A front will bring rain and mountain snow to the area tonight, as well as locally windy conditions this evening. Snow in the mountains will be heavy at times later this evening into early tuesday. A convergence zone is likely to form tuesday with showers decreasing late. Drier weather will begin wednesday, with gradual warming through sunday. Highs could reach the low 60s this weekend.
A vigorous frontal system over the coastal waters this evening will push eastward through the inland waters overnight. Strong southerly winds ahead of the front will become more west to northwest behind the front. Strong west to northwest flow will continue into tuesday night as high pressure gradually builds into the waters from the west.
A gale warning continues for the coastal waters from james island northward and for the northern inland waters until around midnight tonight. Small craft advisories will be in effect for all of the waters except puget sound and hood canal later tonight through tuesday night. Small craft advisory conditions may redevelop over portions of puget sound and hood canal tuesday afternoon or evening. Seas over the coastal waters are building at this time and will reach 14-17 feet later tonight. Seas will slowly subside but remain above 10 feet tuesday through wednesday or wednesday night.
High pressure over the waters on wednesday will give lighter winds. Then a weak front may brush the waters late thursday. albrecht
A strong frontal system is moving through the coastal waters early this evening and will move through the interior later this evening. Southwesterly flow aloft will become northwesterly behind the front. The air mass is stable and moist, and will become somewhat unstable on tuesday.
Conditions are variable with low-end vfr and mvfr conditions across most of the area this evening. Conditions are expected to deteriorate later this evening to mainly mvfr.
Conditions will improve on tuesday as precipitation becomes more showery in nature and clouds/precipitation become increasingly confined to the terrain and convergence zones between kpae and ktcm. Albrecht
Ksea...mvfr conditions will prevail tonight into tuesday morning. Cigs around bkn025 may linger into tuesday evening as it appears that a convergence zone will develop around the terminal and will remain near or just south of the terminal into tuesday night. Winds will be generally sw 9-12kt. Winds will likely be gusty around the convergence zone activity on tuesday and may briefly become northerly tuesday afternoon and evening. Albrecht
Wa...winter storm warning until noon pdt tuesday for cascades of pierce and lewis counties-cascades of snohomish and king counties.
winter weather advisory until noon pdt tuesday for cascades of whatcom and skagit counties.
Pz...small craft advisory until 5 am pdt wednesday for admiralty inlet-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-east entrance u.s. waters strait of juan de fuca.
small craft advisory for rough bar until 5 am pdt wednesday for grays harbor bar.
small craft advisory from 11 pm this evening to 5 am pdt wednesday for coastal waters from cape flattery to james island 10 to 60 nm-coastal waters from cape flattery to james island out 10 nm.
gale warning until 11 pm pdt this evening for coastal waters from cape flattery to james island 10 to 60 nm-coastal waters from cape flattery to james island out 10 nm.
small craft advisory from 2 am tuesday to 5 am pdt wednesday for northern inland waters including the san juan islands.
gale warning until 2 am pdt tuesday for northern inland waters including the san juan islands.
small craft advisory until 11 pm pdt tuesday for west entrance u.s. Waters strait of juan de fuca.
small craft advisory from 5 am tuesday to 5 am pdt wednesday for central u.s. Waters strait of juan de fuca.
small craft advisory until 5 am pdt tuesday for puget sound and hood canal.
/issued 300 pm pdt mon mar 11 2019/
Synopsis...an approaching front will bring rain tonight. Snow in the mountains will become heavy at times this evening into early tuesday. A convergence zone is likely to form tuesday with showers decreasing late. Drier weather will begin wednesday, with gradual warming through sunday. Highs could reach the low 60s this weekend.
Short term /tonight through thursday/...radar shows precipitation off the coast and perhaps just edging into the north interior. Rain will develop this evening everywhere as a frontal system moves into the region from the northwest. The front will move into the cascades 09z-12z. A convergence zone will develop late tonight and persist into tuesday. Northwest flow aloft and forecast pressure gradients indicate the pscz will likely move south tuesday.
Steady rain and mountain snow overnight will taper to showers by tuesday morning. Moderately strong westerly flow aloft will support orographically enhanced snowfall along the west slopes of the cascades and passes. Snow will be heaviest tonight just ahead of the front but the passes and paradise on mt. Rainier will get some additional snowfall tuesday as the convergence zone adds to the precipitation amounts. Total liquid qpf through tuesday should run about a half inch to an inch in the lowlands, and over an inch in the mountains. Snow amounts are forecast to be a foot or so in the north cascades, and possibly two feet in the central and south cascades. A winter storm warning is now in effect for the cascades from snohomish county south, while a winter weather advisory remains in effect for the cascades north of snohomish county.
A ridge of high pressure aloft will build rapidly off the coast wednesday. Residual showers over the mountains should end in the afternoon, and there will be some sun wednesday. This will be the start of a stretch of dry weather and gradual warming. A weak front off the coast could keep clouds over the region thursday, but there will be warm advection and the weather will remain dry. Highs on tuesday will be in the upper 40s in rain, then will rise to around 50 wednesday, and into the low to mid 50s thursday. If ksea can manage to reach 54 degrees on thursday, that will mark the first day the temperature has reached its normal high value since february 1. burke
Long term /friday through monday/...a series of weak fronts make a run at washington in the models through the weekend, but an upper ridge keeps them mostly at bay. The gfs does have a little rain from one of them on saturday night. Have kept pops mainly in the low chance or less category, with sun at times. The temperature will keep rising. Model guidance indicates highs near 60 by saturday, and maybe even the mid 60s by monday. This pattern change is most welcome. Burke
Aviation...a strong frontal system is currently moving onshore along the coast this afternoon and will work its way into the interior during the evening hours. Flow aloft will become westerly, while southerly surface winds will increase ahead of the cold front. Increasing moisture will continue to lower ceilings throughout the afternoon allowing for vfr conditions to lower to mvfr this evening into tuesday. Heavier rain will taper off tuesday morning and become more showery in nature. Should see slight improvement in conditions.
Ksea...vfr conditions will continue through this afternoon, with ceilings lowering to mvfr during the evening hours ahead of the frontal boundary. Rain looks to approach the terminal during the evening hours, continuing into tuesday morning before becoming more showery/hit or miss during the day tuesday. South/southwest winds 5 to 12 knots. A few gusts to 20 kts not out of the question late tonight into tuesday. ceo
Marine...a low pressure system and associated cold front will move through the coastal waters by early this evening and through the inland waters overnight. A gale warning remains in effect for the coastal waters from james island northward and for the northern inland waters. Small craft advisories are in effect for the remainder of the waters.
Behind the front, strong northwesterly winds will produce small craft advisory conditions across most of the waters into tuesday or tuesday night. Steep waves will also develop over the coastal waters in the strong northwesterly flow.
High pressure will build into the waters on wednesday with lighter winds. A weak front may brush the waters late thursday. Albrecht/ceo
Hydrology...flooding is not expected for the next 7 days.