194
FXUS66 KEKA 170046
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
546 PM PDT SUN AUG 16 2026
AVIATION 00Z UPDATE
COASTAL STRATUS REMAINS THIS AFTERNOON
WITH ITS REACH EBBING AND FLOWING OVER COASTAL TERMINALS. HIGH
RESOLUTION MODELS SUGGEST A FAIRLY NARROW STRIP MAY REMAIN FOR THE
COAST TONIGHT, YET OFFSHORE WIND IN DEL NORTE COUNTY COULD KEEP
THE LAYER AWAY FROM KCEC IF THE MARINE LAYER REMAINS DEEP.
AREAS UNDER THE STRATUS CAN EXPECT IFR TO LIFR CONDITIONS ALONG
THE COAST AND WITHIN COASTAL RIVER VALLEYS. SOME MODELS ARE
SUGGESTING THAT SOUTHERLY WINDS COULD FORM WITHIN THE RUSSIAN
RIVER VALLEY, PUSHING STRATUS OVER KUKI, YET CONFIDENCE IS LOW ON
THESE WINDS FORMING WITHIN THE VALLEY, LEAVING A SCT GROUP AT
THIS POINT. THE MARINE LAYER IS EXPECTED TO MIX AND MOVE SLIGHTLY
OFFSHORE, AWAY FROM TERMINALS TOMORROW BY AROUND 17Z (+/- 1HR).
PREV DISCUSSION
/ISSUED 252 PM PDT SUN AUG 16 2026/
KEY MESSAGES...
* SMOKE REMAINS OVER AREAS OUTSIDE OF THE MARINE LAYER DUE TO LOCAL
AND DISTANT WILDFIRES.
* INTERIOR TEMPERATURES ARE EXPECTED TO REMAIN NEAR NORMAL THROUGH
THROUGH FIRST HALF OF THE WEEK WITH HIGHS IN THE LOW TO MID 90S.
* ANOTHER TROUGH IS EXPECTED TO BRING BELOW NORMAL TEMPERATURES
AND THE POTENTIAL FOR A FEW THUNDERSTORMS LATE IN THE WEEK.
SYNOPSIS...A SERIES OF UPPER LEVEL TROUGHS OFF THE WEST COAST IS
EXPECTED TO GENERALLY KEEP INLAND TEMPERATURES NEAR NORMAL IN THE
90S. THIS WILL ALSO KEEP PERSISTENT MARINE CLOUDS ALONG THE COAST
WITH SOME AFTERNOON CLEARING. LATE IN THE WEEK A STRONGER TROUGH
WILL BRING COOLER INLAND TEMPERATURES AND THE POTENTIAL FOR INLAND
THUNDERSTORMS.
DISCUSSION...A VERY BRIEF SHORTWAVE RIDGE IS BUILDING OVER NW CA
TODAY. THIS IS BRINGING A SLIGHT WARMUP IN THE INTERIOR AREAS AND
HELPING TO CLEAR OUT THE COAST. TEMPERATURES IN MANY AREAS ARE
RUNNING 5 TO 10 DEGREES WARMER THAN YESTERDAY. SOME HIGH CLOUDS
HAVE STARTED TO MOVE OVER THE AREA AND THIS MAY SLOW THE WARMING.
THERE IS SOME OFFSHORE FLOW IN DEL NORTE COUNTY AND THIS MAY KEEP
THE COASTAL CLEAR FOR A FEW HOURS INTO THE EVENING. MONDAY ANOTHER
TROUGH APPROACHES FROM THE SOUTHWEST. TEMPERATURES ARE EXPECTED
TO BE SIMILAR TO TODAY. SOME HIGH CLOUDS ARE EXPECTED TO MOVE OVER
THE AREA IN THE AFTERNOON. IN THE AFTERNOON THERE IS INSTABILITY,
BUT IT DOESN'T LOOK LIKE THERE WILL BE ENOUGH MOISTURE FOR ANY
THUNDERSTORMS. THE CAMS AREN'T SHOWING ANY STORMS IN THE AREA AND
THE NBM THUNDER PROBS ARE ONLY AROUND 5 PERCENT. STILL THIS
TROUGH HAS BEEN PRODUCING SOME LIGHTING FROM TIME TO TIME OFF THE
COAST. SO THIS WILL DEFINITELY NEED TO BE WATCHED AS IT GETS
CLOSER, BUT FOR NOW WILL KEEP THUNDERSTORMS OUT OF THE FORECAST.
