Monday, August21, 2017 L-36.com


Marine Weather and Tides
Lincolnwood, IL

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 6:04AMSunset 7:42PM Monday August 21, 2017 12:58 PM CDT (17:58 UTC) Moonrise 5:49AMMoonset 7:48PM Illumination 0% 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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LMZ741 Winthrop Harbor To Wilmette Harbor- Wilmette Harbor To Northerly Island- Northerly Island To Calumet Harbor- 1004 Am Cdt Mon Aug 21 2017
Rest of today..West winds 10 to 15 kt becoming southwest toward midday. Slight chance of showers and Thunderstorms. Waves 1 ft or less.
Tonight..South winds 10 to 20 kt becoming southwest 15 to 20 kt after midnight. Showers and Thunderstorms likely through the night. Waves building to 1 to 3 ft.
Tuesday..West winds 15 to 25 kt becoming north in the afternoon. Chance of Thunderstorms in the morning. Showers likely through the day. Waves 1 to 3 ft building to 3 to 5 ft in the afternoon.
Tuesday night..Northwest winds 15 to 20 kt. Mostly clear. Waves 3 to 5 ft subsiding to 2 to 4 ft after midnight.
LMZ741 Expires:201708212130;;728181 FZUS53 KLOT 211504 NSHLOT NEARSHORE MARINE FORECAST National Weather Service Chicago/Romeoville IL 1004 AM CDT Mon Aug 21 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>742-212130-

7 Day Forecast for Marine Location Near Lincolnwood, IL
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location: 41.95, -87.63     debug


Area Discussion for - Chicago, IL
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Fxus63 klot 211750
afdlot
area forecast discussion
national weather service chicago romeoville, il
1250 pm cdt Mon aug 21 2017

Update
1154 am cdt
an upper shortwave moving eastward across northern illinois
continues to help maintain some rain and isolated convection which
is moving eastward across north central illinois. This combined
with somewhat renewed low mid level moisture advection is expected
to keep precipitation lingering with some new development through
the afternoon. Most vigorous development is expected to focus
southeast of a roughly gary or valparaiso to pontiac line and
this may be a little generous on the north end. Better instability
gradient exists in this area, especially the further south you
go. To the north, surface based instability is pretty well capped
but the higher level ascent should allow for some continued
development. In addition, there is a nne-ssw oriented boundary
appearing on radar crossing the mississippi river which is
focusing some minimal development as it tracks east. Thus areas of
light rain with isolated to scattered stronger cells will likely
continue through early afternoon across much of the area. Tough to
say whether there will be a noticeable break in at least isolated
to scattered precip development but if there were it would likely
be mid late afternoon. Otherwise, cloud cover has thickened but
filtered Sun is being observed when rain is not falling. Do not
expect much change in overall cloud situation in the next few
hours.

Mdb

Short term
345 am cdt
through tonight...

multiple items of interest for today and tonight's forecast. Have
added further time refinement to thunderstorm potential, which is
trending more in two time periods... 1.) from mid-morning through
early afternoon and potentially more so western southern forecast
area and 2.) mid-evening onward tonight areawide, with heaviest
rainfall totals likely across north central illinois. Also given
heightened interest in sky cover forecasts for today's eclipse,
spent additional time collaborating that, and it does look like
there is potential for thinning of clouds spreading from west to
east during the early afternoon.

The large, mainly unorganized area of thunderstorms across
central iowa as of 330 am continues to creep eastward on the nose
of a 35 kt low-level jet. While there is a subtle short wave, it
is quite low amplitude, and as such this convection may struggle
to readily organize into an mcs. Even if it were, it would likely
ease slightly south of east, more so favoring the i-74 corridor of
illinois. There is potential for an MCV to emanate eastward out
of this convection, not all that different from yesterday, except
would be passing earlier in the day. All this said, it does not
lead to the highest confidence in storms this morning, and feel
the better chance coverage if they are able to make it into the
area is south of a dixon-to-joliet-to-valparaiso line... Basically
along the deeper instability gradient. A few stronger storms
through early afternoon may be seen given the modest instability
(mucapes of 2000 j kg) and very high moisture (1.70"+ pwats). The
main threat would be isolated 50+ mph wind gusts through mainly
precipitation loading, and if any were to organize congeal. In
addition, heavy rainfall localized flooding would be a threat,
especially across benton county, which saw 2-3+ inches of rainfall
early this morning.

