866
FXUS66 KEKA 311130
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
430 AM PDT MON MAR 31 2025
SYNOPSIS
GENERAL GUSTY WINDS, SHOWERS AND ISOLATED
THUNDERSTORMS WITH POTENTIAL SMALL HAIL ARE EXPECTED TO CONTINUE
THROUGH TUESDAY ALONG WITH MODERATE TO HEAVY DOWNPOURS TODAY AND
TUESDAY. HEAVY MOUNTAIN SNOW ABOVE 3000 FEET ELEVATION IS
ANTICIPATED THROUGH TUESDAY, AS WELL. LINGERING SHOWERS THROUGH
WEDNESDAY, FOLLOWED BY DRY WEATHER FOR THE REMAINDER OF THE WEEK
ARE FORECAST.
DISCUSSION
KEY MESSAGES:
-CONTINUED SHOWERS AND GUSTY WINDS (GUSTS 25MPH TO 40MPH), WITH
ISOLATED THUNDERSTORMS CAPABLE OF PRODUCING SMALL HAIL AROUND THE
COAST.
-PERIODS OF MODERATE TO HEAVY DOWNPOURS TODAY INTO EARLY TUESDAY.
-HEAVY MOUNTAIN SNOW ABOVE 3000 FEET FOR TRINITY AND HUMBOLDT
COUNTIES INTO MID DAY TUESDAY.
WEATHER PATTERN OVERVIEW:
AN AREA OF LOW PRESSURE CONTINUES ITS APPROACH TOWARD THE PACIFIC
NORTHWEST. SHOWERS CONTINUE TO MOVE THROUGH THE AREA EARLY THIS
MORNING. BY MID TO LATE MORNING, ANOTHER PUSH OF MOISTURE WILL
MOVE INTO NORTHWEST CALIFORNIA. PERIODS OF MODERATE TO HEAVY
RAINFALL AND THE CHANCE FOR ISOLATED THUNDERSTORMS WITH SOME
POTENTIAL FOR SMALL HAIL FOR COASTAL AREAS ARE EXPECTED AS COOLER
AIR INFILTRATES THE REGION. THIS COLDER DEEP-LAYER AIRMASS WILL
SUBSEQUENTLY SPREAD SOUTH ACROSS THE WEST COAST THROUGH TUESDAY.
THE COLD AIRMASS WILL AID IN STEEP LAPSE RATES AND AN INCREASINGLY
UNSTABLE ENVIRONMENT. ISOLATED THUNDERSTORMS, SMALL HAIL AND
BRIEF HEAVY DOWNPOURS WILL BE POSSIBLE WITH THE STRONGEST SHOWERS.
IN ADDITION, GUSTY SOUTHWEST WINDS FROM 25 TO 40 MPH ARE EXPECTED
ACROSS THE AREA LATE THIS AFTERNOON THROUGH TUESDAY AFTERNOON.
MOUNTAIN SNOW IMPACTS ARE LIKELY OVER TRINITY COUNTY AND NORTHERN
INTERIOR HUMBOLDT TODAY THROUGH TUESDAY AFTERNOON. SNOW LEVELS
WILL LIKELY DROP TO 3000 FEET TODAY. HEAVY SNOW, WITH STORM TOTAL
ACCUMULATIONS AT 7 TO 12 INCHES FOR ELEVATIONS ABOVE 3000 FEET,
WITH LOCALLY HIGHER AMOUNTS TO 1.5 FEET ACROSS THE HIGHER RIDGES,
ARE PROBABLE THIS MORNING THROUGH TUESDAY AFTERNOON. SNOW LEVELS
WILL BE GENERALLY ABOVE 3000 FEET. HOWEVER, UNCERTAINTY EXIST WITH
SNOW LEVELS DUE TO THE POSSIBILITY OF LOWER SNOW LEVELS DURING
CONVECTIVE SHOWERS. 2 TO 3 INCHES OF SNOW ARE EXPECTED FOR
ELEVATIONS AS LOW AS 2600 FEET. TRAVEL IMPACTS ARE EXPECTED ACROSS
MUCH OF HIGHWAY 3 NORTH OF WEAVERVILLE AND HAYFORK SUMMIT, HWY
JUNCTION 36 AND 3 AT SOUTH FORK MOUNTAIN, HWY 299 AT BERRY SUMMIT,
BUCKHORN SUMMIT AND OREGON MOUNTAIN.
