A strong front moved to the coast in the afternoon of the 11th.
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The episode as NWS PQR wrote it up.
A strong front moved to the coast in the afternoon of the 11th.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Portland, OR wrote its last area forecast discussion before the first event at Mar 11, 10:18 AM PST, 1 hour 57 minutes earlier.
Area Forecast Discussion
National Weather Service Portland OR
1118 AM PDT Mon Mar 11 2024
.SYNOPSIS...
Few showers around this morning. Next front approaching later today,
with rain spreading inland this afternoon. Rain tonight, with front
moving onshore overnight. Then, showers, with snow levels lowering a
bit overnight into Tuesday. Mix of sun and clouds with decreasing
showers on Wed. Then, high pressure builds, bringing warmer
temperatures and dry weather for Thu, lasting into early next week.
&&
.SHORT TERM...(Today through Wednesday)...Still have some lingering
showers across the region early this morning. NOAA satellite imagery
not showing all that much in way of showers offshore, so will
maintain mostly cloudy skies and scattered showers through this am.
Next frontal system is fast approaching, with leading edge of thicker
clouds about 200 to 250 miles offshore. NOAA satellite imagery shows
another broad upper trough over the northeast Pacific, with main
baroclinic zone N-S along 135W, then extending back to the
west-southwest roughly along 42N. Fairly modest 120 to 130 kt jet
pushing on the backside, so will not take all that long before it
reaches the coast. Models in fairly decent agreement bringing the
front to the coast this evening, then pushing the front across the
interior to the Cascades later this evening. Will trend forecasts to
follow similar timing, with rain increasing along the coast this
afternoon, spreading inland through rest of today into this evening.
Then, showers behind the front.
Overall, the bulk of the rain will be this afternoon into this
evening. Generally, rainfall will be 0.75 to 1.50 inches along the
coast into the Coast Range/Willapa Hills, with 0.35 to 0.75 inch for
the interior lowlands, and 0.75 to 1.50 inches over the Cascades.
Like the front that moved across region on Sunday, will see another
round of breezy southerly winds with the front today into tonight.
Pressure gradients will tighten, but not tight enough to support
damaging winds. So, will tend of have peak gusts along the coast at
45 to 55 mph, though a few highly exposed spots (like Sea Lion Caves)
could reach 60 mph into early evening. Then, winds ease back a bit in
the evening. Day shift can reevaluate models in the event need to
issue any high wind watches or warnings for the coast, in the
unlikely event that Monday day-models suggest stronger winds.
Farther inland, more apt to see breezy south winds later today into
the overnight, with gusts 30 to 40 mph (60-80% chance). High
resolution models suggest strongest winds will be in Willamette
Valley, from Albany through Salem to south side of Portland metro.
Will hold off from issuing any wind advisories, as gusts over 45 mph
likely to be few (generally less than 10%). Will remain breezy over
the Cascades tonight, with southwesterly winds gusting 35 to 50 mph
on exposed ridges and peaks.
Speaking of the Cascades, that precipitation will fall as snow. Snow
levels will rise a bit today, up to 3000 to 3500 ft across south
Washington Cascades, and 4000 to 4500 ft across the Oregon Cascades
(highest over Lane County). But, once front passes, snow levels will
drop about 500 to 1500 feet, down to 2500 to 3000 ft. Have Winter
Weather Advisory up for the Cascades to cover this, with 4 to 10
inches, but 12 to 18 inches above 3000 to 3500 feet.
Showers continue on Tuesday. Even a few thunderstorms are possible,
mainly on Tuesday though could see a few along the coast Monday
night. But, will take until Wed for showers to significantly
decrease. Does appear that will see mix of sun and clouds on
Wednesday, with showers gradually. /Rockey
.LONG TERM...(Thursday through Saturday)...Looking forward to a large
high pressure ridge beginning to build into the region. With
this pattern favoring offshore flow with warming temperatures.
Late this week through the weekend, expect spring-like weather
with an 80% chance of Friday exceeding 65 degrees F and a 60-70%
chance of Saturday, Sunday, and Monday exceeding 70 degrees F.
