textproduct: Portland

SYNOPSIS

Dry weather will prevail today under clear skies and strengthening offshore flow. This will lead to warm temperatures and breezy to locally strong easterly winds through the Columbia River Gorge and Cascade gaps this morning. Onshore flow returns midweek as a weak front brushes the coast, with limited precipitation potential. A broader trough digging into the region from the northeast Pacific will bring better rain chances into the weekend, especially near the coast and across southwest Washington.

LONG TERM...Wednesday through Sunday

A weak front brushing the coast Wednesday will reintroduce onshore flow, though precipitation potential looks minimal. Probabilities for measurable rainfall are 10-20% along the coast Wednesday morning, with dry weather favored inland. Temperatures remain old with highs in the mid to upper 70s inland and mid 60s along the coast.

By Friday, ensemble guidance converges on a generally dry pattern under a narrow ridge, keeping highs in the upper 70s to near 80 inland. A larger-scale trough begins to dig southeastward from the Gulf of alaska into the weekend, increasing rain potential. Precipitation chances climb to 20-40% across the forecast area Saturday through sunday, with higher probabilities (50-70%) along the southwest Washington coast and near Astoria Saturday night into Sunday. Temperatures cool back into the 70s inland and low to mid 60s along the coast under this more unsettled regime. ~Hall

AVIATION

Clear skies and widespread VFR flight conditions prevail through Tuesday as high pressure remains in place across the region. Low-level offshore flow continues this morning, bringing gusty easterly winds up to 30 kt at KTTD and gusts up to 20 kt at KPDX and KHIO. East winds begin gradually decreasing after 20z Tuesday. Offshore winds along the coast turn southerly to southwesterly after 18-21z Tuesday. Winds are generally light and variable from KUAO to KSLE to KEUG.

Probabilities for LIFR to IFR cigs begin to increase along the coast late tonight due to the return of onshore flow. Chances for cigs below 1000 ft increase to 60-80% at KONP between 06-09z Wednesday. Chances reach 50% at KAST by 09z Wednesday before increasing to 60% by 18z Wednesday.

KPDX AND APPROACHES...Clear skies and VFR flight conditions will continue through 18z Wednesday. East winds around 10-12 kt with gusts up to 20-22 kt will continue through today before east winds gradually weaken after sunset. -TK

MARINE

Winds will shift from northeast to east this morning, with localized wind gusts up to 25 kt over the inner waters downwind of gaps in the coastal terrain as well as in the northern half of zones PZZ272 and 252 out to 60 NM. Winds will quickly become southerly and decrease this afternoon at around 10 kt or less in response to a surface front that will be approaching the coastal waters Tuesday night into Wednesday morning. No impacts are expected with this front as it will decay over the waters. However, winds will quickly switch northerly and increase behind this front Wednesday evening into Thursday. Widespread small craft advisory level wind gusts up to 25 kt likely (90% chance). Occasional gusts up to 30 kt cannot be ruled out over the southern waters (50-70% chance). -TK/HEC

PQR WATCHES/WARNINGS/ADVISORIES

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