Area forecast discussion
National Weather Service Seattle Washington
315 PM PDT Sat may 25 2013
Synopsis...low pressure aloft will remain over the region through
the middle of the upcoming week. This will keep the weather pattern
unsettled over the area. Daytime temperatures are expected to run
below normal.
&&
Short term...
precipitation amounts over the western part of the forecast area ended up a
little higher than predicted...with a few gauges on the olympic
peninsula receiving close to a half inch of rain during the 12-hour
period ending at 3 PM PDT. Up to a quarter of an inch is expected
over the far southwest overnight.
No major changes in the overall pattern is anticipated during this
period. The upper low presently over the region will weaken with
time and will exit the area by Memorial Day. Alas...another low
pressure system will quickly follow on its heels during Memorial
Day. This system will linger over the region through Tuesday. Expect
unsettled conditions to persist and daytime temperatures will continue to
run below normal. The main forecast challenge in the short term will
be the timing and location of the main precipitation bands.
Long term...
this period will start off unsettled due to an upper trough remaining
over the Pacific northwest. However...by the end of the period...the
medium range models were generally in agreement that heights and
thicknesses will rise during the latter part of the period.
Therefore have shown a tend toward warmer and drier weather. Some
moisture and instability from an upper low off to our east may wrap
into the Cascades on Saturday for a slight risk of afternoon showers
or thunderstorms.
&&
Aviation...weak upper level trough will remain over western Washington
today with light southwesterly flow aloft and light low level flow
as well. Air mass moist and slightly unstable.
Ceilings expected to be mainly within VFR...ranging from 4k feet to 6k feet.
The exception being near showers...where ceilings will lower to MVFR/IFR
range...or around 1000 feet. There will be occasional breaks in the
clouds...mainly east of Puget Sound sound...but these breaks will be short
lived.
Ksea...S wind 4 to 8 knots today...becoming light and northerly
during the overnight. VFR ceilings expected. Showers may work their way
into the vicinity...which may drop ceilings into MVFR conditions
momentarily. Smr
&&
Marine...light gradients today and tonight as a weak surface low
over the offshore waters slowly moves southeast and dissipates.
Light onshore flow developing on Sunday. The next organized front
reaches the waters on Monday with small craft winds possible over
the coastal waters. Onshore flow pattern will resume for Tuesday and
Wednesday. Felton/smr
&&
Sew watches/warnings/advisories...
Washington...none.
Pz...none.
&&
$$
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