OK, so we have the
special weather statement, a flood watch, a high wind watch, and a small craft
advisory for the inland waters of western Washington.
Good grief, what's next....boils, frogs, flies, pestilence. Sheesh.
Starting with the
forecast for the next two days. The original forecast anticipated most of the
windy conditions to occur Saturday. Now it looks as if that will continue into
Sunday:
Rain. The rain could
be heavy at times. High near 61.
South southwest wind
13 to 20 mph, with gusts as high as 30 mph.
Chance of
precipitation is 100%.
Tonight
Showers. The rain
could be heavy at times. Low around 52. Breezy, with a southwest wind 14 to 22
mph, with gusts as high as 33 mph. Chance of precipitation is 100%.
Sunday
Rain. High near 59.
South wind 15 to 20 mph. Chance of precipitation is 100%.
Sunday Night
Showers. The rain
could be heavy at times. Low around 49. Breezy, with a south southeast wind 22
to 25 mph becoming southwest in the evening. Winds could gust as high as 36
mph. Chance of precipitation is 100%.
Now to the special
weather statement as of late yesterday:
Synopsis:
Saturday will see increasing
rainfall, heavy at times, ahead of a strong Pacific cold front that will reach
the Washington coast Saturday afternoon, and then move inland through Puget
Sound and the Cascades Saturday night. Winds will pick up as the day wears on, with the
strongest winds occurring just ahead of, and with the front. Rain rates will
ease behind the front, however, moist westerly flow aloft will maintain
precipitation through the day Sunday. A second, strong front will reach western
Washington Sunday night. This front has the potential to produce the strongest
winds of the two weekend storm systems. In addition to the stronger
winds, it will bring another round of enhanced rainfall to the area, especially
over the mountains. Snow levels behind the front on Monday could drop as low as
5000 feet, which would impact the highest mountain passes in the Cascades.
Overall, heavy rain and wind
remain the primary impacts of these two storm systems.
Storm Characteristics:
Rainfall (Saturday and Sunday):
Coast - 3 to 5 inches
Mountains - 5 to 10 inches with the highest amounts over the
Olympics, North Cascades and around Mount Rainier
Interior / I-5 corridor - 2 to 4 inches (less in the rain shadow from Sequim to Admiralty Inlet)
- This amount of rain will push the flood prone rivers of western Washington up to near flood stage. The rivers with the most potential for flooding at this point are the Skokomish, Puyallup ( near Orting ), Stillaguamish ( at Arlington ), the Skagit (near Concrete), and the Nooksack ( at North Cedarville ) could also reach flood stage beginning Saturday evening. A flood watch has been issued for all of Western Washington except Island County and the San Juan Islands.
- Heavy rain will lead to brief localized flooding in poorly drained areas as well as ponding of waters on roadways.
Wind (Saturday):
In advance of the front on
Saturday gales are expected over the coastal and northern inland waters. Land
areas near the coast and in places such as the Admiralty Inlet area, the San
Juan islands, Bellingham and the Skagit delta will experience sustained winds
of 20 to 30 mph with gusts of 40 to 45 mph. For most of the Puget Sound lowlands (including the
Seattle metro area) and the Southwest Interior, south winds of 15 to 25 mph
with gusts to 35 mph are likely, but a few communities south of Joint
Base Lewis McChord such as Yelm and Rainier could see higher wind gusts around
45-50 mph.
Wind (Sunday):
HIGH WIND WATCH IN EFFECT FROM
SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT
Local wind gusts of 45 to 50 mph
will occur with a strong front this afternoon. Another stronger weather system
will arrive around Sunday evening, with a chance of damaging high winds over
portions of western Washington.
1053 AM PDT SAT SEP 28 2013
The National Weather Service in
Seattle has issued a high wind watch, which is in effect from Sunday afternoon
through late Sunday night.
Some affected locations, Bangor,
Hood Canal Bridge, Lofall.
- Timing, a strong front will reach the area around Sunday evening.
- Wind, late Sunday afternoon and night south winds of 40 mph with gusts to 60 mph are possible with a strong front.
- Impacts, damaging winds are possible late Sunday afternoon and night.
A high wind watch means there is
the potential for a damaging wind event.
In advance of the front late
Sunday afternoon gales are expected over the coastal and northern inland
waters. Land areas near the coast and in places such as the Admiralty Inlet
area, the San Juan islands, Bellingham and the Skagit delta will experience
sustained winds of 20 to 35 mph with gusts of 40 to 50 mph. For most of the Puget Sound
lowlands (including the Seattle metro area) and the Southwest Interior, south
winds of 20 to 30 mph with gusts to 40 mph are likely, but a few
communities south of Joint Base Lewis McChord such as Yelm and Rainier could
see higher wind gusts around 45-50 mph.
- Deciduous trees are still filled with green leaves. This increases the exposure of these trees to strong wind. Expect more tree damage and downed tree branches than you would normally expect for winds of this strength.
- Wind events of this magnitude can produce isolated power outages.
Snow Level:
Will remain well
above pass levels through Sunday evening, then falling as low as 5000 feet on
Monday. This could bring the slushy snow accumulations to high mountain
locations such as Artist Point, Paradise, Sunrise, Chinook Pass, and Hurricane
Ridge.
Timing:
Heaviest rainfall
will occur Saturday afternoon and evening, and then again Sunday night
Winds will be
strongest just ahead of and with each of the fronts, the second front on Sunday
night is expected to produce the strongest winds.
Lowest Snow Levels
will occur on Monday.
Forecast Confidence:
Confidence is higher
that these two storms systems will produce significant precipitation over the
region, producing rises on area rivers with potential for minor flooding on
some area rivers. In addition, confidence is higher that these fronts will
produce windy conditions for portions of western Washington, especially for the
Coast, Admiralty inlet area, San Juan Islands and North Interior on Sunday
night.
Confidence is lower
for the specific timing and location of the heaviest rainfall.
Uncertainties:
Even after last weekend's
wind, trees remain foliated, which can greatly enhance the impacts from wind
even at sub criteria levels.
