Marine Weather and Tides
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 6:41AM||Sunset 6:42PM||Monday September 25, 2017 3:44 PM CDT (20:44 UTC)||Moonrise 11:56AM||Moonset 10:07PM||Illumination 27%|
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|LMZ742 Winthrop Harbor To Wilmette Harbor- Wilmette Harbor To Northerly Island- Northerly Island To Calumet Harbor- 301 Pm Cdt Mon Sep 25 2017 |
Tonight..Southeast winds around 10 kt becoming south 5 to 10 kt in the late evening and overnight. Mostly clear. Waves 1 to 2 ft.
Tuesday..Southwest winds 5 to 10 kt. Mostly Sunny. Waves 1 ft or less.
Tuesday night..Northwest winds 10 to 15 kt increasing to 15 to 20 kt after midnight. Slight chance of showers and Thunderstorms in the evening. Waves 1 ft or less building to 2 to 4 ft after midnight.
Wednesday..North winds 15 to 20 kt. Mostly Sunny. Waves 2 to 4 ft.
|LMZ742 Expires:201709260345;;923297 FZUS53 KLOT 252001 NSHLOT NEARSHORE MARINE FORECAST National Weather Service Chicago/Romeoville IL 301 PM CDT Mon Sep 25 2017 For waters within five nautical miles of shore on Lake Michigan Waves are provided as a range of significant wave heights, which is the average of the highest 1/3 of the waves, along with the average height of the highest 10 percent of the waves which will occasionally be encountered. LMZ740>742-260345-|
7 Day Forecast for Marine Location Near Chicago, ILHourly EDIT Help
Area Discussion for - Chicago, IL  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus63 klot 251922|
area forecast discussion
national weather service chicago romeoville, il
222 pm cdt Mon sep 25 2017
222 pm cdt
looking at hot but quiet conditions through this afternoon.
Cumulus clouds have sprouted across the region, but not expecting
any precip given 30 degree dewpoint depressions at the surface. A
lake breeze is pushing inland lowering 90 degree temps into the
upper 70s to low 80s. Low temps tonight will be in the mid 60s,
while chicago will be around 70.
Winds become southwest ahead of a front Tuesday morning, and
cloud cover increases. Kept high temps in the upper 80s, but cloud
cover will likely limit warming. 90s are more likely along and
east of i-55 where clouds will take longer to arrive.
I have low confidence in measurable precip Tuesday as the front
moves through the region. The main upper level wave will separate
itself from the front as the wave shifts northwest over minnesota.
Forcing along the front is forecast to weaken as the front moves
through. When I also factor in the recent dry spell, I think
showers and storms will struggle to form.
The best chance for showers and storms will be around rockford
Tuesday afternoon, but isolated showers and storms may occur from
a waukegan to amboy, il line. Severe storms are not expected as
cape will be less than 500 j kg and shear will be around 30 kt.
222 pm cdt
Tuesday night through Monday...
a return to more seasonably average temps is expected mid-week,
before a brief push of colder air arrives Friday and lingers into
the start of the weekend. Other than fairly minimal chances of
showers with the two cold fronts (Tuesday night and early Friday
morning), our dry spell looks to persist through the coming week.
However, a few lake effect showers may bring some spotty rain
mainly to parts of northwest indiana with the cooler weather at
the end of the week.
Guidance remains in good agreement in moving a cold front east
across the forecast area Tuesday evening overnight. While the
presence of a boundary moving into our unseasonably warm air mass
would suggest the threat of showers thunderstorms, the mid-level
short wave associated with low pressure moving through the
northern great lakes is well to our north, with the stronger and
better focused forcing for large scale ascent. In addition, while
surface dew points pool in the mid-60's ahead of the front,
southwesterly winds aloft maintain deeper moisture transport well
north of the cwa. Forecast soundings indicate relatively weak
lapse rates above the immediate boundary layer as well, yielding
weak instability with a bit of weak capping as well. Earlier
sunset times and loss of this diurnal instability will also be
working against significant convective shower thunderstorm
coverage, and model QPF is light and decreasing with eastward
progress of the front as well. All of this points to maintaining
only low slight chances pops along the front for Tuesday
Cooler air spreads in behind the front on Wednesday and Thursday,
as high pressure ridge spreads east southeast across the area.
Low level thermal fields support daytime temps in the low-mid 70's
Wednesday with decreasing cloud cover on breezy north-northwest
winds. Mainly clear skies and light winds in the vicinity of the
surface ridge axis will likely allow for fairly cool min temps
across parts of the forecast area dipping into the low-mid 40's by
sunrise Thursday. NAM depicts dew point temps in the mid-upper
30's across northwest north central il within the surface ridge
axis early Thursday, suggesting some cooler spots may be possible
there. Thursday should see temps similar to Wednesday. With the
cooler air over warm lake waters, lake effect stratocu is likely|
downwind of lake michigan into northwest indiana, through shallow
convective cloud depth and dry air may not support precip with
this first push of cooler air.
