Storm Warning 24, NWS Juneau, AK

912 
FZAK67 PAJK 182308
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
308 PM AKDT Thu Oct 18 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.

PKZ398-191715-
308 PM AKDT Thu Oct 18 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A storm force low will move into the Western Gulf from the south 
Thursday evening with the associated front passing over the 
panhandle Thursday night and Friday. 

$$

PKZ310-191715-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
308 PM AKDT Thu Oct 18 2018

...STORM WARNING TONIGHT THROUGH FRIDAY...

.TONIGHT...SE wind 30 kt increasing to 50 kt. Seas 11 ft building
to 21 ft. Rain...heavy at times. 
.FRI...SW wind 50 kt diminishing to 40 kt in the afternoon. Seas 
24 ft. Showers and isolated thunderstorms in the afternoon. 
.FRI NIGHT...SW gale to 35 kt. Seas 22 ft. 
.SAT...S wind 30 kt. Seas 16 ft. Rain in the afternoon. 
.SAT NIGHT...S gale to 35 kt. Seas 16 ft. Rain.
.SUN...S gale to 35 kt. Seas 18 ft. 
.MON...SE wind 20 kt. Seas 13 ft. 
.TUE...S wind 20 kt. Seas 12 ft. 

$$

471 
FZAK67 PAJK 191147
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
347 AM AKDT Fri Oct 19 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.

PKZ398-200600-
347 AM AKDT Fri Oct 19 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A storm force front will pass over the panhandle Friday morning. 
Wind will shift to the SW behind the front in the afternoon. 
Outlook. Another weather system will move into the Gulf from the 
SW Saturday night with gale force winds. 

$$

PKZ310-200600-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
347 AM AKDT Fri Oct 19 2018

...STORM WARNING TODAY...

.TODAY...SW wind 50 kt. Seas 25 ft. Rain showers early in the 
morning. Isolated thunderstorms in the afternoon. 
.TONIGHT...SW wind 35 kt. Seas 22 ft. 
.SAT...S wind 30 kt. Seas 16 ft. Rain in the afternoon. 
.SAT NIGHT...S gale to 35 kt. Seas 17 ft. Rain.
.SUN...S wind 30 kt. Seas 18 ft. 
.MON...E wind 25 kt. Seas 13 ft. 
.TUE...S gale to 40 kt. Seas 12 ft. 

$$

605 
FZAK67 PAJK 192337
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
337 PM AKDT Fri Oct 19 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.

PKZ398-201745-
337 PM AKDT Fri Oct 19 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
Strong S to SW winds will gradually diminish through Sat.
Another gale force front will move into the Gulf from the SW
Saturday night before stalling and weakening over the eastern
gulf and northern panhandle into Sun night.  

$$

PKZ310-201745-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
337 PM AKDT Fri Oct 19 2018

...GALE WARNING TONIGHT AND SATURDAY...

.TONIGHT...SW wind 45 kt diminishing to 30 kt late. Seas 25 ft
subsiding late. Showers and isolated thunderstorms in the 
evening.
.SAT...S wind 25 kt increasing to 35 kt in the afternoon. Seas 16
ft. SW swell in the morning. Rain in the afternoon. 
.SAT NIGHT...S gale to 35 kt. Seas 18 ft. Rain.
.SUN...S wind 30 kt diminishing to 20 kt in the afternoon.
Seas 20 ft. 
.SUN NIGHT...SE wind 15 kt in the evening becoming variable
less than 15 kt. Seas 15 ft. SW swell. 
.MON...E wind 25 kt. Seas 12 ft. 
.TUE...S gale to 40 kt. Seas 12 ft. 
.WED...E wind 25 kt. Seas 15 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
306 PM AKDT Wed Oct 17 2018

.SHORT TERM.../Through Friday night/ The front that brought all
the rain to the panhandle for the last few days is finally on the
way out. Rain from this front still lingers around the extreme SE
panhandle this afternoon and should move out completely this
evening. Showers rule the day for the rest of the panhandle with
the highest concentration seen in the northern gulf and northern
panhandle.

Into Tonight and Thu, that weather picture does not change all
that much. Showers will continue to concentrate in the north and
overall winds will stay at 20 kt or below for most areas. Some
instability over the gulf due to cooler air aloft and the warm
water temperature may allow some of these showers to become strong
enough to generate some lightning so a slight chance of
thunderstorms remains in the forecast for tonight for some areas.