Regarding cloud cover, the iowa convection has produced a huge
area of convective debris cirrus that is drifting over the cwa.

Would expect this to stick around most of the morning given the
upper level westerly flow and sustainability to the driving
convection. By eclipse time (~12pm-230pm), high and probably even
some mid clouds look likely given forecast rh pwats and high-res
synthetic satellite imagery. However there is certainly potential
for thinning from west to east behind the convective remnants mcv
that inch their way east-southeast this morning. That thinning, or
even some breaks in cloudiness, could occur during the eclipse
time, especially the latter half of it. That all said, forecasting
cirrus trends is very challenging and not routine. The eclipse,
clouds or not, should support temperatures leveling off or a small
dip for a 1-2 hour early afternoon period. Highs are forecast in
the mid 80s, and if some more Sun is realized, upper 80s to around
90 is attainable.

The rest of the afternoon into early evening has the forecast area
under subtle short wave ridging, so there looks to be a defined
lull break in regional convection. By mid-evening, the approaching
upper trough and associated height falls will support forcing for
ascent in a broad zone ahead of the cold front. Convection should
result from wisconsin southwest to kansas missouri by mid-
evening. Isolated development ahead of this into northern illinois
will become more likely by late evening as the modest to strong
low-level jet veers. Storms may organize into a forward
propogating MCS given the mid-level wind field and shear
orientation, as well as support of a couple cam solutions. So the
spc slight risk for mainly severe winds continues in the northern
illinois part of the cwa. Will need to watch if any small scale
waa wings were to develop ahead of the main activity, as training
storms would present a flooding issue given such high ambient
moisture. Even without training, rainfall rates may be enough to
cause at least localized flooding. Have mentioned heavy rainfall
possible in the forecast for north central illinois tonight.

Mtf

Long term
326 am cdt
Tuesday through Sunday...

Tuesday will be a transition day as the pattern shifts from zonal
flow aloft to more highly amplified as a deep upper low settles into
sern canada, broad long wave troughing develops over the ERN conus
while upper ridging builds over the rockies. This will set up cool
nwly flow aloft over the midwest with the cold front pushing quickly
to the south and east of the local area and high pressure builds out
of south-central canada and spreads across the northern plains. By
Wednesday, sfc high pressure will spread across the region while
nwly flow persists aloft. This will set up an extended period of
dry weather with below normal temperatures. For Tuesday through the
weekend, high temps will generally be in the 70s across the region.

A prevailing north component to the wind field will keep temps
along the lakefront in the lower 70s while inland locations should
climb into the middle to upper 70s. The coolest day of the period
should be Thursday as north to northeast winds bring the coolest air
into the area and lakefront locations may see temps only in the
upper 60s while inland locations only see lower to middle 70s, which
would be about 10 degrees below normal. As the surface high drifts
east we should see a return to south-southeast surface winds and a
gradual moderation in temps late in the week and into the weekend,
with temperatures returning back closer normal for late august.

Aviation
For the 18z tafs...

wind trends are the initial focus followed by thunder potential,
primarily tonight. Earlier thunderstorm complex to the west has
decayed but wind fields remain disturbed as what's left of it
passes the terminals. Expect a period of west to southwest winds
at the chicago area terminals early this afternoon before turning
south and even south-southeast. Rockford has already been easterly
and is trending southeast and will end up south-southeast or south
in the next hour or two. South to southwest winds will then
prevail this evening turning southwest late as a cold front
approaches. May need to bump us speeds slightly this evening and
tonight. Winds will then shift northwest late Tuesday morning
behind the front with speeds increasing somewhat with gusts to
near 20 kt.

