Small Craft Advisory 686, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
215 PM AKST Mon Nov 7 2016

.SHORT TERM...A large cyclonic gyre was centered at 49.7N/146.3W
during midday Monday, with an embedded upper disturbance rotating
around its SWRN periphery. The disturbance and an associated
surface wave are forecast to eject NE toward the ERN gulf by
Tuesday afternoon. As this occurs, gale force SELYS will develop
over the outer marine zones, as well as the southern inner
channels. In addition, forcing for ascent associated with the
previously mentioned disturbance combined with a potentially
unstable atmosphere will support isolated thunderstorm development
over the gulf and immediate coast throughout the short term
period. Meanwhile, temperatures will hover near freezing along the
Haines and Klondike Highways. As a result, waves of precipitation
spreading north across the region will yield periods of
snow...though 12 hour accumulations are forecast to remain just
below advisory level at this time.

.LONG TERM...A low will drift N and dissipate over the NW gulf by
late Tue night. Next in parade of systems will move into the gulf
Wed. Strong low will head N toward the SW gulf, while strong
occluded front will move into the SE gulf by Wed evening. The
front will push slowly across the area Wed night and Thu. The low
should move N across the W gulf Thu-Fri while weakening. Another
system will move into the gulf for the weekend, with models still
trying to figure out track of main low center. Models hint that
another system or two will affect the area for early next week,
but they differ somewhat on this. Ended up using a blend of the
12z NAM with previous for 18z Wed-00z Fri, then used mainly latest
WPC for 12z Fri onward.

The showers over the area will persist Tue night with weakening
low over the W gulf. Still threat for TSTMS with the low and
associated vort maxima aloft along mainly the N gulf. Warming
aloft should diminish the TSTM threat from the S during the
night.

More rain and wind will move in with strong occluded front Wed and
Wed night. Looking like storm force winds ahead of the front over
the E gulf mainly Wed night. Will likely need wind headlines for a
good part of the panhandle Wed night into Thu with high winds not
out of the question. Transition back to showers should occur Thu.
Will likely have some TSTM activity around the main low and along
any trofs/vort maxima in post-frontal environment over the gulf
for at least Thu. The wet and windy weather will persist even
behind the front with a strong pressure gradient and onshore flow
persisting over entire area into Fri, and there will likely be one
or more trofs moving across the area that enhance this.

Weekend still looks wet but temps may begin to cool a bit
especially Sun into early next week. Still does not look cold
enough for snow near sea level though.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...STRONG WIND Tuesday afternoon for AKZ025-027.
MARINE...Gale Warning for PKZ033-036-041>043-051-052.
     Small Craft Advisory for PKZ013-021-022-031-032-034-035.
     Small Craft Advisory due to Seas for PKZ053.
&&

Garner/RWT

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