Friday, September17, 2021
Privacy Policy
L-36.com

Marine Weather and Tides
Attu Station, AK

Version 3.4
NOTICE
3/30/2021 -- ANZ330 has been split into ANZ331 and ANZ332. Click EDIT in Marine Forecast and select your new zone.
1/26/2021 -- The West Coast Satellite images havd been updated. They now use GEOS-17.
1/1/2021 -- The 7 day forecast are now working well. Thank you NOAA for your support.

Sunrise 6:08AMSunset 6:21PM Friday September 17, 2021 5:05 PM ChST (07:05 UTC) Moonrise 4:43PMMoonset 12:00AM Illumination 81% Phase: Waxing Gibbous; Moon at 11 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
    EDIT      (on/off)   Help
PKZ178 Kiska To Attu- 344 Pm Akdt Thu Sep 16 2021
.gale warning Friday and Friday night...
Tonight..Variable wind 10 kt becoming se 15 kt after midnight. Seas 7 ft.
Fri..E wind 30 kt becoming ne 40 kt in the afternoon. Seas 6 ft building to 12 ft in the afternoon. Rain.
Fri night..NE wind 45 kt. Seas 19 ft.
Sat..NW wind 35 kt. Seas 15 ft.
Sat night..NW wind 25 kt. Seas 10 ft.
Sun..SW wind 30 kt. Seas 7 ft.
Mon..SE wind 30 kt. Seas 21 ft.
Tue..NE wind 30 kt. Seas 21 ft.


7 Day Forecast for Marine Location Near Attu Station, AK
   Hourly   EDIT   Help
location: 52.84, 173.2     debug


Area Discussion for -
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXAK68 PAFC 170121 AFDAFC

Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 521 PM AKDT Thu Sep 16 2021

ANALYSIS AND UPPER LEVELS.

An elongated upper-level trough embedded with multiple lows continues to influence the domain. It is currently extending from the Bering/Aleutians to the eastern Gulf and continues to slide east. An upper-level low and associated surface trough are positioned south of Unalaska and supported by a 180 kt jet streak. Gale force winds are being reported on the back side of this system as pressure gradient tightens along the central Aleutians due to a building ridge to the west. Further east, radar is showing returns along the eastern side of Cook Inlet, Prince William Sound, and the Copper River Basin as a result from a southeasterly, upslope flow and shortwaves spinning off of another upper-level low southeast of Kodiak. A blanket of low stratus is extending from the Bering, Aleutians, and into the Gulf as the trough propagates east. Satellite is showing another area of clouds moving along the coast and lifting into in the interior as the associated occluding front moves towards Prince William Sound. Gale force winds are developing along and ahead of the front, with strong northeasterly winds also across the Barren Islands, southern Cook Inlet and through Shelikof Strait.

MODEL DISCUSSION.

Models continue to be in good agreement when keying in on impactful synoptic features. A forecast challenge will be how much clearing we will have over the weekend due to a ridge building over Southcentral in the wake of the current trough. The amount of clearing and timing of when/if calmer winds occur will heavily impact the temperatures as we could have our first potential outbreak of cold air for the season and a threat for sub-freezing temperatures at lower elevations over parts of Southcentral and the interior Southwest by Sunday morning. The more clearing we have and the calmer the winds, will result in cooler temperatures. Overall, forecast confidence is high for the short-term, and average moving into next week.

AVIATION.

PANC . Mainly VFR conditions and light north winds will persist. There may be a period or two of MVFR ceilings through the evening, but the overall trend through tomorrow should be for slowly improving conditions.

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

The gale force low continues to move east across the Gulf. Several shortwaves will rotate around the low and increase winds across the northern Gulf. The strongest shortwave will form a surface low this evening and produce storm force winds from between Cape Suckling and Hinchinbrook Island. This low will rotate south and east by Friday morning across the western Gulf with Gales expected off the east coast of the Kenai Peninsula and east of Kodiak Island. The occluded front associated with the low over the Gulf will slowly move north across the northern Gulf with moderate to heavy rain expected from Cordova to Prince William Sound. The rest of Southcentral remains under cloud cover due to this front, however very little rain is expected as downsloping will keep much of the areas west of the Chugach and Coastal Mountains dry. An occasional sprinkle or light rain shower is possible but accumulations will be very light. Some light rain will continue for the Susitna valley due to energy from the weakening low over the interior of Alaska. This rain should wind down later this evening.

