Area Forecast Discussion
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FXAK67 PAJK 151436
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
636 AM AKDT Tue Oct 15 2019

.SHORT TERM.../Through Wednesday night/...A potent, complex surface
low is located southwest of Haida Gwaii as of early this morning.
Numerous short waves embedded within the larger overall
circulation continue to rotate in a cyclonic fashion, each
associated with an area of gale force winds. Gales associated with
the main front have shifted to the northeast gulf and are
diminishing. Meanwhile, gales in Hecate Strait continue to blow
into Clarence Strait, remaining strong until late this evening.
Over land, strong wind gusts continue for zones 27 and 28. By this
afternoon, one of the aforementioned short waves will rotate
north into the southern outer coastal waters, producing more small
craft winds late this afternoon and overnight.

The front associated with the complex low in the gulf has produced
widespread heavy rain over the past 24 hours. In Ketchikan,
slightly less than 5 inches has fallen and nearly an inch as far
north as the Icy Strait corridor. As expected, smaller creeks and
streams are rising. As of this morning, all remain within their
banks and no flooding concerns currently exist. Rain will taper
off later today, but conditions will not dry out except possibly
for the area around Yakutat late tonight and tomorrow morning.
Perhaps the biggest news would be the accumulating snow that
occurred in Haines overnight. Even though this was well forecasted
by previous shifts, the first low elevation accumulating snowfall
is met with anticipation by some, dread by others, and nervous
anxiety by most meteorologists. While the late Autumn and Winter
seasonal forecast are still indicating a high probability of
warmer than normal temperatures across all of Southeast Alaska,
recent below normal temperatures and an early arrival of snowfall
(for Haines) does give one cause for hope of more normal Winter
conditions that we have seen in several years.

.LONG TERM.../Thursday through Tuesday as of 10 pm Monday/
Looks like a fairly flat pattern aloft with main upper level jet
moving along S of the gulf into southern BC through the weekend.
Next week, some hint that a more amplified flow will develop as a
trof tries to deepen over the eastern Bering/N-central PAC with
ridging building over SE AK and western Canada, but models do not
agree how strong these features will get due to complicated stream
interactions. At the sfc, looks like a series of smaller lows
will move E across the far southern gulf through the weekend, then
a stronger system may move more to the NE into the gulf toward
early next week. Again, model differences remain significant on
all these features however. Decided to go ahead and use the 18z
NAM to handle Thu into Thu night, then latest WPC from Fri onward.
These models seemed like a reasonable compromise given the
differences.

For Thu into Fri, we will still have some residual lows in the
eastern gulf left over from the complicated system in the short
term. Looks like these lows will tend to drift W over the northern
gulf as other systems go by them to the S. This would keep some
onshore flow going and precip threat should remain on the high
side during this period.

Over the weekend into early next week, the precip threat becomes
more questionable given important model differences with system
tracks. May see a period of drier weather, but how long will
depend on how far N systems will get. Temps during the period
should remain near normal with no significant warm or cold
airmasses expected to move in. Given all of this, overall
forecast confidence is no better than average.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Strong Wind until 10 AM AKDT this morning for AKZ027-028.
MARINE...Gale Warning for PKZ022-036-043-051.
     Small Craft Advisory for PKZ012-013-021-035-041-042-052-053.

&&

$$

Fritsch/RWT

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