Scientific Forecaster Discussion
fxak67 pajk 292220
Southeast Alaska forecast discussion
National Weather Service Juneau Alaska
220 PM akdt Sat Apr 29 2017
Short term.../Sat night through Monday/ gale force low passing
over haida gwaii currently bringing some clouds and breezy
conditions to areas south of Frederick Sound this afternoon.
Highest winds recorded so far has been one gust to 40 mph at
Klawock around noon. There has also been some light rain observed
as well but so far nothing north of Sumner Strait and southern
Baranof Island. Meanwhile northern Panhandle has a nice afternoon
with only some high clouds moving through.
Wind and rain expected to remain south of Frederick Sound and
diminish tonight as the generating low moves NE over haida gwaii
this evening and into British Columbia weakening rapidly as it
moves inland. Offshore flow north of Frederick Sound will keep the
rest of the Panhandle dry with mainly high to mid level clouds
through the night. Not expecting fog tonight with the persisting
clouds aloft and a full day of drying out the boundary layer by
offshore flow today.
Clouds and showers/rain return on sun and continues into Mon as
flow switches to onshore and strengthens. Rain bands have the
potential to become more widespread and intensify on Mon as a
moderate strength front moves across the Gulf and into the
Panhandle. Not much in the way of wind with this front. However I
did increase winds in the Inner Channels up to 15 to 20 kt in many
places on Mon and increased the north Gulf Coast barrier jet to
30 kt during the same time period as the front moves through.
Favored GFS and Canadian models for guidance today especially with
the low currently moving south of the area. Used some namnest for
Inner Channels winds toward Sun night and Mon.
Long term /Monday through Saturday/...as of 1030 PM Friday night
the models are diverging on their solutions, nudged the inherited
grids with NAM/GFS in the mid range and with a strong nudge to
wpc for next Friday and Saturday.
Monday keeps the ridge of high pressure over the Panhandle and
slowly drifts into Canada as it weakens. This will not be enough
to keep the precipitation from returning across the area. With
poor model agreement the actual intensity is in question. A low
will traverse into the central Gulf mid week with potential for
strong winds over the outside waters. This system will be
monitored over the next few days to see if models continue
trending up. Wet weather is solidly in place through the forecast
Update: 30/00z models came in in good agreement with a storm force
low moving into the central Gulf later Tuesday into Wed.
Development appears to be along 150w. Updated marine wind and seas
outside to reflect this. Anchorage concurs along with wpc.
Marine...Gale Warning for pkz041.
Small Craft Advisory for pkz036.
Small Craft Advisory due to seas for pkz042.