textproduct: Portland

SYNOPSIS

Onshore flow persists over the next week with cooler than normal temperatures through Thursday. Within the zonal flow, weak high pressure forms which will allow for skies to clear and temperatures to warm. Looking at temperatures around more seasonable, or slightly above normal on Friday through at least Tuesday.

DISCUSSION...Now through Wednesday

Very minimal change in current weather conditions and the overall forecast from the last package. The synoptic pattern can be best described as zonal onshore flow, with weak high pressure forming on Friday through early next week. 500 mb height ensembles are in excellentagreement with this overall pattern, and sensible weather forecasts remain on track with very little variation.

Model guidance continues to suggest little change to the overall weather pattern on Thursday in comparison to Wednesday. Clouds will still be present with a few sun breaks but overall, impact wise, the forecast will remain unchanged. Temperatures will rise by a few degrees into the 70s, except into the 60s along the coast. Will note that all chances for precipitation have nearly disappeared or dropped below 5%. Conditions trend sunnier and warmer Friday into the holiday weekend as upper level flow transitions from northwesterly to westerly and 500 mb heights begin to increase a bit. By Friday, widespread highs around 75-80 degrees are expected for inland valleys. Highs will likely warm into the low to mid 80s for July 4-7 (70-90% chance each day), except in the Cowlitz Valley and along the lower Columbia where highs in the mid to upper 70s are the most likely outcome. Despite warmer temperatures inland, the coast will stay stuck in the 60s each day due to persistent onshore flow.

It is important to remember that while things will be warming up, many of our natural water bodies remain cold. Please practice safe water practices and note that rivers are fairly quick moving and can quickly sweep you away. Wear life jackets, and visit with a buddy. -27/23

AVIATION

Widespread cloud cover remains in place across all of northwest Oregon and southwest Washington. Generally VFR with some pockets of MVFR conditions along the coast and areas where the clouds are back building off of the Cascades. Will see minimal change in conditions today and the forecast is mainly wind change driven. Will see a return of diurnally driven winds from the north becoming breezy in the afternoon. Through the western Columbia River Gorge around K4S2, and the southern Willamette Valley, expect breezy winds with gusts up to 20 kt. Overnight, a weak disturbance will pass to the north increasing chances for MVFR CIGs from KTMK northward along the Coast Range and coastal terminals.

KPDX AND APPROACHES...Low-end VFR ceilings around 4000-5000 feet are expected to continue through today. Northwest winds around 5 kt are expected to increase to around 10 kt with occasional gusts up to 15-18 kt around 02Z Thursday with an incoming weak front. Winds should become less gusty after 06Z Thursday. Marine stratus will linger over the next 24 hours. -27/23

MARINE

Seas have been a bit more dynamic today than previously thought. While most of the buoys shows seas less than 7 ft at 10 seconds, buoy 46050 continues to show periodic seas of 8 ft at 9 seconds thus equating to steep seas. However, these conditions are marginal and likely associated a bit with some of the breezier diurnally driven winds. Not expecting these conditions to be widespread though so have allowed the Small Craft Advisory to expire. Cannot rule out periods of these conditions though so be aware if in the outer waters south of Cape Foulweather. Winds are northwesterly around 6-8 kt with gusts of 15 kt except right along the coast where gusts up to 20 kt have been reported. Seas fall to 4-6 feet by late Wednesday night and then hold steady through the upcoming weekend.

Meanwhile, predominately northwest winds are expected to continue through Friday with general wind speeds becoming even weaker each day. A thermally induced surface trough will build northward up the south Oregon coast over the weekend, bringing increasing northerly winds with gusts up to 20-25 kt. As is often the case during this typical summertime pattern, wind speeds will be strongest during the afternoon and evening hours each day with daytime heating. Although significant wave heights are not expected to increase much, the increasing winds will result in choppier seas. -27/23

PQR WATCHES/WARNINGS/ADVISORIES

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