Monday, August21, 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 6:59AMSunset 9:00PM Monday August 21, 2017 7:49 AM EDT (11:49 UTC) Moonrise 5:46AMMoonset 8:07PM Illumination 1% Phase: New Moon; Moon at 29 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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This is a Weather Statement Zone, please check the Date to see if it has expired
LSZ140 342 Pm Cdt Tue Aug 8 2017
.an area of Thunderstorms over western lake superior... The areas affected include... Grand marais to taconite harbor mn... Grand portage to grand marais mn... Lake superior west of a line from saxon harbor wi to grand portage mn beyond 5nm... Silver bay harbor to two harbors mn... Taconite harbor to silver bay harbor mn... At 342 pm cdt...doppler radar indicated an area of Thunderstorms... Capable of producing winds to around 30 knots and frequent cloud to water lightning. This area of Thunderstorms was located along a line extending from near pigeon point...to 8 nm northeast of tofte safe harbor...to near beaver bay...moving east at 30 knots. Locations impacted include... Beaver bay...mouth of the cross river...sugar loaf cove...tofte safe harbor...horseshoe bay and safe harbor...mouth of the poplar river... Hollow rock bay...tofte...and mouth of the little marais river. Precautionary/preparedness actions... Mariners can expect gusty winds to around 33 knots...locally higher waves...and lightning strikes. Boaters should seek safe harbor immediately until these storms pass. && lat...lon 4799 8941 4793 8946 4787 8964 4697 9024 4723 9137 4759 9085 4772 9055 4791 8982 4800 8959
This is a Weather Statement Zone, please check the Date to see if it has expired
LSZ140 Expires:201708082145;;081193 FZUS73 KDLH 082042 MWSDLH MARINE WEATHER STATEMENT NATIONAL WEATHER SERVICE DULUTH MN 342 PM CDT TUE AUG 8 2017 LSZ140>143-162-082145-

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


Area Discussion for - Duluth, MN
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Fxus63 kdlh 211127
afddlh
area forecast discussion
national weather service duluth mn
627 am cdt Mon aug 21 2017

Update
Issued at 627 am cdt Mon aug 21 2017
a batch of showers has quickly developed over pine county,
southern douglas, burnett and washburn counties. Added pops into
these areas to account for the showers. A rumble of thunder is
also possible as MUCAPE is about 250 j kg. Made some adjustments
to account for this activity.

Short term (today through Tuesday)
issued at 337 am cdt Mon aug 21 2017
a fast quasi-zonal flow aloft covered the forecast area at 08z while
high pressure was in charge at the surface. A mix of mid and high
clouds were streaming over the area in advance of several embedded
impulses moving along in the fast flow. Some patchy fog had also
formed. The additional cloud cover arriving from the west may limit
the overall extent of anymore fog forming. The models offer
different solutions on how the morning evolves and if any showers
develop and affect the region. Used a blended approach to pops which
led to some pops over southern price county by mid morning. This is
in response to the impulse in eastern sd at this moment. A second,
stronger impulse moves through the southern portion of the forecast
area in the afternoon. The short term hires models attempt to keep
this area from much in the way of precipitation in northwest wi.

Meanwhile, the deterministic models are more bullish on qpf.

Attempted a blend here as well which led to higher pops over the
southeast corner of the region in the late afternoon. Unfortunately,
with these impulses moving through the area, this will lead to an
expansive cloud cover right at eclipse time.

A vigorous long wave trof will drop south out of canada tonight and
across the region. A strong cold front will accompany this trof.

850mb temps will drop from the teens celsius ahead of the front trof
to the single digits behind the front. Look for showers and
thunderstorms over northwest wi in the evening, diminishing
overnight as the cold front departs. Lower pops farther north
tonight as dry air is advected into the northern half of the region
as the strongest impulse in the base of the upper trof moves quickly
east of the area. A fairly tight pressure gradient will be found
across the area tonight with the cooler temps making it feel very
fall-like.

Model differences prevail once again on Tuesday. A surface trof is
progged to clip the northern third of the forecast area in the
afternoon. The NAM gem arw nmm GFS are all dry, but the ECMWF brings
a swath of QPF into the border region as a channeled area of
vorticity slides into the area. The pops across the north
acknowledge the ECMWF solution, with some weight to the other
models.