TUESDAY THE RIDGE BUILDS BACK TO THE WEST AND CONTINUES TO BRING
HIGH TEMPERATURES IN THE MID 90S. COASTAL CLOUDS MAY SEE A FEW
BREAKS IN THE AFTERNOON, BUT ARE GENERALLY EXPECTED TO BE PRETTY
PERSISTENT. WEDNESDAY THE NEXT TROUGH STARTS TO PUSH THE RIDGE TO
THE EAST, BUT CONDITIONS GENERALLY PERSIST. THE STRATUS AS THE
COAST MAY BE SLIGHTLY MORE STUBBORN AND LINGER THROUGH THE
AFTERNOON.
THURSDAY AND FRIDAY THE NEXT UPPER LEVEL TROUGH IS EXPECTED TO
MOVE BY THE AREA. A COUPLE OF THE MODEL CLUSTERS SHOWING THE
VORTICITY LINING UP WITH THE AFTERNOON HEATING ON FRIDAY. HOWEVER
THERE IS A LOT OF UNCERTAINTY IN HOW MUCH MOISTURE AND
INSTABILITY THERE WILL BE. THIS WILL NEED TO MONITORED AS IT GETS
CLOSER. MKK
MARINE...NORTHERLY WIND ARE IN PLACE ACROSS THE WATERS THIS
AFTERNOON AND THESE ARE EXPECTED TO INCREASE IN THE OUTER WATERS
OVERNIGHT. THESE LOOK TO INCREASE TO AROUND 20 TO 25 KT SO HAVE
EXPANDED THE SMALL CRAFT ADVISORY TO THE SOUTHERN OUTER WATERS.
CLOSER TO THE COAST THE MODELS ARE SHOWING THE LOCAL SOUTHERLY
WINDS RETURNING AGAIN THIS EVENING. THIS CURRENTLY HAS NORTHERLY
WINDS WAVES AROUND 3 TO 4 FEET AND THESE ARE EXPECTED TO INCREASE
OVERNIGHT. ALSO, A SOUTHERLY SWELL IS ALSO MOVING THROUGH THE
WATERS THIS AFTERNOON. CURRENTLY THE CAPE MENDOCINO BUOY IS
SHOWING IT AROUND 3 FEET AT 17 SECONDS.
MONDAY THE NORTHERLY WINDS ARE EXPECTED TO DIMINISH THROUGH THE
DAY AS A SHORTWAVE MOVES BY THE AREA SO HAVE THE SMALL CRAFT
ADVISORY ENDING DURING THE DAY. THE SOUTHERLY SWELL IS EXPECTED
TO CONTINUE AT AROUND 3 FEET AT 14 SECONDS. TUESDAY AND WEDNESDAY
AS HIGH PRESSURE BRIEFLY BUILDS IN NORTHERLY WINDS ARE EXPECTED TO
INCREASE TO AROUND 20 TO 25 KT. THURSDAY AND FRIDAY THE NEXT
TROUGH IS EXPECTED TO ARRIVE AND WINDS ARE EXPECTED TO DIMINISH
AGAIN WITH THE POTENTIAL FOR LOCAL SOUTHERLY WINDS NEAR THE COAST.
MKK
FIRE WEATHER...THE MAIN CHALLENGE FOR THE FIRE WEATHER FORECAST
IS THE POTENTIAL FOR THUNDERSTORMS. MONDAY AFTERNOON A SHORTWAVE
MOVES THROUGH, BUT AT THIS POINT IT DOESN'T LOOK LIKE IT THINGS
WILL LINE UP FOR ANY THUNDERSTORMS. THERE MAY BE SOME INCREASED
INSTABILITY, BUT NOT ENOUGH MOISTURE FOR ANY THUNDER. TUESDAY
THROUGH EARLY THURSDAY WEAK HIGH PRESSURE IS EXPECTED TO BRING
DRY AND FAIRLY STABLE CONDITIONS. THURSDAY NIGHT OR FRIDAY ANOTHER
TROUGH IS EXPECTED TO APPROACH THE AREA. AT THIS POINT IT IS STILL
HARD TO TELL IF THE MOISTURE INSTABILITY AND LIFT WILL LINE UP TO
GET THUNDERSTORMS, BUT IT IS POSSIBLE. THIS WILL NEED TO BE
WATCHED AS IT GETS CLOSER. MKK
EKA WATCHES/WARNINGS/ADVISORIES
CA...
NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 9 PM PDT
MONDAY FOR PZZ470.
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 9 AM PDT
MONDAY FOR PZZ475.
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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