textproduct: Portland

SYNOPSIS

Another coastal weather system will brush the area tonight into Thursday morning bringing light rain, with dry conditions otherwise expected through the workweek. The pattern then shifts wetter and colder this weekend into early next week.

LONG TERM...Saturday through Tuesday

This weekend into early next week, the ridge axis will slowly slide eastward toward the Rockies, allowing the storm track to dip south into the Pacific Northwest and resulting in steadily increasing chances for precipitation across the region by Sunday. Ensemble guidance is coming into better agreement that Saturday will remain mostly dry, though a handful of members continue to indicate the storm track may dip south enough for light precipitation, mainly for the northern portion of the forecast area along the coast and terrain. Beyond Saturday, global ensembles remain in fairly good agreement given the lead time that an upper- level shortwave trough will track toward western Washington or northwestern Oregon, although the timing of this feature remains more uncertain, ranging anywhere from Sunday night through Tuesday. Significant Cascade snow chances have all but disappeared with this system with less than 5% chance of 6 inches or more of snow from Sunday to Tuesday. On the heels of this shortwave, however, another shot of colder temperatures could reach the region toward the middle of next week. -36/03

AVIATION

The initial stages of the front is moving in this afternoon which is going to push upper level stratus over the region. This high stratus is going to inhibit the very stubborn stratus that has lingered in the Willamette Valley. These areas are going to struggle to clear until the main frontal passage arrives after 00Z Thu. Will see widespread rain, MVFR stratus, and locally breezy winds. Southerly winds along the coast will amplify overnight with gusts around 25 kt or greater. Rain will taper after 12Z Thu with CIGs following quickly behind.

KPDX AND APPROACHES...VFR through the next several hours ahead of a frontal system. Overnight, MVFR CIGs are most likely with a 20-25% chance of IFR CIGs between 09-12Z Thu. Due to the low probability have omitted from the TAF and trended slightly higher to low-end MVFR. -27

MARINE

A weak cold frontal system is moving over the waters causing a southerly wind reversal with gusts up to 25 kt. Will see localized gusts up to 30 kt, especially in the inner waters. Seas will slowly rise to 10 ft by Thursday morning. While winds will ease following the front, seas will take over in regards to the Small Craft Advisory. Therefore, the Small Craft bridges the two different scenarios. In the post frontal environment, a low pressure system in the northeast Pacific and Gulf of Alaska will bring in a fresh swell to add on to the background swell. Seas will increase considerably beginning Thursday afternoon. As they build, will see widespread seas greater than 13 ft at 14 seconds. The most likely range for seas (25-75th percentile) is 13-17 ft but there is a 10% chance for seas greater than 18 ft in the far outer waters west of 30 NM from shore. Winds are not going to be amplified during that time. Hazardous Seas expected through Friday morning

This is a quick shot of Hazardous Seas but don't expected settled conditions. For the remainder of the week into the weekend, seas will hover right around 10-14 ft at 14 seconds with a south to southwesterly wind. -27

BEACH HAZARDS

An energetic westerly swell is expected along the northwestern Oregon and southwestern Washington coasts for a long duration from Thursday through next Monday. Initially, the swell will reach 15-18 ft at 15 seconds through much of Thursday, before weakening slightly to 10-12 ft at 12-15 seconds from early Friday afternoon through the the weekend. Even when this swell is slightly lower amplitude, its long-period nature will yield a high risk for sneaker waves along area beaches. These energetic waves can run significantly farther up a beach than normal, including over rocks and jetties, creating potentially life-threatening conditions in the surf zone when beachgoers can be unexpectedly knocked off their feet and pulled out into cold ocean waters.

A Beach Hazards Statement has therefore been issued from 5 AM Thursday through 5 AM Monday. Caution should be used when in or near the water, and beachgoers with children should be especially watchful. Never turn your back on the ocean, and be sure to keep an eye on the waves. Those participating in razor clam digs should additionally exercise caution.-36

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Hazardous Seas Warning from 10 AM Thursday to 4 AM PST Friday for PZZ210-251>253-271>273.

Small Craft Advisory from 7 PM this evening to 10 AM PST Thursday for PZZ251>253.

Small Craft Advisory until 10 AM PST Thursday for PZZ271>273.