914
FXAK68 PAFC 030534
AFDAFC
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
834 PM AKST Sun Mar 2 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through
3)...
A low pressure system moving through Southwest Alaska continues
to draw warm and gusty flow through the eastern gaps such as
Turnagain Arm. Warm temperatures have, and will continue to be,
the talk of the forecast for the next few days for interior
Southcentral. Areas such as Palmer and Homer reaching 50 degrees
this afternoon, a trend expected to continue through the early
portion of the workweek. Gusty southeasterly winds across the
western reaches of Anchorage to diminish tonight as the low over
Southwest shifts further north, and northerly flow sets in out of
the Mat- Su Valleys. Periods of clear skies for Anchorage, the
Western Kenai Peninsula, and the Copper River Basin to come and
go over the next few days, partially contributing towards the
warmer daytime temperatures.
Rain along the Prince William Sound coastline to continue tonight
and tomorrow, diminishing by Monday afternoon and evening. The
break in the coastal precipitation will be halted by yet another
north Pacific low moving north into the Gulf by Tuesday morning,
competing with a stout ridge that is developing over the AlCan
border. However, by Wednesday the northern Gulf coast will likely
be enveloped by a broad trough developing to the west. This will
keep the pattern active and reintroduce some colder air aloft.
Uncertainty is very high with the track of these systems and any
smaller embedded shortwaves as it tracks in from the west. This
would lead to another prolonged period of showers across the
Southcentral coastline, with gusty easterly winds possible again.
Given the difference in upper-level forcing and support,
confidence is low regarding the expected influence from this
upcoming system to areas such as Anchorage, western Kenai, and the
Mat-Su valleys, but given the flow pattern, it initially appears
to be favorable for more downsloping and dry weather.
-CL
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(Days 1 through 3: Sunday afternoon through Wednesday afternoon)...
Active weather continues as several storms move across the Bering
Sea/Aleutian Islands and Southwest Alaska through mid-week. Have
generally trended the forecast warmer, with greater detail for
winds and precipitation as forecast confidence increases. A Winter
Weather Advisory remains in effect for the Kuskokwim Delta coast
and Nunivak Island through midnight tonight. For marine areas,
gale and storm warnings are in effect as a strong low moves into
the Western Bering Sea tomorrow, with heavy freezing spray
warnings in effect for marine areas bordering the sea ice edge.
Although the weather will certainly be active, no additional
hazards are anticipated at this time.
Diving into the details... temperatures today warmed across
Southwest Alaska a bit more quickly than forecast. Snow changed
over to rain early this morning for the Lower Kuskokwim Valley,
and by early this afternoon for the Kuskokwim Delta from about
Bethel east. For the Kuskokwim Delta coast, conditions appear to
be playing out as forecast; the weather station at Mekoryuk is
recording visibilities of less than a mile, while webcams in
Newtok and Toksook Bay show visibilities of one-half mile or less
at times. The threat of blowing snow and reduced visibilities
should end by late this evening as winds weaken.
A couple other notes for Southwest Alaska: while it`s still
possible, the likelihood of freezing rain and ice accumulations
have diminished as forecast temperatures have trended warmer.
There`s still a slight chance for light ice accumulations, but
the expectation is that precipitation will be light to minimal in
the downsloped areas where the thermal profile favors freezing
rain. Speaking of precipitation, precipitation chances in our
forecast are likely leaning on the lower end of the envelope of
possibilities for tomorrow as a rather small low slides north
across the Alaska Peninsula and then along the Southwest Alaska
coastline. With model agreement improving, it seems there may be a
greater chance for precipitation for Kuskokwim Delta and Lower
Kuskokwim Valley than is currently in the forecast.
Shifting focus to the Bering Sea, Aleutian Islands, and a bit of
the Alaska Peninsula: in the near term, snow amounts may be a
little underdone as snow showers move across the Eastern
Aleutians and Alaska Peninsula. As such, these areas could pick up
just a bit more snow tonight into early tomorrow than is currently
in the forecast. By Tuesday, as a broad low begins to occlude in
the Bering Sea, forecast confidence decreases as surface low(s)
attempt to spin up and take advantage of the lingering vorticity.
Keep an eye on the forecast for Tuesday and Wednesday as the
finer details of the forecast may differ depending on which low(s)
dominate.
-Chen
&&
.LONG TERM FORECAST (Days 4 through 7 - Thursday through
Sunday)...
The high amplitude upper level ridge extending over Southeast
Alaska and Western Canada will continue to be pushed east as broad
upper troughing moves in from the Bering Sea and Western Alaska.
