Flash Flood Warning 4, NWS Eureka, CA

080 
WGUS76 KEKA 020459
FFSEKA

Flash Flood Statement
National Weather Service Eureka CA
959 PM PDT Fri Sep 1 2023

CAC015-020509-
/O.CAN.KEKA.FF.W.0004.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte CA-
959 PM PDT Fri Sep 1 2023

...FLASH FLOOD WARNING FOR THE SMITH RIVER AND SLATER BURN SCAR IS 
CANCELLED FOR NORTHEASTERN DEL NORTE COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4186 12365 4176 12392 4186 12397 4200 12391
      4200 12366 4200 12362 4200 12352 4199 12354
      4196 12353 4193 12355 4191 12355 4191 12356
      4190 12357 4191 12359 4188 12361 4189 12364
      4188 12365

$$

ZVS

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
218 PM PDT Fri Sep 1 2023

.SYNOPSIS...Cool weather will persist through Sunday. In
addition, periods of beneficial showers are expected through
Saturday, with isolated thunderstorms possible. Drier weather is
then likely starting Sunday, with warmer temperatures returning
next week.

&&

.DISCUSSION...An upper disturbance was pivoting over NRN CA this
afternoon. Ascent/deep-layer moistening associated with the
disturbance was aiding in widespread beneficial shower development
over much of Trinity, Humboldt, and Del Norte Counties. In
addition, pockets of MUCAPE values up to 1000 J/kg were promoting
embedded isolated/scattered thunderstorm development, which will
generally spread west toward the Del Norte and NRN Humboldt County
coast through the evening. Otherwise, some shower activity will
linger across the region tonight, and then possibly experience an
increase in coverage and intensity during Saturday afternoon with
an increase in daytime heating. In addition, a generally cool
airmass associated with an upper trough centered over the region
will favor unseasonably cool high temperatures (60s and 70s) across
interior valleys through the weekend.

The previously mentioned upper trough is forecast to depart
eastward during Sunday. Drier weather will become probable across
the EKA CWA as a result. Furthermore, interior valley
temperatures will moderate back into the 80s during early to
middle portions of next week as quasi-zonal flow aloft develops
across the West Coast.

Garner

&&

.AVIATION...Low pressure hanging just off the Lost Coast
alongside an associated shield of showers and thunderstorms have
generated a dynamic and inconsistent environment this afternoon.
Along the coast, IFR ceilings have persisted into the early
afternoon with periods of gusty north winds to 25 kts.

As storms approach the coast from the east, periods of LIFR
conditions can be expected with low visibility in rain and erratic
winds. Most showers will be isolated north of the Mendocino County
border. Winds will subside and turn to the south early this evening
as the first round of showers move offshore. Light rain and
associated IFR to LIFR conditions will continue until around sunset.

Showers will subside by midnight, but fog and a ragged marine layer
are still very likely (>80% chance) to bring at least IFR conditions
through the night. Conditions will be better further south, but even
Ukiah may see periods of MVFR ceilings overnight as southerly flow
pushes marine influence northward. A much weakened marine layer is
likely (>60% chance) to allow for clearing to VFR tomorrow. /JHW

&&

.MARINE...Moderate northerly winds have gradually subsided today
as weak low pressure crosses over the waters. There are only a few
remaining gusts over 21kts being recorded in the northern outer
waters. In the northern waters, short periods seas have built to
around 8 feet and at 8 seconds and will gradually fall this
evening. Conditions have remained calm enough in the southern
waters to expire the small craft advisories there early this
afternoon. A small craft will expire later tonight as the northern
waters calm as well. Winds will turn southerly this weekend but
remain moderate at most.

No strong winds over 20 kts. are expected until at least late
Monday evening. Besides wind waves a series of long period
northwesterly swells around 4 feet and southerly swells around 2
feet will continue to influence the overall sea state into early
next week. /JHW

&&

.HYDROLOGY...A band of heavy showers and embedded thunderstorms
will spread west across NWRN CA this evening. Convectively
enhanced precipitation and generally slow storm motions will aid
in rainfall rates potentially exceeding a half inch per hour near
the River Complex, Smith River Complex, Slater, and South Fork
Complex burn scars. Flash flooding due to debris flow will
subsequently be possible across the burn scars...reference the
latest flash flood products for more information. /JG&SEC

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Flash Flood Watch until 11 PM PDT this evening for CAZ102-
     107.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 PM PDT this afternoon for
     PZZ455-475.

     Small Craft Advisory until 9 PM PDT this evening for PZZ470.

&&

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png