Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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000
FXUS66 KHNX 041120
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
420 AM PDT WED MAY 4 2016

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL APPROACH CENTRAL CALIFORNIA TODAY AND
THEN MOVE ACROSS SOUTHERN CALIFORNIA THURSDAY THROUGH SATURDAY. THIS
SYSTEM WILL BRING THE THREAT OF SHOWERS AND THUNDERSTORMS TO MUCH OF
THE REGION ALONG WITH COOLER TEMPERATURES.

&&

.DISCUSSION...
SATELLITE IMAGES SHOW AN UPPER LOW OFF THE CENTRAL CALIFORNIA
COAST. MODERATE SOUTH WINDS AT 50KTS BRINGING AN INCREASE OF MID
TO UPPER LEVEL MOISTURE INTO CENTRAL CALIFORNIA. IR IMAGES SHOW
RAPIDLY COOLING TOPS OVER THE CENTRAL CALIFORNIA COAST DUE TO WIND
SPEED MAX AND DIVERGENCE ALOFT. SATELLITE ESTIMATES OF
PRECIPITABLE WATER RUNNING NEAR 150 PERCENT OF NORMAL. MODELS
INDICATE THE ATMOSPHERE BECOMING UNSTABLE THIS AFTERNOON OVER THE
SIERRA NEVADA AND THE NORTH SECTORS OF THE CENTRAL SAN JOAQUIN
VALLEY. THUS EXPECT INCREASING THREAT OF CONVECTIVE SHOWERS TODAY
WITH ISOLATED THUNDERSTORMS POSSIBLE THIS AFTERNOON. THE LOW WILL
CLOSE OFF AS IT APPROACHES THE COAST DUE TO A COUPLE OF
DISTURBANCES MOVING AROUND THE TROUGH AND MOVE VERY SLOW INLAND.
MODELS TRENDING SLOWER WITH THE MOVEMENT OF THE WEATHER SYSTEM.
THIS WILL WILL RESULT IN A THREAT OF CONVECTIVE STORMS FOR A
COUPLE OF DAYS ACROSS MUCH OF CA. ONE DISTURBANCE WILL MOVE
THROUGH CENTRAL CALIFORNIA TONIGHT EXTENDING THE THUNDERSTORMS
THREAT INTO THE CENTRAL PARTS OF THE VALLEY. ON THURSDAY EXPECT
MORE WIDESPREAD THREAT OF CONVECTIVE STORMS WITH AN UNSTABLE
ATMOSPHERE AND THE UPPER LOW REMAINING NEAR THE CENTRAL CA
COASTLINE.

ON FRIDAY...THE LOW IS PROGGED TO SLOWLY DROP SOUTHEAST TOWARD
SOCAL THEN THE LOW WILL SLOWLY PUSH INLAND ACROSS SOCAL. THIS
WILL RESULT IN MUCH COOLER TEMPERATURES FOR OUR AREA ALONG WITH
INCREASED CLOUD COVER AND PRECIPITATION CHANCES. INSTABILITY WILL
BE SUFFICIENT ENOUGH FOR THUNDERSTORMS ANYWHERE IN OUR THE CENTRAL
CALIFORNIA INTERIOR FRIDAY AFTERNOON AND EVENING. PRECIPITATION
AMOUNTS WILL BE DIFFICULT TO PINPOINT DUE TO THE CONVECTIVE NATURE
OF THE PRECIPITATION. SNOW LEVELS WILL START OUT ABOVE 10KFT TODAY
BUT LOWER TO 7000 THURSDAY NIGHT WITH SEVERAL INCHES OF SNOW
POSSIBLE OVER THE HIGH PEAKS THAT ARE IMPACTED BY HEAVIER SHOWERS.
FRIDAY AND SATURDAY WILL BE UNSEASONABLY COOL FOR EARLY MAY WITH
DAYTIME TEMPERATURES EXPECTED TO BE 10-15 DEGREES BELOW SEASONAL
NORMALS.

THE MEDIUM RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE LOW
MOVING INTO THE DESERT SOUTHWEST BY SUNDAY. WRAP AROUND MOISTURE
WILL CONTINUE TO SPREAD INTO OUR AREA THROUGH THE WEEKEND WHICH WILL
PROVIDE FOR CONTINUED CHANCES OF SHOWERS MAINLY IN THE SIERRA AND
BELOW NORMAL TEMPERATURES ALTHOUGH A SLOW RECOVERY IS EXPECTED.
ENSEMBLE MEANS INDICATE A DRY UPPER RIDGE PUSHING INTO CA ON
MONDAY AND BRING A WARMING AND DRYING TREND TO OUR AREA THROUGH AT
LEAST THE MIDDLE PORTION OF NEXT WEEK.

&&

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

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

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

CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.

&&

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

$$

PUBLIC...MV
AVN/FW...DUDLEY
PREV DISCUSSION...DS
SYNOPSIS...WP

WEATHER.GOV/HANFORD


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