LINGERING SHOWERS ARE EXPECTED THROUGH WEDNESDAY, FOLLOWED BY DRY
WEATHER FOR THE REMAINDER OF THE WEEK AS A LARGE SCALE UPPER LEVEL
RIDGE GRADUALLY BUILDS ACROSS THE REGION IN THE WAKE OF THE
TROUGH.
FORECAST CONFIDENCE AND DEVIATIONS:
RAIN TODAY COULD BE HEIGHTENED DUE TO INCREASED POTENTIAL FOR
CONVECTION, POSSIBLY CREATING INCREASED RAIN RATES AND A SMALL
HAIL THREAT. BY VERY EARLY WEDNESDAY MORNING, COLD AIR ALOFT COULD
ALLOW FOR LOWER SNOW LEVELS ACROSS NW CALIFORNIA. MODELS
CURRENTLY SHOW A STRONG DIURNAL PATTERN WITH SNOW LEVELS DIPPING
TO AROUND 2500 FEET AT NIGHT (NBM) AND JUMPING ABOVE 3000 FEET
DURING THE DAY. ANY SNOW THAT FALLS AT LOWER ELEVATIONS WILL BE
VERY INCONSISTENT AND LIKELY NOT VERY IMPACTFUL.
AVIATION
COASTAL TERMINALS ARE PREDOMINANTLY VFR/MVFR WITH PERIODIC
REDUCTIONS IN VIZ/CEILINGS WITH CONVECTIVE RAIN SHOWERS AND GUSTY
SSW WINDS. A SLIGHTLY QUIETER PERIOD IS EXPECTED THROUGH SUNRISE
BEFORE MORE WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS DEVELOP
FROM OFFSHORE AND CONTINUE THROUGH THE DAY. SIMILAR FLUCTUATING
CONDITIONS ARE EXPECTED AT ALL TERMINALS WITH GUSTY SW WINDS,
ESPECIALLY AT CEC. A BROAD UPPER TROUGH WILL DRIVE THE SURFACE LOW
CLOSER TO THE OR/WA COAST LATE THIS AFTERNOON AND EVENING, WITH A
PERIOD OF LLWS AND GUSTS EXCEEDING 30 KTS POSSIBLE ALONG THE NORTH
COAST AFTER 00Z.
MARINE
SMALL CRAFT WINDS AND SEAS CONTINUE ACROSS ALL ZONES AS A
SURFACE LOW SPINS OFF THE OR/WA COAST. SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH TUESDAY, OCCASIONALLY
PRODUCING GUSTY AND ERRATIC WINDS AND LOCALLY HEAVY DOWNPOURS. AS
THE LOW NEARS THE COAST, NEAR GALE TO GALE GUSTS ARE EXPECTED IN THE
OUTER WATERS OVERNIGHT INTO EARLY TUESDAY. A GALE WATCH HAS BEEN
EXTENDED TO THE SOUTHERN OUTER WATERS DUE TO UNCERTAINTY ON THE
COVERAGE OF THESE WINDS. A LARGE MID-PERIOD WESTERLY SWELL WILL FILL
INTO THE WATERS DURING THE SAME TIME PERIOD, PEAKING EARLY TUESDAY
MORNING. SIGNIFICANT WAVE HEIGHTS 15 TO 17 FEET ARE POSSIBLE BEFORE
QUICKLY DIMINISHING BELOW ADVISORY LEVELS BY WEDNESDAY.
EKA WATCHES/WARNINGS/ADVISORIES
CA...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM
PDT TUESDAY FOR CAZ105.
WINTER STORM WARNING UNTIL 5 PM PDT TUESDAY FOR CAZ107-108.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 3 AM PDT WEDNESDAY FOR PZZ450-
455.
SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR PZZ470-
475.
GALE WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR
PZZ470-475.
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