Wildfire in California, July 17 to 19, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
959 AM PDT TUE JUL 17 2012

.SYNOPSIS...
LOW PRESSURE OFF THE WEST COAST WILL DOMINATE KEEPING MOSTLY CLEAR
SKIES AND BELOW NORMAL TEMPERATURES THROUGH THURSDAY. BY THURSDAY
SOME MOISTURE WILL RETURN AND BRING A FEW HIGH CLOUDS TO THE AREA
ALONG WITH AN INCREASE IN THE CHANCE OF AFTERNOON THUNDERSTORMS TO
THE SIERRA CREST. TEMPERATURES WILL RETURN TO SLIGHTLY ABOVE NORMAL
BEGINNING FRIDAY.

&&

.DISCUSSION...
TEMPS ARE RUNNING AROUND 7-12 DEG LOWER COMPARED TO THIS TIME
YESTERDAY IN THE SAN JOAQUIN VALLEY AND SIERRA FOOTHILLS...WITH
LESS DECREASE ELSEWHERE. ONSHORE FLOW IS PREVALENT OVER MUCH OF
CA WITH UPPER LOW CURRENTLY OVER NORTHWEST CA. MARINE LAYER AS
SHOWN ON FT ORD PROFILER IS ABOUT 4000 FEET DEEP...BUT WILL LIKELY
BECOME MORE SHALLOW DURING THE NEXT 24 HRS. MAX TEMPS ARE EXPECTED
TO BE WELL BELOW AVERAGE TODAY AND WEDNESDAY OVER MUCH OF THE
REGION. NOT PLANNING TO UPDATE THIS AM...AS FORECAST LOOKS GOOD AT
THIS TIME. WED MAY BE SLIGHTLY WARMER OR ABOUT THE SAME AS TODAY
THROUGHOUT INTERIOR CENTRAL CA AS SOME COOLER MARINE AIR WILL
REMAIN OVER THE SJ VALLEY...WITH SOME SYNOPTIC SCALE COOLER OVER
THE REST OF THE AREA. HOWEVER...FORECAST TEMPS FOR WED NIGHT/THU
BECOME MORE TRICKY WITH MID-LEVEL MOISTURE MOVING INTO REGION FROM
SOUTH-SOUTHWEST.

REMNANT MOISTURE FROM TROPICAL STORM FABIO...WHICH IS CURRENTLY
OFF THE COAST OF SOUTHERN BAJA...OR AROUND 22N/120W...IN THE
MID-LEVELS WILL BECOME EMBEDDED IN SOUTHWEST FLOW ALOFT AND INCREASE
OVER THE REGION WED NIGHT AND THU...SO HAVE A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS OVER THE MOUNTAIN AND DESERT AREAS WED NIGHT
THRU THU AFTERNOON. THIS MOISTURE IS EXPECTED TO MOVE EASTWARD BY
FRI AS SOUTHWEST FLOW ALOFT WILL ONCE AGAIN TURN DRIER AS UPPER
LOW EJECTS NORTHEASTWARD OVER THE PAC NW. INCREASING 500 MB HTS
AND 850 TEMPS WILL LIKELY BRING TEMPS BACK TO SLIGHTLY ABOVE
AVERAGE BY FRI.

TEMPS/WEATHER THIS WEEKEND COULD ALSO BE TRICKY AS MODELS TRY TO
BRING MONSOONAL MOISTURE INTO SE CA BY SUN. WHILE 850 MB TEMPS AND
500 MB HEIGHTS CONTINUE TO INCREASE THIS WEEKEND...THERE IS QUITE
A BIT OF SPREAD BETWEEN MODEL SOLUTIONS AS TO HOW MUCH WARMING
WILL OCCUR OVER INTERIOR CENTRAL CA. ALSO...AMOUNT OF CLOUD COVER
AT MID LEVELS COULD SERVE TO REDUCE MAX TEMPS AND INCREASE
MORNING LOWS...WILL HAVE TO MONITOR THIS SHIFT IN PATTERN. IN
TERMS OF MOISTURE...HAVE SLIGHT CHANCE POPS FOR SHOWERS/THUNDERSTORMS
OVER THE DESERT RE TURING BY SUN AFTERNOON AND WITH SOME CHANCE
POPS DURING EARLY NEXT WEEK. AM SEEING THE EURO MODEL IS MORE BOLD
THAN THE GFS IN TERMS OF INFLUX OF MONSOONAL MOISTURE AT THIS
TIME. WILL HAVE TO WAIT AND SEE IF MODELS COME MORE IN LINE WITH
THIS FEATURE...SO FOR NOW HAVE MEDIUM CONFIDENCE AT BEST OVERALL IN
EXTENDED PERIOD.

