332
FXUS66 KEKA 210903
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
203 AM PDT SAT MAR 21 2026
SYNOPSIS
UNSEASONABLE WARMTH WITH WIDESPREAD MINOR HEAT RISK IN
THE INTERIOR IS FORECAST TO ABATE THIS WEEKEND INTO EARLY NEXT WEEK.
COASTAL NORTHERLIES WILL INCREASE ON SATURDAY AFTER PASSAGE OF A
FRONT. NEXT CHANCE FOR RAIN IS EXPECTED TUESDAY INTO WEDNESDAY.
DISCUSSION
A DECAYING COLD FRONT MOVING SOUTHEAST IS BRINGING
MID- TO HIGH-LEVEL MOISTURE ACROSS THE AREA, AND AIDING IN A
DEEPENING MARINE LAYER. ASIDE FROM SOME PATCHES OF MIST AND
COASTAL DRIZZLE FOR THE NORTH COAST, GENERALLY DRY WEATHER
CONDITIONS ARE EXPECTED TO CONTINUE. TODAY WILL BE THE "COOLEST"
DAY, BUT WILL STILL REMAIN ABOVE CLIMATOLOGICAL NORMALS. INTERIOR
HIGH TEMPERATURES ARE FORECAST TO BE GENERALLY IN THE UPPER 60S TO
UPPER 70S, EXCEPT FOR LAKE COUNTY WHERE HIGHS IN THE 80S IS
FORECAST ALONG WITH A PREVAILING MINOR HEAT RISK. COASTAL HIGH
TEMPERATURES ARE FORECAST TO BE IN THE MID 50S TO LOW 60S. IN
ADDITION, BREEZY TO LOCALLY GUSTY W-NW WINDS ARE EXPECTED THIS
AFTERNOON, ESPECIALLY OVER THE COASTAL HEADLANDS, EXPOSED RIDGES,
AND CHANNELED TERRAIN.
TONIGHT INTO SUNDAY, A SURFACE HIGH WILL BUILD UNDER A ZONAL FLOW
ALOFT. OFFSHORE FLOW WILL PROMOTE CHILLY OVERNIGHT TEMPERATURES
WITH LOWS IN THE MID 30S TO MID 40S FOR THE VALLEYS. COOLER
TEMPERATURES ARE FORECAST FOR THE TRINITY VALLEYS WHERE LOW IN THE
MID 20S TO MID 30S ARE FORECAST FOR SUNDAY MORNING.
A BROAD FLAT RIDGE WITH ABOVE NORMAL 500 MB HEIGHTS WILL DOMINATE
THE WEATHER PATTERN FOR NORTHWEST CALIFORNIA SUNDAY THROUGH EARLY
NEXT WEEK. A SLOW WARMING TREND IS EXPECTED TO BEGIN AGAIN ON
SUNDAY AND PERSIST THROUGH EARLY NEXT WEEK AS SURFACE HIGH
PRESSURE STRENGTHENS. BREEZY WINDS ARE ANTICIPATED RIGHT ALONG
SHORE AND CHANNELED ALONG THE EEL RIVER VALLEY SUNDAY AFTERNOON,
WHILE DAYTIME WINDS WILL BE MOSTLY GENTLE AND TERRAIN DRIVEN.
THE HIGH PRESSURE WILL CRAWL EASTWARD EARLY TO MID NEXT WEEK.
MODEL GUIDANCES SUGGEST A STRONG SURFACE LOW APPROACHING THE
PACIFIC NW, WHILE A DECAYING FRONTAL SYSTEM MOVES SOUTHEASTWARD
ACROSS THE AREA. THIS WILL BRING AN INCREASING CHANCE OF
PRECIPITATION MONDAY NIGHT THROUGH TUESDAY, ESPECIALLY FOR DEL
NORTE AND HUMBOLDT COUNTIES. THIS FRONT WILL CONTAIN ANOMALOUSLY
HIGH PRECIPITABLE WATER VALUES (OVER 200% PERCENT OF NORMAL),
ENHANCED 925 MB SOUTHERLY WINDS (AROUND 2000FT UP), AND IVT
VALUES OVER 250 KG/M/S. THE FRONT WILL BE VERY QUICK MOVING, BUT
A BRIEF PERIOD OF HEAVY RAINFALL RATES ARE POSSIBLE FOR THE WEST-
SOUTHWEST WINDWARD FACING TERRAIN IN DEL NORTE COUNTY.
DETERMINISTIC MODELS CONTINUE TO VARY WIDELY WITH TIMING AND
AMOUNTS. IF THE LOW TAKES A FARTHER TRACK NORTH, THERE WILL BE
MUCH LESS RAINFALL AND LIGHTER SOUTHERLY WINDS. OTHERWISE, HIGH
UNCERTAINTIES REMAIN IN THE DETAIL WITH THIS SYSTEM.