The main focus for the short range shows up Thu night as a storm
force low wraps northward into the western gulf pushing a strong
front into the panhandle. Low level jet strength is expected to
reach nearly 70 kt at 850 mb late Thu night along the outer coast
while it weakens to 50 to 65 kt farther inland and in the southern
panhandle. Winds along the front have been increased with the
highest winds expected along the outer coast from Baranof Island
northward where a High Wind Watch has been issued for gusts up to
60 mph possible. Storm force winds are still expected in the
northern and central gulf. The rest of the panhandle can now
expect gusts anywhere from 40 to 55 mph during frontal passage
late Thu night and early Fri. Confidence is moderate for the high
wind as the indicators for high wind gusts are rather border line
with this front. However, confidence for gusts higher then 40 mph
and the storm force winds in the gulf is high given the low level
jet strength and decent agreement in the guidance. Winds will
diminish post front but a strong second wrap to the system is
expected to keep winds at max gale force in the central and
northern gulf through Friday before slowly diminishing Fri night.

The rain will also play a roll in this front. Like the previous
system, the tropical connection is rather robust with high values
of Water Vapor and Water Vapor Transport aimed at the panhandle.
Unlike the previous system, this front is not expected to stall
anywhere and will push the highest rain rates through rather
quickly. Heaviest rainfall is expected late Thu night into mid day
Fri with total rainfall pushing 1 to 2 inches across the
panhandle through some local areas could see higher amounts. A
rapid transition to convective showers is expected post front
with strong onshore flow. Some of these showers could be heavy
with some embedded thunderstorms as a pool of cool air wraps
around behind the system so another area of slight chance of
thunderstorms was added in the gulf and gulf coast for Fri into
Fri night.

LONG TERM.../ Friday to Wednesday as of 10 pm Tuesday / Active
fall weather pattern will continue through early next week. Highly
amplified long wave trough in place over the AK Peninsula
extending well south into the subtropical NPAC. An impressive PV
max on the nose of a 130kt+ upper jet will eject northward into
the northern Gulf by early Friday. These upper features align well
with the low level frontal zone so expect the resultant low/front
to be quite intense. Ensemble IVT probabilities show 80-90%
likelihood of IVT in excess of 500 kg/m/s by mid day Friday which
matches most operational guidance depiction of a deep subtropical
moisture plume being drawn northward into the Panhandle. Another
period of heavy rainfall is likely Friday across much of the
Panhandle. Winds will also increase rapidly over the Gulf with
ensemble probs of storm force conditions over the northern Gulf
quite high for a 72 hr forecast. Models still differ on the
placement of any significant surface wave development on the front
for Friday, with the EC being the odd man in the collection of
models solutions. Stayed with the GFS to WPC solutions as the
support for the small changes in the extended. Bottom line, while
not explicitly in the forecast due to uncertainty at this time,
there is the potential for a strong fall wind storm on Friday for
parts of the Panhandle.

On the plus side, the persistent long wave ridging which has kept
much needed soaking rainfall out of the drought affected areas of
the southern Panhandle shows signs of becoming flatter and more
progressive. This would allow more significant rainfall to affect
even southern areas beginning on Friday and continuing into early
next week.

The tail end of the Day 6 to Day 8 forecast block has the hints
of yet another moist frontal system sweeping across the gulf from
the south as the main low tracks to the eastern Bering Sea. They
are also suggesting that there is at least one more wave on the
front that should roll up along coastal waters and either hit or
graze the southern panhandle. Will need to watch this system as
it develops and there should be a solid band of winds with it.
Long range forecast confidence is average.

&&

.HYDROLOGY...Another period of heavy rain is in the cards for most
of the panhandle. However unlike the previous front, the high
rain rates are not expected to linger. Total expected rainfall is
expected to be around 1 to 2 inches for most areas Thu night into
Fri. We do have a two day period of drier weather before that wet
front moves in though so rivers will have a chance to shed some
of the excess water in their basins. However, soils in the
northern half of the panhandle are mostly saturated from the last
rains, so smaller rivers and streams are expected to rise with
some possibly approaching bankfull by Friday.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...High Wind Watch from late Thursday night through Friday morning
     for AKZ017-022-023.
MARINE...Small Craft Advisory for PKZ022-041>043-051-052.
     Small Craft Advisory due to Seas for PKZ053.

&&

EAL/DEL

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