Marine Weather and Tide Forecast for Fields Landing, CA

DISCUSSION
Coastal fog developed along the north coast and adjacent river valleys overnight. Increasing high level cloud cover is spreading through the area ahead of a weak upper shortwave.
Shallow elevated instability is expected to occur across the eastern portion of Trinity and around the Yolla Bolly this afternoon, but hi-res models show limited shower activity staying mostly east toward the interior valley.

Ridging will once again build back over the west coast on Wednesday bringing warm temperatures to the interior with high temps in valley locations exceeding 80 degrees in some locations. After morning coastal stratus and valley fog, abundant clear skies are expected.

500mb pattern on Thursday will resemble a rex block. A positive height anomaly will remain centered over the Pac NW (Washington and Oregon) and extend southward into northern California. A cut- back trough or closed 500mb cyclonic circulation offshore or over central/southern California will complete the rex-block pattern.
It is possible for wrap around moisture from the closed low to spread over Lake and eastern Mendocino for diurnal convection. All 6-hourly ensemble members from the ENS, GEFS and CMCE indicate no precip. Also, NBM probabilities for thunderstorms > 15% are well to the east and southeast; over the Sierra Nevada MTN range.
Interior high temperature will remain above average on Thu under large scale adiabatic warming from the ridge centered over the Pac NW. High temps in the mid 70's to mid 80's are generally expected, however a few hot spots such Big Bar RAWS will probably exceed 90F. /ZVS/JMM


EXTENDED DISCUSSION
Friday through Sunday...
Get ready for more cool and wet weather. A 500mb trough will dig southward from the Gulf of Alaska and approach NW Cal on Friday.
All deterministic models, GFS, ECMWF, GDPS, ICON as well as ensemble means were is good agreement with driving a frontal boundary across the northern portion of the area on Friday.
24-hour ensemble cluster means continue to depict subtle differences with placement, timing and overall evolution of the cold core aloft. By 5AM Sat, over half an inch will be possible (50% chance) for interior Del Norte. Not a major rain event by any stretch but wet weather will impact outdoor activities and projects. Spring snowfall will also be possible above 4000-4500 feet with 1 to 2 inches of storm total accumulation by 5 AM Sunday.

Interior temperatures will be considerably cooler and well below normal again next weekend (Sat May 3 and Sun May 4). There might even be pockets of morning frost in the interior valleys with min temps below 36F. Precip chances generally diminish as we head into Sunday as the trough heads southward and eastward. /DB



AVIATION
A marine stratus layer remains consistent over the Humboldt coast and nearshore river valleys as the marine layer grows to 2K feet. Strong northerly winds decoupled overnight at the coastal terminals, allowing a southerly flow reversal to develop - stratus has finally reached the Del Norte coast, leaving CEC and ACV IFR beneath overcast ceilings. A weak shortwave is expected to move through the NorCal coast late this morning, disturbing the marine layer and likely producing at least MVFR ceilings at both coastal terminals through early afternoon.
Gusty northerly winds 15 to 25 knots are expected after 21Z following a weak surface frontal passage. Very light drizzle is possible at the coast late this evening. JMM



MARINE
High pressure over the area is expected to bring northerly winds through Wednesday. Thursday a weather system approaching the area will diminish these winds more. Winds Friday will may briefly turn southerly at least in the northern waters.
Saturday and Sunday northerly winds return and they may be near gale or gale force again. Waves will continue to be mainly wind driven through much of the week. Friday a 16 second swell is expected to build to around 4 or 5 feet. MKK/TRN



EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 9 PM PDT Wednesday for PZZ450- 455-470-475.