Have trended the forecast slightly warmer than some of the
longer range models given the shoulder season switches. It's
quite common that models struggle to handle these swift pattern
shifts, so have had to bump up temperatures, especially within
the Willamette Valley, a few degrees. With WPC cluster analysis
in good agreement through Monday regarding the position and
strength of the high pressure, there is high confidence in max
temperatures in the upper 60s to lower 70s for interior lowlands
through the weekend, and 60s along the coast. JH/Muessle
&&
.AVIATION...The leading edge of precipitation reaches the area
shortly, with conditions deteriorating from generally VFR to MVFR
throughout the region by 20-22z. Coastal terminals may see periods
of intermittent IFR conditions as visibility is expected to drop
during periods of heavier rainfall. High resolution models suggest
around a 50% chance of gusts of 50kts at the coast, and closer to
30kts inland. Conditions begin to improve and trend back towards VFR
in the evening around 03-06z Tuesday as we enter a more post-frontal
showery airmass. Winds will begin to weaken after the front passes
as well. There is possibly another wave of moisture arriving to the
area later in the night around 12-15z; current model guidance shows
around a 30-40% chance of dropping to MVFR ceilings at that time.
*Note: The observations out of KONP are generally limited to wind
and pressure at this time. Periodically cloud cover, vis, and
present wx are reported but are unreliable.
PDX AND APPROACHES...Current VFR conditions will give way to MVFR by
around 22z, with 80-90% confidence of MVFR conditions between 22z
and 04z Tuesday. Just ahead of the cold front passage, heavier
rainfall may mildly reduce visibility to 6SM. Winds will also be
increasing during this period, with southerly gusts up to 25-30kts.
Conditions begin to improve and trend back towards VFR in the
evening around 03-06z Tuesday as we enter a more post-frontal
showery airmass. Winds will begin to weaken after the front passes
as well. There is possibly another wave of moisture arriving to the
area later in the night around 12-15z; current model guidance shows
around a 30-40% chance of dropping to MVFR ceilings at that time.
&&
.MARINE...Water vapor satellite imagery depicts a mature low
pressure system over the open Pacific near 50N 145 W early this
morning, with a strong front extending well southeast from the
low center to the offshore waters of the Pacific Northwest. This
front will enter the coastal waters later this morning, bringing
another round of strong Gales and hazardous seas today as rapidly
increasing short period seas and a large westerly swell push
combined seas close to 20 ft this afternoon. Latest guidance
continues to depict sustained winds of 40 kt and gusts to near 50
kt this afternoon into early evening. Contemplated upgrading the
Gale Warning to a Storm Warning for the outer zones with issuance
of the morning package, but feel Storm Force gusts will be
sporadic enough and occur over a relatively short period of time
to stick with the Gale Warning for now.
The front will push onshore by late evening, leaving blustery
conditions characterized by 20-30 kt southwest winds and seas in
the mid teens through tonight. Hazardous Seas Warnings will likely
be needed through Tuesday as the westerly swell continue to build
and maintains steep seas above 15 feet into Tuesday evening. The
post frontal environment will also support another round of
showers with a slight (15-25 percent) chance of thunderstorms
tonight into early Tuesday.
Conditions improve by the middle of the week as high pressure
begins to build offshore and yields a lighter northerly wind
regime. The westerly swell will also subside, resulting in seas
dropping below 10 feet through the latter half of the week. /CB
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...High Wind Watch until 9 PM PDT this evening for ORZ103.
Winter Weather Advisory until 6 PM PDT Tuesday for ORZ126>128.
WA...Winter Weather Advisory until 6 PM PDT Tuesday for WAZ211.
PZ...Gale Warning until 11 PM PDT this evening for PZZ210-251>253-
271>273.
&&
www.weather.gov/portland
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www.twitter.com/NWSPortlandThe national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Peak gust to 63 mph occurred at 1600 PST at Cape Disappointment (82SW1).
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2024Every state in 2024This day in weather historyWarnings in Washington, March 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1164931.