A Taku mountain wave developed as a low tracked to the SE. The tight pressure gradient along the Coast Mountains and strong cold air advection contributed to high winds for the northern inner channels, particularly for late March, and lasted two and a half days.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS AJK wrote it up.
A Taku mountain wave developed as a low tracked to the SE. The tight pressure gradient along the Coast Mountains and strong cold air advection contributed to high winds for the northern inner channels, particularly for late March, and lasted two and a half days.
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 Juneau, AK wrote its last area forecast discussion before the first event at Mar 29, 5:13 AM AKST, 5 hours 49 minutes earlier.
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
613 AM AKDT Sun Mar 29 2020
.SHORT TERM...A surface low is currently situated over the Gulf
this morning providing light snow showers across the southern
panhandle. A surface high is located over NW Canada causing
pressure gradients to tighten to the north as the low pushes
closer to the coast and cold air advection increase. Today's main
focus will be on strong northerly outflow winds and a mnt wave
potential for the Juneau area. Added Strong Wind headlines for
Skagway, Haines, Pelican Cove, and Juneau where gusts over 40 mph
are likely. The strongest winds are expected to occur late
tonight through early Monday morning as the pressure gradient will
be the strongest during this time frame. Gale force winds in Lynn
Canal will increase through the day reaching Storm Force by
tonight. Gales are also expected to flow all the way down through
Chatham Strait. As the outflow winds increase, Gale force plumes
will blow off the coast through interior gap passes along the Gulf
Coast.
Conditions look favorable for Taku winds to impact the
Juneau/Douglas area. Cross barrier flow is strong and an inversion
will be set up over the ridge. A critical level will also set up
during this time frame aiding in the likely of a mtn wave. With
this, a High Wind Watch is in effect from this evening through
Monday afternoon. Winds of 25 to 30 mph are expected with gusts up
to 60 mph possible. This potential will be monitored as new
observations and model guidance arrives.
As the low continues to track SE away from the panhandle and
outflow winds blow, conditions will begin to dry out and cool
down. By Monday night, winds will be on the decrease and precip
chances will have dissipated. Temperatures will have cooled
drastically by this point as cold arctic air will have been
funneling into the Panhandle during the outflow event. Expect high
temps in the mid 20s for the central and northern panhandle and
upper 30s for the southern half. This will make way for a pleasant
but cold Tuesday.
.LONG TERM.../Tuesday through Sunday as of 9 pm/...The long range
portion of the forecast for Southeast Alaska will be dominated by
a pair of blocking features. The first is an omega block that is
positioned over the west coast of Alaska. The eastern low of the
omega block is over the southern Gulf of Alaska. The associated
flow The upper level high portion of the omega moves over to the
Canadian Arctic waters north of the McKenzie delta. This
repositioning of the high heights in omega into a split flow
pattern mid to upper level flow over Southwest Alaska still leaves
the southeast panhandle out of any direct flow pattern to the end
of the week.
As a result there is no significant weather system for the
panhandle for the end of the week and headed into the weekend.
Overall it looks to be dry forecast from midweek onward.
Computer models struggle with blocking ridges, mainly with
respect to timing of the blocking ridge break down or shift in
location and how upstream waves will react. This pattern seems to
be no different due to the fact model spread is rather large as
early as Tuesday evening. Continued to use a blend of GFS/ECMWF
for Tuesday with a transition to WPC for rest of the week.
Forecast confidence is moderate to high, although with low, expect
changes.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...High Wind Watch from this evening through Monday afternoon for
AKZ025.
Strong Wind through this evening for AKZ025.
Strong Wind through late tonight for AKZ018-019-022.
Wind Chill Advisory until 9 AM AKDT this morning for AKZ018.
MARINE...Heavy Freezing Spray Warning for PKZ012.
Storm Warning for PKZ012.
Gale Warning for PKZ011-013-021-022-031>033-041>043-051.
Small Craft Advisory for PKZ034>036-052-053.
&&
CC/Bezenek
Visit us at http://www.weather.gov/Juneau2 high wind. Local standard time, as filed.
The South Douglas Boat Harbor and the Marine Exchange sensors at the Juneau Downtown Docks measured consistent gusts over 60mph during this two and a half day Taku wind event, including peak gusts of 90mph at the AJ Dock throughout Monday March 30th.
Marine Exchange sensor at the Skagway Harbor measured consistent gusts over 60mph during this outflow event, including a peak gust of 82mph at 343pm on Monday March 30th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2020Every state in 2020This day in weather historyWarnings in Alaska, March 2020
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: 874309, 874294.