Gale Warning 52, NWS Juneau, AK

888 
FZAK67 PAJK 230002
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
302 PM AKST Thu Feb 22 2018

Offshore waters forecast for Gulf of Alaska east of 144W

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent the average of the highest
one-third of the combined windwave and swell height.

PKZ398-231815-
302 PM AKST Thu Feb 22 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A gale force low over the northern gulf will move across the 
central panhandle Fri. Another gale force low will move E across 
the northern gulf Sat, then across the central panhandle Sat 
night. 

$$

PKZ310-231815-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
302 PM AKST Thu Feb 22 2018

...GALE WARNING TONIGHT THROUGH FRIDAY...

.TONIGHT...SW wind 30 kt becoming W 40 kt by late evening. Seas 
9 ft building to 17 ft late. Rain early in the evening. 
.FRI...W wind 40 kt. Seas 18 ft. 
.FRI NIGHT...NW wind 30 kt becoming W 20 kt late. Seas 14 ft.
Rain and snow late. 
.SAT...W wind 30 kt increasing to gale to 40 kt in the
afternoon. Seas 14 ft building to 19 ft in the afternoon. Rain
and snow.
.SAT NIGHT...W gale to 40 kt. Seas 23 ft. Rain and snow.
.SUN...NW gale to 35 kt. Seas 18 ft.
.MON...W wind 25 kt. Seas 13 ft. 
.TUE...W wind 20 kt. Seas 12 ft. 

$$

747 
FZAK67 PAJK 231258
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
358 AM AKST Fri Feb 23 2018

Offshore waters forecast for Gulf of Alaska east of 144W

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent the average of the highest
one-third of the combined windwave and swell height.

PKZ398-240700-
358 AM AKST Fri Feb 23 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A weakening gale force low will continue moving southeast over 
the central panhandle on Friday. A second gale force low will 
traverse eastward across the northern Gulf Saturday and over the 
central panhandle by Saturday evening. 

$$

PKZ310-240700-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
358 AM AKST Fri Feb 23 2018

...GALE WARNING THROUGH THIS EVENING AND LATE TONIGHT...

.TODAY...W wind 40 kt. Seas 15 ft. 
.TONIGHT...W wind 35 kt diminishing to 20 kt in the evening, then
increasing to 35 kt late. Seas 13 ft subsiding to 10 ft late. 
Rain late.
.SAT...W gale to 45 kt. Seas 12 ft building to 17 ft in the
afternoon. Rain in the morning. 
.SAT NIGHT...W gale to 45 kt. Seas 19 ft. 
.SUN...W wind 30 kt. Seas 17 ft. 
.MON...W wind 25 kt. Seas 17 ft. 
.TUE...W wind 25 kt. Seas 21 ft. 

$$

170 
FZAK67 PAJK 240028
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
328 PM AKST Fri Feb 23 2018

Offshore waters forecast for Gulf of Alaska east of 144W

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent the average of the highest
one-third of the combined windwave and swell height.

PKZ398-241830-
328 PM AKST Fri Feb 23 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A storm force low will move E through the northern gulf Sat, then
SE across the southern panhandle Sat night and Sun morning. 

$$

PKZ310-241830-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
328 PM AKST Fri Feb 23 2018

...STORM WARNING SATURDAY...

.TONIGHT...NW wind 40 kt becoming W to 25 kt in the evening, then
becoming SW 35 kt late. Strongest winds eastern area in the 
evening, then western area late. Seas 19 ft subsiding to 14 ft 
late. Rain and snow late.
.SAT...W wind 40 kt increasing to 50 kt by afternoon. Seas 17 ft 
building to 23 ft in the afternoon. Rain in the morning, then rain
showers in the afternoon. 
.SAT NIGHT...W gale to 45 kt. Seas 24 ft. Rain showers. 
.SUN...NW gale to 35 kt. Seas 20 ft. 
.SUN NIGHT...W wind 25 kt. Seas 15 ft. W swell in the evening.
Rain and snow late. 
.MON...W wind 25 kt. Seas 17 ft. 
.TUE...W wind 25 kt. Seas 21 ft. 
.WED...NW wind 25 kt. Seas 16 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
239 PM AKST Wed Feb 21 2018

.SHORT TERM.../ Wednesday night to Friday night / Incoming system
on Thursday and Thursday night has been main focus of the forecast
package. Generally minor changes to the strength of the PoPs
tonight into Thursday with the low moving through the area. With
the Winter Storm Watch in place were careful to not overall
disrupt the plans.

A rain snow change over line lies along from north of Sitka to
near Ketchikan, with rain generally southwest of there, while a
snow to wet snow on the north sides. Right now the forecast for
Juneau and Petersburg Wrangell areas are looking like 5 to 9
inches in roughly 12 hours. Will be leaving the watch in effect
for this afternoon rather than making an upgrade as situation is
seeming borderline. Believe one more model will tip the decision
making one way or another.

For Friday and into Saturday after conferring with Anchorage we
adjust winds to handle to a transition into the later periods and
adjust for missing data runs to keep a more fluent weather track.
Most of the editing for this area was in the Saturday time block.

Forecast confidence is average.

.LONG TERM...Friday through Wednesday...As of 9pm Tuesday, we
appear to be heading into a slightly more active and progressive
pattern for the long term. The upper level ridge that will have
been a constant feature up until this point will retreat further
into western Canada and weaken as an upper level trough
strengthens over the panhandle on Friday and takes its place.
According to potential temperature analysis, a weak surface low
will develop along the northeast gulf coast using energy from
this upper level feature and slowly move southeast along the SE
Alaska coastline. This should keep some lingering convective
precipitation going across the panhandle, as forecast soundings
indicate steep lapse rates and plenty of cold air advection as the
low pushes through. An upper level ridge will then fill in behind
this feature Friday night before another shortwave develops out of
mainland Alaska on Saturday and impacts the panhandle Saturday
night into Sunday. Deterministic models have come into better
agreement regarding this developing shortwave, but we were
cautious about really going that route with the forecast, as there
is still plenty of uncertainty regarding the position, strength,
and timing of this low. This will be something that bears
watching as we receive more data.

Generally, we opted not to make very many substantial changes to
the long term forecast due to the uncertainty regarding
deterministic model solutions. We predominantly worked with the
12Z Friday to 12Z Saturday period using a combination of the GFS
and NAM. We also added in NBM for changes to PoP and to decrease
temperatures in the later periods to be in line with model
spreads, and we used GEM for snow ratios and subsequent snow
amounts.

&&

.AVIATION...Flight conditions for Wednesday evening will be VFR
across Southeast Alaska. Conditions will deteriorate overnight
from the northwest. Am expecting Northern panhandle ceilings to
fall into the Marginal Flight rules and Visibilities lowering in
the snow. Will also see this shift southward during the day before
the afternoon.

&&

.MARINE...No Marine hazards through tonight with small craft
advisories starting to arrive for the southern outside waters.
Winds will be increasing during the day Thursday, so northcentral
inner channels increasing to 25 kt with Lynn Canal climbing to 35
kt by late afternoon.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Winter Storm Watch from Thursday morning through late Thursday
     night for AKZ025-026.
MARINE...Gale Warning for PKZ012-013.
     Small Craft Advisory for PKZ021-022-031-032-034-041-043-051-052.
     Small Craft Advisory due to Seas for PKZ042.

&&

Bezenek/Voveris

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