Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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FXUS66 KHNX 241030
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
330 AM PDT FRI OCT 24 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ALOFT WILL PRODUCE MOSTLY CLEAR SKIES AND A
SLIGHT WARMING TREND TODAY. A WEATHER DISTURBANCE WILL BRING
INCREASING CLOUDS ALONG WITH A COOLING TREND AND WINDY CONDITIONS
OVER THE HIGHER ELEVATIONS BY THE WEEKEND. HIGH PRESSURE WILL
BUILD INLAND BY THE MIDDLE OF NEXT WEEK...BRINGING A RETURN TO
WARMER TEMPERATURES.

&&

.DISCUSSION...
CLEAR SKIES WILL DOMINATE THE REGION TODAY AS HEAVY PRECIP...OVER
THE PACIFIC NORTHWEST...SHIFTS FURTHER NORTH. IR SATELLITE IMAGERY
SHOWING A WELL DEFINED BAROCLINIC LEAF TAKING FORM OVER THE
EASTERN PACIFIC. IR IMAGERY ALONG WITH SURFACE PRESSURE ANALYSIS
HAS THE COLD FRONT SOME 500 MILES DUE WEST OF THE BAY AREA.
THEREFORE...THE WEST COAST WILL REMAIN IN THE WARM SECTOR TODAY AS
SURFACE TEMPERATURES REACH INTO THE UPPER 80S ACROSS THE SAN
JOAQUIN VALLEY. YET...THE RIDGE OVER THE WEST COAST WILL BE SHORT
LIVED AS THE UPPER LEVEL TROUGH...AND ASSOCIATED COLD FRONT IS
PROGGED TO MOVE OVER THE WEST COAST...AS THE CENTRAL CALIFORNIA
INTERIOR ON SATURDAY.

BY SATURDAY...THE INTRODUCTION OF THE NEXT WEATHER DISTURBANCE
WILL ALLOW FOR A GOOD CHANGE IN TEMPERATURES AND WINDS ALONG WITH
A SLIGHT POSSIBILITY OF PRECIP OVER MERCED TO MARIPOSA COUNTIES
AND YOSEMITE NP. MODELS PROGGING A SIX DEG-C DROP IN 850MB
TEMP/S...WHICH COULD TRANSLATE IN SOME 5 TO ALMOST 10 DEG-F DROP
IN SURFACE CONDITIONS. AT THE SAME TIME...COLD FRONT IS PROGED TO
SWEEP ACROSS THE CENTRAL CALIFORNIA INTERIOR ON SATURDAY DURING
THE DAY WHICH WILL LEAD TO WINDY CONDITIONS OVER MOST OF THE
DISTRICT. YET...AS THE TRAJECTORY OF THE STORM SYSTEM MAY REMAIN
MAINLY OVER NORTHERN CALIFORNIA...THE STRONG WINDS MAY ONLY REACH
AREAS FROM FRESNO COUNTY NORTHWARD AND MOSTLY OVER THE HIGHER
TERRAIN OF THE SIERRA NEVADA. FURTHERMORE...UPSLOPE OROGRAPHIC
FLOW MAY CONFINED THE BEST CHANCES OF PRECIP TO THE SIERRA NEVADA
...NORTH OF KERN COUNTY...ON SATURDAY. YET...WILL KEEP A MENTION
OF PRECIP...SLIGHT CHANCE...NORTH OF FRESNO COUNTY ON SATURDAY.

AFTERWARD...THE DISTURBANCE IS EXPECTED TO EXIT THE REGION BY
MONDAY MORNING AS A WEAK RIDGE MOVES ON TO THE WEST COAST. MODELS
SHOW LITTLE AMPLIFICATION OF THE RIDGE PATTERN AS ANOTHER TROF
MOVING INTO CANADA WILL HELP MAINTAIN A WESTERLY FLOW ALOFT.
THEREFORE...WILL NOT SEE A DRAMATIC WARM UP TOWARD THE MIDDLE OF
NEXT WEEK. THEREFORE...WILL MAINTAIN A COOLER FORECAST AFTER THIS
WEEKENDS STORM. THE BIGGEST ISSUE WILL BE WITH THE END OF THE
PERIOD AS MODEL CERTAINTY DROPS OFF TOWARD DAY SEVEN AND EIGHT.
ENSEMBLE MODELS CURRENTLY PLACING A LOT OF UNCERTAINTY TOWARD THE
NEXT OF NEXT WEEK WITH THE RELATIVE MEASURE OF PREDICTABILITY AT
NEAR TEN PERCENT OF DEVELOPING A TROUGH PATTERN BY NEXT FRIDAY.
HOWEVER...AT ISSUE WILL BE THE TIMING OF THE TROUGH MOVING ON TO
THE WEST COAST AND NOT IF A TROUGH WILL DEVELOP. THEREFORE...WILL
INTRODUCE VERY LOW CHANCE OF PRECIP AND NOT EXPECT A TOTALLY DRY
FORECAST. GFS/ECMWF COMING INTO BETTER AGREEMENT AND INTRODUCE THE
TROUGH ON SATURDAY/NOV.01/ OF NEXT WEEK.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR
DURING THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.

&&

.CLIMATE...
             RECORDS
SITE DATE    HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR

KFAT 10-24       95:1959     59:1897     63:1982     36:1956
KFAT 10-25       91:1966     61:1998     62:1982     36:1971
KFAT 10-26       89:2003     57:2004     58:1927     35:1939

KBFL 10-24       95:1959     59:1971     67:1982     32:1912
KBFL 10-25       94:1917     62:1939     66:1982     35:1899
KBFL 10-26       92:2003     58:1996     61:1959     35:1939
&&

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

$$

PUBLIC...MOLINA
AVN/FW...DCH
PREV DISCUSSION...99
SYNOPSIS...MOLINA

WEATHER.GOV/HANFORD



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