Area forecast discussion
National Weather Service Seattle Washington
306 PM PDT Friday may 24 2013
Synopsis...a weakening low pressure system will remain over the
region through this weekend but there will be a trend toward less
showers...more sunshine...and warmer afternoon temperatures. Another
upper low will mainly impact the southwest part of the state on
Memorial Day.
&&
Short term...
there were scattered showers...more numerous over the southwest
half...present over the forecast area this afternoon. Much of this
activity will dissipate this evening.
An upper low will remain over the Pacific northwest through this
weekend but will gradually fill and weaken with time. This will
result in a trend toward less showers...more sunshine...and warmer
afternoon temperatures.
The upper trough will move east of the area late Sunday night or early
Monday. However another upper low is expected to dig off the coast on
Memorial Day. This system will head toward Oregon...therefore the
best chance of precipitation will likely be over the southwest portion of
the County Warning Area. Went on ahead and removed the threat of precipitation from much of
the northeast half of the forecast area.
Long term...
much of this period will be unsettled due to a negative tilted upper
trough over the region. Thus anticipate a risk of precipitation...especially
the middle of next week...and generally below normal daytime
temperatures.
&&
Aviation...an upper level trough over Washington will continue to migrate
eastward...entering eastern Washington by this evening. Southerly flow
currently over western Washington will continue into tomorrow. Moist and
slightly unstable. Scattered showers...mostly west of the
sound...will decrease in number by tonight. Less than a 10 percent
chance of isolated thunderstorms this afternoon/early evening.
Ksea...S wind 5 to 8 knots for next 24 hours. Mainly VFR ceilings
expected...dropping to MVFR during showers.
&&
Marine...lighter gradients and winds over most Washington waters today.
Weak onshore flow will increase a bit tonight through the weekend.
Expecting Small Craft Advisory winds to develop late this afternoon
in the central and eastern Strait...thus an advisory is in place.
The next organized front reaches the waters on Monday with small
craft winds probable over the coastal waters.
&&
Sew watches/warnings/advisories...
Washington...none.
Pz...Small Craft Advisory in effect until 2 am PDT Saturday for
the central and eastern Strait of Juan Delaware fuca.
&&
$$
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