textproduct: Portland

SYNOPSIS

Low pressure moving over the area will send a weak cold front through the area tonight. Expect near average daytime highs through the week. Ridging builds back into the area early next week, increasing temperatures back into the mid to upper 80s across the interior lowlands.

DISCUSSION...Today through Saturday

Upper level troughing continues to move northeast toward southwestern Canada. This is supporting light, scattered showers over southwestern Washington and the coast range early this morning. Radar indicates shallow returns over the area and surface observations report rainfall totals of a few hundredths. Showers are expected to dissipate by late this morning as zonal flow develops in the wake of the upper level trough. Highs will again be around to a few degrees below average in the upper 70s to low 80s for interior lowlands. Winds shift from southerly to northerly as surface high pressure builds into the area.

Heading into the work week, ensemble clusters favor ridging over the central CONUS and the PacNW. Warmer temperature are expected to return for Monday and Tuesday. Model spread has decreased for high temperatures between the 10th-90th percentiles now ranging from the upper 80s to low 90s on Monday and mid 80s to low 90s for Tuesday for the interior lowlands. Clusters then favor another trough influencing the region by the middle of the week but exact timing and placement are uncertain but onshore flow and seasonable or below average temperatures would be favored. Currently, the 10th-90th percentiles range from the mid 70s to low 80s. An increasing number of ensemble members indicate that light precipitation is possible during the Thursday-Friday timeframe but nothing significant at this time. -19

AVIATION...12Z TAFs

An upper-level low continues to slowly move northeast, supporting low and mid-level clouds over the region. Current observations have VFR conditions inland with CIGs generally between 4000-5000 ft and a mix of sub-VFR conditions along the coast. Guidance continues to show lowering CIGs inland after 14-16Z with MVFR cloud cover around 2000-3000 feet expected. Flight conditions expected to improve starting around 18Z-20Z for all terminals, with VFR conditions returning by the afternoon.

South/southwest winds will continue through at least 17Z-19Z, shifting to the northwest thereafter. Northerly gusts approaching 25 kt expected along the coast starting around 18Z and will persist through the remainder of the TAF period.

KPDX AND APPROACHES...VFR conditions will lower towards MVFR around 15-16z. Southerly winds expected to persist through around 18Z-20Z with northerly winds thereafter. VFR conditions are also expected to return around the same time period. -19/42

MARINE

Northerly winds increase as high pressure strengthens over the northeast Pacific. Gusty winds will develop over the waters, increasing from south to north from Florence to Cape Shoalwater. Wind gusts up to 25 kt are expected to develop during the evening, persisting through Monday afternoon. Small Craft advisories have been issued starting at 5 PM for waters from Florence north to Cape Falcon and starting at 11 PM for waters north of Cape Falcon to Cape Shoalwater. Gusty winds are also expected for the Columbia River bar starting at 8 AM Monday. Seas will be choppy during this time at 3-6 feet at 7-9 seconds. -19

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.

WA...None.

PZ...Small Craft Advisory from 8 AM to 8 PM PDT Monday for PZZ210.

Small Craft Advisory from 11 PM this evening to 8 PM PDT Monday for PZZ251-271.

Small Craft Advisory from 5 PM this afternoon to 5 PM PDT Monday for PZZ252-253-272-273.