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FXAK67 PAJK 241355

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
555 AM AKDT Mon Jul 24 2017

.SYNOPSIS...Marine layer clouds will persist over the Panhandle
Monday, while high pressure persists over the Gulf into Tuesday. A
weak low pressure system and its associated weather front will
impact the southern Panhandle tomorrow.


.SHORT TERM.../Monday through Tuesday/...As of 500am Monday...The
short term begins with marine layer clouds over the majority of
the Panhandle and high pressure over the Gulf. While conditions
today will remain relatively cloudy, rain is not expected. The
exception is the Juneau area, where some light rain and drizzle
remains ongoing; however, rain is expected to end by the afternoon

Tuesday`s weather will be more active as a low pressure system
tracks east across the Gulf. A weak weather front associated with
the low will begin to impact the southern Panhandle sometime
between late tomorrow morning and the early afternoon hours. Rain
will spread northward through the afternoon and evening with rain
likely reaching as far north as Juneau and Gustavus by late
Tuesday. Significant winds are not expected with this weather

Most alterations to the short term forecast were made in Tuesday`s
timeframe bringing the rain into most of the southern Panhandle by
mid afternoon. Forecast confidence is average with primary
guidance from a blend of the 18 and 00Z NAM with some input from
the NAMnest.

.LONG TERM.../Wednesday through Sunday/...As of 1030pm Sunday...
The upper level low that we`ve been watching for the start of next
week has strengthened in the models now to the point that there
is a surface low/trough reflection...where there used to be
weak/broad high pressure. The upper level low and surface trough
tracks ENE over the southern panhandle on Wednesday. Have
continued the increasing trend for POPs over the southern
panhandle due to the low pressure system. The placement of the low
should allow for lower chances for showers across the far northern
panhandle, however cannot rule out isolated/scattered showers.

After that upper level troughs look to continue to pass over the
region with southerly onshore flow, thus keeping the potential for
showers in the forecast. At the surface, expect a very weak
pressure gradient over the region develops due to broad high
pressure while low pressure settles over the south central gulf.
Have decreased wind speeds over the inner channels some to reflect
the weaker pressure pattern. Will have to watch where the new low
tracks for next weekend.

Used a blend of the GFS/ECMWF and WPC for updates to this forecast
package. Forecast confidence is average.


.AVIATION...Marine air is well established over the entire
Panhandle. This morning is starting out with widespread MVFR
celings and a few visibility obs in light fog plus drizzle in
PAJN. Predicting VFR condtions at the terminals this afternoon
and will lower condtions late tonight back into MVFR with all
this moisture. Outlook: Tue MVFR Rain.


.MARINE...Relatively light winds remain in the short term
forecast. The inner channels will be primarily southerly; however,
some prefrontal northerly winds are likely tomorrow as the front
tracks northward.


.AJK Watches/Warnings/Advisories...




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