Frost Advisory 2, NWS Juneau, AK

219 
WWAK77 PAJK 170713
NPWAJK

URGENT - WEATHER MESSAGE
National Weather Service Juneau AK
1113 PM AKDT Wed May 16 2018

AKZ019>021-025-171600-
/O.CON.PAJK.FR.Y.0002.180517T1000Z-180517T1600Z/
Haines Borough and Lynn Canal-Glacier Bay-
Eastern Chichagof Island-
Juneau Borough and Northern Admiralty Island-
Including the cities of Haines, Gustavus, Hoonah, and Juneau
1113 PM AKDT Wed May 16 2018

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM AKDT THURSDAY...

* LOCATION...Inland valley locations of the northern and central 
  panhandle including Haines, Gustavus, Hoonah and Juneau. 

* TEMPERATURE...30 to 35 degrees.

* TIMING...Coldest temperatures early Thursday morning.

* IMPACTS...Sensitive plants may be damaged if left unprotected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

An advisory means that frost is already occurring or imminent.

Frost advisories are issued during the growing season so that
sensitive plants can be covered or brought inside before damages
occurs.

&&

$$

073 
WWAK77 PAJK 171533
NPWAJK

URGENT - WEATHER MESSAGE
National Weather Service Juneau AK
733 AM AKDT Thu May 17 2018



AKZ019>021-025-171645-
/O.EXP.PAJK.FR.Y.0002.000000T0000Z-180517T1600Z/
Haines Borough and Lynn Canal-Glacier Bay-
Eastern Chichagof Island-
Juneau Borough and Northern Admiralty Island-
Including the cities of Haines, Gustavus, Hoonah, and Juneau
733 AM AKDT Thu May 17 2018

...FROST ADVISORY WILL EXPIRE AT 8 AM AKDT THIS MORNING...

Temperatures have warmed up above freezing this morning. Frost is
no longer expected.

This will be the final statement on this event.


$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
224 PM AKDT Wed May 16 2018

.SHORT TERM...A ridge of high pressure remains over the eastern
gulf, giving SE Alaska another warm and dry day. W-NWLY flow
around the ridge along with sea breezes will dominate the winds,
mostly up to 10-15mph. Clear skies tonight and light winds will
again promote good radiational cooling. Temperatures aloft are not
as cold, but an inversion will likely set up. Have lows near the
freezing point again for the upper Chilkat Valley, Gustavus,
Hoonah and the Juneau Valleys, therefore there is another risk of
frost around dawn Thursday morning.

Temperatures aloft continue to warm Thursday and Friday, so
continued with the warm high temperatures for both days. Have
inland areas reaching the 70 degree mark or better and the outer
coast staying closer to 60. Humidities will be on the low side.
Have the Chilkat and Skagway Valleys falling to 20-25% during the
day making for above average fire danger. Have issued a Special
Weather Statement related to this risk, where fine fuels like
beach grass are the most susceptible.

A weak low will pass south to north across the panhandle late
Thursday night through Friday afternoon. This will cause a period
of offshore low level flow on the north side of it (favoring
warmer temperatures across the north) then a wind shift to the
S-SW and likely some cooler air. This wind shift may have some
gusts assoc with it as it moves through as well. There are
indications of marine layer development prior to this time, so a
wind shift like this could cause those low clouds to advect into
the panhandle. This is most likely for the southern inner channels
early Friday morning, although the rest of the outer coast will
likely see some increasing clouds going into Friday night as well.

Models remained on track with previous thinking. Over all changes
were small. Wind adjustments were made using some hi-res models
and for local effects, like sea breeze/drainage winds.

.LONG TERM.../Friday through Wednesday as of 10 PM Tuesday/ Upper
ridge will begin to be slowly pushed off to the E as several
shortwaves move N through the gulf during Fri-Sun. Still some
model issues to work out in regards to timing of a system moving
in from the SW Sun-Mon. Model differences only increase after Mon
with following systems for midweek. Went with 18z GFS to handle
Fri, then went with mainly latest WPC for Fri night onward.

For Fri into the weekend, stayed with warmer temps on Fri over
the N as it is likely that there will be plenty of sunshine and
even a bit of an offshore flow for at least part of the day.
Further S, it is looking more likely that there will be a marine
push moving up from the S during Fri. Temps were lowered some over
the southern area for this reason. Pretty much kept temps as is
for Sat-Sun with more clouds moving in. Models hint at a system
approaching the area from the SE Sat, which could graze the more
eastern areas. Attm, kept the precip threat mainly E of the Coast
Mtns, where the better thermal gradient will be. POPs were pretty
much kept as is for Sun, with models slowing the next main system
to affect the area, but this idea was already built into the very
low POPs for that time.

For early to middle of next week, models continue to suggest a
wetter and cooler period with systems being allowed to make their
way into the area from the SW, but the model timing differences
also increase during this time. POPs were bumped up some during
this period by blending in WPC with previous forecast. Forecast
confidence is slightly above average for Fri, then it drops to
near average for the weekend through the middle of next week.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Frost Advisory from 2 AM to 8 AM AKDT Thursday for AKZ019>021-
     025.
MARINE...Small Craft Advisory for PKZ022-041-042.

&&

Ferrin/RWT

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

Special Weather Statement
National Weather Service Juneau AK
1142 AM AKDT Wed May 16 2018

AKZ018-019-180100-
Taiya Inlet and Klondike Highway-Haines Borough and Lynn Canal-
Including the cities of Skagway and Haines
1142 AM AKDT Wed May 16 2018

...DRY CONDITIONS AND INCREASED FIRE RISK THURSDAY...

Thursday will see another dry day with relative humidity lowering
to 20-25% by the afternoon and temperatures rising to 70-75
degrees. Light northerly drainage winds are expected in the
morning followed by a southerly sea breeze increasing to 10-15 mph
in the afternoon. The sea breeze will likely cause RH to rise
above threat levels.

Fine fuels such as beach grasses are the most susceptible at this
time, other burnables are still too moist.