Monday, December11, 2017 L-36.com


Marine Weather and Tides
St. George, AK

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 10:02AMSunset 3:44PM Monday December 11, 2017 1:35 PM AKST (22:35 UTC) Moonrise 12:55AMMoonset 1:27PM Illumination 40% 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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7 Day Forecast for Marine Location Near St. George, AK
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location: 57.89, -167.17     debug


Area Discussion for -
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Fxak68 pafc 112133 cca
afdafc
southcentral and southwest alaska forecast discussion
national weather service anchorage ak
1230 pm akst Mon dec 11 2017
corrected typos

Analysis and upper levels
The persistent and deja vu-like pattern continues in the gulf as
yet another storm force low is making landfall early this morning
with another developing system quickly approaching on it heels.

Overnight observations confirmed the departing low as one of the
strongest to cross the gulf over the last week. Widespread storm
force winds with hurricane force gusts were apparent from the barren
islands eastward along the coast to cordova. While the front and
associated winds rain are beginning to diminish, the pressure
gradient along prince william sound and pressure rises behind the
front are increasing. This should allow for increasing gap winds
from turnagain arm eastward to the copper river this morning. Along
the western side of this low, areas of rain snow moved through
bristol bay overnight which are now spreading northward into the
kuskowim river valley delta as the low crosses the aleutian range.

Over the bering sea, a broad area of cold air advection and gale
force northerly winds are evident on satellite imagery from the
persistent northerly flow that has developed over the bering over
the last 2-3 days.

Model discussion
Little change has occurred in the overall model agreement, as they
all remain in great synoptic agreement through about 48 hours. They
then begin to break down with the placement of a gulf low beyond
that. The main challenge comes from what appears to be the last low
that will quickly move through the gulf from this pattern on
Wednesday. Model runs yesterday varied widely as it whether this
system would track towards kodiak (as many of the lows have as of
late) or much further east into the eastern gulf. Overnight runs
have all began to trend further west, towards the GFS and ec
solutions. These have been the most consistent with the more
westward track and this is the preferred track for this morning's
forecast updates.

Aviation
Panc... The primary concern today will be with the timing of se
winds that are expected to develop early this morning as pressure
rises setup through turnagain arm. As these winds begin to increase
there is a possibility of some llws as winds aloft also increase,
but should end as the strongest of the SE winds develop by mid
morning. At this point it still appears that wind gusts should
generally be around 35 kt, though there may be some peak gusts in
the 40-45 kt range, especially between 18-00z today. SE winds should
then diminish early this evening. Otherwise conditions will remain
vfr with persistent downsloping today.

Short term forecast southcentral alaska (days 1 and 2)
The active pattern continues across southcentral alaska. A storm
force low near kodiak island moves to over bristol bay and weakens
this morning. Its associated front will move rapidly north across
southcentral today. Warning level winds will linger on across
turnagain arm and portage valley until pressure gradients
sufficiently weaken by mid to late this morning. Although warning
level winds will diminish in these areas, strong isallobaric
pressure rises behind the front will give rise to gusty and
locally strong winds (mostly southerly) today. In particular,
along the copper river, cook inlet, kenai peninsula, and the
anchorage bowl and matanuska valley. Except for gusty winds along
turnagain arm and portage valley, winds will diminish over most
mainland areas this evening overnight. The next low to affect the
area on Tuesday will be much further to the west near the ak pen
as it tracks north. The front however will move north across the
gulf. These systems will be weaker than the last, but will bring
increased winds, increased precipitation changes (mainly coastal),
and continued mild temperatures.

.Short term forecast southwest alaska (days 1 and 2: Monday and
Tuesday)...

a strong area of low pressure has crossed the alaska peninsula
this morning and is now centered near king salmon. Associated
showers continue over much of the bristol bay area this morning. A
few isolated locations are still mixing with snow, but most areas
by now have turned to rain. The low center will continue tracking
northwestward across southwest alaska today, rapidly weakening as
it does so. Thus, the coverage of showers should continue to
diminish through the day. South to southeast winds will also
develop behind the low, which will continue warming the atmosphere
via downsloping and advection. Thus, the chances for frozen
precipitation will continue dropping as well. In fact, many areas
near the alaska range, where the downsloping will be strongest could
see temperatures topping out into the 40s today.

Precipitation associated with the next low in the set develops
across portions of southwest alaska as early as this evening. Much
of the heaviest precipitation will be from dillingham north and
west as the kuskokwim mountains help to upslope out more moisture.

Due to there being no opportunity for the atmosphere to cool
between now and then, rain will be by far the dominant
precipitation type in the lower elevations, with communities from
king salmon north and east hardly seeing any precipitation at all
due to continued downsloping with strong southeast winds. This
second low will track a bit further west than the first one,
crossing the alaska peninsula Tuesday morning where there is less
terrain interaction, then staying over the eastern bering after
that, tracking along the coast. On this track, nearly all of
southwest alaska will get into the warming southerly flow, with the
exception of the immediate coast. Thus, assuming the flow is
southerly enough, even bethel may mix with or change over to rain
for a time Tuesday afternoon and evening.

.Short term forecast bering sea aleutians (days 1 and 2: Monday
and Tuesday)...

strong northerly gale-force winds with embedded snow showers will
continue to be the rule for much of the bering. The northerly
winds will split the bering between lows tracking through
southwest alaska from the occasional fronts that invade the
western aleutians and bering, causing them to weaken, fall apart,
and retreat back into the north pacific. Such has been the
pattern for much of the past week. However, by Tuesday, the next
front moving into the western bering will have more success
tracking eastward. This is because the last low tracking up the
coast will cause the winds to turn more westerly behind it by
Wednesday, helping aid the progressing front to push eastward.

This will finally help to bring some changes to the weather,
involving colder air mass moving into the eastern bering and a
warmer air mass moving into the western bering by midweek.

Long term forecast (days 3 through 7)
An active pattern remains through the long range forecast as
multiple low pressure systems track to the southern mainland from
the gulf and bering. Tuesday night the persistent pattern
continues with amplified ridging over the southeast, however a
pattern shift begins to take place across the bering and
aleutians. A zonal subtropical jet begins to nose closer to the
aleutian chain sending a storm system northward which pushes a
front across the central aleutians and western bering on
Wednesday. A jet streak puts this storm into eastward motion along
the chain which works to break down the high amplitude ridge by
the end of the work week. There is high confidence for the
anticipated pattern change as all the models are showing these
trends. Only minor changes were made for the extended range
forecast Wednesday through Saturday night with an equally
weighted trend of the operational models and ensembles.

Afc watches warnings advisories
Public... High wind warning 101 125.

Marine... Gale 119 120 121 125 129 130 131 132 136 137 138 139 150
173 174 175 176 178 179 181 185.

Synopsis and model discussion... Dek
southcentral alaska... Rmc
southwest alaska bering sea aleutians... Jw
long term... Kh


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure

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Tide / Current Tables for
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Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
npac_satellite

GOES Local Image of Alaska    EDIT
Geos

Ground Weather Radar Station Bethel, AK
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Disclaimer:
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 L-36.com. 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 L-36.com 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.