A generally unsettled pattered will kick off the long term period
with relatively good model agreement in the upper levels of the
atmosphere and more uncertain surface features locally enhancing
the weather. A surface low supported by Pacific moisture and
troughing aloft will bring a round of moderate precipitation to
Prince William Sound on Thursday before moving on towards the
Panhandle later in the week. Northerly flow on the backside of the
low will bring in colder air and could cause gusty winds through
bays and passes of the Eastern Aleutians and Alaska Peninsula.
Upper ridging will track across the Bering Sea Friday and
Saturday, quickly being followed by another low pressure system.
Drier conditions are expected for Southcentral to start the
weekend as high pressure moves over the state. The low following
the aforementioned ridge will likely bring widespread
precipitation and gusty southerly winds to the Aleutian Chain as
it marches eastward, but there is still uncertainty about the
low`s strength at this time. Most of Alaska will continue to see
warmer than normal temperatures for the next week, with cooler
temperatures possible by the weekend as northerly flow comes in
behind the trough.
&&
.AVIATION...
PANC...VFR conditions will persist throughout the TAF period.
Turnagain Arm winds bending into the terminal are expected to
diminish by 04Z this evening. As winds at the surface decrease and
shift northerly, southeasterly winds may continue to be stronger
above the surface to about 2000 feet at 35 kts. Thus, low level
wind shear may be possible during the initial transition of
surface winds for a few hours tonight. The threat of low level
wind shear should be gone by 09Z.
rux
&&
$$
915
FXAK69 PAFG 030917
AFDAFG
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
1217 AM AKST Mon Mar 3 2025
.SYNOPSIS...
Rounds of snowfall mixed with rain will impact the West Coast and
Western Interior through Wednesday. South flow across the AK
Range will keep it on the warmer side for the Interior. East winds
ramp up over the E Arctic Coast through the week with blowing
snow possible near Kaktovik.
&&
.DISCUSSION...
Upper Levels and Analysis...
There is a large negative tilt upper ridge axis stretching from
the West Coast of the US Mainland all the way into the Interior of
Alaska. There is a deep trough from E Siberia all the way down
through Bristol Bay and into the NPAC. There is a stationary
arctic front extending from Bristol Bay to Point Lay. Blizzard
conditions over the YK Delta are winding down this morning.
Forecast Analysis and Discussion...
The first frontal wave will clear out of the West Coast later this
morning and lift into the Chukchi. A second frontal wave will
bring another round of snow and some mixed rain to the SW Interior
and West Coast tonight through Tue night. A stronger 975 mb low
moves into the N Bering Sea on Wed morning and will bring more
snow and strong gales to the Bering Strait, with blizzard
conditions expected at Saint Lawrence Island to the Bering Strait
coast. South flow will wax and wave over the Interior with warmer
temps persisting as daytime highs are +15 F above norms.
Central and Eastern Interior...
South winds through the AK Range blow to 50 mph through midday
today then wane slowly. East winds over the Tanana Valley will
remain 15 to 30 mph into Wednesday then increase to 35 to 35 mph
Wed. Temps remain 15+ degrees above seasonal norms over the
Interior.
West Coast and Western Interior...
Periods of snow will persist through Wednesday along the coast, as
fronts move up from the south. Mixed rainfall or all rain will
persist over the Yukon Valley. Blizzard conditions are over for
the YK Delta coast, but there will be rounds of snow for that
area into midweek. More east winds increase Wed with strong
northeast winds gusting to 60 mph for the Bering coast and Saint
Lawrence Island Wednesday, with blizzard conditions expected from
Saint Lawrence to Teller.
North Slope and Brooks Range...
East winds increase to 25 to 30 mph along the coast today then
weaken a bit as the main front shifts offshore tomorrow. Minor
blowing snow is expected. Gale force east winds develop over the
E Arctic Wednesday with possible significant blowing snow for
Kaktovik.
Extended Forecast Days 4-7...
A front over the Gulf of AK shifts north across the AK Range Thu
and will bring minor chances for snow and mixed rain to the
Interior Thu and Fri. Temps fall a bit as the south winds decrease
across the AK Range, but temps will remain a tad above seasonal
norms. A brief period of drying for the Mainland looks likely Sun
into Mon with a front moving back into the N Bering Sea for Sun
and Mon.
Coastal Hazard Potential Days 3 and 4...None.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Advisory for AKZ849.
Blizzard Warning for AKZ820-821-827.
Winter Weather Advisory for AKZ822-823.
PK...Brisk Wind Advisory for PKZ801-802.
Brisk Wind Advisory for PKZ805-813-858.
Brisk Wind Advisory for PKZ806-816-817-850-853-854-856.
Brisk Wind Advisory for PKZ807.
Brisk Wind Advisory for PKZ812.
Brisk Wind Advisory for PKZ814.
