Seattle Weather

230 PM PST Monday feb 8 2010

Synopsis: A weak front will bring a chance of rain to the coast tonight but will not affect the interior. Tuesday and Tuesday night will be dry. A chance of rain will develop Wednesday afternoon and evening, and rain will be likely on Thursday. A more active weather pattern will continue into the weekend with rain likely at times.

Short Term: Pretty good clearing this afternoon in the strip between Puget Sound and the Cascades and also in the southwest. The coast began the day under clouds, cleared out, and has clouded up again. Weak front apparent in satellite imagery will keep clouds on the coast tonight and even bring a chance of rain there. This front is forecast to dissipate offshore and not bring any rain inland. However high and mid level clouds will increase this evening and most of the night will be overcast, probably over the whole cwa.

After some patchy morning fog there should be good breakout most areas on Tuesday. Dry conditions will prevail through Tuesday night and into Wednesday. The next system will bring a chance of rain to the coast Wednesday morning and spread that chance inland during the day. Clouds will increase Wednesday and overcast conditions will continue into Thursday. a stronger system, which looks a little like a warm front/cold Front pair, arrives Thursday and Thursday night. Have likely possibilities of precipitation for this system. Amounts are not too impressive but everywhere is likely to see a little rain. High temperatures will be in the upper 40s to low 50s all three days through Thursday. burke

Long Term: Once the system passes Thursday, the door appears open for more systems. The pattern becomes active with storms moving mainly into british columbia but also brushing Washington. The gfs and euro are in broad agreement about the change to more vigorous weather. Sunday looks pretty wet in the gfs, enough to make rivers on the olympic peninsula respond. Monday could be cooler and more showery. Have broad brushed the forecast with likely possibilities of precipitation Friday through Monday. There will be some drier periods during that time and have used rain likely at times wording. The snow level will bounce around between 3000 and 5000 feet, finishing the weekend at the lower end. burke

Hydrology, nothing really significant happens in the models until the weekend. There will be some rain on Thursday and Friday but amounts are unimpressive, rivers will rise but not too much. These events will serve to get the ground wet again however. If the gfs is right Sunday could bring hydrologically significant rainfall to the olympic peninsula. The euro is even faster with the heavy rain beginning on Saturday. Not really ready to put out a statement but this bears watching.

Any heavy rain is currently aimed at the olympic mountains and possibly the north Cascades. The probability of flooding on the green river, in the central Cascades, is low. burke

Aviation: Low level stratus was slow to clear out this afternoon with light sfc flow and weak mixing. Still seeing local cigs around 005-010 in the interior which may only briefly mix out this evening. Otherwise, will see some clearing tonight with areas of fog expected by morning. A weakening front over the coastal waters may bring light rain to the coast tonight, with dry conditions expected for the interior. 33

Ksea, winds will remain light and variable tonight with weak pressure gradients across the interior. Low level clouds will mix out this evening with clearing tonight, then fog developing in the vicinity late. Little change expected in the forecast. 33

Marine: A weakening front will dissipate over the coastal waters tonight, with light surface flow across the region. Light winds are anticipated through Tuesday night. a series of stronger systems will impact western Washington Wednesday through Friday, leading to stronger south/southeast Winds over the waters with swells building over 15 ft. 33

Watches/Warnings/Advisories: Wa, none. Pz, none.