textproduct: Portland

SYNOPSIS

Warm and dry conditions continue through the upcoming week as temperatures gradually moderate towards August normals. Renewed onshore flow will keep smoke east of the Cascades, while precipitation chances remain very low through at least the middle of next week. Temperatures may trend warmer later next week.

DISCUSSION...Today through Saturday

After 5 consecutive days of 90 degree weather, expect temperatures to cool about 4-7 degrees as near average conditions are expected today with highs reaching into the lower to mid-80s. The synoptic flow aloft becomes predominately zonal over the region today into early next week. An embedded shortwave trough will usher in another round of enhanced onshore flow later this afternoon, with breezy northwest winds continuing through this evening. Sunny skies expected inland while marine stratus ebbs and flows near the coast. This pattern generally remains in place through Tuesday.

By Wednesday, ensembles are showing a general trend toward upper level troughing dropping out of British Columbia, though chances for rain here remain very low (below 5%). This could bring in some cooler temperatures by mid-week, as indicated by growing uncertainty in the potential high temperatures into late next week. For example, the spread between the 10th and 90th percentiles on Friday at PDX range between 81 and 96 degrees. That is because ensembles are split between upper level ridging possibly developing offshore, while others show some sort of troughing persisting over the area. /DH

AVIATION...Through 12Z Mon

Westerly flow aloft continues today with predominately VFR conditions and mostly clear skies expected inland across the Willamette Valley. Shallow marine stratus has developed along the coast with IFR to low-end MVFR CIGs at coastal terminals. Conditions are likely (70-80% chance) to improve to VFR at KONP after 18z Sunday while chances for improvement at KAST this afternoon is lower (40-50%). Chances for marine stratus redeveloping at the coast increases again by 03-04z Monday. North to northwest winds increase again this afternoon with gusts up to 25 kt along the coast and up to 20 kt inland.

KPDX AND APPROACHES...VFR through the TAF period with clear skies. There is a 10-20% chance for stratus to develop in the Portland Metro between 12-17z Sunday. Northwest winds increase to around 10-12 kt in the afternoon with gusts up to 20 kt. /DH

MARINE

High pressure offshore will maintain northerly winds through much of next week. Surface pressure gradients tighten this afternoon, bringing high chances for wind gusts up to 25 kt south of Cape Foulweather today and into early next week. As a result, a Small Craft Advisory has been issued for the inner and outer waters south of Cape Foulweather from 12 PM Sunday to 2 AM Monday. Similar small craft conditions may reoccur Monday for the waters south of Cape Foulweather. Wind driven seas are expected to remain around 4 to 6 ft through most of next week. /DH

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory from noon today to 2 AM PDT Monday for PZZ253-273.