000 
FXUS66 KEKA 311420
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
720 AM PDT TUE AUG 31 2004

.UPDATE...VIGOROUS SHORT WAVE LIFTING RAPIDLY NORTH OVER THE 
FORECAST AREA HAS TRIGGERED OROGRAPHIC CONVECTION OVER THE MOUNTAINS 
OF TRINITY COUNTY.  THE FORECAST HAS BEEN UPDATED TO MENTION 
THUNDERSTORMS THROUGH THE EARLY MORNING.  CWS.
&&

.SHORT TERM DISCUSSION...TODAY THRU TUE NIGHT...LITTLE SENSIBLE 
WEATHER CHANGE(S) EXPECTED WITH SEVERAL SHALLOW BUT WELL-DEFINED 
UPPER-LEVEL CIRCULATIONS DRIFTING NEWD AHEAD OF AN UPPER TROUGH AXIS 
CURRENTLY ALONG 140W EXTENDING SWD TO ABOUT 43N. REMNANTS OF BOTH 
UPPER SYSTEMS PASS ACROSS THE FORECAST AREA BUT NOT SEEING MUCH IN 
THE WAY OF MID- AND/OR UPPER-LEVEL CLOUD COVER WHICH MIGHT PRODUCE A 
NOTABLE CHANGE IN TEMPERATURE FROM PREVIOUS DAYS. STRATUS LOOKS TO 
BE LOCKED IN ACROSS THE COASTLINES HOWEVER AND MINIMAL AMOUNTS OF 
SUNSHINE EXPECTED.
 
.LONG TERM DISCUSSION...BEST CHANCE FOR LIGHT PRECIP APPEARS TO BE 
WEDNESDAY...BEGINNING IN DEL NORTE COUNTY AND SPREADING SEWD INTO 
NWRN HUMBOLDT COUNTY BY WED EVENING. 1000-850MB THICKNESS VALUES 
FALL APPRECIABLY...A DEEPENING OF THE MARINE LAYER...ACCOMPANIED BY 
COASTAL DRIZZLE SHOWERS AND LOCAL OROGRAPHIC STRATIFORM RAINS ALONG 
THE WINDWARD COASTAL RANGES OF NRN CAZ003 AND BERRY SUMMIT AREA. 
MARINE-LAYER CLOUD COVER LOOKS SHALLOW AND BRIEFLY PENETRATES INTO 
WRN CAZ004 (TO ABOUT DEL LOMA) AND HALFWAY THROUGH SERN CAZ003 (TO 
BRIDGEVILLE) ON THURSDAY MORNING. THE HIGHER HUMIDITY SERVING TO 
KNOCK BACK TEMPS A TAD ON THURSDAY AFTERNOON ALONG WITH LOWS ON 
THURSDAY NIGHT (EAST OF A ORLEANS-RUTH-COVELO LINE). MADE SOME 
ADJUSTMENTS WITH GRIDDS FOR THIS. THE MARINE LAYER DEEPENS TO 
ROUGHLY 2500-3000FT BUT TROUGH PASSAGE ACTUALLY SERVES TO CLEAR OUT 
CAZ001 COAST THURSDAY NIGHT WITH SLIGHTLY COOLER AIRMASS ALOFT 
FILTERING IN BEHIND SYSTEM. SHOULD SEE PLENTY OF DOWNWARD MIXING ON 
FRIDAY MORNING ...WHICH SHOULD ALLOW FOR THE THIN STRATOCU LAYER(S) 
TO BE ALL-BUT-GONE BY FRIDAY AFTERNOON. ABOVE NORMALS INLAND 
TEMP-WISE IN TIME FOR THE LAST SUMMER HOLIDAY WEEKEND OF THE 
YEAR. BARRING SOME UNFORESEEN CHANGES IN THE FLOW PATTERN ITS NOT A 
STRETCH TO SAY THAT WE SHOULD SEE ABOVE NORMAL TEMPERATURES INLAND 
WITH DESCENDING MOTION ALOFT PARKED NEARBY/OVERHEAD (THE CENTER OF A 
STRONG UPPER-LEVEL ANTICYCLONE). MJV
   
&&

.SYNOPSIS...AN UPPER LEVEL LOW...LOCATED JUST OFF THE CALIFORNIA 
COAST...WILL MOVE INTO NORTHWEST CALIFORNIA THIS AFTERNOON. THIS 
WILL CAUSE THE UPPER LEVEL HIGH RIDGE TO RETREAT INTO THE GREAT 
BASIN. THE LOW WILL BRING LOWER TEMPERATURES TO INLAND AREAS AND 
DEEPEN THE COASTAL MARINE LAYER THROUGH MIDWEEK. THE THERMAL TROUGH 
WILL ALSO WEAKEN AND PUSH WELL INLAND...AS A WEAK FRONTAL BOUNDARY 
CLIPS THE NORTH COAST WEDNESDAY. AS THE TROUGH DEPART EASTWARD...AN 
UPPER LEVEL HIGH WILL AGAIN BUILD ACROSS THE REGION...AND THE 
THERMAL TROUGH WILL STRENGTHEN. THIS WILL RESULT IN VERY HOT INLAND 
TEMPERATURES. TA

&&

.EKA WATCHES/WARNINGS/ADVISORIES...NONE

&&

$$