Brisk Wind Advisory for PKZ815.
Brisk Wind Advisory for PKZ851.
Brisk Wind Advisory for PKZ859.
Brisk Wind Advisory for PKZ860-861.
&&
$$
Ahsenmacher
512
FXAK67 PAJK 022228
AFDAJK
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
128 PM AKST Sun Mar 2 2025
.SHORT TERM...While the same cannot be said about aviation,
lighter winds, low clouds, and possibly the occasional drizzle
will lead to a relatively non impactful end of the week. A weak,
shortwave ridge strengthening slightly into Monday will ensure
winds remain weak overnight with nothing to push out clouds
already in place. With the slightly strengthening ridge on Monday,
however, will promote a drying trend. This will be further
encouraged by dry air being advected aloft over from Canada. The
result will be some clearing of clouds, particularly in the far
inner channels: Juneau, Petersburg, Wrangell, Haines, Skagway, and
possibly Ketchikan and Kake. Towards Monday night, precipitation
chances begin to increase from south to north from a weak front
attempting to push into the panhandle. For more information, see
the long term section.
.LONG TERM..Tuesday a negatively tilted trough will be lifting
into the gulf with an associated gale force surface low,
increasing E-SE winds and seas for coastal zones, along with
allowing cool north/easterly winds to develop in Lynn Canal and
Taku. Any deep moisture downstream of the axis will be sheared
apart as this system weakens in the western gulf, so not expecting
much in terms of precip Tuesday except light showers. Upstream of
this feature a broad longwave trough will slide along the
Aleutian Arc through the remainder of the week, steering warm-
moist air back into the Panhandle by Wednesday. Current forecast
falls in line with weak AR conditions with 1 to maybe 2.5 inches
of precipitation in 24 hours by Thursday.
The biggest question this week is how northerly winds in the
inner channels can prime the northern Panhandle for snow Wednesday
into Thursday. EFIs are starting to highlight both QPF/snow for
northern Lynn Canal, with Haines and Skagway the most likely to
hold on to cold surface temperatures as warm moist air slides over
(looking at you Klukwan west to the border). Something to watch
but low confidence; biased corrected guidance still has
temperatures/dewpoints suggesting rain. By the end of the weekend
colder air arrives aloft, with a pattern more conducive to
snowfall for the northern Panhandle.
Looking at long term and marine impacts, expecting 2 rounds of
storms in the gulf: the first one Tuesday and the second one
Wednesday into Friday. Current pressure guidance suggests the
first storm is more of a Kayak Island to Kenai Peninsula problem
with 30 knots of easterly wind. The second storm has a lot of
uncertainty in part to ensemble guidance struggles with placement
of a secondary surface low. For now late Wednesday, expect
easterly severe gales along Cape Suckling, with southeasterly gale
force for most coastal zones, these winds persist into Thursday.
For inner channels biggest threat is Chatham and Sumner from these
southerly winds. Expect southwest swell to continue through the
week around 9 to 12ft. Wednesday into Thursday we will see fresh
seas associated with the southerly gale force winds, likely
reaching 13 to 15ft south and west of Cape Suckling. As the
secondary low makes landfall Friday, there is a possibility of 16
to 20ft seas along the Chichagof/Baranof Coast and Prince of
Wales, potentially making it as far north as Cross Sound. There is
a lot of uncertainty with this low; something to watch.
&&
.AVIATION...A low stratus deck has persisted across parts of the
area through Sunday, keeping IFR conditions in force across much
of the panhandle. Although some areas have seen improvement to
MVFR or VFR conditions, anticipate that fog will redevelop Sunday
evening and last through Monday morning across much of the area,
resulting in low visibilities and LIFR conditions at times for
some locations. Beyond Monday morning, conditions should improve
substantially as daytime heating removes much of the low lying
stratus deck and fog.
&&
.MARINE...Lighter winds are the main story for the next 36 hours
as an aloft ridge promotes a surface high over the panhandle.
Small craft conditions remain in the gulf waters due to impressive
swell from the SW, however, these conditions will be diminishing
overnight. Fortunately or unfortunately, these conditions will be
short lived as the SW swell looks to resurges on Monday from a
weakening low out in the central gulf. Fresh to strong breezes
look to move in to the gulf waters as the associated front moves
in from the southwest. Seas however look to increase up to 10 ft
from the aforementioned SW swell. Areas of interest with this type
of swell are Cross Sound and near Cape Decision, as NE winds out
from Chatham Strait and Icy Strait opposing SW swell may drive
wave heights higher than currently expected
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ022-053-641>644-651-652-661>664-671-
672.
&&
$$
SHORT TERM...NC
LONG TERM....AP
AVIATION...GFS
MARINE...NC
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