textproduct: Eureka

SYNOPSIS

Dry weather continues today with breezy afternoon winds. Low relative humidities in the interior will bring an elevated fire weather threat. Rain is likely for the North Coast Monday. Much warmer interior temperatures are likely late next week.

KEY MESSAGES

- Near normal temperatures, dry weather, and breezy afternoon winds continue today.

- Elevated fire weather conditions in the interior with low afternoon relative humidity.

- Rain likely Monday for the North Coast, with the highest amounts north of Cape Mendocino.

- Much warmer weather likely next week into the weekend.

DISCUSSION

The effects of a trough moving through the Pacific Northwest are being observed over the CWA despite it barely grazing past us to the north. High level cirrus cloud strands and various mid-level altocumulus and altostratus are likely to reflect shortwave radiation back out to space, keeping temperatures mild through the afternoon for coastal areas and interior areas north of Mendocino county.

Wet weather is expected to return to portions of the area on Monday. Models are in good agreement for generally light to locally moderate rain for Humboldt and Del Norte Counties starting late Monday morning and through the day. Total rain amounts in Del Norte range from just under 1" to localized 1.5" or more in the mountains. Precipitation drops off significantly farther south, with only around 0.10" to 0.50" in Humboldt and coastal Mendocino, and only a few hundredths in Trinity and interior Mendocino. Models have generally been trending wetter, and westerly flow could support higher rain amounts in Humboldt and Del Norte. Some high-res models are showing this possibility with the REFS showing fairly high chances (70%) for over an inch of rain for northern Humboldt. Lake County may only see a few sprinkles, if any. South winds may be breezy in Del Norte, especially in the higher terrain and coastal headlands where gusts could briefly reach 30 to 35 mph Monday afternoon. Interior high temperatures will also drop 5 to 10 degrees, with 60s or 70s forecast for most interior valleys.

This front quickly moves out of the area Tuesday with temperatures rebounding slightly to the high 70s. Low temperatures Tuesday morning may drop into the 30s in the coldest valleys, including Hayfork and Ruth. Frost is currently not expected, but this will need to be watched.

Warming temperatures are expected to start on Wednesday and will likely continue to to warm through the end of the week and into the weekend. Interior high temperatures in the 90s and possibly into the triple digits for the warmest valleys are possible by Thursday and Friday. Warm and dry weather is expected to continue into the weekend. JB /EYS

AVIATION

VFR conditions are in place across the area this afternoon. Winds are currently northwest, but tonight are expected to become southerly as a front approaches the area. It looks like conditions will remain VFR until the rain associated with the front arrives early Monday morning on the north coast. This will gradually spread south through the day bringing MVFR conditions with local areas of IFR conditions. Monday afternoon and Monday night. MKK

MARINE

Northerly winds persist across the waters this afternoon. Local areas of gale force winds are likely occurring south of Cape Mendocino. Farther north winds remain around 5 to 10 kt. Also there is a southwest swell around 3 feet at 15 seconds and a northwest swell around 5 feet at 8 or 9 seconds.

Tonight winds will turn southerly through the night. These are expected to increase to 20 to 25 kt through the morning north of Cape Mendocino and to a lesser amount farther south. Monday night winds are expected to turn northerly once again and start to increase again on Tuesday. Also on Tuesday a fresh northwest swell is expected to build to around 7 feet at 10 seconds. This will diminish and combine with the wind drive waves Tuesday night.

Winds are expected to continue to increase Wednesday with gales possible by Wednesday afternoon. These are expected to continue on Thursday and Friday.

FIRE WEATHER

Breezy west-northwest winds continue today, but are expected to be slightly lighter than previous days. Gusts of 20 to 25 mph are possible over exposed ridges and in channeled terrain. Minimum relative humidity in the afternoon is expected to drop into the teens or 20s for the eastern portions of the area (Trinity, eastern Mendocino, and Lake Counties). These afternoon winds along with low RHs will bring elevated to locally critical fire weather conditions. Wetting rain is very likely for Del Norte, Humboldt, coastal Mendocino, and western Trinity. Probabilities drop off farther south and east to near zero in Lake and southern Mendocino. JB

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 2 PM PDT this afternoon for PZZ455.

Gale Warning until 8 PM PDT this evening for PZZ455.

Small Craft Advisory until 11 PM PDT this evening for PZZ475.