Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
FXUS66 KSEW 242328
Area Forecast Discussion
National Weather Service Seattle WA
328 PM PST Fri Feb 24 2017
.SYNOPSIS...Showers will taper off across the area tonight, making
way for sunny weather on Saturday. On Sunday, a low pressure
system will move down the coast bringing a good chance for lowland
snow on higher terrain north and east of Seattle. A chance of
showers continues through much of next week, with snow levels
rising after Tuesday.
.SHORT TERM...Rain showers around the area today will taper off
as diurnal heating wanes and a low pressure system moves south out
of the offshore waters.
Expect Saturday to be a mostly sunny, dry day as an upper ridge
moves in overhead. However, air temperatures will remain cool and
Saturday night into Sunday, another low pressure system will move
southeastward through the coastal waters and down the Washington
coast. Precipitation amounts will be higher with this system than
with the system today, but temperatures will be slightly warmer.
In heavier showers, snow levels will fall to 500 feet or less late
Saturday night and Sunday morning, affecting the higher hills.
Areas most likely to see snow accumulations at this point look to
be the higher hills north and east of Seattle, including in the
north interior and east Puget Sound lowlands. This system is worth
watching since it has the potential for more widespread snowfall
accumulations of 2 or 3 inches if model solutions change
Sunday night into Monday, a chance of showers continues,
especially in the southern parts of the CWA. Low snow levels
during the night and early morning hours mean that lowland snow is
a continuing possibility, however any amounts will be light.
.LONG TERM...Northwesterly flow aloft with some weak shortwave
troughs keeps a good chance of showers in the forecast through
the end of next week. In the most recent runs, both the ECMWF and
GFS have been indicating somewhat wetter conditions, with limited
breaks in between showery periods. The threat of lowland snow will
diminish after Tuesday with snow levels rising a couple hundred
.AVIATION...Skies will be partly cloudy tonight and Saturday and
weak high pressure will build over the area. Another weather
system will arrive Saturday night and Sunday with increasing moisture
and showers as a low pressure area drops down over the area.
KSEA...Afternoon cumulus will flatten out this evening but skies
should only be partly cloudy. There should be a light NE breeze.
.MARINE...Surface low pressure is moving south out of the area and
will be replaced with weak high pressure. Another low will drop
down from the B.C. coast Saturday night and move over Western WA
on Sunday. After that low departs there will be a period of
stronger northerly flow, especially over the coastal waters
starting around Sunday afternoon or evening. Next week could
see stronger southwest flow developing over the area around
.HYDROLOGY...No flooding is expected during the next week.
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