Friday, August23, 2019

Marine Weather and Tides
Attu Station, AK

Version 3.4
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
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Sunrise 6:07AMSunset 6:38PM Saturday August 24, 2019 12:07 AM ChST (14:07 UTC) Moonrise 10:09PMMoonset 1:20PM Illumination 45% Phase: Third Quarter Moon; Moon at 23 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
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PKZ178 Kiska To Attu- 400 Am Akdt Fri Aug 23 2019
Today..N wind 15 kt. Seas 5 ft.
Tonight..Variable wind 10 kt. Seas 4 ft. Patchy fog.
Sat..Variable wind 10 kt. Seas 3 ft. Patchy fog.
Sat night..Variable wind 10 kt. Seas 3 ft.
Sun..S wind 15 kt. Seas 3 ft.
Mon..SE wind 20 kt. Seas 8 ft.
Tue..SE wind 15 kt. Seas 8 ft.

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

Area Discussion for -
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Fxak68 pafc 231300
southcentral and southwest alaska forecast discussion
national weather service anchorage ak
500 am akdt Fri aug 23 2019

Analysis and upper levels
Two unphased upper level waves are moving east out of the area and
into canada and the panhandle. The gulf low is moving into the
panhandle, and a shortwave trough is moving across the northern
copper river basin. The trough over the northern copper river
basin will dig southwestward today, and will be the catalyst for
any shower activity over southcentral this afternoon and evening.

A separate upper level wave is moving south off the kuskokwim
delta coast. Between all of these features is the axis of a broad
upper level trough that is over all of southern mainland alaska.

Ridging over kamchatka is producing northerly winds between the
trough and the ridge over much of the bering. The north pacific
jet remains aligned essentially straight west to east across the
waters of the north pacific south of the aleutians and the gulf.

Very little precipitation is being picked up on any of the radars
this morning. Other than a few isolated showers over the aleutian
range south and east of king salmon, all of the rest of southwest
and southcentral are dry this morning. All of yesterday
afternoon's mainland soundings show a very unstable atmosphere
from the surface through 700 mb. This is helping mix any wildfire
smoke through a big enough layer of atmosphere that the only dense
smoke is in the area near the fires.

Model discussion
In a change from yesterday, all of the models, including the gfs,
now agree that the upper level wave off the kuskokwim delta coast
will in fact become a cut-off upper level low over the eastern
aleutians by Saturday evening. The canadian is the fastest with
moving the low into the gulf and reopening it into a trough as it
does so. The other models keep the cutoff low near southern kodiak
island into Sunday.

Forecast challenges center around where the wildfire smoke moves
and how dense it will get over the coming days. The wind speeds
through the fires as the winds turn northerly may pose a challenge
as well. The amount of shower activity this afternoon, if any, is
also a point of low-certainty, namely regarding if anything
measurable is seen outside of the mountains. Forecast confidence
is a bit above average, with good large-scale model agreement and
decent agreement on the aforementioned smaller scale forecast

Panc... MVFR smoke is expected to persist around the airport
through the early morning, as south to southwest winds transport
swan lake fire smoke into the area. By late morning, however, the
winds through the low to mid-levels of the atmosphere will flip
around to north to northwest. This should improve visibilities
back toVFR. Haze from the much smaller fires in the susitna
valley is not out of the question, but will not have any impacts.

The northerly low-level winds will persist through the overnight
and into Saturday. Scattered mountain showers will be possible in
the afternoon and evening along the chugach, but are not expected
at the airport, and were not included in the taf.

Fire weather (southcentral)
Winds will remain the primary influence on the fires across
southcentral today. Temperatures and relative humidity values
should be somewhat better than previous days, namely cooler
temperatures, more cloud cover, and higher relative humidity
levels. The winds will turn out of the north today as a dry cold
front moves through.

It cannot be overstated that this upcoming wind shift will be
nowhere near as strong and impactful as last week's wind storm.

The strongest winds of up to 25 mph are only expected to impact
the mountain gap areas in the western susitna valley, and out of
the gaps that open to the gulf, such as resurrection bay and
western prince william sound. Over the area wildfires, winds will
be in the 10 to at most 15 mph range at any time today into

Another factor to consider will be precipitation chances over the
coming days. With today's wind shift along with daytime heating,
isolated showers are possible in the valleys this afternoon and
evening, with scattered showers in the mountains. Isolated
mountain showers are possible Saturday, then on Sunday will be
another somewhat better chance of showers as an upper level wave
moves across the area. Any of these showers have the potential to
locally change wind directions in any rain-cooled air, and
hopefully some move over the fires.

