Wednesday, December13, 2017 L-36.com


Marine Weather and Tides
Grand Marais, MN

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 8:39AMSunset 5:04PM Wednesday December 13, 2017 5:55 AM EST (10:55 UTC) Moonrise 3:47AMMoonset 3:03PM Illumination 25% Phase: Waning Crescent; Moon at 25 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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LSZ162 Lake Superior West Of A Line From Saxon Harbor Wi To Grand Portage Mn Beyond 5nm- 949 Pm Est Tue Dec 12 2017 /849 Pm Cst Tue Dec 12 2017/
Rest of tonight..South winds 5 to 15 knots becoming southeast 10 to 20 knots late. A chance of snow showers late in the evening, then snow showers likely after midnight. Waves calm to 2 feet building to 1 to 3 feet.
Wednesday..East winds 10 to 20 knots becoming northeast 15 to 25 knots by mid afternoon. Snow showers. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet.
Wednesday night..Northeast winds 15 to 25 knots becoming north 10 to 20 knots by midnight, then diminishing to 5 to 15 knots late. A chance of snow showers. Waves subsiding to 1 to 3 feet.
Thursday..Northwest winds 5 to 15 knots. A slight chance of snow showers. Waves subsiding to calm to 2 feet.
Thursday night..Northwest winds 5 to 15 knots increasing to 10 to 20 knots after midnight. A chance of snow showers. Waves building to 1 to 3 feet.
Friday..Northwest winds 10 to 20 knots diminishing to 5 to 15 knots in the afternoon. A chance of snow showers. Waves subsiding to calm to 2 feet.
Friday night..North winds 5 to 15 knots veering east after midnight. A chance of snow showers. Waves calm to 2 feet.
Saturday..South winds 5 to 15 knots. A chance of snow showers. Waves calm to 2 feet.
Sunday..West winds 5 to 15 knots becoming southwest 10 to 20 knots. Waves building to 3 to 5 feet occasionally to 7 feet.
LSZ162 Expires:201712131100;;807569 FZUS63 KMQT 130249 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 949 PM EST Tue Dec 12 2017 For waters beyond five nautical miles of shore on Lake Superior Waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum. .SYNOPSIS...A low pressure system of 29.5 inches over eastern North Dakota will move to southern Lake Michigan on Wednesday. A weak low pressure system of 30.0 inches will then form near Lake Superior Thursday and will strengthen on Friday as it moves over Lake Huron to 29.6 inches by the evening. Weak ridging of 30.2 inches Saturday will give way to another trough on Sunday. LSZ162-131100-

7 Day Forecast for Marine Location Near Grand Marais city, MN
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location: 47.86, -89.87     debug


Area Discussion for - Duluth, MN
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Fxus63 kdlh 130920
afddlh
area forecast discussion
national weather service duluth mn
320 am cst Wed dec 13 2017

Short term (today through Thursday)
issued at 320 am cst Wed dec 13 2017
the main forecast challenge for the short-term period is the snow
and wintry mixed precipitation today.

A complex forecast early this morning with several shortwave
troughs expected to move through the northland today and tonight.

Several periods of wintry mixed precipitation and light snow are
expected. The first shortwave and its fast-moving and strong
clipper system was centered over west-central minnesota early this
morning and is forecast to quickly advance to near milwaukee by
noon today. Strong fgen forcing and height falls with the
shortwave trough have produced a band of light to moderate
precipitation from near fargo to remer, mn to siren, wi as of 215
am. Forecast soundings indicate a warm dry layer wrapping into
the low which has supported a wintry mix of rain, freezing rain,
and sleet over northwest minnesota into portions of central and
north- central minnesota over the past few hours. The wintry
precipitation should continue for the next several hours and may
begin to taper off by 8 am. Light snow continued over the
minnesota arrowhead and is forecast to slide southeastward this
morning into northwest wisconsin. With surface and low-level winds
out of the east or southeast over lake superior, some orographic
and lake enhanced snow is expected along the north shore and
interior portions of the arrowhead. The snow will likely pivot
toward the twin PORTS later this morning and eventually over
northwest wisconsin by late morning and early afternoon.

Another shortwave trough and vort MAX will dive south out of
manitoba this morning resulting in a second round of snow for much
of the northland late this morning through this afternoon. It's
possible there won't be a complete break in the precipitation
between the two shortwaves. The wintry precipitation over portions
of central and east-central minnesota into northwest wisconsin
may make roads slippery this morning and result in a slower
commute. Snow accumulation in the arrowhead and northwest
wisconsin of 2 to 6 inches is expected today, with lower totals
farther west. Have decided to extend the winter weather advisory
to include cass, crow wing, aitkin, pine, and burnett counties
where the greatest potential for ice accumulation is located. May
need to extend the advisory into bayfield, ashland, and iron
counties for the snow this afternoon. Still have a few hours to
make that decision now that the earlier threat is covered.

