South southeasterly flow aloft spreading mid and high level clouds over the area today. A weakening front will arrive from the south monday afternoon and monday night. Breezy conditions for some areas behind the front into tuesday. Low level flow will turn back to offshore as the next system moves inland south of the area in the middle of next week. A weak upper trough will linger over the area into friday.
Satellite imagery shows mid and high level clouds over the area from about the puget sound eastward. Skies cleared along the coast overnight which allowed fog to form. Both hoquiam and quillayute reporting visibility below a mile at 3 am/10z. Temperatures ranged from near freezing at olympia to near 50 in the seattle area.
South southeasterly flow aloft will continue today with mid and high level moisture embedded in the flow aloft remaining over the area. Doppler radar has plenty of precipitation over northeast oregon and southeast washington but as the flow aloft becomes a little more southerly this afternoon this moisture will have a hard time getting much further west than the cascades and the cascade foothills. Will leave a chance of showers in the forecast for those locations this afternoon. For the remainder of the area mostly cloudy or cloudy skies. Highs today in the mid 50s to lower 60s.
Flow aloft becoming southerly tonight with the weak trough axis moving north of the area overnight taking the shower chances with it. Surface gradients turning northerly combined with increasing high clouds from the south will keep fog monday morning patchy at best. Lows tonight in the 30s to mid 40s.
Model trends for monday`s front continuing with each run a little slower and a little weaker. The 00z ecmwf does not even have the precipitation to seattle by 00z tuesday while the gfs spreads rain over most of the area monday afternoon. With the front being negatively tilted and splitting/weakening as it reaches the area favor the slower ecmwf solution at this time and will have just chance pops from seattle north monday afternoon. Highs on monday in the 50s.
Front moving through the area monday night. Rainfall amounts not very impressive, a tenth to a quarter of an inch in most locations. Southerly gradients increasing behind the front with breezy conditions ( 15 to 25 mph winds ) developing overnight into early tuesday morning. Lows monday night in the upper 30s to mid 40s.
Upper level low that the front will spin out of remaining off the coast on tuesday with showers embedded in the southwesterly flow aloft moving over the area. Air mass becoming slightly unstable in the afternoon hours keeping the shower threat intact the whole day. Highs will be in the lower to mid 50s.
Models having trouble coming up with a consistent solution for the upper level low later in the week. Both of the models have the low somewhere off the southern oregon/northern california coast on wednesday but the ecmwf has much more moisture embedded in the southerly flow aloft over the area. Model cross sections show this moisture is just mid and high level moisture and with the low well to the south the air mass over the area will not be very unstable. Will go for a mostly dry day on wednesday. After wednesday the low weakens into an upper level trough and hangs around over the area thursday for a chance of showers before kicking out to the north on friday. model inconsistencies reappear for the weekend with the ecmwf bringing a front into the area saturday night while the gfs is much weaker with this system keeping it offshore. Will keep saturday dry with chance pops for saturday night. Highs through the period in the 50s and lower 60s. Lows mostly in the mid 30s to mid 40s. Felton
River flooding is not expected for the next 7 days.
Wa...none. Pz...small craft advisory for hazardous seas until 11 am pdt this morning 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.
small craft advisory for rough bar until noon pdt today for grays harbor bar.
Weak low level offshore flow will continue through monday morning. The next front will arrive monday afternoon and monday night with small craft advisory winds with and behind the front monday afternoon into tuesday. Low level will turn offshore tuesday night into wednesday then becoming light wednesday night and thursday. Felton
A shortwave trough centered over far ne california and nw nevada will continue to pivot northeastward through the morning hours. This is allowing for a shield of bkn-ovc vfr ceilings in the 040-100 range to push into western washington, mainly puget sound east at the time of this writing. Meanwhile along the coast, fog and stratus have developed, with vsbys being reduced to lifr.
Cloud cover should continue over the area for at least the first half of the day. Ceilings should mostly stay vfr today, with morning fog affecting olm and hqm, and potentially pwt. Model soundings and time heights suggest a brief period of mvfr ceilings could be possible by mid morning, but given current upstream obs will opt to leave that as sct with the ceiling remaining vfr for most. Most of the shower activity is expected to remain confined to the foothills of the cascades and east, but a few light showers could flirt with taf sites east of the sound this afternoon. Will omit from tafs for now.
As aforementioned shortwave continues to pull east/northeast through the afternoon and evening, will see decent clearing of the skies from sw to ne which will continue into monday morning ahead of the next frontal system.
Ksea...vfr ceilings will be the predominate category this cycle. brief period of mvfr not impossible around mid morning. Skies will briefly clear this evening and overnight. Winds overall light and variable, eventually becoming light from the ne.
Kovacik