Brisk Wind Advisory 36, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion...UPDATED
National Weather Service Anchorage AK
857 AM AKST Sun Feb 23 2020

.ANALYSIS AND UPPER LEVELS...

An upper level trough extends from a low north of the Bering
Strait and has interacted with a stacked low in the Gulf of
Alaska, sparking some snow showers for much of Southcentral Alaska
in the overnight hours. The upper trough is responsible for clouds
over much of southwest Alaska, including some fog in the Kusko
Delta. An upper level ridge has built into western Alaska ahead of
the north Pacific low that is bringing some stronger winds and
rain to Dutch Harbor this morning. An area of deformation west of
the Pribilofs has brought a few snow showers to the area this
morning.

&&

.MODEL DISCUSSION...

Models have come into somewhat of a consensus with each other and
agree on low placement up to Monday night. Leading into Tuesday
morning, there begins to be some disagreement with the low's
location as it enters the southern Gulf. However, strength still
seems to be generally agreed upon in the 975 mb range as it enters
the Gulf.

&&

.AVIATION...
PANC...VFR conditions along with northerly winds will persist
through late Monday morning.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
(Today through Monday evening)

The main story in the short term will be cooling conditions with
strong outflow winds developing. Early this morning, the trough
axis aloft is beginning to move into the western Susitna Valley
and Cook Inlet, and this feature will continue eastward through
the day, reaching the ALCAN border by Monday evening. As this
feature moves northeast, drier and colder air follows in its
wake.

Offshore flow today increases with gusty winds for the Passage
Canal, Resurrection Bay, Valdez Narrows, and Copper River Delta.
The wind will also really get going for Thompson pass, where winds
peaking near 50 mph look like a good possibility as the colder
air funnels down the Copper Basin. Here, visibilities will likely
be significantly reduced, and a Winter Storm Watch issuance is a
distinct probability in the next couple forecast cycles.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...

An upper level wave that has brought snow showers to the Kuskokwim
Delta Coast overnight continues to push inland today. Behind this
feature, an upper level ridge, with surface high pressure, quickly
moves in across Southwest Alaska through Monday. This will help to
keep clear skies, along with cooler temperatures today into the
beginning of the week. By Tuesday afternoon, the next front
approaches from the North Pacific towards interior Bristol Bay,
which will help to increase cloud cover and warm temperatures
slightly. This front will also increase the chance for
precipitation, keeping to the southern parts of Bristol Bay and
the Alaska Peninsula.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

As one gale force low departs the western Aleutians back into the
North Pacific this morning, another strong system lifting
northward quickly approaches the central and eastern Aleutians by
this afternoon. This front will be stronger than the previous one,
even bringing a short period of easterly storm force winds this
afternoon to coastal zones south of the Aleutian Chain near Dutch
Harbor. There is still some model uncertainty whether the strong
winds and gusts will make it into Unalaska, along with the
potential for snow showers.

By Monday, this strong low diminishes, but another system south
of Shemya will help to keep widespread gale force winds across
much of the Bering and Aleutians through Tuesday. High pressure
over the eastern Bering will help to keep any precipitation (rain
and snow showers) limited to areas west of the Pribilofs and also
along the Aleutians through the next few days.

&&

.MARINE (Days 3 through 5)...

A low tracking north into the Gulf Tue will continue to bring
widespread gales along the northern Gulf Coast and south of the
AKPEN, with areas of storm force winds in Shelikof Strait and east
of Kodiak Island. Meanwhile, expect widespread small craft advisory
level conditions over the Bering Sea with broad easterly flow under
high pressure. The Gulf low will weaken Wed. Depending on the low
track, a barrier jet could develop and bring easterly gales Wed.
Winds will decrease and seas will subside Wed into Thu over the
Bering Sea.

&&

.LONG TERM FORECAST (Days 4 through 7)...

A weakening low in the Gulf will continue to bring precipitation
along the North Gulf Coast Wed, then gradually exit to the eastern
Gulf Thu. Farther north, expect persistent mostly dry weather,
though clouds streaming in from the Gulf should make for mostly cloudy
skies over Southcentral Wed and Thu. Thu into Sat, a
strengthening Arctic high will bring colder than normal conditions
and clear skies. Looking farther west, expect mostly dry, colder
than normal weather through Fri over the Southwest mainland. A
series of compact lows will track across the Aleutians, bringing
periods of unsettled weather. A strong low will move into the
western Bering Sat.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...

MARINE...Storm Warning 132 150 172 174 352
         Gale Warning 120 121 127 128 130 131 136 138 155 165 170 171
                      173 175 176 178 351 414
         Heavy Freezing Spray 119 121 126 127 129 130 139 150
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...LTB
SOUTHCENTRAL ALASKA...PD
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...AH
MARINE/LONG TERM...MM