Thursday is shaping up drier with light lake effect snow over the
northwest wisconsin snowbelt and a few snow showers or flurries
in minnesota. Snow accumulation should be light, less than one-
half inch.

Long term (Thursday night through Tuesday)
issued at 320 am cst Wed dec 13 2017
an upper level trof will drop through the forecast area Thursday
night. It's surface low will remain nearly stationary over eastern
lake superior. Winds will be west northwesterly with weak cold
air advection behind the trof. Some light snow will accompany the
trof passage with snow fall amounts less than one inch. As this
upper trof departs, a second trof follows behind, but its track is
farther east and associated with a closed upper low moving
through northwest ontario. At the surface, a weak surface trof
overlays northwest wisconsin and the wind remains west northwest
over lake superior. This affects the lake effect snow potential.

There are model differences with wind direction over lake superior
and will stick with the aforementioned direction, which affects
pops along the gogebic range, into north central wisconsin. Have
low chance pops as a result with little snow amounts. Model
differences become larger Friday night as the NAM features high
pressure, the GFS with a baggy low dropping into western minnesota
late, and the ECMWF with high pressure over the north, and low
pressure in eastern south dakota by 12z Saturday. This is due to a
transition to a more progressive flow aloft and associated pieces
of embedded energy. Higher pops on Saturday leaning more toward
the gfs. Saturday night finds a positively tilted upper trof
moving through the northern plains toward the western great lakes.

Followed the GFS here as well with chance pops over the eastern
edge of the forecast area. Will follow the GFS Sunday night
through Tuesday as the model differences remain quite large, and
to keep a bit of consistency.

Aviation (for the 06z tafs through 06z Wednesday night)
issued at 1143 pm cst Tue dec 12 2017
surface low pressure was located along the minnesota, north
dakota, and manitoba border as of late evening. The low will dive
south into southeast minnesota by 12z then continue to pull away
from the region on Wednesday. An area of snow with the possibility
of freezing rain or freezing drizzle was moving through northwest
minnesota toward the northland. Ceilings will be ifr or MVFR
tonight with reduced visibilities developing in snow or mixed
precipitation. As the low pulls away on Wednesday, the
precipitation will diminish and ceilings will increase to MVFR or
lowVFR for most areas. The wind will back around to northerly
through the day Wednesday and be gusty in west southwest areas
including kbrd.

Preliminary point temps pops
Dlh 23 9 18 7 80 20 10 20
inl 19 6 15 2 70 10 20 30
brd 25 13 22 11 90 10 10 10
hyr 21 10 20 9 100 40 20 20
asx 22 13 21 10 90 80 30 40

Dlh watches warnings advisories
Wi... Winter weather advisory until noon cst today for wiz006.

Mn... Winter weather advisory until noon cst today for mnz035-036-038.

Winter weather advisory until 10 am cst this morning for mnz025-
033-034.

Winter weather advisory until 4 pm cst this afternoon for mnz012-
020-021.

Ls... Small craft advisory until 3 pm cst this afternoon for
lsz141>143.

Short term... Huyck
long term... Gsf
aviation... Melde


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
KGNA 26 mi60 min ESE 15 G 20 23°F 1004 hPa19°F
GD5 - 9099090 - Grand Marais, MN 26 mi38 min 22°F 1001.5 hPa22°F
ROAM4 - Rock of Ages, MI 30 mi56 min E 23 G 25 19°F 1005.3 hPa (-3.9)
DISW3 - Devils Island, WI 71 mi56 min E 17 G 19 21°F 1001.3 hPa (-4.0)19°F

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Grand Marais/Cook County Airport, MN27 mi81 minESE 9 G 150.50 miSnow16°F10°F79%999.3 hPa

Wind History from CKC (wind in knots)
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Last 24hrNW4NW5W3NW4NW5NW7NW7W6NW5W3CalmCalmCalmCalmCalmCalmCalmE4E5E3E6SE5E3E8
1 day agoCalmCalmCalmCalmCalmNW3NW15
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NW7NW9NW7NW6
2 days agoNW14
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NW4CalmNW6NW7NW6NW3W7NW5NW4W4CalmCalmNW4CalmCalmCalmCalmCalmS3CalmCalmCalm

Tide / Current Tables for
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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
east_satellite

GOES Local Image of GreatLakes    EDIT
Geos

Wind Forecast for Duluth, MN (5,6,7,8)
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Ground Weather Radar Station Marquette, MI
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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.