601
FXAK68 PAFC 100106
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
506 PM AKDT Sun Jun 9 2024

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

The broad longwave trough over the western Gulf of Alaska
continues to linger and send waves of precipitation over the
gulf coastline due to persistent southeasterly flow. A Flood
Watch is still in effect for Kodiak Island through late tonight,
with precipitation rates decreasing as the evening goes on. Gap
winds for the Turnagain Arm and Knik River Valley are still
ongoing, but should start to dwindle down by tomorrow morning.

By late afternoon on Monday, the alignment of the longwave trough
will result in the flow both out of the surface and aloft to shift
to more of an easterly direction. In addition, weak ridging over
the interior will help support the movement of multiple easterly
waves of showers over Southcentral through the remainder of the
forecast period. This pattern shift will also result in more
widespread cloud cover, causing high temperatures for most
locations to drop below 60 on Tuesday and Wednesday.

The trough over the gulf will slowly move southward towards the
North Pacific by Wednesday afternoon and slowly weaken as it does
so. As a result, precipitation chances over the Gulf coast will
slowly diminish over time, with higher chances occurring over
mainland Southcentral and persisting into the latter portions of
the week.

-BS

&&


SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA AND THE
ALEUTIANS (Days 1 through 3)...

Areas of persistent cloud cover and shower activity knocked high
temperatures down several degrees across Southwest Alaska on
Sunday. Expected highs well into the 60s only managed to warm into
the mid/upper 50s for many areas. A broad but strong area of low
pressure remains southeast of the Alaska Peninsula, and has
maintained a tightened pressure gradient over the Greater Bristol
Bay region. This has promoted elevated winds and showery
conditions through much of the day across Southwest Alaska.
Easterly winds gusting anywhere from 25 to as high as 45 mph have
been observed from Iliamna to King Salmon to Dillingham. These
winds will gradually diminish tonight, but are expected to briefly
redevelop Monday afternoon to a lesser extent as the pressure
gradient finally relaxes Monday night.


Though mostly stationary, the low southeast of the Alaska
Peninsula begins to weaken ever so slightly the next couple of
days. Monday should see slightly warmer temperatures across
Southwest Alaska, mainly due to less cloud cover and shower
activity. Precipitation chances and slightly cooler temperatures
return on Tuesday with the arrival of an easterly wave out of
interior Alaska. While models are not in good agreement with
placement of the wave nor placement of precipitation, rain looks
most likely to occur at this time across the Lower Kuskokwim
Valley and Greater Bristol Bay regions. Additional easterly waves
will be possible into Wednesday along with subsequent shower
activity as low pressure southeast of the Alaska Peninsula finally
shifts eastward into the southern Gulf of Alaska.

Lastly, weak northerly flow is forecast to prevail over the
Bering Monday into Tuesday. High pressure begins to slide into the
Bering from the west on Wednesday with drier conditions forecast.

-BL

&&

.LONG TERM FORECAST (Days 4 through 7) Thursday through Sunday...

The Arctic upper level high continues to build over Mainland
Alaska and ridges into the Bering through the forecast period. A
portion of a North Pacific ridge extends towards the Alaska
Peninsula, and looks to merge with the Mainland ridge through the
period. In the Gulf of Alaska/North Pacific, the closed low
weakens and slips into the Canadian coastal waters for Sunday. Out
West, a Chukotsk upper low swings into the Russian Arctic, but a
North Pacific low moves over the Aleutians to fill in. Several
shortwave troughs rotate throughout the pattern through the
weekend. The Interior ridge should warm and dry much of the
Central portions of the state. Showers are expected along the
North Gulf Coast for the last parts of the workweek. Most of the
Aleutians and Bering should see periods of light rain through the
weekend. The model ensemble means hold good confidence through the
first half of the forecast, but become diffuse towards the ends
as models move into different strengths and tracks.


- Kutz

&&

.AVIATION...

PANC...Strong southeast winds out of the Turnagain Arm are likely
to continue through the evening before abating overnight.
Otherwise VFR conditions prevail.

&&


$$