RIDGING SPRINGS BACK AROUND MID NEXT WEEK AFTER OUR BRIEF SPAT OF
RAIN TUE OR WED. GENERALLY DRY CONDITIONS WITH ABOVE NORMAL INTERIOR
HIGH TEMPS ARE EXPECTED. OVERNIGHT LOW TEMPS MAY COOL DOWN MID OR
LATE NEXT WEEK FOR PERHAPS LOW END FROST FREEZE CONCERNS. /ZVS
AVIATION...(21/06Z TAFS)
LIFR CEILINGS AND VARIABLE VSBY LESS
THAN 3 MILES IN MIST AT COASTAL TERMINALS ARE FORECAST TO DIMINISH
THROUGH THE DAY ON SATURDAY. AT CEC, CHANCES FOR LIFR CONDITIONS
DIMINISHES AFTER 21/12Z TO 50% AND TO LESS THAN 10% AFTER 21/17Z.
LIFR OR IFR CEILINGS AT KACV WILL LAST LONGER. CHANCES FOR IFR
DECREASES TO 60% AROUND 21/18Z AND THEN TO 20% OR LESS AFTER
21/20Z AS NORTHWEST WINDS AND MIXING INCREASES IN THE AFTERNOON.
KUKI IS EXPECTED TO REMAIN VFR THROUGH THIS TAF PERIOD. POTENTIAL
FOR LLWS AND SHALLOW TURBULENCE OVER THE COASTAL RANGES INCREASES
NEARBY KUKI FROM 21/08Z TO 21/16Z. GUSTY N-NW WINDS AND SHALLOW
TURBULENCE IS EXPECTED IN THE AFTERNOON AND EARLY EVENING
THROUGHOUT ON SAT.
MARINE
VERY HAZARDOUS OCEAN CONDITIONS ARE FORECAST THIS
WEEKEND. NORTH WIND GUSTS FROM 34 TO 42 KT ARE HIGHLY PROBABLE
(>80% CHANCE), PRIMARILY OVER THE OUTER WATERS AND INNER WATERS
SOUTH OF CAPE MENDOCINO. A GALE WARNING IS IN EFFECT. A LONG FETCH
OF STRONG NORTHERLY WINDS WILL GENERATE VERY STEEP WAVES FROM 10
TO 15 FEET WITH PERIODS FROM 8 TO 10 SECONDS BY SATURDAY AFTERNOON
AND EVENING. WAVES THIS LARGE AND STEEP WILL BE CAPABLE OF
CAPSIZING SMALL VESSELS AND MARINERS ARE ENCOURAGED TO REMAIN IN
PORT. A HAZARDOUS SEAS WARNING HAS BEEN ISSUED FOR NORTHERN INNER
WATERS WITH VERY STEEP WAVES FORECAST TO BUILD TO 10 FT OR MORE
SAT EVENING AND SAT NIGHT. THESE VERY STEEP WAVES WILL CONTINUE
SUNDAY MORNING. A SECONDARY RAMP UP IN VERY STEEP WAVES WILL OCCUR
SUNDAY AFTERNOON AND EVENING FOR THE INNERS. FOR THE OUTERS,
WAVES WILL REMAIN VERY STEEP AND TREACHEROUS THROUGH AT LEAST
EARLY MONDAY MORNING.
OUTLOOK GOING INTO NEXT WEEK: CONDITIONS WILL BEGIN TO EASE UP AND
SUBSIDE ON MONDAY WITH LOWER SEAS INTO TUE. CONDITIONS DETERIORATE
AGAIN AROUND MID WEEK AS A LARGE MID PERIOD W-NW SWELL ARRIVES AND
POTENTIAL FOR NORTHERLY GALES INCREASES AFTER FRONTAL PASSAGE.
EKA WATCHES/WARNINGS/ADVISORIES
CA...
NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FROM 8 AM TO 5 PM PDT SATURDAY FOR
PZZ450.
HAZARDOUS SEAS WARNING FROM 5 PM SATURDAY TO NOON PDT
SUNDAY FOR PZZ450.
SMALL CRAFT ADVISORY UNTIL 11 AM PDT SATURDAY FOR PZZ455-
470-475.
GALE WARNING FROM 11 AM SATURDAY TO 11 AM PDT SUNDAY FOR
PZZ455.
GALE WARNING FROM 11 AM SATURDAY TO 9 PM PDT SUNDAY FOR
PZZ470-475.
NOTE: THE FULL FORECAST DISCUSSION IS NOW REGULARLY ISSUED BETWEEN
10 AM/PM AND 1 PM/AM. ADDITIONAL UPDATES WILL BE ISSUED AS NEEDED.
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