Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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000
FXUS66 KHNX 310942
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
242 AM PDT FRI OCT 31 2014

.SYNOPSIS...
THE FIRST SIGNIFICANT STORM OF THE WINTER SEASON WILL ARRIVE IN
CENTRAL CALIFORNIA THIS AFTERNOON. RAIN WILL SLIDE INTO THE VALLEY
FROM THE NORTHWEST BEGINNING LATE IN THE AFTERNOON AND COVER MOST
AREAS BY LATE IN THE EVENING. LIKEWISE SNOW WILL BEGIN FALLING IN
THE SIERRA FRIDAY AFTERNOON ABOVE 7500 FEET AT FIRST FALLING TO 5500
FEET BY SATURDAY MORNING. IN THE END MOST AREAS OF THE VALLEY SHOULD
SEE AT LEAST A QUARTER INCH OF RAIN...WITH OVER A FOOT OF SNOW
LIKELY ACROSS THE HIGH SIERRA. TEMPERATURES WILL BE MUCH COOLER THIS
WEEKEND AND SOME FOG WILL BE POSSIBLE SUNDAY AND MONDAY. QUIET AND
WARMER WEATHER WILL RETURN MONDAY AND CONTINUE THROUGH NEXT WEEK
&&

.DISCUSSION...AN UPPER TROUGH REMAINS JUST OFF THE CALIFORNIA
COAST THIS MORNING WITH AN ASSOCIATED COLD FRONT BEGINNING TO
NUDGE INTO NORTHERN CALIFORNIA. THE UPPER TROUGH WILL CONTINUE TO
MOVE EAST INTO CENTRAL CALIFORNIA TODAY INTO EARLY TOMORROW
MORNING. RAIN OVER COASTAL NORTHERN CALIFORNIA IS FORECAST TO
SPREAD SOUTH INTO THE REGION THIS AFTERNOON...IMPACTING THE ENTIRE
REGION BY MIDNIGHT.

THE HIGH RES ARW...THE HRRR...AND THE SREF ALL INDICATE THAT RAIN
WILL MOVE SOUTHEAST INTO FAR NORTHWEST MERCED COUNTY BY 2 PM
PDT...SPREADING SOUTH INTO FRESNO COUNTY BETWEEN 6 PM AND 8
PM...AND INTO KERN COUNTY BY 10 PM. FORECASTER CONFIDENCE IS HIGH
WITH TIMING AS THE SHORT RANGE HIGH RES MODELS ARE IN VERY GOOD
AGREEMENT.

IN ADDITION TO RAIN...THUNDERSTORMS WILL BE POSSIBLE AS THE STORM
SYSTEM MOVES INTO THE AREA...WITH THE SHORT RANGE MODELS
INDICATING DECENT SURFACE INSTABILITY. THE GREATEST THREAT FOR
THUNDERSTORMS WILL BE LATER THIS AFTERNOON INTO EARLY SATURDAY
MORNING...WHERE SURFACE CAPE VALUES PEAK BETWEEN 600 AND 700 J/KG.

SNOW LEVELS WILL ALSO DROP SIGNIFICANTLY AS COLD AIR FILTERS INTO
THE AREA BEHIND THE COLD FRONT. SNOW LEVELS WILL DROP FROM 8500 FT
ON FRIDAY AFTERNOON TO AROUND 5500 FEET BY SATURDAY MORNING. THE
HIGH SIERRA COULD EASILY SEE OVER A FOOT OF SNOW BY SATURDAY
MORNING.

AS FAR AS RAIN TOTALS GO...THE VALLEY COULD SEE BETWEEN A THIRD OF
AN INCH TO NEARLY TWO-THIRDS OF AN INCH BY SATURDAY MORNING. THE
DESERT LOCATIONS WILL SEE A BIT LESS...BETWEEN A FEW HUNDREDTHS TO
AROUND TWO-TENTHS OF AN INCH.

THE UPPER TROUGH IS FORECAST TO SHIFT SLOWLY SOUTH INTO SOUTHERN
CALIFORNIA SATURDAY EVENING INTO SUNDAY MORNING...BRINGING THE
REGION SCATTERED SHOWERS INTO LATE SATURDAY NIGHT. THE SIERRA WILL
LIKELY PICK UP ANOTHER FEW QUICK INCHES OF SNOW...HOWEVER TIMING
AND LOCATION OF THESE SNOW SHOWERS WILL BE DIFFICULT TO NAIL DOWN.

BY SUNDAY AFTERNOON...UPPER LEVEL NORTHERLY FLOW WILL DOMINATE THE
AREA...KEEPING THE REGION DRY AND COOL. TEMPERATURES ON SUNDAY
WILL BE SIMILAR TO THOSE ON SATURDAY...WITH VALLEY TEMPERATURES IN
THE MID 60S.

HIGH PRESSURE WILL SLOWLY BEGIN TO BUILD OVER THE AREA MONDAY INTO
THE FIRST HALF OF THE WEEK...RESULTING IN A WARMING AND DRYING
TREND. BY THURSDAY...VALLEY TEMPERATURES WILL RANGE FROM THE MID
70S TO LOW 80S...NEARLY 10 DEGREES ABOVE NORMAL FOR THE BEGINNING
OF NOVEMBER.

&&

.AVIATION...
AREAS OF MVFR AND LOCAL IFR CONDITIONS WILL DEVELOP AFTER 22Z FRIDAY
AS PRECIPITATION MOVES OVER MERCED COUNTY. PRECIPITATION WILL SPREAD
SOUTHEASTWARD ACROSS THE CENTRAL CALIFORNIA INTERIOR DURING THE
EVENING. OTHERWISE...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 HIGH.

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 10-31       90:1949     57:1974     61:2008     32:1972
KFAT 11-01       88:1966     58:1935     61:2008     33:1971
KFAT 11-02       88:1949     53:1957     56:2012     34:1946

KBFL 10-31       92:1949     55:1923     65:2008     33:1935
KBFL 11-01       90:1966     58:2003     64:2008     30:1907
KBFL 11-02       89:1949     60:1947     58:1992     31:1935
&&

.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 11 AM PDT
SATURDAY ABOVE 7000 FEET FOR THE CAZ097.

WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 11 AM PDT
SATURDAY ABOVE 6000 FEET FOR THE CAZ096.

&&

$$

PUBLIC...RILEY
AVN/FW...MOLINA
SYNOPSIS...WP

WEATHER.GOV/HANFORD



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