Marine Weather and Tide Forecast for Four Corners, OR

SHORT TERM
Now through Thursday...Showers have ended throughout the region as of 2:30am Wednesday, and a brief period of ridging is expected for the rest of tonight and Wednesday daytime hours. With some isolated clearing tonight, there exists a 50-60% chance of frost developing in cold pockets that form tonight, particularly the upper Hood River Valley (Odell, Parkdale). That said, most of the Willamette Valley should remain closer to the upper 30s/near 40s tonight as cloud cover inhibits frost formation.

Wednesday remains dry with elevated temperatures in the afternoon. High temps in the upper 60s/near 70 in the Willamette Valley, with coastal temperatures closer to the upper 50s/near 60. Ridging will be fairly short lived as a weak shortwave trough pushes into the region Wednesday night, bringing some weak insubstantial rain showers over Wednesday night and Thursday AM hours, ending in the afternoon. Temperatures on Thursday will be slightly depressed compared to Wednesday, with temperatures closer to the low to mid 60s in the Willamette Valley.

Brief ridging late tonight into early Wednesday will give way to another shortwave trough sliding across the region late Wednesday into early Thursday. This will bring another round of light precipitation to the region. Ensembles suggest the light rain is most likely to arrive Wednesday evening into Wednesday night with some light precipitation chances lingering into Thursday across mainly the higher terrain. Temperatures look to remain near to slightly below average for the date through Thursday.

LONG TERM
Thursday Night through Tuesday...WPC Clusters suggest the region will be under the influence of a lingering shortwave trough Thursday night into Friday. However, only 10-30% of global ensemble members suggest deep enough troughing over the region to keep some light precipitation continuing mainly over the northern half of the CWA and the higher terrain of the Coast Range and Cascades. Otherwise, precipitation looks too weak to really produce any substantial rain.

Global ensemble membership is generally in agreement that shortwave ridging will build into the Pacific Northwest Saturday into Sunday leading to the area drying out further and temperatures warming to well above average by Sunday. With that said, there is 10-20% of the ensemble guidance that delays shortwave ridging, which keeps Saturday cooler.

Uncertainty in the upper level pattern grows early next week.
The main uncertainty revolves around how long shortwave ridging persists over the region and when the next shortwave trough slides into the Pacific Northwest. The current forecast is very middle of the road, but know there is ~25% chance temperatures in the 80s will persist into early next week and there is a ~25% chance that temperatures drop into the 60s with.



AVIATION
Predominately VFR with scattered to broken mid level cloud cover across the area as weak high pressure builds over the region today. Winds increase out of the NW this afternoon, to around 10-15 kt at coastal sites, but generally remaining below 10 kt inland. High pressure will shift east of the Cascades late in the period, with an arriving disturbance bringing increasing rain chances and lowering CIGs 06-12z Thursday. Increasing chances for MVFR CIGs after 12-14z Thursday.

PDX AND APPROACHES...Mainly VFR conditions through the period.
Light winds increase out of the WNW 18-21z Wed, but generally remain below 8 kt through the period. Rain chances increase after 06z Thu, but VFR likely to persist through at least 12z Thu.
Chances for MVFR CIGs increase by 14z Thu. /DH



MARINE
Buoy observations show light northwest breezes with seas subsiding to 7-9 ft across the waters as of 2 AM Wednesday.
Winds will turn more northerly today and Thursday as weak surface high pressure builds offshore. Inland daytime heating will drive some diurnal strengthening of the coastal pressure gradient, with winds increasing to 15-20 kt during the late afternoon and early evening. Models suggest a 30-50% for gusts as high as 25 kt over the nearshore waters later this afternoon, but do not anticipate adding any small craft headlines at this time as gusts should remain fairly localized. Meanwhile, seas will continue to gradually subside through Thursday as a mid period swell decays below 5 ft. Conditions remain on the quiet side Friday into the weekend as benign onshore flow returns, yielding mainly light breezes and seas below 5 ft. /CB

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.
WA...None.
PZ...None.