Strong Wind in Oregon, March 1, 2022

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
942 PM PST Mon Feb 28 2022

.UPDATE...The main bulk of rain has pushed slightly north, but
that does not mean that the region is rain free. Still expecting
widespread rain throughout the evening into Tuesday, with
periods of heavier rain into Tuesday afternoon. The main area of
concern remains the coast north of Tillamook County, the
Willapa Hills and the north Oregon Cascades. Rainfall totals
here have remained consistent with around a quarter of an inch
falling around Huckleberry RAWs for the last few hours. Likely
will see a similar trend through the night with periods of
slightly higher rainfall totals. For inland areas through the
Willamette Valley, continued heavy rain is of little concern so
have allowed the urban flood advisory to expire. There may still
be some localized ponding and flooding on the smaller rivers,
but should start to see those rivers begin to drain through the
night. Still experiencing flood conditions and the threat of
flooding along the coast, Willapa Hills and north Oregon Coast
Range so have kept the Flood Watch in place, with warnings still
out for the Grays and the Wilson rivers.

Wind wise, winds have begun to ease along the coast so
have let the High Wind Warning expire as well. Still will see
gusty winds with isolated gusts up to 50 mph possible along the
more exposed higher terrain, and over coastal bridges. -Muessle

&&

.SYNOPSIS...
An atmospheric river event will continue to impact
much of the forecast area through Tuesday night. Heaviest
rainfall is expected to occur over the higher terrain of
southwest Washington and the north Oregon coast and Coast Range.
The slow moving frontal boundary finally weakens and exits the
area Wednesday night. A cooler pattern develops late in the week
and continues through the weekend.

&&

.SHORT TERM... THROUGH THURSDAY...A strong atmospheric river
event is ongoing across SW WA and NW OR this afternoon as deep
and moist onshore flow remains focused over the Pacific NW on
the periphery of a broad upper level trough encompassing the
northern Pacific. The axis of the heaviest precipitation is
located along a slow moving, NE-SW oriented baroclinic zone
extending from the Willapa Hills to the far north OR Coast, with
50+ kt 850 mb flow lending strong orographic support along the
higher terrain of the Coast Range. The offshore frontal boundary
is also producing strong winds along the coast, with winds
still gusting into the 45-50 mph range along the beaches and
headlands and some coastal communities as of mid afternoon.
These winds should diminish and allow the existing High Wind
Warning to expire later this afternoon as the boundary shifts to
the southeast. PWAT values above 1 inch and IVT values in the
800-1000 range, both ranging from 3 to 5 standard deviations
above normal, contributed to some robust rainfall rates along
the northern coast and even into northern parts of the
Willamette Valley this morning. Some coastal locations picked up
1-2 inches and parts of the Portland metro measured as much as
1 inch int he span of 3-4 hours, helping to push a few coastal
rivers and many area streams close to bankfull. Changes to the
ongoing flood products are detailed in the hydro section below.

Rainfall rates will continue to level off through this evening
as IVT values fall to around 600-800 and the baroclinic zone
pivots slightly northward towards the Olympic Range. A weak
upper level disturbance riding along the boundary will help it
to shift back to the southeast overnight, bringing another
increase in precipitation through early Tuesday morning and
helping to maintain elevated hydro concerns into Tuesday
afternoon. The boundary will continue to slowly shift
southeastward through Tuesday and Tuesday night, with the most
intense rainfall shifting to the central Coast Range and the
southern half of the Willamette Valley. The atmospheric river
should also continue to weaken through this time, thus limiting
greater hydro concerns for these areas. Snow levels will remain
well above pass levels through Wednesday morning, keeping winter
weather concerns to a minimum.

The upper trough will finally push onshore later Wednesday
into Thursday, with precipitation tapering to showers from west
to east. Snow levels will come back down to the passes Wednesday
night as colder air filters into the region, falling to around
3000 feet Thursday afternoon. QPF amounts will also be tailing
off by this time, which for now should keep snow amounts
limited to a couple of inches.			      -CB

&&

.LONG TERM... THURSDAY NIGHT THROUGH MONDAY...Models and their
ensembles are in relatively good agreement a shortwave trough
will settle over the Pacific Northwest and result in
temperatures cooling to near or slightly below average with some
showers along the coast and mountains in the morning. These
showers should spread into the lowland valleys during the
afternoon as inland temperatures warm and destabilize the lower
atmosphere. The shortwave trough appears likely to linger over
the region into Friday. This should continue to keep
temperatures cool and bring another day with a few mainly
afternoon and evening showers. Snow levels will gradually lower
from ~3000-4000 ft to 2000-3000 feet Thursday into Friday, but
mountain snowfall accumulations should generally remain light.

Our flow will turn more northerly Saturday and Sunday. This will
continue to keep temperatures cool with high temperatures
topping out in the upper 40s to around 50F. Another weak
shortwave trough dropping down the British Columbia coast could
bring another round of mainly light diurnally driven showers
Saturday into Sunday. However, confidence in these materializing
is still relatively low so have kept NBM PoPs largely as is,
which seem to depict the uncertainty well.	       -Neuman

&&

.AVIATION...An atmospheric river will slowly shift southeastward
across the region overnight before stalling out across the
southeastern half of the CWA Tuesday. This will result in
mainly IFR conditions along the coast and conditions
deteriorating into MVFR conditions for most inland taf sites.
Weakening winds and persistent rain may also result in some
patchy IFR conditions developing at interior taf sites on
Tuesday.

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

KPDX AND APPROACHES...A band of moderate to heavy rain will shift
across the terminal over the next few hours. This should result
in conditions deteriorating into MVFR conditions at the terminal.
The most persistent rain should then shift south of the terminal
Tuesday, but cannot rule out occasional light rain. Between
lighter winds and whether or not the more persistent rain sneaks
northward, there is a chance some IFR conditions could at least
briefly develop on Tuesday. /Neuman

&&

.MARINE...A cold front continues to drop southeastward across
the waters. Gale Force southerly winds ahead of this front are mainly
limited to the inner waters off the central coast of Oregon at this
point. These winds will gradually weaken over the next several hours
as the front dissipates and stalls across the waters off the
south-central Oregon coast. This will result in seas subsiding from
the mid teens late this evening to below 10 ft Tuesday afternoon.

However, an incoming west-southwesterly swell will push seas back
up around 10 ft Tuesday night where seas will likely linger into
at least Wednesday afternoon.

A weak surface low pressure will drop southeastward towards the
Pacific Northwest coast Thursday. This will bring a period of
gusty north to northwesterly winds to at least the outer waters
late Thursday. In addition, another round of steep seas pushing
10 ft will likely move into the waters.

Additional weak storm systems will drop southeastward into the
waters from the Gulf of Alaska next weekend into early next week.

BEACH HAZARDS...A tidal overflow advisory is in effect for the
high tide midday Tuesday given rivers will continue to be running
high. This minor tidal overflow flooding will be most prevalent in
bays and estuaries. /Neuman

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Flood Watch through Tuesday afternoon for Coast Range of
     Northwest Oregon-Lower Columbia-North Oregon Coast.

     Coastal Flood Advisory from 10 AM to 2 PM PST Tuesday for North
     Oregon Coast.

WA...Flood Watch through Tuesday afternoon for I-5 Corridor in
     Cowlitz County-South Washington Cascade Foothills-South
     Washington Coast-Willapa Hills.

     Coastal Flood Advisory from 10 AM to 2 PM PST Tuesday for South
     Washington Coast.

PZ...Small Craft Advisory until 2 PM PST Tuesday for coastal waters
     from Cape Shoalwater WA to Cascade Head OR out 60 nm.

     Gale Warning until 10 PM PST this evening for Waters from
     Cascade Head to Florence OR from 10 to 60 nm.

     Gale Warning until 1 AM PST Tuesday for Coastal waters from
     Cascade Head to Florence OR out 10 nm.

     Small Craft Advisory until 7 AM PST Tuesday for Columbia River
     Bar.

     Small Craft Advisory from 2 PM to 6 PM PST Tuesday for Columbia
     River Bar.

&&

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PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PORTLAND OR
702 PM PST MON FEB 28 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 PM     HEAVY RAIN       1 S AMBOY               45.89N 122.45W
02/28/2022  M2.28 INCH       CLARK              WA   TRAINED SPOTTER

&&

CN