FXUS66 KHNX 040526
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
926 PM PST THU DEC 3 2009
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE OVER THE AREA WITH GENERALLY CLEAR
SKIES FOR THE NEXT COUPLE OF DAYS. PATCHY NIGHT AND MORNING FOG
WITH FROST IN THE COOLEST LOCATIONS WILL CONTINUE THROUGH
SATURDAY IN THE SAN JOAQUIN VALLEY. A CHANGE TO A MUCH WETTER
WEATHER PATTERN WILL BEGIN SUNDAY AS THE FIRST IN A SERIES OF
STORMS MOVES ACROSS THE REGION.
&&
.DISCUSSION...
HIGH PRESSURE OVER THE WEST COAST CONTINUES TO DOMINATE THE
WEATHER PATTERN WITH MOSTLY CLEAR MILD AND DRY CONDITIONS
PREVAILING. A DISTURBANCE MOVING OVER THE TOP OF THE RIDGE THROUGH
WESTERN CANADA IS FLATTENING AND SHIFTING THE RIDGE MORE INLAND.
SOME HIGH CLOUDS ARE SPILLING OVER THE TOP OF THE RIDGE AND
DROPPING DOWN THROUGH NORTHERN CALIFORNIA THIS EVENING AND INTO
CENTRAL CALIFORNIA FRIDAY. SURFACE PRESSURE ANALYSIS SHOWS THE
CANADIAN HIGH SLOWLY DRIFTING EAST WITH ITS ASSOCIATED COLD AIR
NOW FLOWING MORE INTO THE GREAT BASIN. CURRENT TEMPERATURES ARE
RUNNING VERY CLOSE TO YESTERDAY IN THE VALLEY AT THIS TIME. SO
WHILE OVERNIGHT LOWS MAY STILL REACH THE FREEZING MARK WITH AREAS
OF FROST...WITH A MORE ONSHORE FLOW ALOFT SURFACE TEMPERATURES ARE
NOT LIKELY TO DROP TO 28 DEG-F AND BELOW. WITH HAZY SKIES AND
CONDITIONS SIMILAR TO THURSDAY MORNING...PATCHY FOG IS LIKELY
TOWARD DAYBREAK...ESPECIALLY IN THE NORMAL FOG PRONE AREAS.
FROM PREVIOUS DISCUSSION /ISSUED 240 PM PST THU DEC 3/...BY
SATURDAY...MODELS SHOW THE DISTURBANCE OVER WESTERN CANADA
DROPPING INTO THE GREAT BASIN WITH SOME UNCERTAINTY ON HOW DEEP
THE TROF MAY BECOME. YET...THE TRAJECTORY IS MORE ONLY AN INSIDE
SLIDER WITH LIMITED MOISTURE. THEREFORE...WHILE THE CHANCE OF
PRECIP REMAINS HIGH...QPF MAY REMAIN AT MINIMAL VALUES. COLD AIR
AND WINDY CONDITIONS MAY BECOME MORE OF AN ISSUE DURING THIS
EVENT. FORECAST DOES MENTION MOUNTAIN RIDGE WIND GUSTING UP TO 50
MPH BY SATURDAY NIGHT AND INTO SUNDAY...PRE-FRONTAL...ALONG WITH
GOOD 250MB JET SUPPORT OF 75KTS TO 85KTS. THE MAIN AREA OF ENERGY
THEN DROPS INTO THE DISTRICT LATER ON SUNDAY WITH PRECIP STARTING
LATE SUNDAY NIGHT. BASED ON THE TRAJECTORY OF THE UPPER TROF...THE
FOCUS OF THE PRECIP WILL BE CONFINED TO MONDAY WITH LINGERING
SHOWERS ON MONDAY NIGHT INTO TUESDAY MORNING. PART OF TUESDAY MAY
DRY OUT BEFORE THE NEXT STORM APPROACH THE WEST COAST AROUND
WEDNESDAY. THIS NEXT STORM WILL HAVE A MORE WESTERLY TRAJECTORY
WITH A BETTER SOURCE OF MOISTURE. WHILE THIS STORM IS FURTHER OUT
IN TIME...WILL NOT GO WITH MORE THEN A CHANCE OF PRECIP AND WAIT
FORE MORE MODEL CONSENSUS ON THE TIMING AND DURATION. THEREFORE...
WILL KEEP WEDNESDAY AND THURSDAY UNSETTLED WITH THE POTENTIAL FOR
PRECIP APPROACHING CLIMO.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...WIDESPREAD MVFR VISIBILITIES IN HAZE
THROUGH 06Z SATURDAY...WITH AREAS IFR AND LCL LIFR IN BR/FG FROM
06Z-18Z FRIDAY. OTHERWISE...VFR CONDITIONS WILL PREVAIL ACROSS THE
CENTRAL CALIFORNIA INTERIOR THROUGH 06Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY DECEMBER 4 2009... UNHEALTHY IN KERN COUNTY. UNHEALTHY
FOR SENSITIVE GROUPS IN FRESNO... KINGS... MADERA AND TULARE
COUNTIES. FIREPLACE/WOOD STOVE BURNING IS PROHIBITED IN FRESNO...
KERN... KINGS... MADERA... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...BEAN
AVN/FW...SANGER
WEATHER.GOV/HANFORD
