Marine Weather and Tides
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.
|Sunrise 5:14AM||Sunset 8:31PM||Saturday June 23, 2018 1:00 PM CDT (18:00 UTC)||Moonrise 4:15PM||Moonset 2:36AM||Illumination 78%|
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|LMZ742 Winthrop Harbor To Wilmette Harbor- Wilmette Harbor To Northerly Island- Northerly Island To Calumet Harbor- 919 Am Cdt Sat Jun 23 2018 |
Rest of today..North winds around 10 kt becoming northeast by early afternoon. Partly cloudy. Waves 1 to 3 ft.
Tonight..East winds 5 to 10 kt becoming variable around 5 kt by late evening. Partly cloudy. Waves 1 ft or less.
Sunday..North winds 5 to 10 kt becoming northeast 10 to 15 kt in the afternoon. Mostly Sunny. Waves 1 ft or less building to 1 to 3 ft in the afternoon.
Sunday night..Northeast winds 10 to 15 kt. Partly cloudy. Waves 1 to 3 ft.
|LMZ742 Expires:201806232130;;987768 FZUS53 KLOT 231419 NSHLOT NEARSHORE MARINE FORECAST National Weather Service Chicago/Romeoville IL 919 AM CDT Sat Jun 23 2018 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>742-232130-|
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 231748|
area forecast discussion
national weather service chicago romeoville, il
1248 pm cdt Sat jun 23 2018
1027 am cdt
clouds and even some drizzle are taking their sweet time to lift
along and south of i-80 this morning. These are parked along the
broad surface trough cool front which will get a little push
southward late today. Until then, have gone more cloudy with
cooler temperatures in that area, with locations possibly failing
to reach or just touch 70. To the north and away from the lake,
upper 70s to around 80 look good.
Still decent potential for at least a few showers along the
confluence of the aforementioned low-level trough, with help from
mid-level wave noted in below discussion. Shallow cloud depths
and weak lapse rates look to keep lightning chances low.
319 am cdt
the upper low that has been driving the cloudy, raining and cool
weather across the region for the past couple of days is now
centered over northeastern in early this morning. This system is
finally expected to shift towards new england later today as it
becomes an open mid-level wave. This should set the stage to less
active and milder weather across most of the region through the
While most of the area will remain dry both today and on Sunday,
it does appear that another mid-level disturbance, now located to
our west over ne, will quickly shift eastward across northern
portions of il this afternoon. As it does so, there looks to be
some scattered shower development, mainly to the south of i-80.
Also cant rule out a thunderstorm or two, but instability should
remain rather swallow, so it is not looking to be a big event, but
there does look to be some showers across southern sections of the
area this afternoon. Elsewhere, expect some breaks in the clouds
today, with highs climbing back into the upper 70s, with the
exception of areas near lake michigan, where an onshore winds will
result in cooler conditions around 70.
319 am cdt
Sunday through Friday...
the forecast concerns during the extend period first focus on the
increasing threat of a couple rounds of thunderstorms, especially
Monday night through Tuesday night. Some of these storms could be
approaching severe limits and also be very heavy rainfall
producers. The forecast concern later in the period, namely
Thursday into the weekend, will be the potential for another heat
wave to impact the area.
The main feature of interest for the Monday night through
Tuesday night period is the upper trough low now digging into the
pacific northwest. This feature is forecast to dig over the
central high plains by late Sunday, then progress eastward across
the upper midwest and western great lakes Tuesday into early
Wednesday. As this occurs, an attendant weak surface low will
drive a surface warm front northeastward across the mid and upper
mississippi valley late Monday and Monday night. The airmass to
the west- southwest of this boundary is expected to be very warm
and moist, and is expected to set the stage for thunderstorm
development well to our west Sunday night and Monday. The threat
for storms locally look to increase across the area Monday night
as warm air advection increases over the area in response to the
uptick in the southwesterly low-level jet. We can't rule out a few
strong storms with this activity Monday night, but very heavy
rainfall will once again become a concern with these storms, and
with the very wet conditions of late, this could result in
additional flooding concerns over the area.
Another round of storms is then possible late Tuesday into
Tuesday night as the mid upper trough shifts towards the western
great lakes. Given some increased deep layer shear an additional
threat for strong to severe storms will be possible, but|
convective trends may be dependent on the Monday night early
Tuesday activity. More heavy rain will be possible with these
storms as well as precipitable water values are likely to remain
aoa 1.7". This period will need to be watched.
The main threat of storms looks to end across the area early
Wednesday as the system shifts towards the eastern great lakes.
