Marine Weather and Tide Forecast for Ferndale, CA

DISCUSSION
Dry northerly flow is promoting abundant clear skies across Northwest California this afternoon. Interior high temperatures are 5 to 15 degrees warmer than yesterday's reading, with highs in the mid 60's to mid 70's. Coastal areas highs persisting the 50's due to the sea breezes. Breezy northwesterly winds with gusts from 25 to 35 mph have been observed along the North Coast, with locally stronger winds over the exposed ridges in Cape Mendocino.
Winds are expected to decouple this evening.

For tonight, coastal clouds will redeveloped in the vicinity of Humboldt Bay and portions of the Mendocino Coast, before expand again into Tuesday morning.

A weak shortwave trough will move southeast across the area on Tuesday. Mid to high level clouds will increase ahead of the shortwave. A shallow elevated instability is expected to occur across the eastern portion of Trinity and around the Yolla Bolly Tuesday afternoon. However, GFS and NAM model soundings depict a well- defined cap that could inhibit convection over most of our CWA
Temperatures are forecast to be similar like today, Monday.

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


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. About 30-45% of cluster members continue to trend wetter than the grand ensemble mean. NBM continues to indicate 50-70% chances for 0.25in of rain in 24 hours Friday- Saturday in Del Norte, 30-50% chances for Humboldt, 20-45% chances of Trinity and 10-25% chances for Mendocino and Lake. 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 day 7 (Sunday) as the trough heads southward and eastward. To what extent and how fast this occurs are still not 100% certain. Precip could wrap back around a potential cut-off low or an upstream kicker may knock down the offshore ridge resulting in more light precip from the west. A faster SEWRD progression with stronger ridging offshore would result in a much drier and gusty north/northwest wind scenario for our forecast area. Most ensemble members support this scenario. Stay tuned. /DB



AVIATION
High pressure building into the area has brought most clear skies and VFR conditions. Breezy conditions are in place at the coast and on the coastal ridges with lighter winds in the valleys. Tonight stratus is expected to return along the coast in the in the near coastal river valleys. The HRRR shows this returning quickly in the evening. As of 230pm there are still clouds around Kneeland and Freshwater. Once the sun goes down these are expected to quickly expand. They are not expected to make it as far up the river valleys as they did this morning. KCEC is expected to stay clear with some offshore flow in Del Norte county, but confidence is low on this. Clearing is expected by late morning midday again tomorrow. MKK



MARINE
High pressure over the area is expected to bring northerly winds through Wednesday. Winds are peaking this afternoon and evening with near gale to gale force winds over much of the waters. Steep waves will peak around 9 to 12 feet. Tonight these winds will diminish slightly, but remain around 20 to 25 kt in the outer waters and slightly lower at night closer to the coast.
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

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

Gale Warning until 11 PM PDT this evening for PZZ475.