Thursday, March23, 2017

Marine Weather and Tides
Grand Marais, MN

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 7:49AMSunset 8:17PM Thursday March 23, 2017 2:18 AM EDT (06:18 UTC) Moonrise 4:36AMMoonset 2:22PM Illumination 20% 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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This is a Weather Statement Zone, please check the Date to see if it has expired
LSZ140 617 Pm Cdt Mon Sep 12 2016
.a large area of strong 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... Taconite harbor to silver bay harbor mn... At 617 pm cdt...doppler radar indicated a large area of Thunderstorms...capable of producing winds up to 33 knots and frequent cloud to water lightning. This area of Thunderstorms was located generally northwest of a line from 17 nm southeast of little marais or 18 nm east-southeast of silver 12 nm southeast of horseshoe bay and safe harbor. The storms were moving northeast at 45 knots. Locations impacted include... Mouth of the poplar river...tofte safe harbor... Mouth of the cross river...horseshoe bay and safe harbor... Sugar loaf cove...mouth of the little marais river... Tofte and hollow rock bay. 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 this storm passes. Intense lightning is occurring with this storm. If caught on the open water...stay below deck if possible and keep away from ungrounded metal objects. && lat...lon 4799 8941 4793 8945 4788 8956 4787 8964 4772 8973 4716 9098 4737 9118 4758 9089 4774 9050 4791 8982 4801 8964
This is a Weather Statement Zone, please check the Date to see if it has expired
LSZ140 Expires:201609130015;;332859 FZUS73 KDLH 122317 MWSDLH MARINE WEATHER STATEMENT NATIONAL WEATHER SERVICE DULUTH MN 617 PM CDT MON SEP 12 2016 LSZ140>142-162-130015-

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 230523
area forecast discussion
national weather service duluth mn
1223 am cdt Thu mar 23 2017

Issued at 949 pm cdt Wed mar 22 2017
minor updates made to adjust hourly temperatures and some slight
adjustments to pops and weather. Precipitation has been slow to
develop, as anticipated, with just the walker mn AWOS reporting a
brief period of light snow with no visibility reduction earlier
this evening. Ceilings remain around 5-6kft, which combined with
the radar echos and mesoanalysis data indicates there is likely
some virga falling across this elevated frontal zone. Some light
snow showers should develop towards late tonight as this frontal
zone moves east, but little accumulation expected.

Short term (this evening through Thursday)
issued at 348 pm cdt Wed mar 22 2017
high pressure over the great lakes region will continue to shift
to the east, and an upper-level ridge will move into the northland
from the west this evening. Southerly flow will bring an influx
of warmer and more humid air into the northland through tonight,
bringing increasing cloud cover. A shortwave trough will lift
from the northern high plains through the northland by the wee
hours of the morning, and the lift from the wave will help deepen
up the atmospheric moisture, likely deep enough to produce some
light snow. The best chances for the snow will be across the
arrowhead, where up to a half inch of snow is possible. Other
parts of the northland could get a light dusting.

The southerly flow will continue Thursday, with the upper-level
ridge axis shifting east of the northland and shortwaves lifting
into the northland in its wake. The shortwaves, combined with the
deepening moisture, will likely result in widespread light rain by
later in the afternoon. Highs will primarily in the 30s, but low
40s are forecast for north central minnesota.

Long term (Thursday night through Wednesday)
issued at 348 pm cdt Wed mar 22 2017
main challenge for the long term include precipitation types
Thursday night through Monday. Temperatures should be cold enough
for a wintry mix during the night with mainly rain during the day.

A quasi-stationary frontal boundary is forecast to extend from
the central plains northeastward into the minnesota arrowhead
Thursday evening. A combination of convergence and isentropic
upglide should provide enough forcing for ascent to yield
precipitation beginning late afternoon or during the evening
hours. Initially, temperatures should be warm enough for all rain,
but a mix of rain, freezing rain, and snow will develop by mid-
evening. Warm temperatures aloft over portions of the minnesota
arrowhead and northwest wisconsin raise concerns regarding the
availability of ice crystals for snow. A deep elevated warm layer
will also contribute to melting any snow which is able to develop.

