Small Craft Advisory 151, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
543 PM AKST Sun Feb 16 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(Days 1 through 3: This afternoon through Wednesday evening)...

The forecast is on track this afternoon as the remnants of an
occluded front continue to spread precipitation across the
northern Gulf Coast and Prince William Sound. Its attendant
surface low is situated southeast of Kodiak Island this afternoon
and is also tracking slowly northwest toward the island. Some
precipitation appears to be making it over Chugach Range and Kenai
Mountains this afternoon according to the Kenai Radar as of 4 pm.
However, the lower to mid-levels remain somewhat drier due to the
cross-barrier flow. There is a chance some moisture could make it
to the ground this afternoon and evening across the Western Kenai
Peninsula, Anchorage, and Mat-Su Valleys. Due to a little bit of
a warm-nose aloft, precipitation could fall in the form of a very
light wintry mix of snow and freezing rain/sprinkles. Meanwhile,
Whittier and Portage have seen mostly rain today with temperatures
getting up into the middle and upper 30s. This will continue to
be mostly the case for precipitation-type for these locations
with continued easterly to east-southeasterly flow off of Prince
William Sound which will help to keep temperatures above freezing.

The southeasterly, cross-barrier flow then strengthens behind a
departing shortwave to the north, keeping conditions dry along
the lee of the Chugach and Kenai Mountains overnight tonight and
into Monday. For coastal locations, precipitation will continue,
but should be more showery in nature. Snow levels will continue to
rise, to around 1,600 ft for Monday.

Another frontal system lifts northward across the Gulf for
Tuesday. This will spread another round of precipitation from
Kodiak Island to the North Gulf Coast and Prince William Sound
through the day. More sea-level rain with snow in the mountains
can be expected with this system. Inland areas in the lee of the
mountains also look to remain on the drier side as well. The story
remains the same for Wednesday as east-southeast flow continues
off the Gulf and Prince William Sound which will keep upslope
precipitation going as well as downslope drying in the lee of the
mountain ranges.

-TM/DAN

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: Tonight through Wednesday)...

The cold and dry pattern over Southwest Alaska will begin to
conclude on Monday as a compact upper level low crossing the
Alaska Peninsula into the Eastern Bering tonight will kick off a
warming trend and bring a wave of precipitation to both the
Bristol Bay and Kuskokwim Delta regions. As the shortwave swings
across the Eastern Bering into the Y-K Delta region, rain will
taper off for the Alaska Peninsula while southeasterly flow will
bring upslope-driven snowfall to the higher elevations of Bristol
Bay. As the system progresses, a brief period of precipitation
from Dillingham to Platinum will begin as snow before a possible
transition to a snow/freezing rain mix through Monday morning as
warmer air aloft moves in from the southeast, though confidence on
precipitation type remains low at this time. By Monday afternoon,
snow and persistent northeasterly offshore winds will be
conducive for periods of blowing snow across the Kuskokwim Delta
coast, including Kipnuk, Kwigillingok, and Mekoryuk, reducing
visibility at times through Tuesday morning.

The remainder of the period will largely be characterized by a
steady stream of shortwave energy from the North Pacific, keeping
the weather pattern active across the Bering Sea and bringing
warmer temperatures across the Aleutians and Southwest Alaska. A
broad low pressure system is set to reach the southern shores of
the Aleutian Chain and AKPen Monday afternoon, bringing a chance
of light rain through the period to many of the Aleutian Islands,
with the heaviest rain expected to be focused along the Eastern
Aleutians and AKPen. As the low tracks northwestward across the
Aleutians and into the Bering Sea throughout the day on Wednesday,
Southwest Alaska is expected to remain dry and warmer with high
temperatures nearing 30 degrees and low temperatures in the low
20s for the Lower Kuskokwim Valley and Kuskokwim Delta.

-JH

&&

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

No significant change from the previous discussion... The broad
upper level troughing over southern and western part of the state
will persist. This coupled with the moderately strong high
pressure ridge along the state's southeast coastline and into the
central interior of the state will dominate the weather pattern
through the forecast period. Equal weight was given between the
GFS, European and Canadian models with the UKMET still being the
consistent outlier.

This pattern will allow for small, fast moving shortwave troughs
and associated surface fronts to quickly move across the Aleutian
Islands and coastal South Central regions. There is some
uncertainty about timing and intensity with these series of
troughs and lows. However, with a more southerly wind pattern,
temperatures will be unseasonably warm across much of the region
with higher precipitation amounts falling mainly as rain along the
northern Gulf coastline and through the Central Aleutians with
potentially heavy snow accumulations in the higher coastal
elevations.

-DD

&&

.AVIATION...

PANC...Light northerly winds and VFR conditions are expected to
persist, but there is a low chance (30%) for a brief period of
very light snow or wintry mix this evening as some precipitation
may spill over the Chugach Mountains.

&&