Area Forecast Discussion
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FXAK67 PAJK 271329

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
529 AM AKDT Thu Oct 27 2016

.SHORT TERM...Relatively quiet short term forecast period is
expected with the main concern being the timing and intensity of
fog across portions of the panhandle. Have a dense fog advisory
out for the early morning for portions of zone 26 - the Petersburg
area in particular. Have also seen some fog in Juneau and a very
low cloud deck has been observed in the Angoon area. With low tide
occurring near daybreak today, there could be some sunrise
surprises in the form of more wide spread fog around the panhandle
later this morning.

Some light precipitation was reported overnight and Sitka and the
radar is showing weak returns offshore and moving off to the NNW.
Included areas of sprinkles for portions of the outer coast for
this morning, but do not think accumulations today will amount to
much at all. Scattered showers expected tonight over the southern
panhandle tonight.

A moderate northerly pressure gradient is in place over the far
northern inner channels courtesy of a low over the southwestern
gulf and weak high pressure over northwestern Canada. Northern and
southern Lynn Canal are beginning the day with marginal small
craft winds and am expecting those to diminish later this
afternoon as the low over the southwestern gulf tracks off to the
southeast. A front associated with the gulf low extends east
across the central gulf, then southeast towards Haida Gwaii. Winds
on the north side of the front forecast to be 25 to 30 kts and all
coastal marine zones are under small craft advisories for either
winds, seas, or both through the short term. Am also expected
small craft easterlies out of Cross Sound, but a lack of
observational data from Cape Spencer Light precludes verification.
Elsewhere, no small craft concerns near the ocean entrances. Will
also see marginal small craft southeasterlies in Clarence Strait

Used a blend of NAM and Canadian NH for updates to pressure with
little to no effect on the wind forecast over the inner channels
or public zones. Updated winds over the gulf using NAM as a
foundation. Blended NAM12 and SREF for updates to PoP with the net
effect being to reduce PoP values over the northern half of the
panhandle. Temps tweaked plus or minus a degree or two with GFS
MOS as the primary guidance source. Overall forecast confidence is

.LONG TERM...Precipitation chances will be minimal across SERN AK
through at least Sunday, as 1) Pacific storm systems will track
well to the south of the region, and 2) deep-layer continental
trajectories will be maintained as a ridge gradually shifts E
across the gulf and upper troughing occurs over NWRN Canada. The
pattern begins to change on Monday and Tuesday, as energetic WLYS
break down the previously mentioned ridge, resulting in a series
of upper troughs and surface waves ejecting E over the area.
Precipitation chances subsequently increase going into the middle
of next week, and marine winds/seas will become potentially more


.AVIATION...IMC conditions due to low CIGS and reduced VSBY over
central panhandle locations this morning. Elsewhere, MVMC or
better. Similar conditions expected late tonight and early Friday
morning as well. Some light chop possible below ridge tops along
Lynn Canal. Elsewhere, smooth.


.AJK Watches/Warnings/Advisories...
PUBLIC...Dense Fog Advisory until 9 AM AKDT this morning for AKZ026.
MARINE...Small Craft Advisory for PKZ012-013-022-036-041>043-051-052.



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