Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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000
FXUS66 KHNX 232030
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
130 PM PDT TUE SEP 23 2014

.SYNOPSIS...
A COOLING TREND WILL BEGIN DURING THE SECOND HALF OF THE WEEK AND
CONTINUE INTO THE WEEKEND. IN ADDITION...LIGHT RAIN SHOWERS WILL BE
POSSIBLE THROUGH AT LEAST THE NORTHWEST SIDE OF THE VALLEY AS EARLY
AS THURSDAY. OVER THE WEEKEND THE SIERRA NEVADA COULD ALSO SEE LIGHT
SHOWERS.

&&

.DISCUSSION...ALTHOUGH TODAY IS OFFICIALLY THE FIRST DAY OF
AUTUMN...YOU WOULD HARDLY KNOW IT. TEMPERATURES THIS AFTERNOON
ARE SKYROCKETING INTO THE 90S IN THE SJ VLY...LOWER FOOTHILLS
AND THE KERN COUNTY DESERT. WEDNESDAY WILL BRING A REPEAT OF
SUMMERLIKE WARMTH AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE
AMPLIFIES OVER THE FOUR CORNERS REGION. WEATHER MORE TYPICAL
OF AUTUMN WILL FINALLY BE UPON US AS THE WEEK DRAWS TO A CLOSE.
THE UPPER LEVEL TROUGH THAT WILL BRING THE COOL CHANGE IS
CURRENTLY SITUATED OVER THE EASTERN PACIFIC. THE MODELS HAVE
SLOWED ITS ARRIVAL INTO THE CENTRAL CA INTERIOR BY A GOOD 24
HOURS. ALTHOUGH THIS SYSTEM WILL BRING A COLD FRONT INTO THE
NORTHWESTERN PART OF OUR CWA DURING THE MIDDAY AND EARLY
AFTERNOON HOURS THURSDAY...THE UPPER LEVEL TROUGH WILL LAG WELL
BEHIND IT AND WILL STILL BE OFFSHORE THE CENTRAL CA COAST.
MOISTURE ASSOCIATED WITH THIS TROUGH IS ALSO QUITE LIMITED
HOWEVER...SPRINKLES COULD FALL OUT OF SOME MID LEVEL CLOUDINESS
ASSOCIATED WITH THE SURFACE COLD FRONT IN THE NORTHWESTERN PART
OF OUR CWA THURSDAY. THE REMAINDER OF OUR CWA WILL BE ON THE
RELATIVELY CLOUDFREE SIDE OF THIS FRONT THURSDAY AND UNDER THE
INFLUENCE OF A DRY SOUTHWEST FLOW ALOFT. ALTHOUGH AN ONSHORE FLOW
IN THE LOW LEVELS COULD BRING A SHALLOW INTRUSION OF MARINE AIR
INTO THE NORTHERN SJ VLY THURSDAY...MAX TEMPS WILL PROBABLY REMAIN
WELL ABOVE NORMAL THROUGHOUT MUCH OF THE CENTRAL CA INTERIOR...
ESPECIALLY IN THE SOUTH VALLEY AND OVER MUCH OF THE HIGHER
TERRAIN.