Long term (Tuesday night through Sunday)
issued at 337 am cdt Mon aug 21 2017
temperatures trend a bit cooler for the start of the long term,
moderating through the end of the week, with a few chances of
showers and thunderstorms.

Tuesday evening will see a stout upper trough over eastern
canada, portions of the great lakes, and new england. Several
shortwave disturbances will be found rotating around the closed
low over northeast ontario and western quebec. Another shortwave
trough will approach from upstream and kick the closed low
farther east Tuesday night and Wednesday. That disturbance will
move out of southern manitoba and into northern minnesota during
the day Wednesday, and may provide enough lift for a few isolated
showers or maybe a thunderstorm. Temperatures aloft will be
somewhat chilly for late august with 850 mb values in the middle
single digits celsius Wednesday afternoon and Wednesday evening.

The cool temperatures aloft and cloud cover associated with the
transient wave should yield afternoon highs in the 60s over the
northland.

High pressure returns in the wake of the passing shortwave trough
bringing mostly sunny to partly cloudy skies to the area and
gradually moderating temperatures. Quiet and mostly sunny
conditions are expected Thursday through Friday afternoon.

Deterministic guidance then diverges with the handling of the
next shortwave trough for Friday afternoon through Saturday
night. The ECMWF brings clouds and precipitation into the
northland as early as Friday afternoon, while the cmc and GFS are
a bit slower. All three models slow the forward progression of
the shortwave due to a deepening trough downstream over quebec
and new england. The consensus of the guidance keeps a chance of
rain in the picture for much of the weekend. Think that's the
right call with this update and have broad-brushed slight and low-
end chance pops across much of the northland for the weekend into
Monday. Temperatures will trend near normal Friday through Monday.

Aviation (for the 06z tafs through 06z Monday night)
issued at 1243 am cdt Mon aug 21 2017
generallyVFR conditions expected through the TAF period at all
sites. Some MVFR fog is developing at kbrd and khyr and MVFR ifr
at khib and should affect those locations through 13z time range.

Convection is expected to form over western wi eastern mn after
15z which may bring showers and thunderstorms to khyr and possibly
also kdlh after 20z. Have included a vcts group for now. Winds to
remain less than 10 kts through most of the TAF period.

Preliminary point temps pops
Dlh 74 53 71 50 20 20 10 0
inl 74 49 70 47 20 20 20 0
brd 73 53 72 50 10 10 0 0
hyr 78 54 71 49 40 50 0 0
asx 77 55 72 51 30 40 10 0

Dlh watches warnings advisories
Wi... None.

Mn... None.

Ls... None.

Update... Gsf
short term... Gsf
long term... Huyck
aviation... Le


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
KGNA 26 mi54 min 4.1 62°F 1016.6 hPa51°F
GD5 - 9099090 - Grand Marais, MN 26 mi50 min 64°F 1016.3 hPa (+1.2)52°F
ROAM4 - Rock of Ages, MI 30 mi50 min NNW 5.1 G 6 63°F 1018.3 hPa (+1.3)
45006 - W SUPERIOR 48NM North of Ironwood, MI 37 mi60 min W 7.8 G 7.8 61°F 60°F1 ft1016.9 hPa (+1.2)
DISW3 - Devils Island, WI 71 mi50 min SW 8 G 8.9 62°F 1017.9 hPa (+1.3)59°F

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Grand Marais, The Bay of Grand Marais, MN26 mi54 minVar 4 mi62°F51°F67%1016.6 hPa

Wind History from GNA (wind in knots)
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Last 24hrCalmNE3CalmSW3SW5SW4S6W7SW73W7SW5W3NW3Calm4NW7NW4W3SW4W3NW3Calm4
1 day agoW5Calm4SW13W7W7W7SW15W9W10W7W9W5W3W3CalmCalmCalmCalmCalmCalmNE3CalmCalm
2 days agoCalm5N644----S6SW9W8W7W4SW5CalmCalmCalmCalmN6SW8CalmSW6NW6CalmSW5

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 (7,2,3,4)
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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.