textproduct: Eureka

SYNOPSIS

Hot and dry weather will briefly build through Tuesday with gusty north winds near shore. Cooler weather will then return later in the week with scattered showers for the southern half of the area possible by Thursday into Friday.

DISCUSSION

High pressure will peak Tuesday with a slight potential (30%) of the hottest valleys just reaching near 100 along the Trinity River. Gusty north winds will generally keep the marine layer weak along shore. A trough will begin to approach the area on Wednesday with temperatures quickly dropping back down into the 80s and an elevated marine layer returning near shore.

As a deep trough gradually approaches shore later in the week, there is high confidence that southerly wind along the trough will pull moisture up from the tropical pacific. By Friday, precipitable water values will most likely soar to between 1 and 1.6 inches all across the area, bringing a the potential for precipitation. The exact character and location of this precipitation is highly uncertain, partially due to possible interactions with a tropical system off the coast of southern California. Unlike most systems over the past several months, the core of rain showers would most likely be focused in the southern half of the area. Most models currently resolve little instability, but showers could manifest as elevated thunderstorms as the trough moves onshore Friday and into the weekend. Most likely Rainfall is currently only 0.1 to 0.4 inches with the greatest rainfall over the Yolla Bollys and only a trace closer to the coast. Again, there remain high uncertainty with a 65% chance of no real precipitation at all. An unsettled and troughy weather patten will most likely persist into early next week with cooler and more moist weather alongside rain shower chances. /JHW

AVIATION...(06zTAFs)

Light offshore flow will aid in drying out the air column which will thwart widespread stratus reformation. A low chance (20%) for patchy LIFR ceilings and fog will develop early Tuesday morning along the north coast, but coverage looks to be very limited; however, southerly flow could bring in low level moisture early Tuesday. In general, flow will turn more southerly Tuesday, tapping into better moisture. With the return of low level moisture, the marine layer will quickly redevelop. Models will continue to struggle with the timing of the stratus resurgence for Tuesday in the near term.

MARINE

The northerly winds and short period seas continue to trend down into Tuesday morning. Seas have dropped below 10 ft in the outer zones (beyond 10 nm). Light westerly winds 5-10 kts and 4- 6 ft seas will remain Tuesday, while nearshore waters see light westerly to southerly winds.

Starting late Tuesday, the northerly winds will begin an increasing trend. The strengthening will start in the southern waters late Tuesday through Wednesday morning, but northerly winds will quickly ramp up Wednesday afternoon in the northern zones as well. A remnant tropical system is forecast to then push northward through Thursday. The pressure gradient will become locally strengthened from the tropical low south and a dominant ridge of high pressure over the north Pacific. Subsequent gale conditions, potentially with sustained gale winds are forecast late Wednesday through Thursday. Large and steep short period hazardous seas will build in excess of 16 feet in response. Winds and seas are currently forecast to ease going into the weekend.

FIRE WEATHER

Briefly hot and very dry conditions through Tuesday will allow for fuels to rapidly dry. Interior valley highs will be int he 90s with RH solidly below 20 percent. Strong thermal belts will promote poor overnight recoveries. Wind will generally be gentle and terrain driven. Conditions will begin to ease again Wednesday through the end of the week as a deeper trough approaches shore. There is potential by Thursday (10% chance) and especially Friday (20%) of scattered showers and Thunderstorms over high terrain. Chances will be greatest over the southern half of the area (35% chance of wetting rain) with lesser chances further north (15% chance wetting rain). Storms would have moderate storm movement and would be relatively wet. Not there is currently high uncertainty in the exact details for showers with a 65% chance of there being no showers at all.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 AM PDT early this morning for PZZ470-475.