Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
FXAK67 PAJK 281543 CCA

Southeast Alaska Forecast Discussion...CORRECTED
National Weather Service Juneau AK
743 AM AKDT Sat Mar 28 2020

.SHORT TERM...The biggest factors to impact the weather for the
next day or so will be the outflow winds and the lows that will
spread rain and/or snow to the southern half of the panhandle.

The winds got a slight boost across the panhandle, for the marine
waters, although the land areas did not quite get the same boost.
The pressure gradient increases Sunday, so expect Lynn Canal winds
to rise to max gales or Storm Force, especially for the Northern
Lynn Canal area. Winds are also a little gusty for downtown Juneau
and Douglas. Outflow from interior passes and a weak mountain wave
over the icefield has wind gusts of 35 to 45 mph. Stronger outflow
should be found Sunday morning to Sunday evening, as it streams out
into the northeast gulf of Alaska. So will see some strong wind
headlines over the next 48 hours.

Cooler air is headed to the northern panhandle so low temps and
highs will be trending lower. Lows may lower to the 10-15F range in
the northern panhandle. If the cold air advection is stronger, may
even see single digits. The cooler temperatures will extend
southward, reaching the mid 20s for the south central panhandle.

One low over the southeastern gulf is responsible for the light snow
or flurries happening this morning for the central panhandle and
rain over the southern panhandle. The low moves to Dixon Entrance /
Southern panhandle and falls apart. A second low will move across
the western Alaska Range, developing a new surface low, and then
deepening slightly as it tracks SE to be west of Dixon Entrance
Sunday morning. The moisture plume will spread more rain and/or snow
into the southern panhandle. In this situation, a band of snow could
cause a couple inches to fall across the south central panhandle
Sunday into Monday. Will keep an eye on the situation but statements
shouldn`t be needed.

The tapering off of pops continues over the panhandle Monday
night so pops in the southern third lowers to chance level.

.LONG TERM.../Monday through Saturday night/...As of 10 pm
Friday...Anomalous upper-level high centered across northeast
mainland Alaska early next week will displace arctic air southward
with temperatures well below normal through mid week. Ensembles
show a general consensus that the upper ridge should gradually
weaken as it shifts eastward through the middle of next week,
eventually breaking down the strong arctic connection and allowing
temperatures to begin slowly warming. Strong outflow winds and
drying conditions continue Monday due to tight pressure gradient
between arctic high over the Yukon and residual low near Haida
Gwaii. Winds gradually weaken through Tuesday as the high shifts
east and the low dissipates. Later in the week with the return to
more seasonable temperatures likely see low pressure systems
return to the gulf.

Computer models don`t like blocking ridges. Mainly with respect to
timing of the blocking ridge break down or shift in location and
how upstream waves will react. This pattern seems to be no
different due to the fact model spread is rather large as early as
Tuesday evening. Continued to use a blend of GFS/ECMWF for Monday
with a transition to WPC for rest of the week. Forecast
confidence is low, expect changes.


.AJK Watches/Warnings/Advisories...
PUBLIC...Strong Wind until 6 AM AKDT early this morning for AKZ025.
     Strong Wind from this evening through late tonight for AKZ018.
MARINE...Gale Warning for PKZ012-013-022-043-051-053.
     Small Craft Advisory for PKZ011-021-031-032-034-041-042-052.




Visit us at is the U.S. government's official web portal to all federal, state and local government web resources and services.