853 
FXUS66 KEKA 291557
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
900 AM PDT SAT MAY 29 2004
 
.DISCUSSION...MORNING SATELLITE IMAGES INDICATE ONLY VALLEY FOG AND 
LOW CLOUDS CURRENTLY ACROSS PARTS OF INTERIOR HUMBOLDT COUNTY AND 
TRINITY COUNTY. LOWER TO MID LEVEL CLOUD DECK OFFSHORE CONTINUES TO 
ERODE AS IT MOVES INTO THE WEAK SURFACE RIDGE THAT HAS BUILD INTO 
SOUTHERN OREGON. LOW CLOUDS INLAND SET TO DISAPPEAR WITHIN THE HOUR. 
BUT WITH THE LINGERING MOISTURE ACROSS THE INTERIOR...WE MAY SEE 
SOME CUMULUS DEVELOP OVER THE HILLS TODAY. MODELS IN GOOD AGREEMENT 
WITH KEEPING LOWER LEVEL MOISTURE OFFSHORE OTHERWISE. POSSIBILITY 
ALSO EXISTS OF SOME WISPY HIGH LEVEL CLOUDS AS WAVE MOVING INTO THE 
PACIFIC NORTHWEST MAY SCRAPE EXTREME NW CALIFORNIA. FARTHER SOUTH 
ACROSS MENDOCINO COUNTY IT LOOKS COMPLETELY CLEAR NOW...AND LIKELY 
TO REMAIN THAT WAY AS STRONG NORTHERLY WIND PREVAILS. HAVE UPDATED 
ALL ZONES TO REFLECT THIS SITUATION.

&&

.PREVIOUS DISCUSSION...CUMULUS FIELD AND ONSHORE FLOW PREVAILS FOR 
ANOTHER 6-12 HOURS AT BEST. ONLY THREAT FOR SHALLOW CONVECTION LOOKS 
TO BE OVER HIGHER TERRAIN OF DEL NORTE/EXTREME NORTHEASTERN HUMBOLDT 
COUNTIES THIS AFTERNOON. THE UPPER-LEVEL RIDGE AXIS HAS MOVED INSIDE 
OF 140W...AND LOOKS PROGRESSIVE...MOVING EAST AT 30-40 KTS. STABLE 
CONDITIONS ALOFT SHOULD DEVELOP QUICKLY.   

MODEL DATA IN AGREEMENT WITH THE LONGWAVE PATTERN THROUGH DAY7. SOME 
VARIANCE IN HANDLING OF THE LOW-LEVEL FEATURES AND POSITION OF THE 
THERMAL TROUGH (WARMEST AIR) SUN THROUGH TUE. THE MARINE LAYER STILL 
LOOKS TO DEEPEN ON MON AND INTO TUE. THIS WILL AFFECT TEMPERATURES 
ON THE COAST AND CLOUD FORECASTS. EXPECT TEMPERATURES TO RISE BACK 
INTO THE 80S INLAND AND EASTWARD ALONG THE COASTAL RANGES FOR THE 
HOLIDAY (MON). BY MID WEEK...GOOD CHANCE THAT SOME LOWER 90S WILL 
PREVAIL ACROSS CAZ004-076 VALLEYS. VERY LATE IN THIS PACKAGE...MRF 
BUILDS AN UPPER LEVEL RIDGE OVER SOCAL AND BAJA TO 592DM AT H5. THIS 
LOOKS LIKE SUMMER CLIMO...BUT WORTH WATCHING OUT FOR AS A SOURCE OF 
SUBTROPICAL MOISTURE.
          
&&

.SYNOPSIS...HIGH PRESSURE IN THE UPPER LEVELS OF THE ATMOSPHERE 
ALONG WITH AN INTENSIFYING THERMAL TROUGH OVER INTERIOR CALIFORNIA 
WILL BRING WARM AND DRY WEATHER TO NORTHWEST CALIFORNIA FOR THE 
HOLIDAY WEEKEND AND MUCH OF THE COMING WEEK AHEAD.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...SCA IN PZZ455-475 WATERS.

&&

$$
ST/MJV