textproduct: Eureka

KEY MESSAGES

* Light rain Monday afternoon in Del Norte and Humboldt counties. * Minor coastal flooding is likely around Humboldt Bay from Sunday through Tuesday.

* Breaking waves of 20 to 25 feet are expected today and these may coincide with a very high tide generating significant wave run-up.

* Stronger storm systems with more rain late in the week.

SYNOPSIS

A series of cold fronts are expected to bring light rain in the northern areas of the CWA again on Monday. Mainly dry and unseasonably warm conditions are expected on Tuesday and Wednesday. Thursday may start to see some cooling, but still generally dry conditions. Friday and into the weekend may see some more significant rain.

DISCUSSION

A cold front passed through early this morning, bringing light rain to Del Norte and Humboldt county with the highest rainfall near central Del Norte. Camp six RAWS reporting 0.74 inches since 7pm last night. Higher recordings of precipitation were in the inland mountain ranges of Del Norte. The exception would be Klamath areas of Turwar and Salt Creek with around 0.48 and 0.58 inches respectively, closer to the coast. Winds will veer southerly late tonight/early Mon

Sunday night southerly winds and clouds are expected ahead of another frontal boundary. This is expected to be slightly stronger than the system early Sunday and rainfall is expected to make it slightly farther east and south. There is a 70 percent chance in Del Norte county of over a half inch of rain. This drops to only a 30 percent by Trinidad and quickly lower as goes farther south. A wetting rain is possible in northwestern Trinity county and possibly some of the higher terrain in western Trinity such as South Fork Ridge. Much of Mendocino and Lake counties are expected to remain dry as well as eastern Trinity county. This will generally keep temperatures a few degrees cooler than Sunday.

Tuesday is expected to see some warming and dry once again as high pressure builds into the area. Many of the inland areas are expected to warm into the 70s again with upper 70s possible in the south. Wednesday may be even warmer in many areas. Locations in the shade such as the deeper valleys will remain cooler.

Thursday an upper level trough approaches the area, but the models are still not in very good agreement on the prospect for rain. Two of the ensemble clusters show show light to moderate rain while the two others show no rain. This split generally continues on Friday, although the two wet clusters show heavier rain. Saturday all four of the clusters are starting to show rain, but there are still some pretty big differences in the amounts. So the potential continues for a pattern switch to a wetter pattern, but so far we aren't really seeing anything that would increase our confidence in it actually happening. MKK/EYS

AVIATION

Post front, winds have turned northerly and cloud cover initially broken to scattered is likely to return to overcast tonight as high resolution models show heavy cloud cover filling in ahead of the next frontal boundary, expected by 12z or so Monday morning. More immediately we have diminished visibility at the coastal terminals due to haze and mist, likely from the high surf and wave action off the Del Norte and Humboldt coast. Rain is expected Monday morning at KCEC and KACV. Expect overcast skies with gusty southerly winds as the front arrives by 16z. Ceilings will improve as the boundary lifts the cloud deck from 300ft/LIFR to 5000ft with reduced visibility as hydrometeors obscure. Possible LIFR until the early evening Monday. /EYS

MARINE

Large WNW swell has arrived, quickly building in this afternoon. The swell is already around 18 to 20 ft, with a period of 15- 17 seconds. Buoys to the north are showing wave heights up to 23-24ft so there is the possibility of even larger surf and increased hazards in the area waters. There is still some uncertainty on the size of this swell and it is possible this will come in larger than expected. The swell will then ease late tonight through Monday.

Southerly fresh breezes develop again Monday with another front. These are expected to diminish with gentle to moderate southerly breezes on Tuesday and early Wednesday. Wednesday afternoon southerly winds may briefly increase before diminishing again.

BEACH HAZARDS

A large swell has arrived and could cause large breaking waves of 22 to 24 feet for west to northwest facing beaches through Monday morning. A High Surf Advisory remains in place for this threat. Extra caution is advised near beaches this weekend due to the increased swell activity. These waves are also expected to arrive at the same time as the high tide and this will allow waves to run farther up on the beach.

COASTAL FLOODING

Water levels inside Humboldt Bay continue to run 1.2 to 1.3 feet over the astronomical tides. Southerly winds expected to return with the next front early Monday morning, ~12z or so and may increase these slightly with water levels inside Humboldt bay reaching 8.8 to 9.0 ft on Sunday. The large swell on top of this high water may impact some areas even inside Humboldt Bay.

Outside of Humboldt Bay on the open coast, Crescent City and Arena Cove tide gauges are running 0.5 to 1.0 feet above astronomical tides. The southerly winds may increase this slightly too. These are expected to remain below flood advisory levels; however, the large breaking waves may briefly flood minor roads and parking lots that are exposed at high tide. MKK/EYS

EKA WATCHES/WARNINGS/ADVISORIES

CA... High Surf Advisory until 10 PM PST this evening for CAZ101- 103-104-109.

Coastal Flood Advisory from 10 AM to noon PST Monday for CAZ103.

NORTHWEST CALIFORNIA COASTAL WATERS... Coastal Flood Advisory from 10 AM to noon PST Monday for PZZ415.

Hazardous Seas Warning until 9 PM PST this evening for PZZ450-470-475.

Small Craft Advisory until 9 PM PST Monday for PZZ455.