textproduct: Seattle/Tacoma

SYNOPSIS

Weak front moving into the northern portion of the area today will dissipate tonight. Weak upper level trough over Western Washington Friday will dissipate Friday night. Slow warming trend over the weekend into next week with large upper level ridge over the Southwest and Southern Rockies building to the northwest. Dry weather beginning Saturday continuing into the middle of next week.

SHORT TERM /TODAY THROUGH SATURDAY/

Satellite imagery shows front moving down from the northwest about half way through Vancouver Island. Mostly cloudy skies over the southern portion of the area with mostly clear skies over the northern portion. High clouds ahead of the front just west of the Puget Sound at 3 am/10z. Temperatures were in the upper 40s to upper 50s.

Front will continue to move southeast today approaching the north coast late in the afternoon. Rain out ahead of the front spreading over the north coast/Western Strait of Juan de Fuca in the afternoon. Increasing middle level clouds over the remainder of the area with a slight chance of rain over the northern portions late in the afternoon. Under cloudy skies highs in the upper 50s to mid 60s.

Front dissipating over the Northwest Interior tonight. Rain along the north coast and Northwest Interior coming to an end by midnight. For the remainder of the area a chance of rain from about I-90 northward until about midnight. Temperatures will only drop into the 50s with cloudy skies.

Weak upper level trough over the area Friday dissipating Friday night as an upper level ridge centered well southeast of Western Washington begins building to the northwest. Could see a shower or two in the North Cascades Friday otherwise mostly cloudy skies with highs in the mid 60s to mid 70s. Lows Friday night in the upper 40s to mid 50s.

Pretty normal first week of July day Saturday with zonal flow aloft and light low level onshore flow. Morning stratus will give way to mostly sunny skies in the afternoon. Highs in the upper 60s to mid 70s over the interior and mid 60s along the coast. Felton

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Little change in the extended forecast this morning with zonal flow aloft through Sunday night becoming southwesterly Monday through Wednesday. Dissipating front moving through Tuesday night into Wednesday just increasing the cloud cover. 500 mb heights in the mid 570 dms to near 580 dms Sunday night into Tuesday lowering a touch with the dissipating front Wednesday. Low level onshore flow through the period will keep high temperatures in check. For the interior highs mostly in the 70s except mid 70s to lower 80s Monday. For the coast onshore flow will keep highs in the 60s. Lows in the upper 40s to mid 50s.

Minor HeatRisk through the period for the interior with a 15-25% chance of moderate HeatRisk over the Central Puget Sound Monday through Wednesday.

AVIATION

Stratus continues to fill in for the interior terminals, slightly earlier than what was suggested by guidance. Expecting ceilings to lower to MVFR by 11z. With guidance struggling to resolve today's stratus, there is some uncertainty when VFR cigs will return today. However, high-res guidance does suggest that ceilings will gradually improve after 15z-19z. Terminals along the coast and Strait of Juan de Fuca are very unlikely to see any improvement. Guidance is in good agreement that MVFR cigs will return for interior terminals after 06z-09z, with latest probabilities 50-80%. Variable winds to light SW flow this morning increase to 6-12 kt in the afternoon. Terminals in the Kitsap Peninsula and central Puget Sound may see some breezy winds this evening with occasional gusts to 15-18 kt.

KSEA...MVFR cigs this morning with stratus having filled in earlier than anticipated. With guidance struggling to resolve the lower cigs this morning, there is some uncertainty when conditions will improve. Some of the high-res guidance suggests gradual improvement to VFR after 15z-18z. There is moderate to high confidence (50-70%) for MVFR cigs to return after 09z Friday, with a slight chance (20%) of IFR cigs. SW winds will increase this afternoon to 5-10 kt. May see some breezy winds this evening with gusts up to 15 kt.

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MARINE

Broad high pressure offshore and low pressure inland will continue for the majority of the week, maintaining onshore flow. However, today a frontal system moving area waters will slightly weaken onshore flow. High pressure will start rebuilding over the coastal waters on Friday and remain through early next week. This will result in periods of diurnally driven westerly pushes through the Strait of Juan de Fuca. The next westerly push that has potential for reaching small craft thresholds is Friday evening, with current probabilities around 45-65%. Saturday's push looks to be even stronger, with higher confidence (70-90%) of winds meeting small craft thresholds.

Combined seas expected to remain below 10 ft for the majority of the week. Seas 3 to 5 feet through Saturday evening will then build to 6 to 10 ft by Sunday evening. Seas subside below 10 ft early Monday morning.

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FIRE WEATHER

Little in the way of fire weather concerns in the week ahead. Weak front combined with upper level troughing maintaining cool and cloudy conditions with high relative humidity values today and tonight. Drier, sunnier, and more seasonable temperatures beginning Friday continuing into the middle of next week. Highs temperatures peaking Monday in the mid 70s to lower 80s over the interior. Low level onshore flow continuing through the middle of next week will moderate daytime minimum RH values and bring good RH recovery each night. Felton

SEW WATCHES/WARNINGS/ADVISORIES

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