FXUS66 KHNX 241306
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
506 AM PST THU DEC 24 2009
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH THE END OF THE WEEK...PROVIDING
FROSTY NIGHTS AND SEASONABLY COOL DAYS. A SERIES OF LOW PRESSURE
SYSTEMS WILL BRING UNSETTLED CONDITIONS SUNDAY THROUGH THE MIDDLE
OF NEXT WEEK.
&&
.DISCUSSION...A WEST COAST UPPER RIDGE IS PROVIDING CLEAR SKIES
AND LIGHT WINDS ACROSS INTERIOR CENTRAL CALIFORNIA...AND WITH A
RELATIVELY COLD AND DRY AIRMASS IN PLACE TEMPERATURES HAVE FALLEN
TO FREEZING OR BELOW ACROSS MUCH OF THE SAN JOAQUIN VALLEY. SOME
OF THE COLDER LOCATIONS ARE CURRENTLY IN THE UPPER 20S. A FREEZE
WARNING REMAINS IN EFFECT THIS MORNING AS TEMPERATURES WILL
CONTINUE TO DROP A FEW MORE DEGREES THROUGH DAYBREAK.
THE AIRMASS WILL MODIFY A BIT DURING THE NEXT COUPLE OF DAYS AS
THE RIDGE REMAINS OVERHEAD...PRODUCING A SLIGHT WARMUP THROUGH THE
END OF THE WEEK. THERE SHOULD BE FROSTY CONDITIONS IN THE VALLEY
AGAIN TONIGHT BUT EXPECTED TO MAINLY STAY ABOVE 28 DEGREES.
A WEAKENING SHORTWAVE TROUGH IS PROGGED TO BRUSH THE DISTRICT
SATURDAY AND SATURDAY NIGHT WITH ADDITIONAL ENERGY FOLLOWING
BEHIND ON SUNDAY AND SUNDAY NIGHT. MODELS HAVE SOME DIFFERENCES IN
TIMING AND TRAJECTORY OF THE SECONDARY SHORTWAVE IMPULSE BUT
GENERALLY DROP IT SOUTHEAST TOWARD SOUTHERN CALIFORNIA/NORTHERN
BAJA. THIS SYSTEM WILL PROVIDE SLIGHT CHANCE TO CHANCE POPS ACROSS
THE DISTRICT SATURDAY NIGHT INTO MONDAY. MODEL DIFFERENCES
CONTINUE WITH THE NEXT APPROACHING SHORTWAVE TROUGH. FOR NOW...A
RATHER BROAD BRUSHED EXTENDED FORECAST SUFFICES...WITH TEMPERATURES
HOLDING NEAR CLIMO THROUGH THE MIDDLE OF NEXT WEEK AND JUST SOME
SLIGHT CHANCE POPS...MAINLY OVER THE MOUNTAIN ZONES. &&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...VFR EXCEPT AREAS OF MVFR AND LOCAL IFR
VISIBILITIES IN HAZE AND MIST THROUGH 19Z THURSDAY AND AGAIN AFTER
06Z FRIDAY. REMAINDER OF THE CENTRAL CA INTERIOR...VFR THROUGH 12Z
FRIDAY.
&&
.AIR QUALITY ISSUES...
NONE
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 8 AM PST THIS MORNING FOR CAZ089>092.
&&
$$
PUBLIC...JEB
AVN/FW...DCH
SYNOPSIS...TLM
WEATHER.GOV/HANFORD
