Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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FXUS66 KHNX 310036 AAA
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
435 PM PST FRI JAN 30 2015

...UPDATED AIR QUALITY SECTION...

.SYNOPSIS...
A LOW PRESSURE SYSTEM CENTERED OVER SOUTHERN CALIFORNIA WILL BRING A
CHANCE OF SHOWERS TO THE MOUNTAINS AND DESERT THROUGH TONIGHT. DRY
WEATHER AND ABOVE NORMAL AFTERNOON TEMPERATURES WILL PREVAIL THIS
WEEKEND AS A RIDGE OF HIGH PRESSURE BUILDS INTO CENTRAL CALIFORNIA.
AREAS OF NIGHT AND MORNING FOG CAN BE EXPECTED IN THE SAN JOAQUIN
VALLEY THROUGH THE PERIOD.

&&

.DISCUSSION...
PATCHY DENSE FOG IN THE SAN JOAQUIN VALLEY FROM THIS MORNING HAS
DISSIPATED AND ALLOWED TEMPERATURES TO REBOUND NICELY.
HOWEVER...SOME MID AND HIGH LEVEL WRAP AROUND DEBRIS CLOUDS FROM
THE NORTHEAST MOVING TROUGH CENTERED OVER WESTERN NEVADA HAS
TEMPERED THE INCOMING SOLAR INSOLATION KEEPING TEMPS FROM GETTING
INTO THE UPPER 60S IN THE SAN JOAQUIN VALLEY AND DESERT AREAS.
THESE SAME DEBRIS CLOUDS HAVE BROUGHT SCATTERED RAIN SHOWERS TO
PARTS OF THE KERN COUNTY DESERT AREA AND TEHACHAPI MOUNTAINS. MANY
LOCATIONS REPORTED A FEW HUNDREDTHS OF AN INCH AND EVEN A FEW
LOCALIZED SITES IN THE HIGHER ELEVATIONS OF THE KERN COUNTY
MOUNTAINS RECEIVED A COUPLE TENTHS OF AN INCH THIS MORNING.
SCATTERED SHOWERS WILL CONTINUE THROUGH THIS EVENING INTO EARLY
TOMORROW MORNING IN THE HIGHER ELEVATIONS OF THE SIERRA AND KERN
COUNTY MOUNTAINS AS WELL AS THE KERN COUNTY DESERT AREAS.

THERE WAS ONE QUESTION IN THE SHORT TERM FORECAST...WILL THE SAN
JOAQUIN VALLEY TULE FOG MONSTER MAKE IT/S PRESENCE KNOWN OVERNIGHT
AND INTO TOMORROW MORNING AND IF SO HOW PREVALENT? NORMALLY IT
WOULD BE A NO BRAINER SINCE THERE IS MORE THAN AMPLE MOISTURE
PRESENT AND WE SHOULD GET CLEARING ESPECIALLY IN THE WESTERN SAN
JOAQUIN VALLEY OVERNIGHT. HOWEVER...A WEAK SHORT WAVE WILL MOVE
SOUTH OVER THE COAST OVERNIGHT WHICH MAY ALLOW SOME MIXING TO
OCCUR. CURRENT THINKING IS WE WILL SEE PATCHY FOG AND IN A FEW
AREAS THE FOG MAY BECOME LOCALLY DENSE. WITH THE MANY COMPLEX
VARIABLES OF FOG FORMATION AND THE COMPLEXITY OF FORECASTING THIS
PHENOMENON THIS FORECASTER HAS DECIDED TO DEFER ANY ISSUANCE OF
A DENSE FOG ADVISORY TO SUCCEEDING SHIFTS. THIS WILL ALLOW FOR
OBSERVATION MONITORING AND LETTING MOTHER NATURE TIP HER HAND. AS
A COMRADE HAS MENTIONED MANY TIMES...FORECASTING FOG IN THE SAN
JOAQUIN VALLEY IS THE EQUIVALENT OF HERDING CATS. THAT WAS THE
ONLY REAL FORECAST PROBLEM CHILD FOR TODAY AS EVERYTHING ELSE
LOOKS TO REMAIN ON TRACK.

RIDGING WILL BEGIN MOVING INTO THE AREA SATURDAY AFTERNOON
ALLOWING A RETURN TO DRIER CONDITIONS AND WARMER TEMPERATURES FOR
AREAS OUTSIDE OF THE SAN JOAQUIN VALLEY. AN INCREASE IN FOG
COVERAGE AND CHANCES WITH THE MORE IDEAL SYNOPTIC CONDITIONS FOR FOG
DEVELOPMENT WILL HAMPER SOLAR INSOLATION AND THEREFORE KEEP HIGH
TEMPERATURES IN THE SAN JOAQUIN VALLEY LOWER THAN WOULD BE
EXPECTED. ESPECIALLY IF THE OVERNIGHT/MORNING FOG PERSISTS INTO
THE NOON TIME FRAME ON DAYS OF FOG OCCURRENCE. THIS PATTERN
SHOULD REMAIN UNTIL THURSDAY AFTERNOON WHEN A SYSTEM WILL BEGIN
APPROACHING THE REGION. THIS LOOKS TO INCREASE CHANCES FOR
PRECIPITATION IN THE THURSDAY/FRIDAY TIME PERIOD. THE PATTERN AT
THIS TIME LOOKS FAVORABLE FOR SOME TROPICAL MOISTURE INFLUX WHICH
COULD HELP WITH AMOUNTS AND COVERAGES. WILL NEED TO CONTINUE TO
MONITOR THIS DEVELOPING SITUATION.

&&

.AVIATION...
AREAS OF MVFR VISIBILITIES IN HAZE/MIST ACROSS THE SAN JOAQUIN
VALLEY...BECOMING AREAS IFR IN MIST WITH LOCAL LIFR/VLIFR IN FOG
FROM 06Z-18Z SATURDAY. LOCAL IFR/MOUNTAIN OBSCURATIONS ACROSS THE
SOUTHERN SIERRA IN SHOWERS THROUGH 18Z SATURDAY. OTHERWISE...VFR
CONDITIONS FOR THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
ON SATURDAY JANUARY 31 2015...UNHEALTHY FOR SENSITIVE GROUPS IN KERN
AND TULARE COUNTIES.  FIREPLACE/WOOD STOVE BURNING STATUS IS: NO BURNING
UNLESS REGISTERED IN FRESNO... KERN... KINGS... MADERA... MERCED AND TULARE
COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
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 01-30       74:1984     41:1923     56:1911     25:1946
KFAT 01-31       75:1984     39:1969     55:1963     26:1949
KFAT 02-01       73:1991     43:1939     54:1905     25:1950

KBFL 01-30       77:1911     44:1951     60:1911     23:1902
KBFL 01-31       82:1984     45:1969     57:1963     23:1902
KBFL 02-01       76:1928     45:1965     55:1963     24:1902
&&

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

$$

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

WEATHER.GOV/HANFORD



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