Marine Weather and Tide Forecast for Kalama, WA

DISCUSSION

KEY MESSAGES:

- Areas of late night and morning valley fog followed by warm days through Monday.

- A series of weak fronts approaching the region will bring increasing chances for light rain this week. The increase in onshore flow will produce cooling temperatures Tuesday through Friday.

- >80% of the ensembles indicate a return to shortwave ridging and warming temperatures over the Pacific Northwest next weekend.

WEATHER PATTERN OVERVIEW:

Shortwave ridging over the Pacific Northwest will bring plenty of sunshine, above average high temperatures, cool nights and some areas of valley fog late at night and each morning through at least Monday. Given warming temperatures, frost should be less of an issue the next few nights even in our typically coldest locations so no frost/freeze highlights are anticipated in the short term.

A shortwave trough over the Gulf of Alaska will gradually shift closer to the Pacific Northwest Monday into Tuesday, which will initiate a cooling trend across the region. A weak front and attendant band of light rain will slide southeastward towards the region on Tuesday, but there is a lot of uncertainty in how far southeastward in the forecast area the front and band of light rain will make it, but it appears unlikely (<10% chance) to reach the fires still smoldering/burning in eastern Lane County. Additional fronts appear more likely than not to push towards the region late in the week, but timing uncertainty in when rain will arrive is still only producing a 30-50% of rain in any given 6-hour time period across the region Friday. It should be noted that the NBM's highest probabilities (~10-30%) for temperatures capable of producing frost in our colder locations like the Upper Hood River Valley, Battle Ground, Vernonia, Hillsboro and Colton are Thursday and Friday nights.

More ensemble members from the EPS, GEFS and GEPS come around to the idea of shortwave ridging building across the Pacific Northwest next weekend with more than 80% of the members producing mild temperatures and dry weather across the region next weekend.

FORECAST CONFIDENCE AND DEVIATIONS...Made few deviations from the NBM in the official forecast given it appears to fall in the middle of the ensemble space with regards to temperatures, precipitation chances, etc..


AVIATION
Fog and low stratus have cleared from the area as high pressure builds into the area. VFR conditions are expected into the evening with clear skies and light north winds at 5 to 10 knots. Clear skies this evening and weakening winds should set the stage for additional fog and low clouds to develop for several inland taf sites. TAF guidance suggests IFR or lower conditions developing between 6-12Z for most locations and lasting until 15-18Z. However, HRRR probabilities suggest little to no fog/stratus formation tonight and digging deeper into the higher res models, little to no sub-VFR conditions. Deterministic NBM does suggests fog developing from KUAO south to KEUG. If fog does develop, it will likely dissipate faster than today given conditions have remained dry today.

PDX APPROACHES...VFR conditions expected through this evening. Light winds and clear skies will lead to possible fog development but probabilities continue to decrease with a 10-15% chance between 10-15Z Sunday. -Batz

MARINE
Benign conditions expected as high pressure over the region will stay in place for next several days, with thermal low pressure along the south Oregon coast. As such, will see northerly winds on the coastal waters, generally at 10 to 15 kt. Even with that, the strongest winds will stay south of the Newport. Seas 4 to 5 feet will increase to around 6 to 7 feet on Monday as a system moves well to our north. Seas subside a foot or two into the latter part of next week. -Batz

PQR WATCHES/WARNINGS/ADVISORIES
OR...None.
WA...None.
PZ...None.