FXAK67 PAJK 242247
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
247 PM AKDT Thu May 24 2018
.SHORT TERM...Raise your hands if you like August weather in May!
As we read most of your minds, that is what we thought.
Broad but weak ridging over Southeast Alaska has resulted in a
"dirty" break of sorts between systems. However, like clockwork,
breaks in the clouds have resulted in surface warming that has
incited a little more shower activity this afternoon than what we
experienced this morning. Meanwhile, greater ridging heights has
suppressed clouds in the far southern Inner Channels. Peering
oceanside from the coast, we spy a front emerging from the south.
This front will support increasing lift this evening as off and on
showers and then rain overspreads much of the Panhandle. With
this system, we expect breezes to increase Friday. The Friday
front will no doubt "wet" Southeast Alaskans appetites for the
main course of fall weather beginning Saturday and more and more
likely increasing through the holiday weekend. Note with most
areas getting around a half inch of rain, this looks to be the
"dry day of the weekend." Most winds have been on the lighter side
today, but convective mixing and a pre-frontal ridge has sustained
stronger winds than expected through Juneau and Lynn Canal. But
these winds should weaken as the front approaches shore tonight.
Saturday, as noted above, a gale force front with a deep fetch of
moisture moves into our gulf waters from the south. Southeast and
easterly winds will rise across the Panhandle at first from the
south and then moving northward through the day. With it, the
coast from Prince of Wales Island up to Chichagof should receive
an inch of rain Saturday and Saturday night. But more exposed Ketchikan
could receive up to 2 inches. While this looks to present no hydro
concerns, we do think it could challenge the enjoyment of some
outdoor holiday weekend activities, especially with the added
bonus of stiff southeast winds. Gusts on Prince of Wales Island
looks to be quite strong for this time of year: around 45 mph.
Boaters in the Inner Channels on Saturday should be wary with
increasing winds and seas with the greatest concerns in the
southern and central Inner Channels. Reacting to the approaching
front to the south, northern Inner Channels may actually see a
light turn to the north and conditions here should be a little
Overall, we used mainly GFS for any changes through Saturday
morning, but going into Saturday night, models still are quite
argumentative on the low's future dance moves in the gulf. But
anyway way you sort it, it looks wet through the weekend.
.LONG TERM.../Sunday through Thursday as of 10 PM Wednesday/ The
ECMWF is running a bit fast and strong with the low that moves in
this weekend, nudged the forecast using NAM/GFS and Canadian where
With a low likely in the eastern gulf, Sunday into Monday looks to
be wet across most of the Panhandle and a Special weather
statement will be reissued for recreational activities and travel
into the holiday weekend. But all hope is not lost, there is
potential for a break from the active fall-type weather after the
low pushes onshore early next week.
Winds will be 20 kt or less over the gulf by late Sunday night
and 15 kt or less over the Panhandle and inside waters. By Tuesday
winds should be 15 kt or less through Thursday.
The low will move into the central gulf Sunday evening. Overnight
the low will move near the Fairweather grounds, quickly filling
Monday night before dropping southeast and becoming a trof by
Tuesday morning. A ridge of high pressure will build over the
Panhandle Tuesday through Thursday.
Lowered temperatures again for Sunday a couple of degrees.
Temperatures are still expected to remain in the mid to upper 50s
during the day and range into the 40s overnight. With less clouds
possible with the building ridge, temperatures rise a few degrees
through mid week.
MARINE...Small Craft Advisory for PKZ036-041>043-051-052.
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