Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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FXUS66 KHNX 022155
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
255 PM PDT SUN AUG 2 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE SIERRA NEVADA THIS
AFTERNOON AND EVENING. OTHERWISE...A GRADUAL COOLING TREND WILL TAKE
PLACE OVER CENTRAL CALIFORNIA THROUGH TUESDAY WITH DRY CONDITIONS.

&&

.DISCUSSION...UPPER LEVEL HIGH PRESSURE CONTINUES TO NUDGE EAST
OUT OF CENTRAL CALIFORNIA RESULTING IN A COOLING TREND AND PUSHING
MONSOONAL MOISTURE EAST. THE MARINE LAYER HOVERED BETWEEN 2000 AND
2500 FEET OVERNIGHT INTO THE EARLY AFTERNOON HOURS...A FEW HUNDRED
FEET DEEPER COMPARED TO YESTERDAY. THIS DEEPER MARINE LAYER HAD A
SIGNIFICANT IMPACT ON SAN JOAQIN VALLEY TEMPERATURES...WITH MOST
LOCATIONS RUNNING BETWEEN 2 AND 4 DEGREES COOLER COMPARED TO 24
HOURS AGO...WITH READINGS IN THE LOW TO MID 90S. TEMPERATURES ARE
FORECAST TO WARM TO NEAR NORMAL FOR THE BEGINNING OF
AUGUST...GENERALLY IN THE UPPER 90S.

OTHERWISE...THE THUNDERSTORM THREAT OVER THE SIERRA NEVADA CREST
LOOKS MARGINAL AT BEST...WITH VERY LITTLE CU DEVELOPMENT FROM
FRESNO COUNTY NORTHWARD. THE BULK OF THE CURRENT ACTIVITY REMAINS
ON THE EAST SIDE OF THE CREST IN MONO COUNTY. THE HRRR...HIGH RES
ARW...AND NMM ALL INDICATE THAT SHOWERS AND THUNDERSTORMS WILL
REMAIN ON THE EAST SIDE OF THE CREST. WE WILL CONTINUE TO
ADVERTISE THE SLIGHT CHANCE OF THUNDERSTORMS ALONG THE
CREST...HOWEVER CONFIDENCE IS VERY LOW THAT THIS WILL HAPPEN.

THE COOLING TREND WILL CONTINUE TO IMPACT THE REGION MONDAY AND
TUESDAY AS THE UPPER LEVEL RIDGE FLATTENS IN RESPONSE TO AN UPPER
LEVEL SHORTWAVE MOVING EAST TOWARD THE REGION FROM THE EASTERN
PACIFIC. TUESDAY WILL BE THE COOLEST DAY OF THE WEEK...WITH SAN
JOAQUIN VALLEY TEMPERATURES TOPPING OUT IN THE LOW TO MID
90S...BETWEEN 2 AND 6 DEGREES BELOW NORMAL.

THE UPPER LEVEL SHORTWAVE WILL EXIT NORTHEAST OUT OF THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING...ALLOWING UPPER LEVEL HIGH
PRESSURE OVER SOUTHERN CALIFORNIA TO BUILD NORTH INTO CENTRAL
CALIFORNIA. THIS WILL BRING YET ANOTHER WARMING TREND TO THE AREA
INTO THURSDAY...HOWEVER ALL VALLEY LOCATIONS ARE FORECAST TO
REMAIN BELOW THE CENTURY MARK.

A NEARLY STAGNANT UPPER LOW OVER THE EASTERN PACIFIC WILL BEGIN TO
MOVE SLOWLY EAST TOWARD THE CALIFORNIA COASTLINE WEDNESDAY AND
ARRIVE NEAR THE SAN FRANCISCO BAY ON FRIDAY. THIS LOW WILL BRING
ANOTHER COOLING TREND TO THE AREA FRIDAY INTO THE WEEKEND.
ADDITIONALLY...THE MEDIUM RANGE MODELS INDICATE THAT THE SIERRA
NEVADA CREST...MAINLY FROM MADERA COUNTY NORTHWARD...MAY SEE
SCATTERED SHOWERS AND THUNDERSTORMS AS THE UPPER LOW OPENS AND
LIFTS NORTHEAST INTO NORTHERN CALIFORNIA FRIDAY INTO SATURDAY. WE
HAVE INTRODUCED A SLIGHT CHANCE OF THUNDERSTORMS FOR THE SIERRA
CREST GENERALLY FROM FRESNO COUNTY NORTHWARD. NCEPS GLOBAL
ENSEMBLE IS STILL SHOWING LOW PREDICTABILITY FOR THAT TIME
FRAME...HOWEVER THE NAEFS PROBABILITY OF MEASUREABLE PRECIPITATION
HAS BEEN TRENDING HIGHER FOR THE PAST FEW MODEL RUNS. EITHER
WAY...CONTINUE TO MONITOR THE FORECAST FOR THE LATEST
INFORMATION...AS WE FINE TUNE THE TIMING AND PROBABILITY OF
PRECIPITATION OVER THE MOUNTAINS.

&&

.AVIATION...
ISOLATED THUNDERSTORMS OVER THE SIERRA HIGH COUNTRY POSSIBLE WITH
LOCAL MVFR CONDITIONS UNTIL 04Z MON. OTHERWISE...VFR CONDITIONS WILL
PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24
HOURS.

&&

.AIR QUALITY ISSUES...
ON MONDAY AUGUST 3 2015... UNHEALTHY FOR SENSITIVE GROUPS IN
MADERA COUNTY.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG

&&

.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 08-02      112:1908     83:1953     82:1908     53:1956
KFAT 08-03      110:1946     80:1976     78:2014     55:1953
KFAT 08-04      110:1889     83:1976     82:1901     53:1956

KBFL 08-02      109:1979     86:1976     84:1977     53:1912
KBFL 08-03      112:1938     81:1953     81:1974     53:1912
KBFL 08-04      109:1901     85:1953     85:1909     53:1903
&&

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

$$

PUBLIC...RILEY
AVN/FW...MV
SYNOPSIS...RILEY

WEATHER.GOV/HANFORD



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