269
FXUS66 KEKA 180713
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1213 AM PDT SAT APR 18 2026
SYNOPSIS
NEAR-FREEZING TO FREEZING LOW TEMPERATURES FORECASTED
FOR THE COLDEST AREAS SATURDAY MORNING. RAIN RETURNING SUNDAY
AFTERNOON OR EVENING CONTINUES INTO NEXT WEEK. DRIER WEATHER IS
EXPECTED FOR LATE IN THE WEEK.
DISCUSSION
DRY AIR OVER THE AREA WILL CAUSE OVERNIGHT TEMPERATURES
FOR THE INTERIOR TO DROP AS LOW AS FREEZING AGAIN BY EARLY THIS MORNING.
FREEZE WARNING AND FROST ADVISORIES HAVE BEEN ISSUED FOR SOME OF THE
COLDEST INTERIOR VALLEYS. IT IS RECOMMENDED TO COVER SENSITIVE PLANTS
AND TAKE OTHER PRECAUTIONS TO PROTECT AGRICULTURAL PROPERTY. ICY ROADS
ALSO POSE A POSSIBLE THREAT THROUGH THE MORNING. COASTAL AREAS WILL
REMAIN SLIGHTLY WARMER THIS MORNING AS COASTAL STRATUS FORMS.
THIS WEEKEND'S STORM TRACK HAS CONTINUED TO VARY. GLOBAL MODELS
CONTINUE TO SIGNAL A CUTOFF LOW FORMING AND LINGERING JUST EAST
OF THE 140W LONGITUDE FROM TODAY THROUGH WEDNESDAY. THIS STORM
WILL MOVE SOUTHWARD BEFORE STALLING, INCREASING THE CHANCE FOR
RAINFALL ACROSS THE ENTIRE CWA. AMPLE MOISTURE WILL BE AVAILABLE,
THE MAIN UNCERTAINTY WILL BE IF THE MAIN MOISTURE FLUX LINES UP
WITH OROGRAPHIC LIFT. GLOBAL ENSEMBLE MODELS SHOWS >80%
PROBABILITIES OF IVT VALUES OVER 250KG/M/S FROM SUNDAY AFTERNOON
THROUGH MONDAY AFTERNOON. A MAJORITY OF ENSEMBLES MEMBERS SHOW IVT
VALUES BETWEEN 200-400 IVT. THIS VERY WEAK AR WILL FUNNEL THIS
MOISTURE OVER THE AREA FROM SUNDAY THROUGH TUESDAY, YET SUNDAY
AFTERNOON THROUGH MONDAY AFTERNOON LOOKS TO BE RAINIEST PERIOD AS
THE MOISTURE PLUME FLOWS OVER THE TERRAIN. NBM DATA SHOWS THE
HEAVIEST RAINFALL TOTALS OF 1.50-3.00" FOR THE KING RANGE AND
MOUNTAINS IN NORTHERN MENDOCINO COUNTY. ELSEWHERE, RAIN LOOKS TO
BE BETWEEN 0.50- 1.00" FOR VALLEYS AND BETWEEN 0.75-1.50" FOR
INTERIOR MOUNTAINS NOT MENTIONED ABOVE. SNOW LEVELS ARE GENERALLY
EXPECTED TO BE AROUND 5,000 FEET AND ONLY A SLIGHT DUSTING OF
SNOW (~1.0") IS FORECASTED FOR SCOTT MOUNTAIN PASS (5,450FT).
WIDESPREAD RAIN COULD EVOLVE INTO RAINSHOWERS AS SOON AS MONDAY
EVENING LESSENING THE WIDESPREAD COVERAGE. SHOWERS MAY LINGER
AS LATE AS THURSDAY MORNING AS THE UPPER LEVEL LOW SLOWLY TAKES
ITS TIME MOVING EASTWARD, CONTINUING TO FUNNEL MOISTURE INTO THE
AREA. THE GFS AND ECMWF BOTH SHOW DRY WEATHER WITH WARM DAYTIME
HIGHS AND COLD NIGHTTIME LOWS RETURNING FOR THE END OF THE COMING
WEEK. DS
AVIATION...(06Z TAFS)
DEPENDING ON HOW MUCH OFFSHORE FLOW WEAKENS
EARLY THIS MORNING, STRATUS MAY FORM NEAR THE COAST, ESPECIALLY
AROUND HUMBOLDT BAY. SOME MODELS ARE SHOWING A SOUTHERLY WIND
REVERSAL DEVELOPING OFF THE NORTH COAST BEFORE SUNRISE, WHICH WOULD
PUSH ANY STRATUS TOWARDS CEC. NBM SHOWS AROUND A 60% TO 65% CHANCE
FOR AT LEAST MVFR CONDITIONS AT BOTH CEC AND ACV. SHOULD STRATUS
DEVELOP AND IMPACT THE TERMINALS, IFR/LIFR CONDITIONS ARE LIKELY.
ANY STRATUS AND FOG WILL LIKELY LIFT BY MID/LATE MORNING. VFR IS
ANTICIPATED FOR MOST INLAND TERMINALS
MARINE
NORTHERLY WINDS HAVE GENERALLY SUBSIDED TODAY, THOUGH
SOME AREAS OF 15 TO 20 KT GUSTS ARE POSSIBLE IN THE OUTER WATERS AND
THE LEE OF CAPE MENDOCINO EARLY THIS MORNING. SEAS REMAIN STEEP AT
AROUND 6 TO 8 FT AT 8 TO 10 SECONDS. THESE WILL CONTINUE TO SUBSIDE
AS WINDS EASE THROUGH TODAY. A FRONTAL SYSTEM MOVES THROUGH THE AREA
SUNDAY MORNING. WINDS WILL INCREASE AND TURN SOUTHERLY. WIND GUSTS
ARE FORECAST TO PEAK AT AROUND 20 TO 25 KTS, BUT THERE IS A LOW-END
CHANCE (20%) FOR GALE FORCE GUSTS SUNDAY AND MONDAY IN THE OUTER
WATERS. WIND SPEEDS AND DIRECTION IS HIGHLY DEPENDENT ON THE TRACK
OF THE LOW, WHICH IS CURRENTLY FORECAST TO MOVE NEAR OR THROUGH THE
WATERS MONDAY INTO TUESDAY. A MID-PERIOD WEST SWELL WILL ALSO ARRIVE
MONDAY, PEAKING AT AROUND 8 TO 10 FT AT 12 SECONDS. WINDS AND SEAS
GRADUALLY SUBSIDE LATE TUESDAY INTO WEDNESDAY AS THE LOW MOVES OUT
OF THE AREA. STRONGER NORTHERLY WINDS RETURN LATE NEXT WEEK BEHIND
THIS LOW. JB
EKA WATCHES/WARNINGS/ADVISORIES
CA...
FROST ADVISORY UNTIL 8 AM PDT THIS MORNING FOR CAZ106-110-
114-118.
FREEZE WARNING UNTIL 8 AM PDT THIS MORNING FOR CAZ108-116-
117.
NORTHWEST CALIFORNIA COASTAL WATERS...
NONE.
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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