Marine Weather and Tide Forecast for Maywood Park, OR

SHORT TERM
Now through Saturday...Early this morning satellite and radar observations depict continued shower activity across the region as the tilted axis of a broad upper- level trough passes overhead. Models are in excellent agreement this upper-level low exiting eastward through the day today allows for building heights and a switch drier northerly flow aloft. Rain showers gradually dwindle in coverage as a result by midday with most dry conditions returning to the entire region by the mid to late afternoon hours excluding the Cascades where slight chance (15-25%) for showers still holds on due to terrain forcing.

We're anticipating another round of cool temperatures tonight into Friday morning. Conditions appear even more supportive of effective radiational cooling compared to the night prior with additional clearing and lighter winds, albeit with an airmass that'll be slowly moderating. A Freeze Watch remains in effect from 1-9 AM Friday for the areas most likely to see temperatures fall below freezing, namely the Upper Hood River Valley and the Cascade foothills of Marion, Linn, and Lane Counties. Should model guidance continue to support the overall set-up and forecast low temperatures in the 30s across other portions of the inland/coast range valleys, widespread Frost Advisories may once again be needed. The southern Willamette Valley is an area of particular concern beyond those mentioned above for frost/freeze impacts. Agricultural interests and those with sensitive outdoor plants should plan to take protective action to prevent plant damage.

Confidence is high upper-level ridging builds further on Friday into Saturday, ushering in drier and warmer weather across the region, although there remains some uncertainty in the progression of yet another upper low over the Northeast Pacific. This low or open trough may move nearer to the region and bring clouds and showers, the chances for the latter only reach around 15-25% along the coast come Saturday afternoon, increasing further Saturday evening. It should be quickly noted beyond some isolated pockets of cooler temperatures in the upper Hood River Valley, far southern Willamette Valley, and other coast range/Cascade valleys, the threat for frost will be rather limited Friday night into Saturday morning -99/36

LONG TERM
Sunday through Wednesday...All eye are on the progression of an upper-level low or open trough tracking southward from the Gulf of Alaska over the Northeast Pacific early next week as it will be the driver of sensible weather going forward. The forecast and potential impacts remain extremely sensitive to this feature's evolution. An upper low located nearby will favor cloudy skies and rainfall chances, while a position well to the west would see continued warm and dry weather. The current forecast as far as temperatures is concerned is somewhere in-between. If the upper-level low located off the northern CA or southern OR coast, the pattern could allow sufficient moisture to move northward on its eastern flank to support convection along the Cascades early next week.
To help highlight this forecast uncertainty, the projected high temperature spread in the NBM ensemble ranges from 83 degrees (90th percentile) to 57 degrees (10th percentile) on Monday, a 26 degree spread. Tt's not often we see that much uncertainty on day 4-5 of the forecast. At least there is a decent consensus this upper-level low or trough feature kicks eastward by the middle of the week leaving us in a more typical onshore flow pattern. That said, the exact transition and thus potential impacts remain nebulous at this time. -99/36

AVIATION
Showers continue across the region early this morning with generally VFR conditions overhead. Especially over the next few hours (through 15-16z), any activity when passing over a terminal may briefly drop CIGs /VIS to MVFR.
Fortunately, lingering showers and thus chances for MVFR flight conditions decrease by the midday hours before remaining rather isolated during the afternoon hours. Both early this morning near sunrise, and tonight into Friday morning, temperatures could be cold enough for frost formation over exposed surfaces, although for the former period it will be highly dependent on partial clearing. Winds remain fairly light, generally less than 5 to 10 knots at all sites.

KPDX AND APPROACHES...Expect mainly VFR conditions, falling to MVFR briefly near showers this morning before ~15z. High confidence in prevailing dry weather and VFR conditions after this point through the afternoon and evening. -99

MARINE
Broad northwesterly flow continues today with lingering showers decreasing through the day. We'll see Small Craft Seas at 8-11 feet at 9-10 seconds persist as well due to a fresh WNW swell combined with a WNW wind wave. In addition, there will also be a strong ebb this morning for the Columbia River Bar helping to keep waves steep. Expect wave heights to slowly wane through the day across both the inner and outer waters. Winds will remain W-WNW through Friday morning, then shift to the north as a high pressure ridge sets up overhead.
This summer-like weather pattern is fairly short-lived however, switching southerly on Saturday and increasing across the outer waters. Guidance suggest a 40-60% chance for gusts above 21+ knots across the outer waters Saturday evening/night. Fairly benign conditions continue during the early to middle portion of next week with wave heights holding in the 4 to 7 feet. -99/27

PQR WATCHES/WARNINGS/ADVISORIES

OR...Frost Advisory until 9 AM PDT this morning for ORZ104>110- 114>118.

Freeze Warning until 9 AM PDT this morning for ORZ121-123>125.

Freeze Watch from late tonight through Friday morning for ORZ121-124-125.

WA...Frost Advisory until 9 AM PDT this morning for WAZ203>205-208.

PZ...Small Craft Advisory until 11 AM PDT this morning for PZZ210.

Small Craft Advisory until 5 PM PDT this afternoon for PZZ251>253-271>273.