470
FXUS66 KEKA 252222
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
322 PM PDT Wed Sep 25 2024

.SYNOPSIS...Dry weather and above normal temperatures are forecast
to return in the interior Friday through this weekend. Hotter
weather conditions will likely arrive early next week. Coastal
areas are forecast to have occasional low clouds through this weekend.

&&

.DISCUSSION...Southern end of a weak trough moving into the Pacific
NW has resulted in substantial cooling for the entire forecast
area today. Not much precipitation has occurred with only a few
sprinkles from elevated cells passing over Del Norte county. Surface
high pressure will rebuild behind the trough tonight and Thu. Interior
temperatures will recover to around seasonal averages (85-91) on
Thu as 500mb heights and 850mb temps increase slightly. Deeper
humid layer tonight will likely result in a rejuvenation of stratus
and patchy fog along the coast and coastal river valleys. The low
clouds will likely scour out with daytime heating and mixing.

Deterministic and ensemble guidance indicates above normal 500mb
heights and above normal 850mb temperatures returning Friday.
Above normal interior temperature will most likely return Friday
and remain above normal through the weekend. In fact, latest NBM
guidance indicates 100F likely (70% chance) for southern Mendo
(KUKI) on Friday. Widespread highs in the lower to mid 90s are
probable elsewhere for the interior. Heat risk will increase to
moderate levels on Friday in the interior valleys. A weak trough
will probably knock temperatures down some over the weekend in
the interior, but it will still remain warm and above normal.
Northerlies and steady influx of cool-damp marine air will
probably result in night and morning stratus for the North
Coast through this weekend. NBM indicates clear skies while
NAM12 BUFKIT shows favorable thermodynamic profiles for stratus
generation.

Ridge will amplify early next week leading to another round of
hot weather in the interior valleys. Offshore flow may propel high
temperatures into the lower to mid 70s along the coast Mon or Tue
next week. Unlike the last offshore event, this one will lack
deep layer easterlies and marine air may hinder the warming for
coastal areas. For inland areas, anomalous warming is much more
probable. Significant rain (a tenth of an inch) remains highly
unlikely for the next 7 days. DB

&&

.AVIATION...Diverse layers of clouds covered the whole region
through the day; all these layers made difficult observing the
marine stratus that blanketed the Redwood Coast. Stratus impacts
on flying weather were greatest at ACV and CEC Taf sites due to
mostly IFR/LIFR conditions. By 1 PM, ACV had lifted into MVFR then
VFR. BINOVC is expected in the mid-late afternoon. The abundant
cloud advection has been associated with a weak disturbance moving
into the region. Noonday satellite imagery indicated light precip
along the North Coast...no doubt mostly Virga. Inland: Ukiah
reported some low clouds that pushed up along the Russian River
this morning. Also, lots of low clouds moved over the Mendocino
Near-Coastal Range as the marine layer deepened to about 2500
feet, but just couldn`t spill over into the UKI valley. /TA

&&

.MARINE...Northerlies around 20-25 kt and steep wind waves around
8 ft will warrant issuance of a small craft advisory for the southern
outer waters Thu and Fri. Northerlies will strengthen north of Cape
Mendo on Friday with potential for gale force gusts and large steep
waves over 10 feet - mostly over the outer waters. Elevated northerly
winds and large steep seas over 10 ft are forecast to continue
into the weekend. Highest seas are forecast outside 20NN. DB

&&

.FIRE WEATHER...Much higher humidity and cooler temperatures have
occurred today with passage of a trough into the Pac NW. Humidity
will trend drier and temperatures warmer over the next couple of
days with northwesterly and westerly diurnal breezes each day.
Northerlies will return to the coastal ranges tonight and continue
for the remainder of the week. Strong gusts over 30 mph will likely
occur over exposed ridges of zone 201 (King Range) and exposed
southern ridges of zone 202. Humidity will most likely remain high
with these strong northerlies. Transient upper trough will most
likely disrupt the warming trend over the weekend. Broad flat
ridge will build early next week leading to hotter weather and
very low RH`s. The building heat coupled with dry E-NE flow may
yield elevated to locally critical conditions late Sunday into
Monday and Tuesday. DB

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 3 AM Thursday to 9 AM PDT Friday
     for PZZ475.

&&

$$

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