textproduct: Eureka

KEY MESSAGES

- Warmer drier conditions for the interior Monday and Tuesday with gusty winds near the Trinity horn will elevate fire weather conditions.

SYNOPSIS

Dry, seasonable weather is likely for the early part of the week. Slightly warmer interior temperatures are expected Monday and Tuesday before another trough brings cooler temperatures mid-week. Coastal stratus is likely to clear out again Monday afternoon but may be more persistent later in the week.

DISCUSSION

Weak high pressure fills in over the area today bringing slightly warmer temperatures this afternoon for the interior. Most interior areas will see highs in the 90s with a stray triple digit possible for the warmest valleys. The previously deep marine layer is now shallower as high pressure fills in but will continue to bring stratus to the river valleys near coast. Expect clearing out again Monday afternoon as breezy coastal winds are likely to scatter any remaining stratus bringing mostly clear, yet breezy conditions to the coast. Temperatures will increase for the next few days as weak ridging sets in, with southerly winds oddly enough swooping into the area late tonight into early Monday morning. These southerlies will find their way into channeled terrain and into the central valley, focusing and funneling up the interior which will bring fire weather concerns as air parcels are pulled downslope into valleys near the Oregon border. (see fire weather below)

Through the middle of the week, a trough starts to approach the area bringing slightly cooler interior temperatures along with a deeper marine layer. Light winds offshore may lead to coastal stratus to be persistent into the afternoons. Moisture and instability is limited with this troughing pattern, which will limit thunderstorm potential. Generally mild, seasonable weather is likely towards the end of the week. /EYS

AVIATION

Gusty winds at KCEC will ease to southerly by the early Monday morning hours overnight. Southerly winds also fill in overnight at KACV around the same time as KCEC, 04-07z. With this southerly surge there will be a reduction in flight categories as stratus and the marine layer make their way on shore and into the coastal flight terminals. A much stronger signal for LIFR and reduced visibility are being shown by MOS guidance with NBM also putting a probability to 1/2sm visibility around 35% at the coastal terminals. With the southerly wind pattern KUKI flight categories become a concern as stratus usually pushes up the adjacent river valleys. The lack of depth of the marine layer and calm winds at KUKI may hamper this development. NBM probs only have a < 10% chance of ceilings below 3000ft near KUKI overnight. /EYS

MARINE

Northerly winds continue to increase across the outer waters, in the lee of Cape Mendocino. Localized gale force gusts are possible downstream from Cape Mendocino. Steep seas are likely to propagate into the inner waters even as winds remain light. Winds diminish Monday as a frontal boundary arrives.

FIRE WEATHER

A warmer drier trend for the next 36 hours for areas of the interior, particularly Trinity county bordering Siskiyou. Gusty diurnal southerly winds coming up the north valley will be channeled into mountainous terrain, possibly warming air parcels as they descend into river valleys of Siskiyou. Exposed ridges will also be of concern. Otherwise, recoveries will be moderate to good in the lower elevations and poor in the higher elevations. Winds generally remain light and terrain driven for our CWA with typical afternoon breezes. A deeper marine layer returns mid week.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 AM PDT Monday for PZZ450.

Small Craft Advisory until 9 AM PDT Monday for PZZ455.

Small Craft Advisory until 6 PM PDT Monday for PZZ470-475.