Area Forecast Discussion
Issued by NWS Juneau, AK

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FXAK67 PAJK 240104 CCA

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
235 PM AKDT Mon May 23 2022

.SHORT TERM.../Through Tue night/ Today is much different than
yesterday weather wise. For starters, what remains of a weak front
is over the northern panhandle bringing rain and clouds to that
area. Meanwhile, onshore flow behind the front is bringing
showers and clouds to the rest of the panhandle. Consequently,
temperatures are a good 15 degrees cooler then they were at this
time yesterday due to the precipitation and cloud cover. As for
winds, 20 kt southerlies are blowing through Lynn Canal and Skagway
this afternoon as a thermal trough in the southern Yukon persists
and ridging builds over the panhandle.

Through the next 36 hours, clouds and showers continue into Tue
as the front pushes into Canada and onshore flow persists. There
will be a gradual diminishing trend with the showers though. The
trend will start in the south tonight and work its way north
through Tue night as ridging builds north. Southern panhandle
should be mostly dry by Tue afternoon while the north will have to
wait until late Wed night as stronger onshore flow is aimed
there. QPF amounts are expected to be light overall. The continued
showers and clouds will keep temperatures rather cool with lows
in the 40s and highs in the 50s. Though any extended breaks in the
clouds could lead to higher temps during the day or cooler temps
at night.

Winds will mostly be low for the period. Highest winds will
actually be tonight with 20 kt of wind in Lynn Canal, Skagway,
and parts of Stephens Passage. Winds will then start to diminish
Tue and even start to flip north Wed night due to southerly
pressure gradients weakening as the ridging over the panhandle
builds farther north.

Forecast changes were mostly minor with mostly local effects for
temperature and wind taking up most of them.

.LONG TERM.../Wednesday through Saturday/ On Wednesday, a low
situates itself south of Haida Gwaii while a weak area of high
pressure develops in the gulf. Through Wednesday afternoon, the
low shifts NE and dissolves. This will keep cloud cover over the
southern panhandle with a chance of light showers near Hyder. For
the rest of the panhandle, conditions dry out as high pressure
blocks any advancing energy from the west and sends it south.
Thursday also looks mostly dry. Per usual, models are showing
convection along the BC border and it can be a challenge to forecast
whether or not any showers make it over the Coast Mountains. For
now, going with a drier solution through Friday.

For the third day, the GFS is modeling a low pressure system
advancing north into the southern panhandle Friday. ECMWF, Canadian,
and Nam solutions develop this system later and keep it south of the
panhandle. This is more in line with ensemble solutions so decided
to have only slight chance for the far southern panhandle Friday.
Going into the weekend, chances look better for some precipitation
along the Coast Mountains and southern panhandle as an easterly wave
develops. Confidence is low on timing and location at this time.

Temperature will have a slight rising trend through the mid range
with coolest temperatures on Wednesday in the upper 50s warming
into the mid 60s Thursday and Friday, warmest where cloud cover
breaks out. Overall flow will be along shore without a strong
offshore component. At mid levels, an area of low pressure
develops which could cause additional cloud cover. Thursday and
Friday look the most favorable for partly cloudy skies.






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