000
FXUS66 KHNX 211728
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
928 AM PST SAT NOV 21 2009

.SYNOPSIS...EXPECT COOLER TEMPERATURES TODAY IN THE WAKE OF THE COLD
FRONT THAT PASSED THROUGH THE AREA. HIGH PRESSURE WILL RETURN WITH
DRY CONDITIONS AND GRADUALLY WARMING TEMPERATURES THROUGH THE END OF
THE WEEK.

.DISCUSSION...

TYPICAL UPSLOPE CLOUDS BANKED ALONG THE NORTH AND WEST FACING
SLOPES OF THE TEHACHAPI MOUNTAINS THIS MORNING WITH SOME LIGHT
PRECIP EXPECTED AS THE TROUGH MOVES THROUGH TODAY. CURRENT FORECAST
LOOKS ON TRACK AS SOME CLOUDS ARE EXPECTED TO DEVELOP ACROSS THE
SIERRA CREST TODAY. FOG IS EXPECTED TO DEVELOP IN THE VALLEY
TONIGHT. TEMPS WILL BE BELOW NORMAL TODAY AND TONIGHT.

.PREV DISCUSSION... /ISSUED 257 AM PST SAT NOV 21 2009/

DISCUSSION...INITIAL FRONTAL BOUNDARY HAS PUSHED WELL INTO KERN
COUNTY AND A EXPECTED THE PRECIPITATION WAS RATHER LIGHT. RADAR
DOES CONTINUE TO SHOW SOME NORTHWARD BOUND ECHOES FROM FRESNO
NORTH INTO YOSEMITE AND THIS SCENARIO IS MOST LIKELY CAUSED BY A
SECONDARY SHORTWAVE TROUGH NOW PUSHING RAPIDLY ACROSS NORTHERN
CALIFORNIA. IN THE VERY FAST FLOW ACROSS NORTHERN CALIFORNIA
FORECAST MODELS RACE YET ANOTHER SHORT WAVE ACROSS THE NORTH STATE
TONIGHT HOWEVER THIS FEATURE SHOULD PASS WELL TO THE NORTH OF THE
HANFORD FORECAST AREA. FOR THE NEXT SEVERAL HOURS THE ISOLATED
RAIN AND SNOW SHOWERS OVER THE EAST SAN JOAQUIN VALLEY AND THE
SIERRA WILL CONTINUE AND THEN DECLINE BY SUNRISE. MEANWHILE OVER
KERN COUNTY THE UPSLOPE FLOW WILL WRING OUT SOME PRECIPITATION
ALONG THE TEHACHAPI AND GRAPEVINE AREA MOUNTAINS. BEGINNING LATER
SUNDAY A RIDGE OF HIGH PRESSURE IS PROJECTED BY ALL MODELS TO
BUILD OVER CALIFORNIA AND THIS WILL QUITE EFFECTIVELY PUSH THE
STORM TRACK WELL NORTH INTO THE PACIFIC NORTHWEST. THROUGH
WEDNESDAY GOOD AGREEMENT REMAINS BETWEEN THE GFS AND ECMWF MODELS
IN KEEPING THE RIDGE IN PLACE HOWEVER ON THANKSGIVING THE ECMWF
BREAKS DOWN THE RIDGE AND DRIVES A SHORTWAVE TROUGH INTO NORTHERN
CALIFORNIA WHILE THE GFS KEEPS THE STRONG ANTICYCLONE IN PLACE. FOR
CENTRAL CALIFORNIA IT WILL BE DRY EITHER WAY INTO THE WEEKEND. AT
THIS POINT I DONT SEE ANY TRAVEL PROBLEMS FOR THE BIG
THANKSGIVING TRAVEL PERIOD OUTSIDE OF MORNING FOG IN THE SAN
JOAQUIN VALLEY. WILL NEED TO WATCH JUST IF AND HOW WIDESPREAD THE
FOG MIGHT GET UNDER A RIDGE IN LATE NOVEMBER.

.AVIATION...
LOW CLOUDS ARE VERY SLOWLY ERODING ACROSS THE TEHACHAPI MOUNTAINS
AND ADJACENT FOOTHILLS. MOUNTAIN WAVE CLOUDS EVIDENT ON VISB SAT
THIS MORNING ON THE SOUTHEASTERN SIDE OF THE TEHACHAPIS. LOW CLOUDS
ALSO SLOW TO ERODE ACROSS THE SOUTHERN EXTENT OF THE SIERRA. SOME
RAIN/SNOW SHOWERS ALSO POSSIBLE IN THE UPSLOPE SECTIONS OF THE
SOUTHERN SIERRA AND TEHACHAPIS THROUGH 22Z THIS AFTERNOON. THESE
CLOUDS SHOULD SCATTER OUT THIS AFTERNOON BUT WILL BE SLOWEST IN THE
TEHACHAPIS. GUSTY WINDS TO AFFECT THE TAF SITES THIS AFTN...WITH
G20KTS OR SO LIKELY. VALLEY FOG LIKELY AT THE TERMINALS TONIGHT WITH
LIFR PREDICTED AT ONLY KVIS FOR NOW AND IFR TO MVFR AT THE OTHER
SITES.

.AIR QUALITY ISSUES...
NONE

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.

PUBLIC...JDB
AVN/FW...BROTHERTON

WEATHER.GOV/HANFORD