945
FXUS66 KEKA 022156
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
300 PM PDT THU JUL 2 2009
SYNOPSIS
A WEAK AREA OF LOW PRESSURE JUST OFF THE NORTHERN
CALIFORNIA COAST WILL MOVE ACROSS THE REGION FRIDAY AND FRIDAY
NIGHT...MAINTAINING THE THREAT OF ISOLATED THUNDERSTORMS ACROSS
TRINITY COUNTY. OTHERWISE...INLAND AREAS WILL UNDERGO A COOLING
TREND BEGINNING LATE IN THE WEEKEND AND INTO NEXT WEEK.
SHORT TERM...TONIGHT THROUGH SUNDAY
THE MAIN FORECAST CHALLENGE
IS CONVECTION THIS EVENING AND AGAIN FRIDAY AFTERNOON/EVENING.
VAPOR PIX INDICATE A WEAK LOW JUST SW OF CAPE MENDOCINO AT EARLY
AFTERNOON. NO THUNDERSTORM ACTIVITY HAS OCCURRED AS OF YET...BUT
WILL RETAIN ISOLATED/SCATTERED CHANCES ACROSS EASTERN ZONES FOR THIS
EVENING. ANYTHING THAT FORMS WILL DIMINISH NOT LONG AFTER IT FORMS
AS THE SITUATION IS PURELY DIURNALLY DRIVEN. MEANWHILE ALONG THE
COAST...A STRONG INVERSION IS PRESENT AND WILL KEEP THE COAST LOCKED
IN WITH CLOUDS/FOG AND PROBABLY A LITTLE DRIZZLE OVERNIGHT.
THE AFOREMENTIONED LOW WILL SLOWLY MOVE NE TO THE COAST TOMORROW.
THUNDERSTORM DEVELOPMENT IS AGAIN PROBABLE ACROSS TRINITY
COUNTY BUT THE CONVECTIVE SIGNATURES ARE NOT QUITE AS STRONG AS
THOSE FROM TODAY...SO COVERAGE WILL PROBABLY BE A LITTLE MORE
LIMITED. BY SATURDAY THE LOW WILL FILL AND SHIFT INLAND EFFECTIVELY
ENDING THE THREAT FOR ORGANIZED CONVECTION...ALTHOUGH WE WILL RETAIN
<=10 POPS FOR THE TRINITY COUNTY MOUNTAINS AS SOME WEAKNESS IN THE
UPSTAIRS PATTERN PERSISTS. IN OUR BEST ESTIMATION...THE EVENING
FESTIVITIES OF THE 4TH OF JULY WOULD APPEAR TO FEATURE A LOW
OVERCAST HERE AT THE COAST...BUT INLAND LOCALES WILL EXPERIENCE
PLEASANT AND CLEAR WEATHER. SOME RELIEF FROM THE HOT TEMPERATURES AS
OF LATE FOR INLAND AREAS IS IN STORE...AND THIS COOLING TREND WILL
COMMENCE ON SUNDAY. BURGER
LONG TERM...SUNDAY THROUGH THURSDAY
MODELS AGREE ON AN UPPER
LEVEL LOW OVER THE PACNW WITH A BROAD TROUGH STRETCHING OFF THE
CENTRAL CALIFORNIA COAST. THIS TROUGH WILL BRING MUCH COOLER TEMPS
TO INLAND LOCATIONS WITH THE POSSIBILITY OF CONVECTION OVER THE
HIGHER TERRAIN TUE AND WED. FOR NOW...WITH UNCERTAINTY IN TIMING OF
THIS TROUGH...WE WILL LEAVE OUT ANY T-STORM MENTION AFTER
COORDINATION WITH NEIGHBORING OFFICES. THIS TROUGH MOVES VERY LITTLE
SO THE WX PATTERN WILL BE STAGNANT FOR MUCH OF THE WEEK. JCA
AVIATION...LIKE YESTERDAY
THE MARINE STRATUS ENGULFS THE ENTIRE
NORTH COAST. VSBYS HAVE BECOME VFR...BUT CIGS WILL REMAIN IFR. A FEW
BREAKS MAY BE SEEN LATER THIS AFTERNOON AS THE STRATUS LAYER WAFFLES
SLIGHTLY. LIFR CONDITIONS WILL RETURN AFTER SUNSET. VFR
INLAND...WITH SCATTERED THUNDERSTORMS OVER THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. JCA
MARINE
THE PRESSURE GRADIENT ALONG THE COAST HAS WEAKENED AND LOW
PRESSURE IN THE AREA WILL KEEP IT THAT WAY THROUGH THE END OF THE
FCST PD. SEAS HAVE LAID DOWN AND WINDS WILL REMAIN LIGHT THROUGH THE
WEEKEND. A LONG PD S SWELL AND SHORT PD NW SWELL WILL DOMINATE
DURING THIS TIME. CLARK
FIRE WEATHER
ISOLATED TO SCATTERED THUNDERSTORMS REMAIN POSSIBLE
INTO THE EVENING HOURS ACROSS THE SHASTA-TRINITY...MENDOCINO...AND
SIX RIVERS NF. LIGHTNING STRIKES WILL BE CAPABLE OF INDUCING
ADDITIONAL WILDFIRE STARTS AS WETTING RAINS (EXCEPT DIRECTLY
UNDERNEATH THUNDERSTORM CORES) ARE NOT LIKELY AND FUELS CONTINUE TO
DRY OUT. THE THREAT FOR THUNDERSTORMS WILL BE BACK TOMORROW
AFTERNOON AND EVENING ALTHOUGH THEIR EXTENT AND MAGNITUDE WILL NOT
WARRANT ANY FIRE WEATHER HEADLINES. BURGER
EKA WATCHES/WARNINGS/ADVISORIES
NONE.
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