FXUS66 KHNX 260412
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
812 PM PST FRI DEC 25 2009
.SYNOPSIS...
HIGH PRESSURE PREVAILS THROUGH THE REST OF THIS WEEK...COLD AIR IS
IN PLACE WITH AREAS OF FREEZING TEMPERATURES AS WELL AS PATCHY FOG
EXPECTED OVERNIGHT TONIGHT THROUGH SATURDAY MORNING IN THE SAN
JOAQUIN VALLEY. A SERIES OF LOW PRESSURE SYSTEMS COULD BRING
UNSETTLED CONDITIONS SUNDAY THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...
WESTERN CONUS RIDGE KEEPING CLEAR SKIES ACROSS OUR AREA THIS
EVENING. THE RIDGE IS HAVING DIFFICULTY MOVING FURTHER INLAND
BECAUSE OF A LARGE RETROGRADING LOW PRESSURE SYSTEM OVER THE
MIDWEST WHICH HAS BASICALLY STALLED THE EASTWARD MOVEMENT OF
SYSTEMS BEHIND IT. THE MODELS HAVE HAD DIFFICULTY WITH THIS
PATTERN...BUT AFTER THE 12Z MODELS SHOWED SOME PROGRESSION...THE
18Z WRF/GFS RUNS SLOWED THINGS DOWN AGAIN AND WERE ALSO FURTHER
OFFSHORE WITH A LOW PRESSURE CENTER PROGGED TO DROP SOUTHWARD OFF
THE CA ON SUNDAY THEN CROSS BAJA MONDAY AND MONDAY NIGHT. IN THE
MEANTIME OUR AREA WILL HAVE ANOTHER MOSTLY CLEAR NIGHT.
TEMPERATURES ARE GENERALLY RUNNING 2-3 DEG F ABOVE YDAY AND ARE ON
TRACK TO REACH PROJECTED MINIMUMS TONIGHT. AM THEREFORE NOT
PLANNING TO UPDATE THIS EVENING. OTHER THAN SOME PATCHES OF
MORNING FOG IN THE SAN JOAQUIN VALLEY DO NOT EXPECT SIGNIFICANT
WEATHER ON SATURDAY.
AS THE APPROACHING LOW NEAR 138W PUSHES IT/S WAY TOWARD THE CA
COAST. THE BAND OF MID/HIGH CLOUDS OUT AHEAD OF IT WILL INCH IT/S
WAY CLOSER TO US AND SPREAD INCREASING CLOUDS OVER OUR AREA ON
SATURDAY AND SATURDAY NIGHT. THE LOW MEANWHILE WILL THEN HIT THE
LOG JAM IN FRONT OF IT AND RIDE NORTHWARD AHEAD OF THE RIDGE WHILE
IT PULLS ANOTHER LOW SOUTHWARD OFF THE CA COAST ON SUNDAY BEHIND
IT. DON/T EXPECT MUCH IN THE WAY OF MOISTURE/QPF FROM THE SYSTEM
TO AFFECT OUR AREA...BUT THERE WILL BE SLIGHT CHANCE OT LOW CHANCE
OF LIGHT SHOWERY PRECIPITATION ACROSS MOST OF OUR AREA ON SUNDAY
WITH THE SNOW LEVEL RANGING FROM AROUND 5000 AT YOSEMITE PARK TO
AROUND 5500 FEET OVER KERN COUNTY. THE SHOWERS ARE EXPECTED TO
TAPER OFF ON SUNDAY NIGHT AS THE LOW NEARS BAJA THEN A QUIETER
DAYS IS EXPECTED ON MONDAY ALTHOUGH DEFORMATION WILL LIKELY KEEP
SOME MID/HIGH CLOUDS OVER OUR AREA.
LOW CONFIDENCE EXISTS FOR TUESDAY ONWARD BASED ON THE FACT THE THE
MODELS ARE NOT HANDLING THE MIDWESTERN STORM THAT WELL WHICH
SUBSEQUENTLY IMPACTS THE UPSTREAM PATTERN. THE MODEL CONSENSUS
HOWEVER...HINTS AT THE STORM TRACK REMAINING NORTH OF OUR AREA FOR
MUCH OF NEXT WEEK SO WHILE SOME SYSTEMS MAY GRAZE THE NORTHERN
PORTION OF OF OUR CWFA AT TIMES...DO NOT EXPECT ANY MAJOR STORMS
TO IMPACT OUR AREA FOR THE REMAINING OF THE CALENDER YEAR.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...PATCHY FOG DEVELOPING TONIGHT IN LOW
LYING AREAS RESULTING IN AREAS OF MVFR AND LOCAL IFR VISIBILITIES IN
FREEZING FOG THROUGH 17Z. HIGH LEVEL CLOUDS WILL BE ON THE INCREASE
DURING SATURDAY AFTERNOON AS AN AREA OF LOW PRESSURE APPROACHES THE
COAST. HOWEVER CONDITIONS ARE EXPECTED TO REMAIN VFR ACROSS THE
REMAINDER OF THE CENTRAL CA INTERIOR THROUGH 06Z SUNDAY.
&&
.AIR QUALITY ISSUES...
ON SATURDAY DECEMBER 26 2009... UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO AND KERN COUNTIES. FIREPLACE/WOOD STOVE BURNING IS
PROHIBITED IN FRESNO... KERN... KINGS AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...DS
AVN/FW...DUDLEY
SYNOPSIS...PJ
WEATHER.GOV/HANFORD
