A strong low in the Gulf of Alaska intensified as it moved into the Panhandle. An accompanying trough moved across Prince William Sound from the east and brought high winds through Thompson Pass to Valdez.
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 AFC wrote it up.
A strong low in the Gulf of Alaska intensified as it moved into the Panhandle. An accompanying trough moved across Prince William Sound from the east and brought high winds through Thompson Pass to Valdez.
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 Anchorage, AK wrote its last area forecast discussion before the first event at Mar 2, 5:04 AM AKST, 46 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
504 AM AKST Thu Mar 2 2017
.ANALYSIS AND UPPER LEVELS...
An omega blocking pattern dominates the early morning weather map
with a ridge of high pressure encompassing much of the Bering Sea
and upper level lows residing near Shemya and over the Gulf of
Alaska. This blocking pattern has kept conditions across much of
Alaska pretty steady-state the past 24 hours. However, cold air
has continued to filter southward across the state from a very
cold air mass extending as far north as 80 degrees N which has
allowed temperatures to plummet across the state. As of this
morning, many locations across Southwest and Southcentral Alaska
has dropped into the single digits with quite a few locations
dropping below zero.
Pretty sizable thermal gradients have developed across portions of
the Matanuska Valley and Copper River Basin as several sites have
decoupled and allowed them to cool off while other sites remain
windy and a bit warmer. It's been quite difficult, and will
continue to be difficult through this weekend, determining which
locations will decouple which can lead to a tricky temperature
forecast at night. Speaking of winds, outflow winds have been
increasing overnight across much of Southcentral Alaska as high
pressure builds over the interior of Alaska and an area of low
pressure spins in the Gulf of Alaska. The strongest winds have
been observed through Thompson Pass, Valdez, Whittier and the
Copper River Delta.
The Space Weather Prediction Center is forecasting pretty good
chances for aurora viewing the next couple of days. In addition,
sky cover will remain mostly clear which should allow for those
with an interest in the aurora to get an opportunity for a decent
show of the northern lights. Just remember to dress warmly as
temperatures will be below normal with some areas seeing temperatures
and/or wind chills below zero.
&&
.MODEL DISCUSSION...
Numerical guidance remains in very good agreement with the
blocking pattern situated across Alaska and the Bering Sea. There
are some slight deviations in some of the guidance on how much
cold air moves south and how quickly which can complicate the
temperature forecast a bit but it's safe to say temperatures will
remain a good bit below normal through next week. There is also a
little discrepancy on how quickly the outflow winds taper off on
Friday but the strongest winds are expected today and the models
are in pretty good agreement on the onset of the strongest winds
starting late this morning. The NAMnest was utilized for wind
update as it handles the gap winds very well due to the resolution
and a blend of the NAM and GFS was used for the rest of the
forecast package.
&&
.AVIATION...
PANC...VFR conditions and gusty northerly winds are expected to
persist into Friday morning.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The forecast pretty much holds steady state over the next couple
of days. Low pressure will continue over the Gulf with high
pressure and colder temperatures over the mainland. As a result
pressure gradients will remain fairly tight and continue brisk to
very strong gap flows through Friday. Valdez and Thompson pass
will be the areas of greatest concern for warning level winds
beginning later this morning and continuing through Friday
afternoon. Cold air pooling in the Copper River Basin will
strengthen the thermal gradients. Combined with strong pressure
gradients, northerly flow aloft, and strong downward momentum
transport will be enough to kick winds into warning levels. Winds
should drop below warning Friday afternoon as gradients relax
some. Elsewhere across the mainland gusty gap flows will continue
through Friday. This will make for tricky temperature forecasts,
as windy areas will be well mixed and generally have higher
temperatures. While calm areas or areas that decouple will radiate
out and see fairly cold temps.
A strong upper short wave dropping south across Kodiak Island
will kick up marine winds over the western Gulf this afternoon and
evenings. These areas will likely see winds increasing to storms
in some areas, especially across the Barren island marine areas.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (through Sunday)...
Widespread offshore flow over the Southwest Mainland will
continue to bring generally cold and dry conditions into the
weekend as a blocking high remains just to the west. One
exception to this will be as a slight chance of flurries or light
snow showers develop this evening as a weak shortwave quickly
passes overhead. Moisture is however extremely limited with this
feature, so anything that does form will likely be light, short
lived, and mostly confined to north facing slopes. Beginning on
Saturday, the omega block over the Bering will begin to erode
away, allowing the remnants of a frontal system to slide over the
northern edge of it, bringing increasing clouds and a chance of
snow back to the region for late Saturday-Sunday. There remains
significant uncertainty as how far inland this snowfall will
reach, so at this point it appears that the most likely areas to
receive snowfall will be the Kuskokwim Delta and coastal Bristol
Bay.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The current weather pattern over the Bering Sea will continue to
hold into Friday, allowing for northerly gale force winds and snow
showers to continue to over the Eastern Bering/AK Pen. Starting
late friday the omega block over the Central Bering will begin to
break down allowing for rain and snow to spread into the Pribilofs
on Saturday from a weakening front. Further to the south however,
it appears that the omega block will remain strong enough to keep
much of the precipitation from this front just north of the
Eastern Aleutians/AK Pen on Saturday. This front will then spread
into the AK Pen on Sunday, bringing a light snow back into that
area.
&&
.LONG TERM FORECAST (Days 3 through 7)...
Colder and drier conditions are expected through the extended
forecast as the Bering ridge blocks any organized storm systems
from the southern mainland. On Friday night the upper ridge is
forced a little further south back into the Pacific as low
pressure in the western Bering, along with a second system from
the Arctic, send strong shortwaves toward the southern mainland. A
weak front which manages to undercut the ridge in the western
Bering sends a front into the central and northern Bering, however
it weakens rapidly as the upper wave shears apart as it rides
along the northern periphery of the ridge. The ridge re-amplifies
across the Bering late weekend as the energy from the shortwave
flows downstream of the ridge. The ECMWF maintained the best
consistency through the middle of next week and was the primary
influence in making minimal grid updates with this slowly evolving
pattern.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning 131.
MARINE...Storm 127 130 131 132 138 150.
Gale 119 120 121 126 128 136 137 155 160 175 176 177 178 180.
Heavy Freezing Spray 121 126 127 129 130 131 139 150 160 180.
&&
SYNOPSIS AND MODEL DISCUSSION...MMC
SOUTHCENTRAL ALASKA...RMC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DEK
LONG TERM...KH1 high wind. Local standard time, as filed.
Alaska Department of Transportation Road Weather Information System measured winds to 93 mph. Numerous windows were blown out in town.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2017Every state in 2017This day in weather historyWarnings in Alaska, March 2017
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: 683118.