE RIVER KERN RAWS ALL REPORTING A HIGH OF 75.
FRESNO/S HIGH OF 72 DEGREES WAS ONLY 3 DEGREES SHY OF ITS RECORD FOR
TODAY OF 75 DEGREES...SET IN 1914. THE RECORD HIGH FOR BAKERSFIELD
FOR TODAY IS 90 DEGREES...SET IN 1907. THIS IS THE LATEST 90-DEGREE
RECORD IN THE YEAR FOR BAKERSFIELD. THE NEXT 90-DEGREE RECORD FOR
BAKERSFIELD IS MARCH 11TH...WITH A RECORD HIGH OF 94 SET IN 1916.
/FRESNO/S LATEST 90-DEGREE RECORD WAS ON OCTOBER 31ST...WHEN IT
REACHED 90 IN 1949. FRESNO/S RECORD HIGH WILL NOT REACH 90 AGAIN
UNTIL MARCH 17TH...WHEN IT HIT 90 IN 1972./
CONSIDERABLE CHANGES WILL OCCUR THE OVER THE NEXT 48 HOURS AS A
DEVELOPING PACIFIC STORM REACHES CENTRAL CALIFORNIA LATE FRIDAY
AFTERNOON. BOTH THE MODELS AND RFC GUIDANCE CONTINUE TO TREND
TOWARD A WET SOLUTION...WITH THE LATEST /21Z/ RFC GUIDANCE
FORECASTING A QPF OF 0.08 INCH FOR FRESNO...0.33 INCH FOR YOSEMITE
AND 0.23 INCH FOR GIANT FOREST IN THE TULARE COUNTY MOUNTAINS. THE
QPF FOR YOSEMITE IS IN AGREEMENT WITH THOSE OF THE 00Z NAM AND 18Z
GFS...BUT IS WETTER FOR GIANT FOREST THAN THE 00Z NAM /0.13 INCH/
ALTHOUGH CONSIDERABLY DRIER THAN THE 18Z GFS /0.65 INCH/.
SNOW LEVELS WILL START AROUND 6500 FEET AT YOSEMITE FRIDAY AFTERNOON
BUT DROP TO AROUND 4500 FEET BY SATURDAY MORNING. FURTHER SOUTH...
THE SNOW LEVEL WILL BE AROUND 5500 FEET FRIDAY NIGHT...FALLING TO
AROUND 4500 FEET SATURDAY. THE SNOW LEVEL IN THE PIUTES WILL START
OUT NEAR THE LEVEL OF THE WALKER PASS...THEN DROP ALLOWING SOME
ACCUMULATION AT THE CREST OF THE PASS. BY SATURDAY...THE SNOW LEVEL
WILL BE NEAR THE CREST OF GRAPEVINE AND TEHACHAPI PASS. AS THIS WILL
IMPACT TRAVEL ON INTERSTATE 5 AND HIGHWAYS 58 AND 178...HAVE ISSUED
A SPECIAL WEATHER STATEMENT /SFOSPSHNX OR WWUS86 KHNX/ ON IMPACTS OF
THE WEATHER ON TRAVEL DURING THE THANKSGIVING HOLIDAY WEEKEND.
A CLOSED LOW IS FORECAST TO DEVELOP OVER COASTAL CENTRAL CALIFORNIA
IN THE BASE OF THE TROUGH BY 06Z SATURDAY. AS THE TROUGH MOVES SOUTH
OF THE HANFORD WARNING/FORECAST AREA SATURDAY NIGHT...A STRONG UPPER-
LEVEL NORTHEAST JET DIVES DOWN THE BACK OF THE TROUGH...WHILE AT THE
SURFACE...A STRONG OFFSHORE PRESSURE GRADIENT TIGHTENS. THIS PATTERN
POTENTIALLY COULD SUPPORT THE DEVELOPMENT OF MONO WINDS OVER THE
SOUTHERN SIERRA NEVADA SATURDAY NIGHT INTO SUNDAY MORNING...SO WILL
LEAVE THE HIGH WIND WATCH IN PLACE.
&&
.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 06Z 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
&&
.PREV DISCUSSION... /ISSUED 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
THE FOOTHILLS AND HIGHER ELEVATIONS OF THE SOUTHERN SIERRA NEVADA
FROM YOSEMITE NATIONAL PARK TO KINGS CANYON /CAZ093-096/.
&&
$$
PUBLIC/FW...SANGER
AVN.........BSO
PREVIOUS DISCUSSION...PUBLIC...BEAN
AVN/FW...DCH
WEATHER.GOV/HANFORD
