Small Craft Advisory 126, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
406 PM AKST Thu Mar 2 2017

.SHORT TERM...Active weather continues through the next 24hrs. Low
pressure in the gulf has multiple vort lobes with bands of showers
wrapping around it. These will move across the central panhandle
through the evening and give heavy snow showers to Sitka and up to
Juneau and the Icy Strait region through tonight. Have added and
extended some winter weather advisories and warnings for this
region. Expecting 8-16 inches for Pelican to Juneau and 6-12in in
Sitka. Places just north and south of the warning area will be
closer to the 3-7in range. Have also included a slight chance of
thunderstorms near the low center tonight and grazing Baranof
Island with the heavier bands through the evening. Expecting
occasional ice pellets during this timeframe as well.

A wave wrapping around the low looks to move into the far southern
panhandle late tonight or early Friday morning. This will cause
snow showers to continue through Friday afternoon down there (but
starting to clear out across the north). Expecting around 1-3in
tonight and another 1-3in tomorrow. Due to the nature of these
showers, amounts will vary widely. Will need to monitor this wave
for potential higher amounts and need of advisories.

The low in the gulf has caused strong outflow winds in the Yakutat
area today and north winds through Lynn Canal. As a result those
places have seen some blowing snow today. Expect that trend to
continue through tomorrow.

Used an ensemble approach for changes today. The Canadian and
ECMWF initialized the low center well and the frontal bands were
reflected well by the NAM. Forecast confidence is above average on
the active weather, but somewhat lower for the highly variable
snow amounts.

.LONG TERM...Low over the gulf will finally weaken but high
pressure will persist over northwest Canada starting Friday night.
Stronger and colder winds will rush through mountain passes and
north- south channels through the weekend. This will also offer
a good setup for local Taku winds in downtown Juneau at times.
Given any strong wave that sinks south in cold air advection,
there is some argument that outflow winds could spread beyond
typical areas, but this will be monitored. Skies will clear from
north to south this weekend. With the aid of a colder air mass,
fresh snowcover, and clearing skies, we expect temperatures to
lower to the lower to middle 20s for the south, widespread teens
for the central Panhandle and temperatures near 10 above for the
northern Panhandle come Sunday morning. Next week, skies are
hedged toward mostly cloudy and temperatures remain cool but yet
appear to moderate somewhat towards climatology with a chance of
snow mainly for the southern areas. All the action is to the
north. Forecast confidence good in synoptics, not as good for
specifics.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Winter Weather Advisory until midnight AKST tonight for AKZ024.
     Winter Storm Warning until 6 AM AKST Friday for AKZ021-022-025.
     Strong Wind through Friday afternoon for AKZ022.
     Winter Storm Warning until midnight AKST tonight for AKZ023.
     Winter Weather Advisory until 6 AM AKST Friday for AKZ020.
     Winter Weather Advisory until 6 PM AKST this evening for AKZ029.
     Winter Weather Advisory until midnight AKST tonight for AKZ019.
     Strong Wind through Friday afternoon for AKZ018.
     Strong Wind through Friday afternoon for AKZ017.
MARINE...Heavy Freezing Spray Warning for PKZ012.
     Gale Warning for PKZ011>013-021-022-031-042-043-051-053.
     Small Craft Advisory for PKZ032>036-041-052.
&&

Ferrin/JWA

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