Small Craft Advisory 745, NWS Juneau, AK

Southeast Alaska Forecast Discussion...CORRECTED
National Weather Service Juneau AK
902 AM AKST Mon Nov 28 2016

.SHORT TERM...Monday morning through Tuesday night.

...Significant storm system to impact Southeast Alaska Monday
night into Tuesday...

A dumbbell low near Cape Yakataga and west of Yakutat is slowly
filling in place. Keeping the easterly winds in the Yakutat area
this morning before shifting to the south to southwest to join the
rest of the wind in the panhandle. Not a lot of changes to the
forecast as a whole with minor adjustments to the placement of the
precipitation this morning as the advancement of this next system
is slightly slower. Showers in the northern panhandle will start
out as snow near sea level and then turn to rain by late morning.
Snow amounts up to 1 inch. Winds increasing today with small craft
advisory winds developing in the northern inside waters by this
afternoon. Winds and seas in the Gulf of Alaska are on a
diminishing trend today, although a healthy swell will keep seas
ranging from 15 to 20 feet. Showers and clouds are going to be on
the diminishing trend today as the frontal band slowly pushes
across the panhandle, then hangs up along the Coast Mountains.

As we head into tonight our attention turns to a potent low which
will move northeast into the gulf Tuesday, then inland around
Yakutat Bay Tuesday night. A warm front will move to the northeast
gulf Tuesday morning, with a cold front moving across the area
Tuesday afternoon and evening. There remains some differences in
the exact track and timing of this system, but the previous
forecast still remains a good compromise. This system will be
very dynamic with significant wind, rain, and snow for the
panhandle. Looking like storm force winds will occur ahead of both
fronts and on the south side of the low as it wraps up. Low level
jet forecast at 925 mb reaches 65-75 KT in these areas. Expecting
most land areas to see strong to very strong winds as well, with
strongest winds along the outer coast. The high wind watch for
zones 23 and 27 has been upgraded to a warning. Additionally, a
high wind warning has been issued for zones 26 and 28 on Tuesday.
Many other areas will need strong wind headlines Tuesday with
winds gusting to 45-55 mph. Gave some consideration to a high wind
watch for a large portion of the central and northern panhandle
especially near Skagway and Juneau but wanted to let the next
shift take a look at the 12z model guidance and make a
determination.

Impressive moisture transport and lift associated with this system
will result in heavy precipitation. Most of the area is expected
to be warm enough for rain, but the far north will remain in a
light northerly flow regime through a large portion of Tuesday.
Therefore, the winter storm watch has been upgraded to a winter
storm warning for zones 18 and 19. Snowfall totals of up to 18
inches are expected with the highest amounts near White Pass and
Pleasant Camp. Strong southerly low level flow will eventually
reach the far north by late Tuesday afternoon which will change
precip to liquid at sea level.

Tuesday night will see the low move inland in the vicinity of
Yakutat Bay and a strong strengthening southerly gradient over the
area. Gale force winds and gusty land winds will continue over
much of the area. Strong westerly winds will be ongoing across the
gulf and develop in Cross Sound. Stratiform precip will
transition to showers as the front pushes inland.

The NAM was mainly used for the minor adjustments needed for
todays forecast with the 00z ECWMF/06z GEM favored for the tonight
through Tuesday night period. The forecast confidence is average.

.LONG TERM...The remains of the frontal system moves inland
through early Wednesday, a short lived ridge is leading another
frontal band across the gulf to impact SEAK on Thursday. Expect
showers of rain, with snow in a few local areas, especially over
the northern parts of Lynn Canal and the higher elevations. The
west to southwest jet stream aloft is in the 140-160 kt range
early Thursday across the southern Gulf of Alaska aiding the fast
storm movements across the gulf. A secondary developing wave
behind the initial wave for Friday is starting to exhibit a few
similarities to the Tuesday system in the long range model
solutions.

After that weather system, a change of the pattern is being
hinted at into the early part of next week. High pressure with
cold air builds over the Alaskan interior and Northwest Canada.
Starting to see models showing a fair bit of cooling Sunday and
Monday with cooler air spilling in and solid off shore gradient.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...High Wind Warning from 9 AM to 6 PM AKST Tuesday for AKZ026-028.
     High Wind Warning from 6 AM to 3 PM AKST Tuesday for AKZ023-027.
     Strong Wind late tonight for AKZ022.
     Winter Storm Warning from 3 AM to 6 PM AKST Tuesday for AKZ018-
     019.
MARINE...Storm Warning for PKZ042-043.
     Gale Warning for PKZ022-033-035-036-041-051-052.
     Small Craft Advisory for PKZ012-013-021-031-032-034-053.
&&

KAV - TPS/Bezenek

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