Marine Weather and Tides
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
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|Sunrise 8:32AM||Sunset 5:04PM||Saturday December 7, 2019 6:35 AM EST (11:35 UTC)||Moonrise 3:11PM||Moonset 3:21AM||Illumination 80%|
7 Day Forecast for Marine Location Near Grand Marais, MNHourly EDIT Help
Area Discussion for - Duluth, MN  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS63 KDLH 071134 AFDDLH
Area Forecast Discussion National Weather Service Duluth MN 534 AM CST Sat Dec 7 2019
SHORT TERM. (Today through Sunday) Issued at 352 AM CST Sat Dec 7 2019
Main concerns during the short term involve precipitation types with warm frontal passage today and with another chance of precip on Sunday.
High pressure was centered over Lower Michigan early this morning with a warm front arcing from southern Alberta to eastern South Dakota. Low stratus was found over much of the Northland, with the exception of an area of clear skies over interior portions of the Minnesota Arrowhead. The warm front will lift northeastward across northwest and north-central Minnesota this morning and continue off to the northeast this afternoon and evening. Isentropic forcing for ascent near the surface and mid-level omega will set up a complex precipitation cascade on either side of the front. Low-level saturation would seem to support a potential of freezing drizzle. Meanwhile a second cloud layer aloft will be located within a zone of negative omega and temperatures cold enough for snow. The main question is whether the snow crystal growth will be sufficient to survive a 5 to 8 kft dry air layer before full column saturation occurs. The forcing for ascent is co-located with the dendritic growth zone aloft, so snow crystal growth of small dendrites seems favored. If those snow crystals survive the dry air below, the will likely become rimed with liquid droplets resulting in snow grains or rimed snowflakes at the surface. If there is insufficient growth aloft, the snow crystals would sublimate and the low-level moisture would yield freezing drizzle. For now have leaned toward the snow side of the fence, but can’t entirely rule out freezing drizzle.
The warm frontal precipitation will move out of the Northland tonight. A cold front will move into the region tonight, which will set up a potential for post-frontal precipitation early Sunday morning through the afternoon. The precipitation on Sunday may start as drizzle or freezing drizzle with warm air near the surface. There are similar concerns regarding the depth of the ice layer aloft and dry air between that area and the low-level moisture as with today’s forecast. Hedged more on the freezing drizzle potential through mid-morning Sunday. A North Shore gravity wave may develop along the Lake Superior shoreline, and would enhance forcing for ascent from the Twin Ports to Grand Portage. Have included a band of freezing drizzle associated with this feature before the main cold frontal precip arrives later in the day.
Snow and ice accumulations during the short term will be light, a glaze of ice and up to one-half inch of snow accumulation are expected.
LONG TERM. (Sunday night through Friday) Issued at 352 AM CST Sat Dec 7 2019
A positively tilted upper level long wave trof will reach the eastern Dakotas Sunday night. Its associated surface low will move toward northern Illinois. There are some differences amongst the models on the location of the low, as well as the QPF signal. NAM and ECMWF are similar with location and timing of highest QPF. The GFS/GEM are also similar with their respective QPF, and are farther east by 12Z Monday. Blended these solutions which focuses the highest QPF/snow amounts over the southern half of the forecast area. These differences continue on Monday, although the 00Z/7 run of the ECMWF is wetter/slower than the other models. Prefer the faster consensus. With the warm air in place Saturday evening, will see some mixed precipitation from the I35 corridor east through northwest Wisconsin, becoming all snow from west to east as the night progresses and cold Arctic air changes the precipitation type to all snow overnight. Accumulation is likely along and south of the Iron Range, and through all of northwest Wisconsin. Will hold off on any headlines at this moment due to the variability amongst the models in timing and coverage.
The upper trof moves into the western Great Lakes Monday night while the surface low moves into Quebec. A cold front extends back into the region from this surface low and will be the focus for some additional light snow. Amounts will be light, as much drier air with the Arctic cold, settles into the area. Some lake effect snow is possible over north central Wisconsin, but the surface winds are rather light. The aforementioned drier air will also play a role in any accumulations.
The Arctic air remains locked over the region through Tuesday night. Northwest flow continues to generate some lake effect snow showers along the south shore of Lake Superior. However, there is some variability in the surface wind direction and speed which affects potential accumulation. The lake effect diminishes on Wednesday as high pressure moves into southern Minnesota and turns the wind into a westerly direction. Low wind chill values will occur Monday night through Wednesday night, with hazardous wind chills possible Tuesday night.
The high drifts to the southern Great Lakes Wednesday night with some ridging remaining nearby. Models diverge in the handling of the next short wave and its potential to bring snow to the area. A blended approach favors a dry forecast overnight. Model differences continue to grow quite large with the handling of short waves affecting the area through Friday, and there subsequent potential for precipitation. Kept with the blended approach to resolve the differences.
AVIATION. (For the 12Z TAFS through 12Z Sunday morning) Issued at 534 AM CST Sat Dec 7 2019
A warm front was lifting north through central Minnesota at the outset. Mainly MVFR cigs, with some pockets of IFR and VFR were dotting the region. As the front moves north through the day, a brief improvement of cigs to VFR at all sites. However, an approaching upper level wave will bring MVFR cigs back with some light wintry mix, mainly over HIB and INL. Used a VCSH mention for timing questions. Gusty winds are also possible after fropa. A brief period of LLWS is on tap overnight as a low level jet moves through the area in conjunction with the upper wave.
MARINE. Issued at 352 AM CST Sat Dec 7 2019
A southwest wind of 10 to 15 knots is forecast today, with some higher gusts from Taconite Harbor to Grand Marais tonight through Saturday morning. Waves will build to 3 to 5 feet in this area and will have a Small Craft Advisory in effect from 6pm tonight until 9am Sunday. The wind turns northwest Sunday morning, then switches to the north northeast in the afternoon, and maintains this direction through Sunday night. Wave heights will increase along the south shore, but will hold off on additional headlines as confidence is low on speed, gusts and wave heights.
PRELIMINARY POINT TEMPS/POPS. DLH 29 26 31 7 / 10 20 60 70 INL 29 17 24 -3 / 40 30 20 20 BRD 31 26 29 6 / 20 10 50 70 HYR 33 29 34 17 / 10 10 60 80 ASX 32 29 35 17 / 20 10 70 80
DLH WATCHES/WARNINGS/ADVISORIES. WI . None. MN . None. LS . Small Craft Advisory from 6 PM this evening to 8 AM CST Sunday for LSZ140-141.
SHORT TERM . Huyck LONG TERM . GSF AVIATION . GSF MARINE . GSF
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|KGNA||26 mi||40 min||W 6||25°F||1022.8 hPa||20°F|
|GD5 - 9099090 - Grand Marais, MN||26 mi||48 min||1021 hPa|
|ROAM4 - Rock of Ages, MI||30 mi||36 min||WSW 17 G 19||29°F||1023.7 hPa (-1.0)|
|DISW3 - Devils Island, WI||71 mi||36 min||SSW 8.9 G 13||24°F||1022.5 hPa (-0.9)||16°F|
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.
|Grand Marais, The Bay of Grand Marais, MN||26 mi||40 min||W 6||mi||25°F||19°F||81%||1022.8 hPa|
Link to 5 minute data for KGNA
Wind History from GNA (wind in knots)
|1 day ago||E||N||Calm||Calm||NE||Calm||Calm||Calm||Calm||Calm||Calm||NW||Calm||SW||W|
|2 days ago||W||W||W||W||W||W|
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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.
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Wind Forecast for Duluth, MN (6,6,7,8)(on/off)  Help
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