Medium range guidance solutions continue to indicate another
digging mid-level short wave will amplify the trough across the
great lakes region Thursday night, with a reinforcing push of
colder air arriving behind an associated cold front which arrives
very late Thursday night early Friday morning. Forecast soundings
depict fairly dry thermodynamic profiles with rain shower
potential looking fairly minimal with the front, and little no qpf
generated. While guidance has trended a little more
progressive less closed off with amplifying mid-level trough, h8
temps still drop into the +3 to +4c range across the region. This
sets the stage for daytime temps only in the 60's fri-sat (and
perhaps only low-mid 60's in many spots Saturday). Colder air
aloft should support lake effect cloud cover into northwest
indiana and perhaps some showers, as lake surface to h8 delta-t
increases to 15 16c, and convective cloud depth is significantly
deeper. Flow turns more northeasterly Saturday as surface high
builds in from the northwest, which may bring some lake clouds
into northeast il.
With amplified but progressive upper pattern indicated,
moderation in temps occurs back to around average for early
october for Sunday and Monday. Return flow becomes more
established across the plains and mississippi late in the period,
which along with moderation in temps would potentially bring the
next chance for more organized rain Monday, or more likely
For the 18z tafs...
light winds andVFR conditions are being reported across the area
on the backside of departing high pressure.VFR CU will continue
to form this afternoon. A lake breeze is pushing inland, and looks
like it will reach ord and mdw btwn 21z and 22z. I have medium-
high confidence in when the lake breeze will turn winds easterly
at ord and mdw. At least the initial push of wind should be around
Winds become southwest ahead of a front Tuesday morning.VFR
clouds increase, but I have low confidence in precip occurring.
The main wave of upper level energy will lift northwest over
minnesota and southern ontario. Meanwhile energy along the front
is forecast to weaken as it moves through the region. Throw in the
dry spell, and I think showers will struggle to form. However, if
any isolated showers or storms form, they will be near rfd after
18z. I doubt that any of the eastern sites will receive precip.
222 pm cdt
the western edge of a high pressure ridge will extend over the
western great lakes while a front will extend from northwest wi
through western ia. Southerly winds will become northwest to
north 15-25 kt behind the cold front Tuesday night. A small craft
advisory may be needed for the in nearshore waters. Another strong
push of northerly winds is expected Friday morning behind another
cold front. While low end gales will be possible, northerly winds
will be at least 25-30 kt through Friday evening, and a small
craft may be needed. High pressure will spread over the lake
Saturday. Winds will diminish and become southernly by Sunday
Lot watches warnings advisories
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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|
|CNII2||1 mi||30 min||79°F|
|OKSI2||4 mi||105 min||ESE 2.9||82°F|
|CHII2 - Chicago, IL||5 mi||45 min||ESE 16 G 17||79°F||67°F|
|JAKI2||5 mi||105 min||ESE 6||78°F|
|FSTI2||9 mi||105 min||ESE 5.1||76°F|
|CMTI2 - 9087044 - Calumet, IL||9 mi||45 min||ENE 9.9 G 13||82°F||1013.6 hPa (-1.7)||65°F|
|45174||20 mi||25 min||ESE 9.7 G 14||76°F||72°F||1 ft||69°F|
|BHRI3 - Burns Harbor, IN||28 mi||65 min||SSE 7 G 12||89°F||1014.9 hPa|
|45170||34 mi||25 min||ENE 3.9 G 5.8||79°F||76°F||69°F|
|WHRI2 - Waukegan Harbor, IL||37 mi||65 min||S 5.1 G 7||81°F|
|MCYI3 - Michigan City, IN||37 mi||45 min||NNW 2.9 G 5.1||87°F||56°F|
Wind History for Calumet Harbor, IL(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Chicago, Chicago Midway Airport, IL||9 mi||52 min||E 10||10.00 mi||Partly Cloudy||91°F||57°F||32%||1012.4 hPa|
|Chicago, Chicago-O'Hare International Airport, IL||18 mi||54 min||SE 10||10.00 mi||Partly Cloudy||92°F||55°F||29%||1012.8 hPa|
|Gary Regional Airport, IN||19 mi||60 min||E 6||10.00 mi||Partly Cloudy||90°F||48°F||24%||1014.6 hPa|
|Lansing Municipal Airport, IL||22 mi||50 min||S 5||10.00 mi||Fair||89°F||61°F||40%||1014.2 hPa|
|Chicago / Wheeling, Pal-Waukee Airport, IL||24 mi||53 min||ESE 9||10.00 mi||Fair||91°F||60°F||35%||1013.7 hPa|
Wind History from MDW (wind in knots)
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|2 days ago||S||S||S||S||SE||E||SE||SE||SE||S||SW||Calm||Calm||S||S||S||S||S||SW||S||E||SE||E |
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Weather Map and Satellite Images(on/off)  Help
|Weather Map ||IR Satellite Image from GEOS|
GOES Local Image of Midwest EDIT
Wind Forecast for Chicago, IL (16,3,4,5)(on/off)  Help
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