Friday most areas north of the coast are expected to be dry with clouds slowly thinning out with a few sunny breaks possible by afternoon. This will be due to the low moving east across the Gulf and an Arctic trough moving into Western Alaska. However, rain will continue along the north Gulf coast and the Chugach Mountains may see some lingering light rain as the front weakens. Friday night and Saturday morning the Arctic shortwave will begin its trek across Southcentral this will usher in stronger northwesterly gap winds in the usual places. Expect Gales and possibly storm force winds across Kamishak Bay and the Barren Islands. Otherwise Seward and Whittier and adjacent marine areas will see north and westerly winds increase Saturday. This Arctic shortwave will move through the area by Saturday evening, which will usher in the coldest air of the season Sunday morning with low temperatures in the 30s in many locations and 20s possible especially across the Copper River Basin. Winds will also be gusty out of the Copper River Delta Saturday afternoon through early Sunday which may kick up some glacial silt. Otherwise winds will begin to decrease on Sunday as the pressure gradient weakens and cold air advection ends. Expect bright sunny skies Saturday afternoon and Sunday across much of the area as dry and cold air temporally takes up residence this weekend.

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Tonight through Sunday afternoon) .

Clearing skies and colder temperatures are forecast for the Southwest in the coming days. A shortwave moves through the area tonight through Friday afternoon. Light rain is possible with the passage of this shortwave, though it will mostly be limited to the Kuskokwim Delta coast and higher elevations. From Friday afternoon through Sunday afternoon, ridging overhead will bring partly cloudy to clear skies over much of the Southwest. Decreased cloud cover and the continued advection of cooler air will allow temperatures to drop near freezing Friday and Saturday night. While coastal areas will remain in the mid 30s to low 40s, inland areas in the Kuskokwim Valley will see temperatures in the upper 20s. A North Pacific low approaches on Sunday, leading to increasing cloud cover and rain chances over Bristol Bay. With the track of the low remaining to the south, the Kuskokwim Delta and Lower Kuskokwim Valley will continue to be dry and partly cloudy.

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3/Tonight through Sunday afternoon) .

Conditions remain cloudy and rainy throughout the Bering and Aleutians for the next several days. As a ridge moves across the Chain, gusty northerly winds persist through the Eastern Aleutians and AKPEN through Saturday afternoon. The strongest winds are expected over the AKPEN Friday evening as a shortwave moves overhead. In the Western and Central Aleutians, a low in the North Pacific brings gusty winds and areas of moderate to heavy rainfall Friday morning. The low occludes and weakens as it tracks along the Aleutian Chain through Sunday morning, moving south of the AKPEN afterwards.

MARINE (Days 3 through 5/Saturday through Monday).

Gulf of Alaska . An Aleutian Islands upper low on Sunday will progress eastward and into the Gulf by Monday. East to southeast winds gusting to gale force and seas of 10 to 15 ft will accompany the front's arrival to the Gulf Coast by Monday night. Enhanced north to northeast winds will follow in the wake of the low, first impacting the Aleutians Sunday into Monday, and then impacting the western Gulf Monday into Tuesday. Northwesterly offshore gales develop Monday night and Tuesday morning across the Barren Islands, with slightly weaker offshore northerly winds impacting the locations of Seward and Prince William Sound.

Bering/Aleutians . High pressure remains over the Northern Bering Sunday into early next week. Across the Southern Bering low pressure over the Aleutians on Sunday will progress eastward and into the Gulf of Alaska by Monday. East to northeast gales with local areas of storm force winds will exist on the backside of the low. These winds cross the Aleutians over the same time period and before the low exits the Aleutians to the east. As the pressure gradient changes and offshore flow develops, winds with gusts to gale force will exist offshore of the Kuskokwim Delta, Bristol Bay, and especially for the Eastern Aleutians and Alaska Peninsula, which are more susceptible to gap winds. Seas to 20 ft on the Pacific side of the Aleutians and Alaska Peninsula on Monday.

