07:16 PM Saturday March 09

Dry conditions and clear skies are expected to continue into monday morning as high pressure aloft remains over western washington. Temperatures are expected to remain cold in the morning with lows in the 20s to lower 30s. Afternoon highs will be mild, around 50, but will still be 2-4 degrees below normal for this time of year. The next front will arrive later monday into tuesday with breezy and wet conditions. Drier weather will return by the middle of next week.

UPDATE /TONIGHT THROUGH SUNDAY NIGHT/

An upper level trough extending from the canadian prairies southwestward into north- central oregon will move slowly southeastward as a ridge of high pressure from central british columbia into the ne pacific drops southeast into the area. This ridge will give dry weather to the area trough sunday night.

With dry air in place and good radiational cooling, expect temperatures to rapidly fall into the 20s to lower 30s tonight and again sunday night. Strong march sunshine and light flow on sunday will result in a couple degrees or so warming sunday afternoon. Forecasts were updated to increase the diurnal temperature range through sunday night. The remainder of the forecast is on track as a frontal system dropping southeastward into the area brings some rain monday into monday night and a upper level low brings showers into tuesday. Albrecht

MARINE

Light northeast to east flow will continue through sunday. The only advisories will be for the coastal waters where a westerly 10-11 ft swell at 18-20 seconds will move through the offshore waters sunday morning and into the nearshore coastal waters sunday afternoon and evening.

A front will reach the area monday afternoon and night and move inland tuesday morning. Expect small craft advisory southerly winds to develop ahead of the front starting monday morning and continuing until the front passes when winds will turn west to northwesterly.

Winds will diminish on wednesday as high pressure moves into the waters. Albrecht

SEW WATCHES/WARNINGS/ADVISORIES

Wa...none. Pz...small craft advisory for hazardous seas from midnight pst tonight to 1 am pdt monday for coastal waters from cape flattery to james island 10 to 60 nm-coastal waters from james island to point grenville 10 to 60 nm-coastal waters from point grenville to cape shoalwater 10 to 60 nm.

 small craft advisory for hazardous seas from 11 am sunday to 1       am pdt monday for coastal waters from cape flattery to       james island out 10 nm-coastal waters from james island to       point grenville out 10 nm-coastal waters from point       grenville to cape shoalwater out 10 nm.

PREV DISCUSSION

/issued 300 pm pst sat mar 9 2019/

Synopsis...dry conditions and clear skies are expected to continue into monday morning as high pressure aloft remains over western washington. Temperatures are expected to remain cold in the morning with lows near freezing while afternoon highs will get close to 50 in some spots. The next front arrives later monday and tuesday with breezy and wet conditions. Drier weather returns by the middle of next week.

Short term /today through monday/...some lingering clouds over portions of w wa this afternoon although there is a swath of clear skies along the eastern sound...including the seattle metro area. temperatures are running anywhere from 3 to 10 degrees warmer than 24 hours ago which might put inherited highs for today maybe a little too cool. Still...if that is the only cause for concern in the short term then it is a good day indeed.

Models still on track for high pressure to bring another clear day tomorrow with afternoon temps bumping up close to 50 in some locations...putting temps close to normal. Model agreement also extends to the next frontal system approaching the area and impacting w wa by monday evening. Consensus remains that snow levels with this system will remain above 1000 feet and as such...no concern for lowland snow. However...looking at qpf over the cascades for the monday night thru tuesday morning period...winter weather headlines might be needed over the cascades as current forecast amounts would bump up against advisory criteria there. Will pass this on to next shift as that particular time frame is still 48 hours out and plenty of time for models to alter those amounts. Even with clouds moving over the area in advance of the aforementioned front...high temps really do not dip all that much for monday with upper 40s to around 50 expected once again. smr

Long term /tuesday through friday/...although the front pushes through late monday night/early tuesday morning...the parent upper level trough and its associated moisture will pass over the area tuesday keeping showers in the forecast into tuesday night. Like with the exiting system yesterday...models differ on how quickly moisture and thus precip chances clear out with the gfs keeping in some lingering spotty showers while the ecmwf clears things out pretty quickly. Given how today has turned out...willing to side with drier ecmwf as an upper level ridge pushes into the area by early wednesday morning. Models start to fall out of agreement here as the gfs wants to quickly break down the ridge with a bit of a shortwave disturbance for thursday while the ecmwf keeps the ridge pretty strong and in place over the area for the entire second half of the week. Have kind of split the difference in the forecast but did end up leaning a little closer to the drier euro solution as pops that far out only get into slight chance at best.

Both snow levels and daytime high temps will look to steadily climb throughout the extended with the prospect of mid to upper 50s possible during the second half of next week with snow levels pushing into the 2000 to almost 5000 feet range. While still a little gun shy to bet heavily on that given seemingly perpetual nature of this past winter...and please let it be in the past tense...the fact that models seem to be somewhat consistent with this makes it all the more appealing. smr

Aviation...some cumulus will dissipate this evening with clear skies tonight--except for some fog or low clouds over parts of southwest washington by morning. Olympia and maybe hoquiam will be the two tafs that have a few hours of morning fog or low clouds, otherwise clear with light northeast winds into sunday.

Ksea...clear skies through sunday morning and a ne breeze.

Marine...light offshore flow through sunday. A front will reach the area monday afternoon and night and move inland tuesday morning. westerly flow will increase during the day on tuesday as high pressure builds toward the area--it looks like the strongest winds on tuesday will be northwest winds over the coastal waters. Onshore flow will diminish into wednesday as the high pressure shifts over the area.

Hydrology...river flooding is not expected for the next 7 days.

AVIATION

An upper low over eastern washington will move southeast of the area tonight as an upper level ridge from central british columbia southwestward moves toward the area. The ridge will dominate sunday into sunday night. Northeast flow aloft tonight and sunday will back to northwesterly late sunday night. The airmass is mainly dry and stable.

Good vfr conditions are expected tonight through sunday night across most of the area. The exception will be over the interior from about kpwt and kshn southward through the southwest interior valleys and westward through the chehalis gap to khqm where areas of ifr conditions in freezing fog and stratus can be expected 09z- 18z. Albrecht

Ksea...clear skies. Ne winds around 6 kt will become northwesterly after 20z sunday. Albrecht