textproduct: Portland

SYNOPSIS

High pressure will keep the region dry and warm through the weekend, though temperatures ease down a bit after today. Clouds will increase late Sunday/early Monday ahead of a frontal system, with rain and cooler temperatures returning for the start of the week. Breezy conditions are possible with the front, which could affect outdoor Memorial Day plans. For the remainder of next week, cooler and drier conditions are expected through the remainder of the week.

LONG TERM...Monday through Friday

Looking towards the start of next week, Memorial Day looks to be cool and wet as the Alaskan Low mentioned above moves from the northwest to the southeast. This system looks to bring anywhere from 0.20" to 1.00" within a 24 hour period (5AM Mon-5AM Tues). Generally speaking, the probabilities for 24 hour rainfall totals of at least 0.25" across are 50% or higher, with the highest probabilities along the Coast and within the Coast Range and Cascades. Looking at the probabilities for 0.50" or more the chances sharply decrease with the Willamette Valley dropping to 10-25% chance, while the Coast, Coast Range and Cascades drop to around 50-90% chance. As for the probabilities for 1.00" or more, from Lincoln City, OR towards the Long Beach Peninsula, there is a 35-55% chance for 24 hour totals to reach 1.00" or more. The other factor to consider for Memorial Day, is the potential of thunderstorms. CAMs are showing the potential for thunderstorms on Monday with CAPE values ranging from 70-300 J/kg. Now, the higher CAPE values are coming from the Canadian Model, which have a tendency to run "hot". Still, this is a semi-favorable patter which does warrant a 15-20% chance for thunderstorms on Monday. The Alaskan Low, will also usher in cooler temperatures across the CWA with daytime highs on Monday in the mid 50s to mid 60s.

In addition to the rain, Monday may turn breezy as the front moves through. Currently, there is a 70-90% chance for gusts exceeding 25 mph across the entire CWA. A 30-65% chance of gusts exceeding 30 mph for inland locations with 60-80% chance along the coast. Focusing in on 35 mph gusts, inland locations have a 5-15% chance, while coastal locations have a 20-40% chance. These speeds are not currently suggestive of advisory- level winds, but could create minor issues for unsecured tents, canopies or other light outdoor gear.

As the upper level continues to march southeastward on Tuesday, afternoon thunderstorms return to the forecast along with light precipitation totals around 0.05-0.15". While the bulk of the precipitation looks to occur on Monday, some ensembles are slowing the system down which could push the precipitation more into Tuesday. As for the middle and latter parts of next week, cooler and drier conditions are expected to prevail as weak high pressure/zonal flow looks to develop. Overall, expect cooler conditions through the majority of next week, with rain on Monday and Tuesday followed by drier conditions prevailing for the middle and latter parts of next week. /42

On a slightly personal note, with Monday being Memorial Day, it is time to remember those who served that are no longer with us. I want to remind everyone that if you are a fellow veteran or know a veteran that needs help, you can always call the VA Crisis Line by dialing 988 and pressing 1 or text 838255 24/7/365. We must take care of and look out those who stood besides us, who came before us and who will follow in our footsteps. Semper Fi. /42

AVIATION

Satellite imagery and terminal observations as of early Friday afternoon depicts clear skies with VFR conditions across the Willamette Valley while marine stratus lingers along the coast bringing IFR conditions. There is high confidence that marine stratus will hold along the coast throughout the day, though there could be intermittent breaks to VFR at KONP. Meanwhile, high pressure will maintain VFR conditions with clear skies continue through this evening for inland terminals. Northerly to northwesterly winds generally around 5-10 kt for most terminals this afternoon, except breezier at KONP with gusts up to 20-25 kt. Tonight, winds weaken as pressure gradients ease and LIFR/IFR conditions return along the coast as marine stratus re- builds. Across the Willamette Valley, increased moisture will support stratus development tomorrow morning with a 30-50% chance for MVFR CIGs at any given hour between 12-17z Sat. Morning stratus should break out with daytime heating after 17-18z Sat.

KPDX AND APPROACHES...VFR conditions through the majority of the TAF period. Moister conditions will support a return of low-end VFR CIGs (less than 4 kft) after 12z Sat. There is a 20-40% chance for MVFR CIGs at any given hour between 12-17z Sat for KPDX. Northwesterly winds around 5-8 kt today, weakening below 5 kt tonight. -10

MARINE

High pressure offshore will maintain breezy northerly winds through Saturday. The strongest winds are expected during the afternoon and evening periods as the surface thermal trough strengthens over the northern CA/southern OR coast. Small Craft Advisories for northerly wind gusts up to 25 kt remain in effect for the waters south of Cape Falcon through 5 AM Sunday, and through 11 PM Friday for the waters north of Cape Falcon and beyond 10 NM offshore. Seas 6 to 9 feet are expected across all waters through this weekend. The summer-like pattern is expected to break down Sunday night as a front approaches the waters. This system will return breezy southwesterly winds by early Monday morning and a westerly swell that will likely (>80% chance) build seas above 10 ft by Monday afternoon. -10

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory until 5 AM PDT Sunday for PZZ252-253-272- 273.

Small Craft Advisory until 11 PM PDT this evening for PZZ271.