Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
000
FXAK67 PAJK 231413
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
613 AM AKDT Thu Mar 23 2017

.SHORT TERM...A low over the eastern gulf will spread showers
northward across the panhandle today. As of 6am showers have
reached as far north as Sitka and Angoon. Most have been in the
form of rain but few spots have reported a mix or snow
occasionally. Offshore flow over the far northern panhandle will
limit amounts and onset of showers until the afternoon. A couple
showers overnight were a bit more robust with one near Ketchikan
even reporting 2 lightning strikes. There is a low probability of
this happening again, so have left it out of this forecast
package. Think some ice pellets with a stronger shower and a brief
erratic/gusty wind is more likely.

Winds will be generally on the light side with many locations
becoming variable in the afternoon. A new low center moving up
from the south tonight will cause winds to flip back northerly
through the inside waters and gradually increase 15-20kt. Precip
with this second low will likely reach the far southern zones
around midnight. Breaks in the clouds between systems will likely
cause temperatures to fall near the freezing point in the evening
before precip moves back in, so have both rain and snow mentioned
late tonight, but minor accumulations.

Preferred the NAM for any adjustments, which were minimal and
mostly for local effects/current conditions. Forecast confidence
is average.

.LONG TERM...Models remain in decent agreement with an upper level
low remaining over the N gulf into early next week. This will
maintain an active weather pattern for SE AK as minor shortwaves
rotating around the parent low move across the region. Period
begins with one wave moving N across the panhandle Fri. Local
guidance indicates marginal conditions for Taku winds for a few
hours Fri as the wave moves across the region potentially inducing
a critical layer. Given the cross barrier flow is weak, feel this
will be fairly short lived with strongest winds, 30 MPH, closer
to Taku Inlet and weaker, 20 MPH, towards Juneau/Douglas.
Active pattern will persist through the weekend with ptype likely
RA over southern panhandle, SN/RASN over the central panhandle in
the morning before becoming all RA in the afternoon and SN over
the northern panhandle. Precip amounts will be heaviest further S
with QPF amounts through the weekend around 1". Trend is
diminishing amounts heading N with 0.25" expected over the N
panhandle through the weekend. Model solutions diverge heading
into next week, but all maintain an active weather pattern over SE
AK to varying degrees. Kept generally broadbrush forecast as
temporal details come into better focus. Little change to
inherited forecast with periods of precip/winds and a gradual
warming trend as impulses move quickly through the region in S-SW
upper level flow. Overall, forecast confidence in pattern remains
average.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036.
&&

$$

Ferrin/BC

Visit us at http://www.weather.gov/Juneau



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