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Southcentral and southwest Alaska forecast discussion 
National Weather Service Anchorage Alaska
146 PM akdt sun Apr 20 2014

Analysis and upper levels...
a low over the north Gulf and associated frontal system is producing
gale force east/NE winds and rain across the northern Gulf. A few
showers are spreading inland across the Kenai Peninsula as well as
over the southern Copper River Basin. A stacked low center SW of
the Aleutians is moving north toward the central Aleutians. The
associated frontal system to the north is spreading gale force
easterly winds and rain/snow over the central and western
Aleutians.

&&

Model discussion...
models in general are in fairly good agreement and reasonable.
Some minor differences exist in positioning and timing of the
frontal system as it moves east across the Aleutians/Alaska Peninsula. The
European model (ecmwf)/GFS will be generally used in the west. The higher res Gem
reg and NAM provide the best detail on gap flows across
southcentral today/eve...otherwise relatively minor synoptic
scale differences in models through the short term in the east.

&&

Short term forecast...
south central Alaska...
the weakening 980s stacked low over the SW Gulf continues moves
southeast and weakens. A secondary low over the central Gulf moves west
today then south tonight/Monday and slowly weakens. Its associated
frontal through weakens as it moves west across the northern Gulf
tonight. Strong east/NE winds spread west across the Gulf through
this afternoon then weaken tonight/Monday as the low central tracks
south. Pressure rises over the north Gulf Coast and pressure
falls due to heating over the Susitna Valley will produce brisk
gap flows across Turnagain Arm and the Knik River Valley this
afternoon and evening. Winds should diminish again late this
evening as gradients relax. After today nocturnal (drainage) and
diurnal(sea breezes) will be the dominate flow patterns through
early this week. The organized precipitation associated with the
front moving across the Gulf today will give way to somewhat drier
conditions across the north Gulf and weak afternoon and evening
convection inland through middle week. A weakening front system
moving across the Aleutians may bring some light rain to Kodiak on
Wednesday.

Southwest Alaska...ridging over the northern Mainland which has
brought a brief clearing to the southwest Mainland today will be
forced back east by an upper level wave from the west tomorrow
morning. The wave will move through the area and rapidly dissipate
by tomorrow afternoon...bringing scattered showers to the lower
Kuskokwim Delta and a chance of precipitation to the Bristol Bay
area. A frontal system associated with an Aleutian low will push
into the southwestern coast Tuesday morning...producing wetter and
windier conditions along the Alaska Peninsula and western coast through
Tuesday afternoon.

Bering Sea/Aleutians...the strong North Pacific low south of
Shemya...currently producing strong east winds and snow/rain over
the western Aleutians will track over the western Aleutians
tomorrow morning. The low will then stall out and slowly dissipate
over the central Aleutians on Tuesday...which will bring clouds
and widespread precipitation to the entire region through middle
week. An associated strong front will move over the central
Aleutians this evening...bringing widespread rains and strong wind
gusts to the central Aleutians. The front will then quickly push
into the eastern Aleutians and pribilofs by Monday
morning...before diminishing considerably in intensity on Monday
evening as it tracks inland.

&&

Long term forecast...
while there has not been a large change in the long term
forecast...the models are beginning to struggle late this week
with the track of the next low through the Aleutians. The general
pattern of ridging over most of the Mainland and lows over the
Bering or North Pacific will remain mostly in tact...but the devil
still remains in the details. The models are struggling with how
far north into the Pacific that the Mainland ridge will allow an
Aleutian low to travel this weekend...so rain for the Gulf Coast
cannot be ruled out this weekend. It does still appear that the
interior southern Mainland will remain mostly clear and dry for
the next week.

&&

Afc watches/warnings/advisories...
public...none.
Marine...gale 119 120 131 132 155 170 172 173 174 175 176 177 178
351 411 412 413.
Fire weather...none.

&&

$$

Rmc Apr 14