&&

.PREV DISCUSSION...
THE UPPER LOW SPINNING NEAR THE NORTHERN CALIFORNIA COAST HAS
WEAKENED THE NEARBY HIGH PRESSURE RIDGE AS WELL AS SIGNIFICANTLY
ELEVATING THE MARINE LAYER AND PRODUCING A MODERATE ONSHORE FLOW.
THIS HAS RESULTED IN COOLER TEMPERATURES OVER THE
AREA...ESPECIALLY IN THE VALLEY WHERE THE COOLER MARINE AIR HAS
RUSHED IN.

THE COOLING TREND WILL CONTINUE TODAY...WITH AFTERNOON HIGHS
TOPPING OUT AS MUCH AS 10-15 DEGREES BELOW CLIMO. MODELS ARE IN
GENERAL AGREEMENT IN SHOWING THE HIGH PRESSURE RIDGE REBUILDING
WESTWARD BY WEDNESDAY...BEGINNING A WARMING TREND OVER OUR AREA
AND CONTINUING THROUGH THE END OF THE WEEK. GUIDANCE IS SHOWING
TEMPERATURES RETURNING TO NEAR SEASONAL AVERAGES BY FRIDAY AND
CONTINUING TO WARM SEVERAL DEGREES THROUGH THE WEEKEND. SOME VERY
SLIGHT COOLING IS PROGGED FOR EARLY NEXT WEEK AS A WEAK
DISTURBANCE ROUNDS THE BOTTOM OF THE RIDGE.

DRY SOUTHWESTERLY FLOW CONTINUES THROUGH WEDNESDAY...THEN MODELS
CONTINUE TO SHOW SOME RESIDUAL FABIO MOISTURE ENTRAINED INTO THE
AREA BY THURSDAY. THIS WILL PROVIDE A SLIGHT CHANCE FOR CONVECTION
OVER THE MOUNTAIN AND DESERT ZONES...TAPERING OFF BY FRIDAY AS THE
BULK OF THE MOISTURE LIFTS OUT. CHANCES FOR MOUNTAIN AND DESERT
CONVECTION WILL TREND UPWARD AGAIN FOR THE FIRST PART OF NEXT
WEEK AS THE WEAK DISTURBANCE MOVES INTO THE AREA ALONG WITH A
SURGE OF MONSOONAL MOISTURE.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED ACROSS THE CENTRAL CA INTERIOR THROUGH
18Z WEDNESDAY.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.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.

&&

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

PUBLIC...BSO/JEB
AVN/FW...DCH
SYNOPSIS...PJ

WEATHER.GOV/HANFORD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
503 AM PDT TUE JUL 17 2012

CAZ093>099-181200-
MARIPOSA MADERA AND FRESNO COUNTY FOOTHILLS-
TULARE COUNTY FOOTHILLS-KERN COUNTY MOUNTAINS-
SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON-
TULARE COUNTY MOUNTAINS-INDIAN WELLS VALLEY-
SOUTHEASTERN KERN COUNTY DESERT-
503 AM PDT TUE JUL 17 2012

...THUNDERSTORMS POSSIBLE LATER THIS WEEK...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SOUTHERN SIERRA NEVADA
INCLUDING THE FOOTHILLS...THE TEHACHAPI MOUNTAINS AND THE KERN
COUNTY DESERTS.

.DAY ONE...TODAY AND TONIGHT

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS BY THURSDAY
AND CONTINUING THROUGH FRIDAY NIGHT. THUNDERSTORM ACTIVITY WILL
DIMINISH FROM THE SOUTH SATURDAY. THE THREAT OF THUNDERSTORMS WILL
THEN INCREASE SUNDAY THROUGH TUESDAY AS MONSOONAL MOISTURE MOVES
INTO THE REGION.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS NOT ANTICIPATED.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR
UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE.