textproduct: Eureka

SYNOPSIS

Monsoon moisture is bringing widespread high clouds this afternoon and this is expected to continue through Wednesday. Slightly above normal temperatures continue Tuesday. There is a slight chance for afternoon thunderstorms in the interior Tuesday and Wednesday. Drier weather is expected late in the week with temperatures near or slightly below seasonal normals.

DISCUSSION

An area of low pressure, the the remnants from Hurricane Elida, is moving up off the California coast. This is bringing moisture with it. Today this is bringing mainly high clouds and a few light showers or sprinkles. There is only minimal, if any instability with this moisture which is limiting the thunder potential. The better dynamics remain off the coast. So don't really expected any thunderstorms this afternoon, but hard to rule one out. Warmer temperatures are expected again Tuesday with highs in the warmer valleys in the mid to upper 90s. Tuesday late in the afternoon and evening some of the models are showing a small amount of instability, but there really isn't any forcing to set off a thunderstorm. Still one or two are possible in northern Trinity county in the evening.

Wednesday the area of low pressure starts to move past the area and this is expected to bring a little bit of forcing and some instability in the afternoon and evening. This looks like the most likely time for thunderstorms to develop this week. However, if any storms do form they will be moving north and may move into Siskiyou county fairly quickly.

Thursday the upper level trough is expected to get closer to the area and this is expected to start bringing cooler temperatures, back to near or slightly below normal with highs in the upper 80s. This is expected to bring some stronger wind west to southwest winds in the afternoon. Similar temperatures and winds are expected to continue on Friday. For details see the fire weather section. High pressure is expected to bring warmer temperatures to the area for the weekend with dry weather.

AVIATION

Skies have cleared out this afternoon, but stratus remains 5 to 10 miles off the coast. This is expected to move back in this evening, but confidence is low on how quickly it will return. It will likely return around sunset. When clouds do return, models are indicating conditions will quickly drop to LIFR and possibly less than a quarter mile. VFR conditions are expected to return fairly quickly on Tuesday.

MARINE

Light northerly winds continue on the offshore waters, but closer to the coast winds are light and south to southwest. The steeper are diminishing this afternoon as well. A 3 to 4 foot southerly swell at 12 seconds is moving through the waters along with a 2 foot northwest swell.

These conditions are generally expected to continue through much of the week. The swells will fluctuate slightly, but generally remain small. Winds are expected to increase slightly to 10 to 15 kt Tuesday night and early Wednesday before diminishing again to less than 10 kt. Thursday afternoon northwest winds start to pick up once again in the southern waters to around 10 to 15 kt. Winds continue to increase over the weekend. MKK

FIRE WEATHER

Monsoonal moisture has brought widespread high clouds to the area this afternoon. There is still the potential for a few dry thunderstorms this evening, but the chances are diminishing due to very limited instability. Tuesday There is another chance for thunderstorms, but this looks like a low probability. Some weak ridging pushes over the area keeping the strong inversion at higher levels. Did add a slight chance for northern Trinity county late in the afternoon and evening. Wednesday the upper level low related to the departing tropical system moves closer to the area and increase the potential for some thunder in the afternoon. Confidence remains low on this, but have added thunderstorms to the forecast Wednesday afternoon and evening.

Thursday and Friday the threat for thunderstorms diminishes, however some stronger west to southwest winds are expected. At this point it looks like the RH will be too high to warrant a fire weather watch. Will likely add a headline to the forecast once it gets within range of the higher resolution models if the winds remain in the forecast. MKK

Afternoon RH continues to be low with most interior areas seeing teens and 20s. High temperates return closer to average early week as high pressure weakens. Winds generally remain light and terrain driven. Monsoonal moisture has arrived and will continue to influence the area through Wednesday. There will be multiple low chances (15% or less) of thunderstorms for the interior areas tonight through Wednesday. Dry low levels will limit precipitation from reaching the ground.

EKA WATCHES/WARNINGS/ADVISORIES

CA... Red Flag Warning until 6 PM PDT this evening for CAZ403-406- 409>412.

NORTHWEST CALIFORNIA COASTAL WATERS... None.