The next concern will be the building heat across the central
part of the country mid to late week. Forecast guidance continues
to be in decent agreement with the general larger scale pattern
across the CONUS later in the week transitioning to a building
upper ridge across the central and eastern CONUS as a trough digs
over the western conus. There does, however, remain some detail
differences in the magnitude of the ridging over the region into
next weekend, and this will ultimately determine if we are in the
heat, or on the edge of the heat with periods of thunderstorms.
At the present time, it does appear that we could fall within
another period of storms as upper disturbances top the periphery
of the building ridge and move across our area. This looks most
probable Thursday into early Friday. Thereafter, the ridge may
begin to build enough to steer the main thunderstorm threat north
of the area. If this does occur, we would likely be setting up
for another possible period of significant heat (90s with heat
indices around 100) Friday and into next weekend. While there are
still uncertainties to iron out with this potential period of
heat next weekend, it is another period to watch closely.
For the 18z tafs...
only item of note for the chicago area airports are northeast wind
speeds that look to inch up this afternoon, and then be stronger
Light variable or northerly flow is seen across much of northern
illinois early this afternoon. Enough of a temperature difference
is building that a marine layer influence shift to the northeast
is expected in winds at ord and mdw, but the speeds may remain
quite light, especially at first. Confidence on speeds of 8 kt is
low-medium. Winds should become variable tonight before light
northwesterly again to start the day on Sunday. As brief surface
ridging moves over, winds should turn northeast and pick up in
speed, likely already by noon. Confidence on this is medium.
An upper level disturbance will move over the area this evening
into early overnight. Cannot completely rule out a stray shower
with this but coverage and impacts with any will be low.
212 am cdt
buoys indicate that waves no longer pose a threat to small craft,
so I will let the small craft advisory go.
The surface low over the in oh state line will slowly drift east
today while high pressure settles over hudson bay. North to
northeast winds are expected today as is a lake breeze this
afternoon. A cold front will shift down the lake tonight and
Sunday, and north winds are expected behind the front.
High pressure builds over the great lakes Monday, and winds become
east as the high shifts to the east coast. Southeast winds may
increase to 15-25 kt Monday night-Tuesday as the pressure gradient
tightens between the departing high and low pressure over the
plains upper midwest. The next low passes over the northern end of
the lake Wednesday morning, and winds become westerly behind its
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||E 1.9 G 7||66°F||56°F|
|45177||3 mi||120 min||65°F||1 ft|
|OKSI2||4 mi||120 min||ENE 1.9 G 2.9||65°F|
|JAKI2||5 mi||120 min||E 1.9 G 2.9||65°F|
|CHII2 - Chicago, IL||5 mi||40 min||Calm G 0||66°F||55°F|
|FSTI2||9 mi||120 min||ENE 6||63°F|
|45174||20 mi||30 min||NW 3.9 G 3.9||62°F||59°F||1 ft||55°F|
|BHRI3 - Burns Harbor, IN||28 mi||60 min||Calm G 4.1||62°F||1008.5 hPa (+0.0)|
|45170||34 mi||30 min||W 5.8 G 5.8||60°F||58°F||2 ft||58°F|
|WHRI2 - Waukegan Harbor, IL||37 mi||80 min||NE 5.1 G 6||61°F|
|MCYI3 - Michigan City, IN||37 mi||40 min||WSW 9.9 G 9.9||59°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||67 min||N 0||10.00 mi||Mostly Cloudy||73°F||57°F||57%||1006.8 hPa|
|Chicago, Chicago-O'Hare International Airport, IL||18 mi||69 min||N 0||10.00 mi||Mostly Cloudy||75°F||55°F||50%||1007 hPa|
|Gary Regional Airport, IN||19 mi||75 min||N 0||10.00 mi||Overcast||68°F||57°F||69%||1008.1 hPa|
|Lansing Municipal Airport, IL||22 mi||65 min||WSW 3||10.00 mi||Overcast||69°F||63°F||82%||1007.8 hPa|
|Chicago / Wheeling, Pal-Waukee Airport, IL||24 mi||68 min||N 0||10.00 mi||Partly Cloudy||75°F||55°F||50%||1007.4 hPa|
Wind History from MDW (wind in knots)
|1 day ago||E||E||E||E||E|
|2 days ago||NE||NE||NE||E||E||NE||NE||E||NE||E||E||NE||E||E||E||E||E||E||E||E||E||E |
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GOES Local Image of Midwest EDIT
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 Chicago, IL (14,3,4,5)(on/off)  Help
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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 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.