The potential for freezing rain is greatest over those areas,
with the highest ice accumulation over portions of ashland, iron,
and price counties. As with most freezing rain events, antecedent
surface temperatures will play a significant role in the
precipitation type. Temperatures on Thursday should be in the
middle to upper 30s and could result in all rain for much of the
event. Given the continued uncertainty, elected not to issue any
headline products on this shift. Ice accumulation of around one-
tenth of an inch is possible, especially over portions of price
county, and later shifts will need to re-evaluate the need for

The band of precipitation will gradually drift southeastward
through our forecast area by late Friday morning as the front sags
south. Precipitation should change back to rain as intensity
slows. The 12z deterministic models all trended drier over the
northland for Friday through early Saturday morning, but the
ensemble members warrant keeping pops over northwest wisconsin. An
area of low pressure, which is forecast to loiter over the
central plains Thursday night and Friday, will wobble
northeastward Saturday and Sunday bringing a wintry mix back into
the picture. By Monday, high pressure will begin to push into the
area and will bring the precipitation to an end. Dry and quiet
conditions are expected for Tuesday and Tuesday night before
another chance of showers pushes into the area.

Aviation (for the 06z tafs through 06z Thursday night)
issued at 1223 am cdt Thu mar 23 2017
vfr conditions are expected overnight as the previously forecast
lower ceilings have generally failed to materialize due to a
significant dry layer at low levels depicted on the inl and mpx
upper air soundings. A few flurries are possible overnight, but any
visibility-reducing snow will be very limited in duration. On
Thursday south-southeast winds will increase with a few gusts to 20-
25 knots possible. Ceilings will begin to rapidly lower in the
afternoon as light rain develops. Visibility and ceilings will be
reduced to MVFR levels in the afternoon with periods of ifr
conditions possible late in the afternoon and into the evening

At this point precipitation type will be right on the edge between
rain and freezing rain. The dry air at low levels right now would
lead to wet bulb temperatures below freezing, meaning dew points
will need to rise enough in the southerly flow this morning to
result in a wet bulb temperature above freezing. This is a very
difficult forecast since temperatures are right on the edge, but
given the southerly flow this morning we have leaned on more of a
rain scenario with fog/mist reducing visibility to a mile or less at
times Thursday late afternoon/evening. Winds diminish towards the
evening to around 5 knots out of the south-southeast.

Preliminary point temps/pops
Dlh 26 37 30 43 / 30 50 80 20
inl 27 43 29 40 / 20 40 50 0
brd 32 39 32 47 / 10 50 70 20
hyr 28 38 33 45 / 20 40 90 50
asx 23 39 31 44 / 40 40 90 30

Dlh watches/warnings/advisories
Wi... None.

Mn... None.

Ls... Small craft advisory from 10 am this morning to 4 pm cdt this
afternoon for lsz140.

Update... Jjm
short term... Grochocinski
long term... Huyck
aviation... Jjm

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
KGNA 26 mi23 min NNE 2.9 29°F 1029 hPa20°F
GD5 - 9099090 - Grand Marais, MN 26 mi49 min 28°F 21°F
ROAM4 - Rock of Ages, MI 30 mi79 min SE 18 G 19 29°F 1030.3 hPa (-2.5)
DISW3 - Devils Island, WI 71 mi79 min SE 7 G 8.9 31°F 1028.6 hPa (-1.6)24°F

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Grand Marais, The Bay of Grand Marais, MN26 mi23 minNNE 3 mi29°F19°F69%1029 hPa

Wind History from GNA (wind in knots)
Last 24hrCalmNE5CalmCalmN4N4CalmE5E5CalmCalmW3CalmSW4S4Calm3E3N4NE3NE5NE4N3NE3
1 day agoW8
2 days agoW4W4N3CalmNE6CalmSW4W5W6SW8W7W6W5W10W11W10W8W3CalmCalmW76W10NW7

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
IR Satellite Image from GEOS

GOES Local Image of GreatLakes    EDIT

Wind Forecast for Duluth, MN (2,6,7,8)
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Ground Weather Radar Station Marquette, MI
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weather_mapweather_map weather_map

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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.