High Surf in Washington, February 25 to 26, 2021

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
827 PM PST Thu Feb 25 2021

Updated Aviation and Marine Sections

.SYNOPSIS...Cool northwest flow aloft will maintain plenty of showers
through Friday night, some with small hail. Snow levels stay in the
2000 to 2500 ft range, which means a lot of snow for the Cascades,
with some snow also in the Coast Range and Willapa Hills. Gradually
drying on Saturday, with dry weather into early Sunday. But, will see
another chance of showers arriving to close the weekend, and into
early next week. But, temperatures for the lowlands will be more
seasonal early March, with highs in the lower 50s next week.
&&

.SHORT TERM...Tonight through Sunday...Rather strong cold front
pushed across the region earlier today. Now, have steady stream of
cooler unstable air riding modest northwest winds into the Pac NW.
This will maintain plenty of showers. With snow levels rather low,
mostly at 2500 to 3500 feet tonight, will see small hail in the
heavier showers tonight and Friday.

Higher up, will see rather robust snowfall across the Cascades, where
will see 6 to 12 inches falling about every 12 hours, perhaps more in
spots. Showers will gradually decrease later Friday night into
Saturday morning. Snow levels will lower a bit more on Friday,
running at 2000 to 2500 feet. Could see 3 to 8 inches of new snow for
the higher ridges of the Cascades foothills, but the jackpot snowfall
will be over over the higher Cascades above 3000 feet. As of now,
total new snowfall for tonight through Saturday morning on the order
of 1 to 2 feet for the Cascades in Lane County, and 2 to 3 feet for
the north Oregon Cascades and the south Washington Cascades. Will
maintain current Winter Storm Warnings for the Cascades through late
Friday night into Saturday morning.

Even the higher peaks of the Willapa Hills and Coast Range may see 2
to 5 inches of new snow during that timeframe. But, will not issue
any winter weather statements for those areas as snow level stays
just a bit too high, with little if any impact on the passes.

Showers decreasing on Saturday, as main upper flow weakens and air
mass moderates a bit. This will stabilize the air mass, with showers
ending for most areas by late morning, through may still have a
lingering snow shower over the Cascades into the afternoon.

Dry weather continues into Sunday. But, models have been suggesting
another weak front approaching later in the day. Not sold on much in
way of any precipitation for the area during the day, aside from very
minor chance of showers for areas north of a Tillamook to Kelso line.
Think will wind up with just mix of sun and clouds for most areas.
Will trend forecasts in this direction.

Larger fetch of swell arriving this evening, with seas jumping to 18
to 22 feet. Will maintain High Surf Advisory for the coastal beach
areas for tonight through Fri afternoon. Even though tides getting  a
bit stronger, am not expecting any issues with coastal lowland
flooding.					      /Rockey

.LONG TERM...Sunday night through Friday...Models having issues in
resolving what is more likely to happen next week. For now, will lean
to more of a blended approach for Mon through Wed, with some chance
of showers. Will see decreasing chance of precipitation next week, so
will trend forecasts as such. But, will see somewhat milder
temperatures to start March, with highs warming into the lower 50s
for the lowlands toward middle of next week.	      /Rockey

&&

.AVIATION...Northwest flow aloft to be the dominant pattern
through the 06Z TAF period. Considerable shower activity will
continue through the period, with the most numerous showers over
the higher terrain. All TAF sites will have a mix of VFR and MVFR
conditions. Northwest wind gusts to 25 kt will be common late
tonight through Fri afternoon, with 40 to 50 kt gusts around FL
050. Although thunderstorms are not expected, small hail will be
possible in heavier showers. Mountains will be obscured through
the period.

For detailed regional Pac NW aviation weather information, go
online to: https://weather.gov/zse

KPDX AND APPROACHES...Cigs will generally be in the 035-045 range
at the terminal and vicinity through 06Z Sat. Expect periodic
bouts of MVFR cigs through the period. Small hail will also be
possible in heavier showers Fri. W-NW wind gusts around 25 kt
will be common late tonight through Fri. However, stronger wind
aloft of 40-50 kt at FL050 has the potential to mix toward the
surface. Weishaar

&&

.MARINE...No changes to marine forecast. Seas slow to come up
this evening. However, at 04Z buoy 46005 was up to 23 ft. This
would decay to around 20 ft at buoy 46029 by 14Z. At 04Z buoy
46248 was at 15 ft, or about 3 ft lower than the 18Z spectral
guidance run for buoy 46029. The current forecast shows seas to
25 ft over the far outer waters of PZZ270 by 12Z. This may be a
little on the high side, but will leave the forecast as is, in
case even larger waves move across buoy 46005 over the next few
hours. Weishaar

Remainder of discussion follows: Very active weather tonight
through Saturday as a strong system pushes inland over the waters.
This system is quite dynamic as it is creating very gusty winds
and increased swells. A Gale Warning is in effect for the northern
inner and outer waters today through Friday early afternoon with
westerly winds expected around 25-30 kt with gusts up to 40 kt.
The most elevated winds will be north and west of 45.65N,
-124.51W. Here could see gusts up to 45 kt, but not expected to
be widespread or persistent. Gusts should slowly ease to 30 kt by
Fri afternoon. While some gusts could remain within gale force
levels, most areas will see more persistent small craft winds.
This will be the trend through Sat afternoon before winds appear
to almost completely drop off as high pressure develops.
Expecting winds to remain 10 to 15 kt with gusts to 20 kt through
the remainder of the weekend.

Seas will also be quite elevated, although they are trending just
a tad slower than previously expected. Have lowered seas slightly
at the beginning of the afternoon forecast, but still expecting
seas near at least 20 ft at 14 seconds overnight. Seas should
ease from near 20 ft by Sat morning although likely will stay
above 15 ft at 13 seconds. The main impact will be the wind wave
and it's impact on the swell. In general, expecting more settled
weather through next week. Muessle

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory from 1 AM to 7 PM PST Friday for Central
     Oregon Coast-North Oregon Coast.

     Winter Storm Warning until 4 AM PST Saturday for Northern
     Oregon Cascades.

     Winter Storm Warning until 10 AM PST Saturday for Cascades in
     Lane County.

WA...High Surf Advisory from 1 AM to 7 PM PST Friday for South
     Washington Coast.

     Winter Storm Warning until 4 AM PST Saturday for South
     Washington Cascades.

PZ...Gale Warning until noon PST Friday for coastal waters from Cape
     Shoalwater WA to Cascade Head OR out 60 NM.

     Small Craft Advisory until 4 AM PST Sunday for coastal waters
     from Cascade Head OR to Florence OR out 60 NM.

     Small Craft Advisory until 4 PM PST Friday for Columbia River
     Bar.

&&

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