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...Tonight through Friday

An upper level trough will continue to progress northeast tonight, sending a weak cold front through the area. As the low moves further inland, zonal flow aloft will develop on Sunday. Zonal flow will maintain seasonal temperatures across the forecast area. Looking ahead through the early next week, ensemble clusters favor ridging over the central CONUS which will spread into the PacNW. As the ridge builds over the area, warmer temperature are expected to return Monday and Tuesday. There remains some uncertainly as to how warm the start of next week will be as the 10th-90th percentiles for daytime highs range from the mid 80s to low 90s for the interior lowlands on Monday and Tuesday. Clusters favor another trough influencing the region by mid-week but exact timing and upper level pattern are uncertain but onshore flow and seasonable or below average temperatures would be favored. When looking at Wednesday and Thursday, the 10th-90th percentiles range from the low 70s to low 80s. There is also no clear signal for any precipitation associated with the mid week trough. approximately 15-25% of members show very light rain possible during the Thursday-Friday timeframe but nothing significant at this time. /42-19

AVIATION...06Z TAFs

An upper-level low continues to slowly move north/northeast tonight. Current observations have VFR conditions inland with VFR to IFR conditions along the coast. Overall flight conditions are expected to lower through the next few hours, with IFR/LIFR conditions along the coast and MVFR conditions for all inland locations. Flight conditions expected to improve starting around 18Z-20Z Sunday, with VFR conditions expected for inland locations and IFR/MVFR conditions along the coast, with brief periods of VFR possible from 18Z Sunday through 02Z Monday.

South/southwest winds will continue through at least 17Z-19Z Sunday, afterwards expect northerly winds across the airspace. Northerly gusts approaching 25 kt expected along the coast starting around 18Z Sunday and will persist through the remainder of the TAF period.

KPDX AND APPROACHES...VFR conditions will lower towards MVFR over the next few hours. Southerly winds expected to persist through around 18Z-20Z Sunday, with northerly winds returning afterwards. VFR conditions are also expected to return around the same time period. These conditions expected to persist through the remainder of the TAF period. /42

MARINE

South to southwest winds continue through tonight as a low pressure system moves over the northeast Pacific. High pressure and northerly winds return by Sunday, with a 40-70% chance for northerly wind gusts up to 25 kt in the evening and continuing into Monday. Seas of 4-6 ft persist through the period. /42

PQR WATCHES/WARNINGS/ADVISORIES

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