480
FXAK68 PAFC 110029
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
429 PM AKDT Mon Jun 10 2024

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

A large upper level low and associated surface low south of
Kodiak Island continues to bring scattered rain showers along the
Southcentral coast amidst southeasterly flow. Gusty southeasterly
gap winds will slowly diminish through early tonight, with the
Turnagain Arm wind to make a return during the afternoon tomorrow.

Multiple easterly shortwaves will rotate between weak riding over
mainland Alaska and around this upper low over the next few days
with considerable uncertainty on their strength and especially
timing. Regardless, precipitation chances increase for the Copper
River Basin later tonight through tomorrow morning, then spreading
west into the Susitna Valley Tuesday afternoon and evening. Rain
showers may also develop near the foothills of the western Kenai
mountains and the western Chugach mountains. At the same, steady
rainfall will also shut off for the Gulf coast, Kodiak Island, and
Prince William Sound.

Model guidance then diverges even more considerably in the
strength and timing of another easterly wave exiting out of the
southern Yukon Wednesday morning. Should this feature be stronger
and track over Southcentral, more widespread precipitation is
possible again during the day Wednesday for many of the same areas
as Tuesday through the Copper River Basin, Anchorage, and MatSu.
Regardless, at the very least with a weaker shortwave solution,
Wednesday is likely to remain unsettled with widespread cloud
cover and scattered rain showers across the aforementioned areas.

With widespread cloud cover and precipitation, high temperatures
on Tuesday and Wednesday for Southcentral will remain on the
relatively cooler side, in the mid 50s to near 60.

-ME

&&


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

Southwest Alaska remains on the northern periphery of a broad low
to the south of the Alaska Peninsula. An enhanced pressure
gradient has been promoting easterly winds gusting between 25 to
35 mph across much of the Greater Bristol Bay area, with King
Salmon feeling some of the higher winds. Despite some earlier
showers, breaks in cloud cover have allowed temperatures to warm
into the upper 50s/mid 60s. Sleetmute could feasibly reach 70
degrees in the next few hours though it will be close.

Tonight into tomorrow low pressure south of the Alaska Peninsula
will begin to shift eastward with the pressure gradient across
Bristol Bay finally relaxing. Models have keyed in on an easterly
wave or two moving into the Western Alaska Range and Greater Bay
regions over the second half of the day on Tuesday. Despite
somewhat cooler temperatures in the mid to upper 50s, daytime
heating should allow for the development of at least weak
instability, especially nudged up against the Western Alaska Range
(fire weather zone 162). Thus, wet thunderstorm chances will be non-
zero Tuesday afternoon and evening. The Kuskokwim Delta will
remain west and north of the shower activity, staying mostly dry
with high temperatures in the mid 60s.

Across the Bering, northerly surface winds below 20 knots will
prevail through Tuesday evening. Some gap winds through the
Eastern Aleutians and Alaska Peninsula could result in gusts to 25
knots. High pressure will begin working its way into the western
Bering Tuesday, overspreading the rest of the Bering by Wednesday
morning. A North Pacific low and its attendant front will bring
showery conditions and small craft winds to the Western Aleutians
on Wednesday,

BL

&&
.LONG TERM FORECAST (Days 4 through 7) Friday through Monday...

High pressure looks to continue for the interior of the state
while much of the Bering Sea, North Pacific, and Gulf of Alaska
will remain under the influence of low pressure. This pattern will
continue to promote dry and warm weather inland with cool and
showery conditions for the Gulf coast, Aleutian Chain, and Alaska
Peninsula. There are still some questions in how each of these
pressure cells orients themselves throughout the long-term. No one
period looks to be a washout, rather there can be transient
periods of drier weather between shortwaves moving through the
flow along the Gulf and Aleutian Chain. While there is very
general agreement with the synoptic pattern, there are plenty of
disagreements with placement and track of mesoscale shortwaves
embedded within the synoptic flow.

&&

.AVIATION...

PANC...Gusty southeast winds out of Turnagain Arm are expected
again. While the wind will abate some overnight and through
tomorrow, expect south-to-southeast winds throughout much, if not
all, of the TAF period. CIGs will remain VFR throughout the TAF
period, with some general lowering if showers develop in the
vicinity on Tuesday.

-MJB

&&
$$