Scattered showers and possibly an isolated storm will move across
the terminals through mid this afternoon. Some new development is
possible but the chance is low. Additional isolated activity is
possible into early this evening but the chance is also low.

Attention turns to late this evening and especially overnight as
the front approaches. Thunderstorms will become more likely with
time from about late evening onward with the best chance after
06z and probably closer to 08z as storms approach from the west.

Gusty winds may occur with the storms along with reduced
visibility which could briefly fall below the 2sm advertised in
the current tafs. Showers may linger through daybreak but then
exit with MVFR clouds expected. Improvement toVFR is expected
through late morning.

Mdb

Marine
326 am cdt
a weak trough of low pressure extends across the upper great lakes
with an associated frontal boundary extending southwest to low
pressure over the western plains. The front will remain nearly
stationary through Tuesday evening. High pressure building out of
central canada will force the front south down lake michigan Monday
night and pushing south of the lake by Tuesday afternoon.

Winds will turn northerly and strengthen following the frontal
passage, with winds and waves reaching small craft advisory levels
Tuesday and Tuesday night, especially for the indiana nearshore
waters. At this point, it looks like the illinois nearshore waters
may remain just under small craft advisory levels. High pressure
will then park over the upper midwest through midweek and gradually
spread east through the rest of the week and into the weekend. As
the high spreads across the lake, winds should diminish, but a
generally northerly component to the wind field should persist into
the weekend.

Lot watches warnings advisories
Il... None.

In... None.

Lm... None.

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
FSTI2 2 mi118 min NW 8.9 82°F
OKSI2 3 mi118 min N 5.1 82°F
CHII2 - Chicago, IL 4 mi38 min NW 1.9 G 2.9 81°F 71°F
45177 4 mi118 min 76°F
JAKI2 12 mi118 min NNW 5.1 83°F
45174 13 mi28 min NNW 1.9 G 3.9 76°F 75°F1 ft73°F
CMTI2 - 9087044 - Calumet, IL 16 mi40 min SSW 2.9 G 4.1 82°F 1017.6 hPa71°F
WHRI2 - Waukegan Harbor, IL 30 mi78 min WNW 7 G 12 78°F
BHRI3 - Burns Harbor, IN 33 mi49 min NW 4.1 G 8.9 77°F 1019.3 hPa
45170 38 mi28 min W 3.9 G 5.8 76°F 75°F1 ft72°F
MCYI3 - Michigan City, IN 41 mi38 min SSW 6 G 6 75°F 71°F
KNSW3 - Kenosha, WI 45 mi58 min WNW 7 G 13 80°F 1017.6 hPa (+0.0)

Wind History for Calumet Harbor, IL
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago, Chicago Midway Airport, IL13 mi65 minVar 510.00 miOvercast81°F72°F74%1017.2 hPa
Chicago, Chicago-O'Hare International Airport, IL14 mi67 minNW 510.00 miOvercast82°F71°F69%1017.5 hPa
Chicago / Wheeling, Pal-Waukee Airport, IL18 mi66 minVar 310.00 miFair81°F73°F77%1017.9 hPa

Wind History from MDW (wind in knots)
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Last 24hrSW7SW10SW8W7SW10
G18
S8S6S6S5S4SE5SE6SE5S3SE4S6S9S7S7SW7SW8SW9W9W10
1 day agoNE64E8E6E7E8E9E7E6SE5SE5S4S3S4S4S5S5SE5S5SE5S4S5S8S3
2 days ago--W10
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W12W12W11W9W6W5NW5NW10N9NW9N7N6NW4W3W4NW5NE4E4Calm

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 Midwest    EDIT
Geos

Wind Forecast for Chicago, IL (13,3,4,5)
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Ground Weather Radar Station Chicago, IL
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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.