Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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FXUS66 KHNX 020030 AAA
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
428 PM PST SUN FEB 1 2015

...UPDATED AIR QUALITY SECTION...

.SYNOPSIS...A RIDGE OF HIGH PRESSURE WILL BRING DRY WEATHER AND
ABOVE NORMAL AFTERNOON TEMPERATURES TO THE CENTRAL CALIFORNIA
INTERIOR THROUGH AT LEAST THURSDAY WITH AREAS OF NIGHT AND MORNING
FOG IN THE SAN JOAQUIN VALLEY.

&&

.DISCUSSION...A DRY UPPER RIDGE IS CONTINUING TO STRENGTHEN OVER
CENTRAL CA TODAY. WV IMAGERY INDICATING SOME UPPER LEVEL MOISTURE
PUSHING THROUGH THE RIDGE WHICH HAS PROVIDED FOR SOME HIGH CLOUDS
OVER OUR AREA TODAY. TEMPERATURES ARE RUNNING A FEW DEGREES ABOVE
YDAY AT MOST LOCATIONS IN RESPONSE TO RISING HEIGHTS AND
THICKNESSES ASSOCIATED WITH THE BUILDING RIDGE.

THE 12Z WRF MUCH LIKE IT/S PRECEDING RUNS IS INDICATING THE RIDGE
WILL REMAIN DOMINANT OVER CENTRAL CA THROUGH WEDNESDAY KEEPING A
MILD AND DRY AIRMASS IN PLACE OVER OUR AREA WITH TEMPERATURES
RUNNING ABOVE SEASONAL NORMALS AND GENERALLY LIGHT AND TERRAIN
DRIVEN WINDS. THERE IS SOME UNCERTAINTY WITH HOW EXTENSIVE LATE
NIGHT AND MORNING FOG WILL BE IN THE SAN JOAQUIN VALLEY. THE FOG
WAS MUCH LESS PREVALENT TODAY THAN THE PAST SEVERAL MORNINGS
DESPITE THE BUILDING RIDGE OVER THE AREA. WITH LIGHT WINDS AND
ONLY THIN HIGH CLOUDS PRESENT...PATCHY FOG WILL FORM IN THE SAN
JOAQUIN VALLEY...BUT IT IS VERY DIFFICULT TO PINPOINT WHICH
LOCATIONS WILL BE IMPACTED BY FOG AT THIS TIME SO FEEL THAT IT IS
BEST TO HANDLE ANY FOG IN THE SAN JOAQUIN VALLEY ON A DAY BY DAY
BASIS.

THE RIDGE IS PROGGED TO FLATTEN AND SHIFT SLIGHTLY EASTWARD ON
THURSDAY AS SHORTWAVE ENERGY PUSHES INTO THE PAC NW. THE MEDIUM
RANGE MODELS ARE GOOD AGREEMENT SHOWING THE RIDGE WILL AMPLIFY
OVER THE GREAT BASIN BY FRIDAY WHILE A AN UPPER TROUGH DEEPENS
OFF THE COAST NEAR 135W. THIS WILL RESULT IN A MILD SOUTHWEST
FLOW OVER CENTRAL CA FRIDAY THROUGH NEXT WEEKEND. RH PROGS ARE
INDICATING A FETCH OF DEEP MOISTURE EMBEDDED IN THE SOUTHWEST FLOW
DURING THIS TIME PERIOD TAKING AIM AT NORCAL AND THE PAC NW...BUT
THE ENSEMBLE MEANS OF BOTH THE GFS AND ECWMF ARE INDICATING HIGHER
HEIGHTS OVER CENTRAL CA THAN THEIR 12Z OPERATIONAL RUNS SUGGESTING
LITTLE IF ANY PRECIPITATION WILL BE IN STORE FOR OUR AREA ALTHOUGH
THERE IS A LOT OF SPREAD AMONGST THE INDIVIDUAL ENSEMBLE MEMBERS.
WITH THE RELATIVE MEASURE OF PREDICTABILITY SHOWING A STRONGER
TREND TOWARD RIDGING AND THE MOD TREND CONFIDENCE TOOL INDICATING
HIGHER HEIGHTS OVER THE WESTERN CONUS DURING THE LATTER PORTION OF
NEXT WEEK....BELIEVE THAT THE OPERATIONAL MODELS ARE TOO
AGGRESSIVE IN BRINGING PRECIPITATION INTO OUR AREA.
HOWEVER...WILL CONTINUE TO MENTION A SLIGHT CHANCE TO LOW CHANCE
OF PRECIPITATION FROM FRESNO COUNTY NORTHWARD FOR THIS PERIOD
WITH TWO FAIRLY POTENT STORMS TRACKING TO THE NORTH OF OUR AREA
LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOLLOWED BY ANOTHER ON
SUNDAY AFTERNOON AND EVENING WHICH WILL BRING AMPLE PRECIPITATION
TO MUCH OF NORTHERN CA.

WITH A WARM AIRMASS PREVAILING OVER CENTRAL CA...ANY SNOW IN OUR
AREA WILL LIKELY BE CONFINED TO ELEVATIONS ABOVE 8500 FEET. WE
SHOULD HAVE A BETTER GRASP ON WHERE THE SOUTHERN EXTENT OF THE
PRECIPITATION WILL BE BY TUESDAY WHEN THE FRIDAY STORM COMES
WITHIN RANGE OF THE WRF AND THE HIGHER RESOLUTION MODELS. UNTIL
THEN...CONFIDENCE IN ANY ONE MODEL SOLUTION FOR THE FRIDAY THROUGH
SUNDAY TIME FRAME WILL BE LOW.

&&

.AVIATION... MAINLY MVFR CIGS WITH HAZE WILL BE PRESENT AT THE
TERMINALS THROUGH THE AFTERNOON AND EARLY EVENING HOURS. POSSIBLE
DENSE FOG AGAIN EARLY MONDAY MORNING...GENERALLY AFTER 12Z FOR ALL
TERMINALS EXCEPT KBFL. FORECAST CONFIDENCE LOW.

&&

.AIR QUALITY ISSUES... ON MONDAY FEBRUARY 2 2015...UNHEALTHY FOR
SENSITIVE GROUPS IN FRESNO... KINGS AND MADERA 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 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 02-01       73:1991     43:1939     54:1905     25:1950
KFAT 02-02       74:1928     44:1903     57:1907     26:1950
KFAT 02-03       77:2000     46:1989     50:1995     25:1957

KBFL 02-01       76:1928     45:1965     55:1963     24:1902
KBFL 02-02       80:1928     44:1971     61:1958     23:1893
KBFL 02-03       79:2009     48:1980     59:1973     25:1923
&&

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

&&

$$

PUBLIC...DS
AVN/FW...RILEY
SYNOPSIS...ANDERSEN

WEATHER.GOV/HANFORD


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