FXUS66 KHNX 091650
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
850 AM PST WED DEC 9 2009

.SYNOPSIS...
COLD TEMPERATURES CONTINUE TODAY AND TOMORROW AS ARCTIC AIRMASS 
REMAINS OVER THE AREA. A FRONTAL SYSTEM MOVING INTO THE AREA 
THURSDAY NIGHT WILL WARM TEMPERATURES AND PRODUCE AREAS OF RAIN IN 
THE VALLEY AND MOUNTAIN SNOW THROUGH THE WEEKEND.

&&

.DISCUSSION...ARCTIC AIR CONTINUES TO BE PULLED SOUTHWARD INTO
CENTRAL CA IN A NORTHERLY FLOW ALOFT. THIS BROUGHT ANOTHER MORNING
OF WIDESPREAD SUB-FREEZING TEMPERATURES TO THE SAN JOAQUIN VALLEY
UNDER MAINLY CLEAR SKIES AND LIGHT WINDS. TEMPERATURES ARE NOW ON
THE RISE WITH DAYTIME HEATING AND WILL BE ABOVE FREEZING AT MOST
VALLEY LOCATIONS BY 900 AM PST SO WILL ALLOW THE FREEZE WARNING TO
EXPIRE AT THIS TIME. TEMPERATURES ARE ON TRACK THIS MORNING TO
REACH PROJECTED MAXIMUMS WHICH WILL GENERALLY BE FROM 8 TO 10 DEG
F BELOW CLIMO TODAY. SINCE THE FORECAST FOR TODAY APPEARS TO BE IN
GOOD SHAPE...ONLY UPDATE FOR THIS MORNING WILL BE TO EXPIRE THE
FREEZE WARNING.

IR IS INDICATING THE NEXT PAC SHORTWAVE NEAR 130W SPLITTING APART
AS IT RUNS INTO THE DENSE ARCTIC AIRMASS. AS A RESULT...EXPECT 
SKIES TO REMAIN MAINLY CLEAR ACROSS OUR AREA WELL INTO TONIGHT
WHICH WILL ALLOW FOR TEMPERATURES TO DROP BELOW FREEZING ONCE
AGAIN ACROSS THE CENTRAL AND SOUTH SAN JOAQUIN VALLEY SO WILL
CONTINUE THE FREEZE WARNING FOR THESE AREAS FOR TONIGHT. A
STRONGER SHORTWAVE CURRENTLY NEAR 143W WILL SPREAD INCREASING
CLOUDS AND SOME UVM INTO OUR AREA ON THURSDAY. THIS WILL PROVIDE
OUR AREA WITH A CHANCE OF SOME LIGHT PRECIPITATION BY THURSDAY
AFTERNOON AND WILL HELP MIX OUT THE ARCTIC AIR. MET/MAV GUIDANCE
SUGGESTS MINIMUM TEMPERATURES ON FRIDAY MORNING WILL BE 7-12 DEG F
WARMER AT MOST LOCATIONS SO DO NOT EXPECT ANY FROST IN THE VALLEY
ON THURSDAY NIGHT.

PROGS ARE INDICATING INCREASING WAA ON FRIDAY SPREADING DEEPER
MOISTURE ACROSS OUR AREA BEFORE A POTENTIALLY STRONG STORM ARRIVES
ON SATURDAY SPREADING SIGNIFICANT QPF ACROSS OUR AREA. PROJECTED MEAN
THICKNESS VALUES INDICATE SNOW LEVELS WILL RANGE FROM AROUND 5000
FEET OVER YOSEMITE PARK TO 6000 FEET OVER KERN COUNTY. THE
PRECIPITATION WILL BECOME MORE SHOWERY ON SUNDAY BEHIND THE MAIN
COLD FRONT WHICH IS PROGGED TO CROSS OUR AREA ON SUNDAY MORNING. A
SPECIAL WEATHER STATEMENT WAS ISSUED BY THE PREVIOUS SHIFT TO
HIGHLIGHT THIS POTENTIALLY STRONG STORM.

MEDIUM RANGE PROGS AND THE MAJORITY OF THEIR ENSEMBLE MEMBERS ARE
COMING INTO BETTER AGREEMENT WITH UPPER RIDGING OVER CENTRAL CA 
MONDAY THROUGH WEDNESDAY WITH THE STORM TRACK SHIFTING WELL TO
THE NORTH OF OUR AREA. AS A RESULT...CHANGES WILL BE MADE TO THE
EXTENDED PERIOD IN THE AFTERNOON PACKAGE TO REFLECT A DRIER...AND
FOR THE SAN JOAQUIN VALLEY A FOGGIER...PATTERN.

&&

.AVIATION...
AREAS OF MVFR IN HAZE/MIST IN THE SAN JOAQUIN VALLEY UNTIL 20Z 
TODAY THEN AREAS OF MVFR IN HAZE/MIST RETURNING AFTER 06Z THURSDAY. 
LOCAL IFR CONDITIONS RETURNING IN MIST/FOG THURSDAY MORNING FROM 
10Z-17Z. OTHERWISE...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL 
CA INTERIOR THROUGH 18Z THURSDAY.

&&

.AIR QUALITY ISSUES...
ON WEDNESDAY DECEMBER 9 2009... FIREPLACE/WOOD STOVE BURNING IS
PROHIBITED IN FRESNO COUNTY. FURTHER INFORMATION IS AVAILABLE AT
VALLEYAIR.ORG

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 10 PM THIS EVENING TO 9 AM PST THURSDAY FOR
CAZ089>092.

&&

$$

PUBLIC...DS
AVN/FW...MV
SYNOPSIS...WP

WEATHER.GOV/HANFORD