Wednesday, March29, 2017 L-36.com


Marine Weather and Tides
Niles, IL

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 6:35AMSunset 7:15PM Wednesday March 29, 2017 4:16 AM CDT (09:16 UTC) Moonrise 7:50AMMoonset 9:17PM Illumination 4% Phase: Waxing Crescent; Moon at 2 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- 313 Am Cdt Wed Mar 29 2017
.dense fog advisory in effect until 9 am cdt this morning...
.small craft advisory in effect from this afternoon through late Friday night...
Today..Northeast winds 10 to 15 kt increasing to 20 to 25 kt in the afternoon. Widespread fog in the morning. Waves 2 to 4 ft building to 3 to 5 ft occasionally to 7 ft in the late morning and afternoon.
Tonight..Northeast winds 20 to 25 kt becoming east to 30 kt. Chance of rain in the evening, then rain after midnight. Waves 3 to 6 ft occasionally to 8 ft building to 6 to 9 ft occasionally to 11 ft after midnight.
Thursday..East winds to 30 kt. Rain and slight chance of Thunderstorms. Waves 7 to 10 ft occasionally to 13 ft.
Thursday night..Northeast winds 15 to 25 kt. Slight chance of Thunderstorms in the evening. Rain likely through the night. Waves 5 to 8 ft occasionally to 10 ft subsiding to 3 to 6 ft occasionally to 8 ft after midnight.
LMZ741 Expires:201703291515;;250400 FZUS53 KLOT 290813 NSHLOT NEARSHORE MARINE FORECAST NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 313 AM CDT WED MAR 29 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>742-291515-

7 Day Forecast for Marine Location Near Niles, IL
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Area Discussion for - Chicago, IL
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Fxus63 klot 290834
afdlot
area forecast discussion
national weather service chicago/romeoville, il
334 am cdt Wed mar 29 2017

Short term
332 am cdt
through today...

main forecast concerns/challenges are with dense fog this
morning, and then shower and thunderstorm chances increasing
tonight into Thursday with a threat of strong to severe
thunderstorms along/south of the kankakee river in east central
illinois and northwest indiana Thursday afternoon/evening.

Continue to monitor fog trends here this morning, with the
overall trend overnight has been for the dense fog to slowly move
west. Can see low stratus and fog on satellite, however, surface
obs and webcams show the more dense fog situated from northern
lake/porter counties northwest through cook, and into
boone/mchenry counties. The most dense fog is still likely right
along areas near lake michigan, and then closer to the il/wi
border. Have expanded the advisory overnight with the most recent
updates to include boone, mchenry, and now winnebago counties.

Although there is likely fog across dekalb, kane, and dupage
counties at this time, the more dense fog is likely situated just
to the north. Will continue to monitor these areas including will
for possible dense fog and expansion of current advisory. Short
term guidance which has a fairly decent handle on the trends, has
further expansion of dense fog into these areas in the 9-11z time
frame. Morning commuters should be prepared for this dense fog to
impact travel this morning, with vis at or below one quarter mile
creating hazardous travel. Improvement still anticipated by mid
morning, but areas closer to the lake may see this dense fog
linger longer into late morning or midday.

Expect most locations to remain dry for much of the day, but
guidance is still varying to the extent of any upstream precip to
move overhead later today into the afternoon. Drier air in place
and strongest focus for much of the day remaining to the west are
likely complicating factors with these precip trends. So kept
areas dry through midday but I do introduce slight chance pops by
early afternoon for areas along/west of i-39, and then slowly
increase to low chance pops by late afternoon. Areas elsewhere
should stay dry, although latest runs of the hrrr are showing some
light showery development by late afternoon. Can't completely
rule out this light precip, but do expect to remain thunder free
with any development today.

Rodriguez

Long term
332 am cdt
tonight through Tuesday...

upper level low will continue to slowly move through the central
conus through tonight, with attendant surface low likely reaching
northern mo. Increasing ascent from approaching shortwave energy,
lifting boundary, and strong LLJ will really help precip spread
across the area tonight. However, LLJ and isentropic ascent do
appear to initially be focused over northern illinois for much of
the evening. So have highest pops situated over north central
illinois for the evening but then as LLJ begins to veer, should
see precip spread into remaining areas in northeast illinois and
northwest indiana overnight. Despite weaker instability tonight,
strong/focused ascent should allow isolated thunder to spread
across the cwa. So have expanded thunder mention tonight. Don't
anticipate severe tonight, however, can't rule out an isolated
stronger storm across the southern cwa.

Showers and thunderstorms still likely to be ongoing over the
entire area Thursday morning, with similar trends to intensity
possible over the southern CWA during that time. Surface low and
boundary expected to lift northeast throughout the day Thursday,
with guidance now indicating a strong possibility for this
boundary to lift north into the CWA by the afternoon. Although
some variability with placement, do think at least the far
southern area along/south of the kankakee river could get into the
warm sector. This presents an increased threat for strong to
severe weather for this area Thursday afternoon into the early
evening. Guidance indicating surface based instability south of
the boundary as well as the potential for steeper lapse rates.

