National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS66 KHNX 161650
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
950 AM PDT THU MAY 16 2013

.UPDATE...
LOWERED TODAY/S TEMPERATURES AND RAISED POPS FOR EARLY THIS
AFTERNOON AND EVENING FOR THE NORTHERN PARTS OF THE SOUTHERN SAN
JOAQUIN VALLEY WITH A SYSTEM MOVING SOUTHWARD INTO THE CENTRAL
CALIFORNIA REGION.

&&

.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL TRANSIT THROUGH CENTRAL CALIFORNIA
THROUGH FRIDAY. THIS SYSTEM WILL HELP LOWER TEMPERATURES THROUGH OUT
THE REGION AS WELL AS INCREASE THE CHANCE FOR A RAIN SHOWER THIS
EVENING THROUGH FRIDAY MORNING.


&&

.DISCUSSION...
A BAND OF CLOUDS AND LIGHT PRECIPITATION ASSOCIATED WITH A WEAK
COLD FRONT IS ORIENTATED FROM THE NORTHEAST TO THE SOUTHWEST AND
IS DRAPED OVER NORTHERN CALIFORNIA AND WILL CONTINUE TO MOVE
SOUTHWARD OVER THE CENTRAL CALIFORNIA REGION THIS MORNING AND
EARLY AFTERNOON. THE ASSOCIATED CLOUDS WITH THIS SYSTEM WILL
GREATLY REDUCE SOLAR INSOLATION AND KEEP TEMPERATURES MUCH
LOWER...LOWER 7OS IN THE NORTHERN PARTS OF THE SOUTHERN SAN
JOAQUIN VALLEY...LOWER 80S WILL BE LIKELY IN THE SOUTH END OF THE
SAN JOAQUIN VALLEY WHERE MINIMAL CLOUDS THROUGH THE DAY WILL ALLOW
DECENT WARMING TO TAKE PLACE. WITH THE LOWER LEVELS INITIALLY
BEING DRY...PRECIPITATION WILL BE LIGHT TO NON- EXISTENT AT THE
ONSET BUT WILL BEGIN TO MOISTEN THROUGH THE EARLY AFTERNOON
ALLOWING LIGHT RAIN SHOWERS TO BEGIN REACHING THE GROUND IN THE
NORTHERN PARTS OF THE SOUTHERN SAN JOAQUIN VALLEY ...ESPECIALLY IN
THE MERCED AREA. BEHIND THE FRONTAL SYSTEM A STRONGER ONSHORE FLOW
WHICH WILL INCREASE THE WINDS MOVING THROUGH THE PACHECO PASS
AREA WHICH ACCOUNTS FOR THE WIND ADVISORY THAT IS IN EFFECT FOR
THE NORTHWESTERN PARTS OF THE SOUTHERN SAN JOAQUIN VALLEY THIS
EVENING.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA INTERIOR THROUGH
20Z THURSDAY. LOCAL MVFR CONDITIONS DEVELOPING AFTER 20Z THURSDAY
OVER THE CENTRAL SAN JOAQUIN VALLEY AND AREAS MVFR IN THE SOUTHERN
SIERRA NEVADA WITH MTN OBSCURED IFR CONDITIONS IN SHOWERS POSSIBLE
NORTH OF KINGS CANYON NP...EXTENDING SOUTH INTO THE KERN COUNTY
MOUNTAINS AFTER 03Z FRIDAY. GUSTY WINDS CONTINUING...ESPECIALLY IN
THE VICINITY OF MOUNTAIN PASSES.

&&

.PREV DISC... /ISSUED 255 AM PDT THU MAY 16 2013/

DISCUSSION...
24 HOUR TRENDS ARE DOWN 3 TO 7 DEGREES OVER THE REGION ATTM. SO
THE GOOD NEWS IS THAT WE ARE COOLING DOWN AS PACIFIC MARINE AIR
IS BEING PUSHED THROUGH THE DELTA AND THROUGH THE WEST SIDE PASSES
IN RESPONSE TO A TROUGH OF LOW PRESSURE THAT HAS BEEN WELL
ADVERTISED FOR SEVERAL DAYS THAT WILL MOVE THROUGH THE AREA.

SFC PRESSURE GRADIENTS ARE IMPRESSIVE ENOUGH TO KEEP THE COOLING
TO CONTINUE TODAY AS THE TROUGH MOVES THROUGH. WE WILL ALSO SEE
SOME COOLING IN THE HIGHER ELEVATIONS WITH THE POSSIBILITY OF
SOME PRECIPITATION ACROSS THE SIERRA NEVADA. WE ARE EVEN LOOKING
FOR A FEW SPRINKLES POSSIBLE ACROSS THE SJV AS THE TROUGH MOVES
THROUGH LATE TONIGHT AND INTO FRIDAY. NO MEASURABLE PRECIPITATION
IS EXPECTED AT THIS POINT.

THE TROUGH IS FORECAST TO MOVE THROUGH THE REGION SATURDAY WITH
SEASONAL TEMPS OVER THE WEEKEND. WE WILL ONCE AGAIN BE UNDER THE
INFLUENCE OF HIGH PRESSURE RIDGE WITH WARMING TEMPERATURES EARLY
NEXT WEEK. ANOTHER VERY IMPRESSIVE LOW PRESSURE CENTER WILL DROP
OUT OF CANADA BY WED AND REMAIN NEARLY STATIONARY OVER THE PAC NW
INTO THURSDAY. LARGE SCALE OMEGA BLOCKING PATTERN OVER THE ENTIRE
US WILL KEEP US COOL FOR A FEW DAYS LATE NEXT WEEK.

&&

.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 05-16      103:1970     63:2011     71:2008     40:1894
KFAT 05-17      106:2009     64:2011     73:2008     44:1974
KFAT 05-18      103:2008     63:1994     73:2008     42:1893

KBFL 05-16      105:1970     63:1962     71:2008     39:1918
KBFL 05-17      105:2009     68:1998     73:2009     41:1906
KBFL 05-18      102:2009     68:2011     76:1973     41:1893
&&

.HNX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT PDT TONIGHT CAZ095.

WIND ADVISORY UNTIL MIDNIGHT PDT TONIGHT BELOW 10000 FEET FOR
THE CAZ098-099.

WIND ADVISORY UNTIL 8 PM PDT THIS EVENING BELOW 10000 FEET FOR
THE CAZ089.

&&

$$

PUBLIC...ANDERSEN
AVN/FW...MOLINA
PREV DISCUSSION...JDB
SYNOPSIS...WP

WEATHER.GOV/HANFORD