430
FXAK67 PAJK 050544
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
944 PM AKDT Fri Jul 4 2025

.UPDATE...Aviation section updated for 6z set of tafs.

&&

SHORT TERM...Light winds, some clearing, and normal temperatures
for this time of year describes this Fourth of July Friday well.
Looking aloft, we still have an upper level low drifting eastward
through Saturday, keeping some onshore flow directed at the
panhandle. Additionally, we have an eastward propagating trough
across the northern panhandle, generating a mid level cloud deck.
The result of these two features is widespread clouds for the
panhandle, but too little upward motion to result in any rain
showers. A dry slot along the coast does look to be pushing
northward, making it ways towards the Icy Strait area. With
incoming solar radiation along with the cold upper level low,
these two features mostly cancel themselves out, keeping
temperatures at the aforementioned normal for this time of year.

Not expecting much change between today and Saturday, with chances
of precipitation for the extreme northern panhandle only due to
terrain driven processes. A weak surface features does look to skirt
the extreme southern portion of the panhandle, associated with a
trough from the upper level low. Not expecting much in terms of
precipitation, as light winds aloft and constant dry air being
advected into the moisture flow looks to keep rain chances low.

LONG TERM...Key messages:
- Temperatures remain seasonable heading into next week.
- Front to bring widespread rain to the panhandle Sunday.
- The next low pressure system enters the gulf at the start of next
  week.
- Heavy rain still on track for far southern panhandle Monday
  into Tuesday.

Details: Toward the end of the weekend, a low will slide into the
northwest gulf and a trough extending from it will bring a shift
to more southerly flow over the panhandle and increasing
precipitation rates. The heaviest precipitation currently looks to
be more focused on the northern panhandle than the central and
southern areas for Sunday. Another system will move into the
southern gulf early next week bringing widespread moderate rain,
with heavy rain on tap for the far southern panhandle along with
increased marine winds. For more information see the marine
discussion.

Model discrepancies still exist with the track of this early week
system, however overall the trend has winds increasing along the
eastern gulf to fresh to strong breezes by Tuesday along with a
fresh influx of rain for the southern panhandle, spreading
northwards Tuesday. Ensemble trends continue to show a signal for
heavy rain with this early week system impacting the far southern
panhandle. The ECMWF Extreme Forecast Index still has SoT values
near 2 for QPF for the far southeastern panhandle of more than 80%
members, for the 24 hr period from Monday afternoon through
Tuesday afternoon. The track of the plume of moisture responsible
for producing this heavy rain and the surface low that is guiding
it will be the primary forecast challenge heading into the next
work week. While continued model uncertainty is still providing a
spread range of potential impacts for this system, forecaster
confidence continues to grow for heavy rainfall for the southern
panhandle. Stay tuned for further developments through the holiday
weekend.

AVIATION.../until 6z Sunday/ VFR conditions under cloud cover of
around 5000 to 7000 ft remains the rule around the panhandle this
evening. For the most part those clouds will remain through
tomorrow with not much change in ceiling height expected except in
a few areas of the far north where some fog or low clouds could
develop late tonight. In those cases may have some MVFR or IFR
conditions develop that may last through mid morning. Some
potential for some scattered rain showers over the southern
panhandle overnight with possibly some ceilings dipping into MVFR
categories briefly for the far south. The sea breeze winds from
early this evening have diminished for the night and light winds
are expected for the rest of the night. Expect a return of the sea
breezes tomorrow with similar strengths to what was experienced
today that will last into the evening hours.

MARINE...

Outer waters: Surface ridging will keep winds light near the
coastline, and keep the fresh breezes out in the center gulf from
intruding near the coast. There is more chances for fog tonight
from descending stratus clouds, although these chances are mostly
near the shoreline in lighter winds. Saturday will see a slight
breakdown of the ridge, and an increase in winds from the
southeast from the weak feature extending all the way from Kodiak
Island. Expecting a maximum of a moderate to fresh breeze, mainly
from a mild barrier jet along the coastline.

Inside waters: Lighter winds and a heavy emphases on local
effects continue to dominate the inner waters forecast. Sea
breezes have developed in either thermal gradient between the
inside waters and Canada (think Taiya Inlet) or areas currently
seeing the sun (currently Sitka is an example). Expect these
winds, maximizing around 10 knots, to continue through late
tonight before relaxing, then returning yet again Saturday
afternoon. As the weak front extends over from Kodiak Island
Saturday night, cloud cover will cause winds to relax, just to
increase yet again Sunday morning as the front moves over the
panhandle.

HYDROLOGY...Main story for hydro is heavy rain potential for the
far southern panhandle Monday into Tuesday. A front moving into
the panhandle on SUnday could serve as a primer for streams down
there, however the forecasted location of the parent low means the
heaviest rainfall Sunday will be limited to the northern and
central panhandle.

For Monday and Tuesday, the track of the surface low is key to the
amount of time the heaviest banding of rainfall and overall
moisture plume will be aimed at the southern panhandle. A more
impactful model solution would see 24 hr rainfall totals for
Metlakatla and Ketchikan reaching upwards of 2.5 inches, with
heaviest rain rates projected for Monday night into Tuesday
morning as of this discussion. A less impactful solution would see
rainfall totals near 1 inch over the warned area, due to the
system being much more progressive, limiting the period for heavy
rainfall over the area. Either way, periods of heavy rainfall are
expected with this system early next week with river and stream
rises to bankfull are possible, though no flooding is expected at
this time. Stay tuned for updates as we go through the holiday
weekend.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

$$

SHORT TERM...NC
LONG TERM....STJ
AVIATION...EAL
MARINE...NC
HYDROLOGY...STJ

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