textproduct: Portland

SYNOPSIS

Another frontal system will bring widespread rain, breezy winds from the south, and a 20-30% chance for thunderstorms today. Any passing thunderstorms may produce lightning, heavy rain, gusty erratic winds, small hail, and/or a funnel cloud. Chances for lingering showers continue through the weekend with cooler than average temperatures. Drier conditions early next week.

LONG TERM...Saturday through Wednesday

Over the weekend, the majority of ensemble members continue to show broad upper-level troughing over the Pacific Northwest. However, there is uncertainty with whether or not we remain dry or continue with lingering showers. While 75% of ensemble members suggest showers continuing over the region Saturday-Sunday, the other 25% keep us dry. What we can say with higher confidence is that this upper-level low will maintain below-average 500 mb heights and keep high temperatures slightly cooler than average for this time of year. Early next week, the majority of ensemble members show the upper low weakening and beginning to move eastward. This would favor drier conditions, but there remains uncertainty with how much high pressure will re-build over our area, and how warm/dry we get. /42-10

AVIATION...Through 18Z Friday

Moist, southwest flow aloft will persist today as a low pressure system moves toward the Oregon coast. This system will maintain widespread rain showers across the area with around a 15-30% chance of thunderstorms through this afternoon, highest chances along the coast. Predominately VFR conditions are expected to prevail, except with the heavier showers which are likely to produce brief periods of MVFR to IFR reductions in visibility and CIGs. Rain is expected to gradually taper off from north to south through this evening. Probabilities for widespread MVFR or worse remains relatively low at around 20% or less, except at KONP where probs are closer to around 30-40%. Generally expected south to southeasterly winds with brief gusts possible up to 20 kt. Any thunderstorms that do develop will have the potential to produce lightning and gusty/erratic winds.

KPDX AND APPROACHES...Predominately VFR expected with brief and intermittent MVFR conditions possible with heavier showers. Generally less than a 20% chance for MVFR at any given hour through the period. There is also around a 10-20% chance for thunderstorms through this afternoon. South to southeast winds around 5-10 kt expected to ease after 02z Friday. /DH

MARINE

Current observations show seas around 9-11 ft at 8-10 seconds with southerly gusts up to 30 kt. These conditions are expected to continue through tonight as a fresh west/northwest swell overnight into Thursday maintains conditions. Due to the continued sea state and breezy winds, a Small Craft Advisory is in effect through at least tonight. There'll also be 15-30% chance for thunderstorms through Thursday with the best relative chances Thursday afternoon. Any of these storms will be capable of producing gusty/erratic winds, small hail, and lightning.

While relatively active weather with lingering rain showers will continue into the weekend, marine conditions will subside by Friday with seas holding in the 4-6 ft range by Friday afternoon. Similar conditions persist into early next week while winds occasionally gust to 15-20 knots.

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ210- 251>253-271>273.