textproduct: Seattle/Tacoma

SYNOPSIS

A weak frontal system passes across the region today, bringing some reinforcing cloud cover and some light rain chances across mostly the western and northern parts of the area. Conditions trend drier and warmer Wednesday through Friday, but a return of cooler and cloudier conditions are expected for much of the area this weekend.

SHORT TERM /TODAY THROUGH THURSDAY/

A weak frontal system will move into the region today, providing for some breezy southerly winds ahead of the front and some reinforcing cloud cover across much of the region this morning. This system will bring some light rain chances across the coastal areas and across the northwestern portions of the area, but it won't be organized or strong enough to bring much in the way of impact to the most of the interior portions of the region. The exception could be northern Whatcom County where around a 15% chance of a thunderstorm exists (generally north and east of Bellingham).

Behind this system, a bit of a transitional day is expected on Wednesday with heights beginning to rise a bit but a typical pattern of morning clouds and sun in the afternoon yielding temperatures near normal. A bit more of an uptick in temperatures Thursday, with Minor HeatRisk across most of the area as afternoon high temperatures return to the mid to upper 70s.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/

Ensemble guidance remains in fairly good agreement for the start of the long term period with Friday likely to be shaping up as the warmest day of the week across most of the area with the ridge amplifying and daytime high temperatures reaching the lower to mid 80s across the interior. With this warm up, HeatRisk is expected to remain only in the Minor (Yellow) category for nearly all of the area given the current overnight low temperature forecast. That said, if the pattern shifts earlier enough for a longer stretch of warming that allows for warmer overnight temperatures, this could end up increasing the potential for areas of Moderate HeatRisk to emerge.

Looking ahead, ensembles suggest the most likely scenario to be a return of a cooler, cloudier and potentially showery pattern for the weekend. This would bring temperatures near or slightly below seasonal normals, but again keep the rain chances highest near the coastal areas.

AVIATION

Weak front moving inland this afternoon and evening and dissipating. Southwesterly flow aloft. MVFR ceilings along the coast with VFR ceilings inland. MVFR ceilings developing inland 13z-16z with ceilings lifting back to VFR after 19z.

KSEA...VFR ceilings around 4500 feet lowering to 2000 to 3000 feet 13z-15z. Ceilings lifting back up to near 4000 feet around 19z. VFR ceilings continuing through Wednesday morning. Southerly winds 4 to 8 knots increasing to 10 to 15 knots around 18z. Winds easing after 03z. Felton

MARINE

Weak cold front moving through the waters today. High pressure will build in behind the front tonight then remain over the waters through Friday. Another weak system will reach the waters over the weekend.

Small craft advisory winds over the inland waters into the early afternoon hours today. Small craft advisory winds likely Friday and Saturday evening in the Strait of Juan de Fuca.

Seas generally in the 4 to 5 foot range into the weekend. Felton

FIRE WEATHER

A weak front pushes across the region this morning. While there's around 40-50% chance of a wetting rain across the northern coast and in the Olympics, elsewhere showers will remain rather light. There is still around a 15% chance of a thunderstorm, but lightning coverage is expected to be rather limited at best if any does develop. Drier and warmer conditions then return Wednesday through Friday, with minimum humidity values reaching the upper 20s and approaching critical thresholds on Friday. However, low-level flow remains onshore to provide for good to excellent overnight recoveries, and this looks to be a short-lived trend as the pattern shifts back to cooler and cloudier conditions for the weekend.

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory from 5 AM early this morning to 1 PM PDT this afternoon for Northern Inland Waters Including The San Juan Islands-Puget Sound and Hood Canal.