.LONG TERM FORECAST (Days 4 through 7/Monday through Thursday) .

The week begins with a highly amplified upper-level patten stretching from the Kamchatka Peninsula east to the Canadian Rockies. The main trough axis is expected to be positioned over the state, with a potent polar low centered over the North Slope and a second upper-level low at the base of the trough, over the central Gulf of Alaska. This feature will support a surface low in the western Gulf and front extending toward the northern Gulf with rain along the Southcentral coast.

A strong shortwave is forecast to eject from the polar low and dive south, phasing with the Gulf low by Tuesday morning. This is in conjunction with the polar jet also digging south and phasing with the subtropical jet. While guidance is all showing this solution, there is some uncertainty as to where (AKPen and western Gulf or farther east) this phasing may take place. The result, however, will be the potential for a surge of arctic air over the Southern Mainland overnight Monday through early Wednesday with very strong northerly and westerly gap winds along coastal locations as a surface ridge builds over the interior and a secondary surface low develops and rapidly deepens over the northern Gulf. 850 mb temperatures (~4,500 ft AGL) could drop as low as -5C to -10C across parts of interior Southwest and Southcentral by Tuesday, with any lingering precipitation behind the cold air advection turning to snow over the mountains. The 12z GFS and GEM are also hinting that enough cold air may work into the Copper River Basin by Tuesday that lingering rain could change to snow at lower elevations before ending. Clear and colder conditions then look to prevail mid-week as the trough moves east and an upper-level ridge builds.

Father west, the upper-level ridge over the Bering for the start of the week moves east toward the Mainland as another potential storm-force low moves from south of Attu east across Chain to a position south of the AKPen by Thursday. Expect northerly gap winds across the eastern Aleutians and AKPen Monday, tapering off Tuesday as the ridge crests overhead. Easterly gales and rain are then likely across the Chain from west to east Tuesday through early Thursday.

AFC WATCHES/WARNINGS/ADVISORIES. PUBLIC . Storm 119 130 Gale 120 131 132 138 139 150 155. MARINE . NONE. FIRE WEATHER . NONE.

SYNOPSIS AND MODEL DISCUSSION . TM SOUTHCENTRAL ALASKA . RC SOUTHWEST ALASKA/BERING SEA/ALEUTIANS . KC MARINE/LONG TERM . BL


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Shemya, Eareckson AFB, AK49 mi67 minWNW 67.00 miFair49°F45°F87%1025.4 hPa

Link to 5 minute data for PASY

Wind History from ASY (wind in knots)
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
Last 24hrNW21
G26
NW19
G25
NW18
G24
NW18NW14NW18NW17NW17
G21
NW11NW15NW12NW12NW11NW10W9NW11W7W8W9W9W9W8W8NW6
1 day ago------N21
G29
N20NW22
G27
NW16
G23
NW18NW19NW19
G23
NW17
G23
NW16NW18NW19
G23
NW22
G26
NW20
G29
NW21
G27
NW25
G32
W16NW24
G27
NW21
G28
NW23
G30
NW20
G28
NW25
G31
2 days ago--------E30
G39
E27
G38
E30
G36
E30
G40
E26
G33
E23
G29
E16E10E6S3S4S9SW3N16N22----------

Tide / Current Tables for
   EDIT   Weekend mode (on/off)   (on/off)   Help
Tide / Current Tables for
   EDIT      (on/off)   Help
Weather Map
       (on/off)   Help Weather Map
wmap_A
GEOS Local Image of    EDIT
NOTE: This section has been updated as of 1/26/2021. If the image you are expecting is not showing, please let me know. You may use the EDIT function to update your location.

Other links: GEOS-West     Contential US     Full GOES-East
Ground Weather Radar Station




Please read website Cookie, Privacy, and Disclamers by clicking HERE.