.Short term forecast southcentral alaska (days 1 through 3 today
through Sunday night)...

as a moderate strength low over the central gulf exits toward
southeast alaska today, a broad and weak trough will drop down
from the north. Multiple short-waves will cross the region
through Saturday, triggering some isolated to scattered diurnal
convection primarily over the mountains. Valleys will see a few
showers, but they will be few and far between and any rain that
falls will be brief and light. Thus, dry conditions will persist
across most of the region.

As for the wind forecast, the combination of the exiting gulf low
and arrival of the short-wave will lead to periods of gusty winds
along the gulf coast and prince william sound. This includes
seward resurrection bay, whittier passage canal, and the valdez
coastal waters. Southerly flow overnight has brought smoke from
the swan lake fire and low visibilities to anchorage. As the upper
trough drops down today, low level flow will shift to
northwesterly and smoke from the fire will track south and east
across the interior kenai peninsula and down to seward and the
gulf coast. A dense smoke advisory remains in effect for the
interior kenai peninsula through early this afternoon. Assuming
there is no change in amount of smoke being generated by the fire,
this will likely need to be extended in time and area - to
include moose pass down to seward.

Gusty northerly winds will develop behind the first short-wave
today, primarily along the alaska range. There will be a slight
increase in winds across much of the susitna valley this evening
through Saturday morning. However, this is not like last
weekend's wind event; forcing is much, much weaker and winds will
generally be in the 10 to 15 mph range with localized stronger
gusts. Winds will lighten up across southcentral by Saturday

There is high uncertainty in the forecast for Sunday. Models are
struggling with track of an upper level low moving in from the
bering sea and whether this will impact southcentral or be
confined to the gulf of alaska. Based on latest model trends have
increased clouds for Sunday and included a broad-brush chance of

Short term forecast southwest alaska (days 1 through 3)
A shortwave trough will dive southward through the eastern bering,
and as its axis traverses the southwest mainland, showers are
possible. In general, convective indices look weak but a
thunderstorm or three can't be ruled out over the mountains. With
decent northeast steering flow, it's possible a stray thunderstorm
could make it into lower lying areas of bristol bay. Smoke will
continue to be evident in port alsworth and levelock, and probably
everywhere in between. The trough should bring some improvement.

Whether the improvement is short-lived will depend on fire
activity. In any case, quiet weather will return Saturday, with a
cooling trend over the next few days as cold air advection
persists behind the trough.

Short term forecast bering sea aleutians (days 1 through 3)
Mostly benign conditions are forecast over the bering as broad
north flow persists over the next few days. Patchy fog is likely
as cold air passes over warmer water. Of note, stronger north
winds are expected out of bays and gaps in the eastern aleutians.

Marine (days 3 through 5: Sunday through Tuesday)
Westerly flow will persist across the gulf through the long term
period. There is increasing confidence that a low will develop
south of the alaska peninsula Sunday and track eastward into the
gulf of alaska Monday with small craft winds likely. A second,
potentially stronger low forms in the north pacific and tracks
northward into the gulf late Tuesday. Currently, there is low
confidence in the track and strength of this second low. Meanwhile
in the bering, a ridge of high pressure remains in place through
Tuesday ahead of an incoming low entering the western bering by

.Long term forecast (days 4 through 7: Monday through

the general long-term pattern consists of an upper level longwave
trough draped over the state with an upper level ridge building
over the bering. An unsettled weather pattern is expected for
the southern mainland with cloudy skies and showery conditions
in store for early next week. A new feature of note is a north
pacific low that approaches the gulf of alaska as early as
Tuesday, though model solutions disagree on the position and track
of this low through the end of the week. One main steering factor
for the low's track will be a ridge building over the alcan
border Thursday.

Afc watches warnings advisories
Public... Dense smoke advisory: 121.

Flood advisory: 121 125.

Marine... Gale warning: 352.

Fire weather... None.

Synopsis and model discussion... Jpw
southcentral alaska... Seb
southwest alaska bering sea aleutians... Mm
marine long term... Ko

Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Shemya, Eareckson AFB, AK49 mi2.2 hrsNNE 77.00 miOvercast49°F43°F82%1019.6 hPa

Link to 5 minute data for PASY

Wind History from ASY (wind in knots)
Last 24hrNE16NE17NE17NE17NE18NE15NE14NE15NE15NE14NE15NE15NE18------N12N10N11--N11N8NE7N7
1 day ago--NE20NE19NE18NE19NE18
2 days ago--NE23

Tide / Current Tables for
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Weather Map and Satellite Images
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NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for (10,2,3,4)
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Ground Weather Radar Station Anderson AFB, Guam
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The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.