Southcentral and southwest Alaska forecast discussion
National Weather Service Anchorage Alaska
519 am akdt sun may 19 2013
Analysis and upper levels...
the remnants of the system that brought a late season snowfall to
much of southcentral Alaska on Friday and Saturday has become a
vertically stacked low near middelton island. This low will slowly
slide to the east as it dissipates today. The next Aleutian low is
currently located 500 miles southwest of Shemya...and is progressing
off to the northeast. The associated front from this low currently
over the western Aleutians will move to the eastern Bering by Monday.
An upper level Arctic low is also clipping the extreme northwestern
edge of the state...and will remain well out of the aor as the
Aleutian low pushes it towards the North Pole.
Model discussion...
the models have now all come into very good agreement with both the
track and intensity of the Aleutian low through middle week...with good
run to run consistency in the NAM and ec. Previous runs of the GFS
were slightly slower than the NAM/ec solutions...however later GFS
runs have since come into line with the rest.
Short term forecast...
southcentral...clouds will continue to decrease throughout much of
southcentral as the Gulf low continues to weaken. This will lead to a
warmer afternoon under clear skies for most areas with the exception
of the Copper River basin...although temperatures will remain below
normal for at least another day. The only chance of precipitation in the
area today will be along the Wrangell Mountains of the Copper River
basin. The gusty westerly winds near Kodiak Island...Barren
Islands...and Whittier will diminish this morning as the Gulf low
continues to weaken and move east.
Southwest/akpenn...the most significant weather to note for the
southwest Mainland is a band of isolated snow showers currently
moving through the Kuskokwim Delta. This band will bring a quick shot
of snow to the Bethel area this morning...then into the western
Kuskokwim Delta this afternoon before dissipating over the Kuskokwim
Mountains. Otherwise the weather will remain mostly clear with below
normal temperatures until Monday when the front ahead of the Aleutian
low will begin affecting the southwest coast.
Bering Sea/Aleutians...most of active weather today will be centered
here as the Aleutian low progresses through the area. This system
will bring a round of rain and strong winds throughout the Aleutian
and Pribilof Islands through Monday evening.
Long term forecast...
the models remain in good agreement in developing ridging over the
Gulf of Alaska middle week...which will keep systems moving through the
Aleutians on more northerly tracks into next weekend. While there is
considerable disagreement as to exactly where these next Aleutian
lows will be located...this setup will not only keep most of the
active weather west of Mainland Alaska...but will also bring near to
even above normal temperatures into the area.
Aer/alu...watch/warning summary
public...none
marine...155 160 165 170 171 172 175 179 180
fire weather...none
Dek may 13