However, confidence to the extent of any instability in this area
remains lower given the high likelihood for cloud cover to be
present for most of the day. As upper level trough/low lift
northeast in the afternoon and forcing and mid/upper level flow
increases, the possibility for more robust development will
arrive. This area appears to be right on the northern extent of
the stronger shear though. Nonetheless, enough ingredients in
place to monitor for a damaging wind/hail threat Thursday
afternoon for areas along/south of the kankakee river in east
central illinois and northwest indiana. Although thunderstorms
will likely linger Thursday evening, the threat of any stronger
development should end during this time.

Rodriguez

Aviation
For the 06z tafs...

another challenging forecast on tap with several concerns
throughout the period. First and most pressing is the developing
low stratus and fog moving in off of lake michigan. Areas
immediately adjacent to lake michigan have fallen to less than a
quarter mile in dense fog. While the fog has been lifting as it
moves inland, there have been rapid falls over the past hour in
ceilings and more recently visibility. Dense fog of 1/4sm or less
is a distinct possibility but right now there is higher confidence
in 1/2sm to 1sm visibility. Expect low conditions to persist
overnight with improvement expected mid to late Wednesday morning,
around 15z or so. Winds will become gusty out of the ene tomorrow
afternoon.

Meanwhile, low pressure is progged to lift across the southern and
central plains through the period. Several models have become much
faster bringing precip to the terminals, however forecast
soundings indicate very dry air in place through most of the day
tomorrow. With that in mind, leaning towards slower arrival of
precip to the terminals, around or after midnight local time late
Wednesday. Weak instability is now progged to lift north into the
chicagoland area, so cannot completely rule out an isolated
thunderstorm or two around the terminals.

Bmd

Marine
312 am cdt
northeast to east flow is expected to increase again this
afternoon and evening as low pressure lifts from the southern to
central plains. The low is expected to track east from missouri
Wednesday night to northern indiana Thursday night. East winds are
expected to peak late Wednesday night into Thursday around 30 kt
with occasional gale force gusts to 35 kt expected, mainly across
the south half of the lake. The low will continue east to the
atlantic coast Friday night with winds over lake michigan backing
to the north, but remaining moderately strong around 30 kt. High
pressure will begin to build over the region on Saturday allowing
winds to relax some over the weekend before another low takes a
similar track south of lake michigan early next week.

Bmd

Lot watches/warnings/advisories
Il... Dense fog advisory... Ilz003-ilz004-ilz005-ilz006-ilz014 until 9
am Wednesday.

In... Dense fog advisory... Inz001-inz002 until 9 am Wednesday.

Lm... Dense fog advisory... Lmz740-lmz741-lmz742-lmz743-lmz744-lmz745-
lmz777-lmz779 until 9 am Wednesday.

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
FSTI2 9 mi136 min NNE 9.9 33°F
OKSI2 12 mi136 min NE 5.1 35°F
CHII2 - Chicago, IL 14 mi26 min NNE 8.9 G 9.9 35°F 35°F
CNII2 15 mi16 min NNE 9.9 G 11 34°F
JAKI2 20 mi136 min ENE 7 34°F
CMTI2 - 9087044 - Calumet, IL 24 mi46 min NNE 7 G 9.9 34°F 1023.1 hPa34°F
WHRI2 - Waukegan Harbor, IL 25 mi36 min NE 8.9 G 9.9 32°F
KNSW3 - Kenosha, WI 41 mi76 min Calm G 2.9 32°F 1024 hPa (-0.0)
BHRI3 - Burns Harbor, IN 43 mi36 min NE 8 G 9.9 36°F 1023.7 hPa

Wind History for Calumet Harbor, IL
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Last
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G11

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago, Chicago-O'Hare International Airport, IL5 mi25 minNE 80.75 miFog/Mist35°F34°F96%1023.8 hPa
Chicago / Wheeling, Pal-Waukee Airport, IL9 mi24 minNE 61.00 miFog/Mist33°F33°F100%1024.6 hPa
Chicago, Chicago Midway Airport, IL15 mi23 minNE 71.25 miFog/Mist36°F35°F97%1024.3 hPa
Chicago / West Chicago, Dupage Airport, IL24 mi24 minENE 71.25 miFog/Mist36°F36°F100%1023.4 hPa

Wind History from ORD (wind in knots)
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Last 24hrN10
G28
N11NE11NE10N9NE10N9NE10N11N11NE10NE12NE11NE8NE6NE4NE7NE8NE9NE9NE8NE6NE8NE8
1 day agoNW5NW6W3N4NE6E4E5E4E6E5NE8NE6NE8NE8NE7NE8NE9NE10NE8N6N9N8N9N9
2 days agoNE5NE5NE5E3SE7S8S6CalmSW6SW8W8SW11SW9
G16
W8W10SW7SW5SW6SW7W8SW9W7NW7W4

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 (5,6,7,8)
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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.