textproduct: Seattle/Tacoma

SYNOPSIS

Showers will taper off today as high pressure builds into Western Washington. This will kick off a warming and drying trend through the weekend and into early next week. Chances of precipitation increase towards the middle of next week as a series of troughs pass over British Columbia.

SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/

Only update this evening is the addition of a frost advisory for the Chehalis Valley-Olympia area for tonight. Frost potential is greatest for areas away from water. Otherwise the forecast remains on track with convergence zone activity remaining in southern Snohomish County this evening. -HPR

Lowland rain and mountain snow will continue to taper off throughout tonight as a low pressure system progresses further inland. Post-frontal convergence zone activity will linger between King and Snohomish Counties into the evening, bringing potential for locally heavy rain and breezy winds. Elsewhere, more benign conditions will settle into the region today under cloudy skies with some sun breaks and highs in the low 50s.

An upper level ridge will continue to amplify into the region into Saturday, bringing in drier and warmer conditions. A weak system moving over Vancouver Island on Friday may bring light rain showers to the Olympic Peninsula and North Interior, but rainfall accumulations are expected to be minimal. Highs will warm up to near- normal on Friday with highs in the mid to upper 50s for most areas. The warming trend will continue on Saturday, with highs reaching the upper 50s to mid 60s for the lowlands.

LONG TERM /SUNDAY THROUGH THURSDAY/

Sunday and Monday will bring the warmest conditions of the year so far for most areas as high pressure remains overhead, with high temperatures in the upper 60s to low 70s. The warmest temperatures are favored across the south Sound and along the Cascade Foothills. This also introduces Minor (Yellow) HeatRisk for areas south and east of the Puget Sound on Sunday and Monday.

While deterministic forecast models maintain dry conditions through much of next week, a series of troughs is set to move through British Columbia towards the middle of next week, with chances for light precipitation returning for western Washington.

AVIATION

West to northwesterly flow aloft through Friday with weak ridging building into the area. VFR conditions this evening with widespread mid clouds. Weak convergence also continues in the vicinity of Snohomish County with lingering showers along the Olympic Peninsula. Cigs are expected to range between 025-060 for the majority of tonight through Friday morning, with cigs lifting and improving towards FEW/SCT from south to north Friday PM. Southerly surface winds into Friday will transition more light north during Friday evening.

KSEA...VFR cigs with continued mid clouds this evening. Cigs are expected to range between 030-060 for the majority of tonight into Friday. The probability of MVFR cigs peaks between 11 to 18z around 25%. Conditions will become more FEW/SCT by late Friday afternoon through the evening. S/SW surface winds ranging between 5 to 10 kts tonight into Friday. Winds may transition more N/NW Friday evening, but are expected to remain light at this time under 5 kts. JD

HYDROLOGY

No river flooding is expected over the next 7 days.

SEW WATCHES/WARNINGS/ADVISORIES

WA...Frost Advisory until 9 AM PDT Friday for Foothills and Valleys of Thurston and Lewis Counties-Lowlands of Lewis and Southern Thurston Counties-Middle Chehalis River Valley- Olympia and Southern Puget Sound-Willapa and Black Hills.

PZ...Small Craft Advisory until 2 AM PDT Friday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From Cape Flattery To James Island Out 10 Nm- Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm-Grays Harbor Bar.

Small Craft Advisory until 10 PM PDT this evening for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca.