Vancouver, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

339
FXUS66 KPQR 231039
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
240 AM PST Mon Dec 23 2024

.SYNOPSIS...A break in the weather for the region today, with mostly
dry weather and variable clouds. But, the next in a series of fronts
will push inland tonight, with more rain. Showers for Tuesday with
cooler unstable air mass. The very active weather continues Wednesday
through the coming weekend. As such, next strong front will bring
rain later Wed into Thu, with locally heavy rain. Rain at times, with
snow in the higher Cascades for Fri into the weekend.
&&

.SHORT TERM...(Today through Wednesday)...After a rather wet weekend,
region will get a break today, at least through mid-afternoon. Few
lingering showers over the Cascades early, otherwise, looks to be dry
with areas of morning fog. Air mass still somewhat mild, considering
the time of year. As such, not all that cool this am, then a mild day
with lowlands back into the lower to middle 50s. Still cool in the
Cascades, with 30s and 40s.

Next in series of weather systems will approach this afternoon, with
increasing clouds. The main low will remain well offshore as it moves
northward along 135W on its way to British Columbia. The cold front
will push to the coast tonight, and inland late tonight. Will see
rain, then transition to showers later tonight as cool unstable air
spreads across the region. This front will not take too long to move
inland, but enough to produce 0.25 to 0.50 inch of rain, with 0.75 to
1.25 inch in the Coast Range/Willapa Hills, as well as the Cascades.
Snow levels will gradually rise through this evening, up to about
7500 ft by midnight. But, once the front shifts across, snow levels
will lower overnight, back to 4000 ft for Tuesday. But as it with
showers, precipitation becomes more spotty and hit-n-miss. Even so,
think will see 2 to 8 inches of snow in the Cascades late tonight
through Tuesday, with higher amounts being 1 to 4 inches for areas
between 4000 and 5000 ft, but 4 to 9 inches likely above 5000 ft. A
few spots, such as the high volcanic peaks, could see a foot or more
for late tonight through Tue evening.

Showers decreasing later Tuesday night, giving way to another brief
break in the weather. A strong low over the southeast Gulf of Alaska
will push a strong baroclinic southward into the region on WED. As
such, increasing clouds on Wed, with rain spreading inland through
the day. Still have a good moisture tap with this system, as
atmospheric river will be feeding this system. Rain will becoming
heavy at times later WED night into Thu. As the front draws closer
late WED into WED night, will see increasing south to southeast winds
along the coast, and offshore. Gusts to 40 to 50 mph not out of the
question for the coast. But, winds likely to be stronger on the
headlands and open beaches, with gusts 50 to 60 mph. May need a high
wind watch for the Headlands/Beaches at that time, but will wait a
bit and see how todays and perhaps Tue models trend. Nonetheless,
will be wet and breezy late WED/WED night, especially along the
coast.      /     ROCKEY

.LONG TERM...(Thursday through Saturday)...GFS and Euro model
ensembles are coming into better agreement on indicating this
system is a moderate to strong atmospheric river with an IVT
plume of 750 kg/ms aimed directly towards Oregon. 13z NBM
run indicates fairly steady most likely scenario and high end
scenario of 48 hour QPF ending 4 AM Friday from previous
forecasts (2-5 inches and 6-8 inches over the coast, Coast
Range, and Cascades and 1-3 inches for the interior lowlands,
respectively). However, the low end 10th percentile scenario has
increased from previous forecasts with 2-4 inches over the coast,
Coast Range, and Cascades, and 0.75-1.5 inches over the interior
lowlands.With all the rain, will see small creeks and streams running
full later this week. Larger rivers will be on the rise as well,
especially those draining the Coast Range and Willapa Hills. However,
any flooding may not become a concern until Fri or Sat. At that time,
new incoming fronts will bring more rain, locally heavy at times.
Overall, guidance indicates a 25-45% chance of rivers along the Coast
Range and Willapa Hills reaching minor flood stage anytime Fri into
the weekend.

Wind will also be more of a factor with these storm systems. NBM
indicates a 50-75% chance of wind gusts over 50 mph and 20-50%
chance of wind gusts 60 mph or stronger along the coast Thursday
through Friday. Breezy inland, but gusts more likely to stay in the
30 to 40 mph range. Additionally, more Cascade snow is forecast with
these systems as snow levels won`t be able to rise as much in between
each system. Snow levels will mostly remain around 4500-5500 ft.
Model trends suggest a foot of new snow on the passes from Wednesday
night through Saturday morning, though the 90th percentile high end
scenario indicates up to 2 feet is possible. Will see heavier
snowfall higher up on the mountains. So, if your travel plans include
going over the passes in the Cascades, be prepared for snow and
snow-covered roads. Keep an eye on the forecast as these systems
become better resolved.   /HEF/Rockey
&&


.AVIATION...Currently most sites are sitting at VFR conditions as
we enter a quick lull between weather disturbances. All lingering
shower activity has exclusively reverted to the coast range and
Cascades. Headed into sunrise hours partial clearing and a decrease
in winds could lead to fog developing in the south Willamette Valley
and Tualatin Valley - something to watch closely. The next front
will bring another round of rain starting around 00-04z Tuesday at
all terminals. CIGs/VIS likely drop to MVFR overnight into Tuesday
morning as well.

PDX AND APPROACHES...VFR conditions with south winds around 10 knots
or less shifting easterly as the morning goes on. After dry weather
through the day, the next front will bring a return of rain after 03-
04z Tuesday. -Schuldt

&&

.MARINE...We currently sit between frontal disturbances however
even though the weather has calmed briefly and winds have backed off
to 18-25 knots we still await the arrival of an energetic long
period swell a little later this morning. Buoy 6, which is well
offshore of northern California had observed 32 to 38 feet seas with
the next incoming swell and while we won`t experience seas nearly as
high here, guidance did struggle to forecast the magnitude of the
swell at this point - it was underdone by 4-6 feet. Maintained an
increase in wave heights locally pushing seas up to 20-24 feet at 20
seconds for this afternoon. Then the focus shifts to another quick
hitting front slated to move through the area this evening with a
period of solid Gales after 4-7 PM. Confidence is high winds will
decrease into the 18-30 knot range late tonight into sunrise Tuesday
morning.

After wave heights ease a touch back into the upper teens Tuesday
and early Wednesday morning, a strong weather system mid to late
week will increase winds to at least high-end Gales and usher in
seas around and above 20 feet. Expect the highest seas during the
Wednesday night through Thursday time period. The latest NBM
maintains a 30-45% chance for Storm Force (>48 knot) gusts Wednesday
afternoon and evening across the outer waters, mainly south of Cape
Disappointment. It does not appear the active weather pattern will
let up anytime soon, or at least through the weekend, so Mariners
should be prepare for continued hazardous conditions going forward.
/Schuldt

&&

.BEACH HAZARDS...A High Surf Warning is in effect today. A buoy
well offshore of California indicates that the ocean swell that will
produce the large and dangerous surf for the Oregon and Washington
beaches is slightly larger than what was previously forecasted. A
west swell with heights of 20-24 feet and wave periods of 20-21
seconds is still expected to produce breaker heights up to 30 feet
near the beaches. The high energy nature of this swell is what is
most concerning as ocean conditions similar to this in the past has
resulted in damage to coastal property and buildings, produced large
sneaker waves, or resulted in injuries due to logs moving on the
beaches. Use extreme caution if you choose to venture onto the local
beaches today. We`ll continue to closely watch potential for
additional beach hazards going forward due to the active nature of
the pattern over the eastern Pacific.        /Schuldt/TJ

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...High Surf Warning through 10 PM today for ORZ101>103.

WA...High Surf Warning through 10 PM today for WAZ201.

PZ...Hazardous Seas Warning until 7 PM today for PZZ210.

     Gale Warning 7 PM today to 1 AM TUE for PZZ210.

     Gale Warning 4 PM today to 1 AM TUE for PZZ251>253-271>273.

     Hazardous Seas Warning today for PZZ251>253-271>273.
&&


$$

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