THE DYING REMNANTS OF THE SURFACE COLD FRONT WILL SLIP SOUTHWARD
THROUGH THE CWA THURSDAY EVENING OR NIGHT. IN ITS WAKE...THE
ONSHORE FLOW WILL STRENGTHEN FRIDAY AND SUPPORT GUSTY WINDS
THROUGH AND BELOW THE MOUNTAIN PASSES OF KERN COUNTY IN ADDITION
TO THE WEST SIDE OF THE SJ VLY. WE ARE NOT EXPECTING ADVISORY
LEVEL WINDS ANY LONGER ON FRIDAY AS SURFACE WINDS WILL NOT BE
IN PHASE WITH THE FLOW ALOFT WHICH WILL STILL BE SOUTHWESTERLY.
THE MODELS ALSO BRING ADDITIONAL MID LEVEL MOISTURE IN THIS SW
FLOW ACROSS THE KERN COUNTY MOUNTAINS AND DESERT...SO WE HAVE
INCREASED SKY COVER IN THESE AREAS FOR FRIDAY. THIS WILL ALSO BE
A REGION WHERE THE SURFACE COLD FRONT WILL LIKELY WASH OUT. IN THE
MEANTIME...THE MODELS DEEPEN THE UPPER LEVEL TROUGH AND FORM A
CLOSED LOW NEAR THE NORTHERN CA COAST BY THE END OF THIS WEEK.
WHILE MOISTURE WILL BE VERY LIMITED WITH THIS SYSTEM...HEIGHT
FALLS AND COOLING ALOFT WILL PROBABLY GENERATE ISOLATED SHOWERS
OVER THE HIGHER ELEVATIONS OF THE SIERRA FRIDAY AFTERNOON AND
EVENING.

SATURDAY WILL BE MUCH COOLER AS THIS TROUGH MOVES INLAND.
INSTABILITY CUMULUS IS POSSIBLE IN THE SJ VLY AND ADJACENT
FOOTHILLS SATURDAY AFTERNOON AND EVENING WHILE THE HIGHER
ELEVATIONS OF THE SIERRA MAY SEE A SCATTERING OF SHOWERS...SOME
OF WHICH COULD BE MIXED WITH SNOW ABOVE 9000 FEET SATURDAY EVE
INTO SUNDAY MORNING. SINCE 700 MB TEMPS ARE NOT PROGGED TO FALL
BELOW 1 C...IT IS DOUBTFUL THAT THERE WILL BE ANY MORE THAN A
DUSTING OF SNOW OVER THE HIGHEST PEAKS OF THE SIERRA SAT NIGHT.
THE BIGGEST IMPACTS OF THIS SYSTEM WILL BE HOW MARKEDLY COOLER IT
BECOMES THIS WEEKEND...ESPECIALLY OVER THE HIGHER TERRAIN. WE
ARE HIGHLIGHTING THIS WELL THROUGH SOCIAL MEDIA FOR THOSE THAT
WILL BE CAMPING AND HIKING IN THE SIERRA HIGH COUNTRY THIS
WEEKEND. ALL IN ALL...SATURDAY IS ON TARGET TO BE THE COOLEST
DAY IN THE CENTRAL CA INTERIOR SINCE MAY 21ST.

THE GFS AND ECM SOLNS MOVE THE CLOSED LOW INTO THE GREAT BASIN
SUNDAY. WHILE THERE MIGHT STILL BE A FEW LINGERING SHOWERS NEAR
THE SIERRA CREST...A DRY NORTHWESTERLY FLOW ALOFT WILL LIKELY
PREVAIL OVER THE CWA DURING THE SECOND HALF OF THE WEEKEND WITH
A CONTINUATION OF COOLER THAN NORMAL TEMPERATURES.

A WARMING TREND WILL GET UNDERWAY EARLY NEXT WEEK AS AN EPAC
RIDGE SLOWLY BUILDS INTO CA. MAX TEMPS COULD REACH THE 90 DEGREE
MARK AGAIN IN THE WARMEST PARTS OF THE SJ VLY NEXT TUESDAY.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA 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 LOW.

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 09-23      105:1949     66:1904     70:2011     47:1968
KFAT 09-24      102:1899     62:1904     73:1939     46:1945
KFAT 09-25      100:2009     69:1923     69:2002     43:1948

KBFL 09-23      107:1943     71:1986     72:1949     31:1903
KBFL 09-24      103:1919     72:1920     74:2009     35:1908
KBFL 09-25      103:1975     72:1971     73:1991     34:1908
&&

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

$$

PUBLIC...DURFEE
AVN/FW...DCH
SYNOPSIS...WP

WEATHER.GOV/HANFORD



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