Thursday, April27, 2017 L-36.com


Marine Weather and Tides
Lincolnwood, 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 5:49AMSunset 7:47PM Thursday April 27, 2017 1:44 PM CDT (18:44 UTC) Moonrise 7:01AMMoonset 9:19PM Illumination 3% 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- 923 Am Cdt Thu Apr 27 2017
.small craft advisory in effect until 7 pm cdt this evening...
Rest of today..Southwest winds to 30 kt easing to 20 to 25 kt late in the day. Occasional gale force gusts through noon. Cloudy. Waves 3 to 5 ft occasionally to 7 ft.
Tonight..Southwest winds 10 to 20 kt diminishing to 5 to 10 kt after midnight. Mostly cloudy. Waves subsiding to 1 to 2 ft.
Friday..Southeast winds 5 to 10 kt becoming east 10 to 15 kt in the afternoon. Chance of showers. Waves around 1 ft.
Friday night..North winds increasing to 15 to 25 kt. Chance of showers. Waves building to 3 to 5 ft occasionally to 7 ft.
LMZ741 Expires:201704272130;;348498 FZUS53 KLOT 271423 NSHLOT NEARSHORE MARINE FORECAST NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 923 AM CDT THU APR 27 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>742-272130-

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 271754
afdlot
area forecast discussion
national weather service chicago/romeoville, il
1254 pm cdt Thu apr 27 2017

Update
1030 am cdt
rain and drizzle are pulling out of the area late this morning as
expected, with even some brief rain/snow reported earlier just
north of the il/wi state line (near monroe wi). The deep low, now
at 991 mb over northern lake michigan, will continue breezy west-
southwest winds and cold advection. This advection regime will be
offset some by daytime heating, but thicker clouds over north
central illinois have prompted lowering forecast afternoon
temperatures a few degrees. The 40s for much of the CWA (lower 50s
south) this afternoon will be the coolest afternoon temperatures
in about three weeks.

Mtf

Short term
244 am cdt
through tonight...

expect to wake up to a little different airmass then you may have
been used to this past week. Steady rains continue this early
this morning as a deep negatively tilted trough axis swing
northward. The flow is nearly due south to north with rain bands
following this trajectory. The system is still strengthening, so
in spite of a loss of instability, moderate rains will occur at
times as the cold front oozes eastward. There are several surface
lows that will consolidate. The system's main surface low,
across central illinois will pass northeast this morning,
reaching the southern tip of lake michigan in the coming hours,
then strengthen further across the eastern shores of the lake
this morning. Cold advection and quick pressure rises will lead to
a quick surge in west winds through mid to late morning, which
when coupled with falling rain for a little longer will make it
feel a bit raw outside.

Fortunately, in spite of the cool and continued breezy conditions
today, the low will quickly lift northeast late this morning, and
drier air will filter in from the back side of the system. Lower
clouds will lift some but not fully dissipate until later in the
day, and will be eroding from southwest to northeast. The clearing
will be brief as clouds will thicken again later this evening and
overnight. Chilly highs today will only reach the 50s in many
spots, but possibly only upper 40s in northern/north central
illinois. Lows tonight fall into the upper 30s to mid 40s.

Kmd

Long term
244 am cdt
Friday through Wednesday...

unfortunately for those with outdoor plans this weekend, we will
still need to forecast rain, and quite a bit of it. Expect very
damp conditions, and possible localized flooding as well.

By Friday morning our current weather maker will have lifted north
of the northern great lakes, while our next big upper low will be
taking shape out across the western u.S.A. In between these two
systems across the upper midwest and close to the area a weak
ridge will at least initially keep the real deep moisture from
getting up this far north. Strong southwest flow between the deep
low and high pressure of the southeast us will set up favorable
pattern for bringing gulf moisture northward.

A lead wave on Friday will lift an elevated warm front through
Friday leading to a batch of somewhat lighter rain showers,
generally speaking, though they could be moderate briefly on the
nose of the low level jet. The surface warm front will likely get
into our far southern CWA but that appears to be it. The high to
our northwest will allow this boundary to sag back southward
through the night, thus a brief lull in the action.

The gulf will reload through the day Saturday and into Sunday. The
global models try to bring precip back north as early as Saturday
morning, whereas some higher res models keep cool northeast flow
in place to lock the moisture south a bit longer and keep the
morning drier, especially north of i-80. Eventually with a deep
low that is deepening, strong frontogenesis with cool northeast
flow to the north and very warm moist air to the south, and
finally the sheer strength of the southwest flow and the
magnitude of the moisture transport will allow the door to open a
bit more in our area. Expect the rain to increase through the
afternoon, with global guidance maximizing the moisture transport
Saturday night into early Sunday, with rain continuing off and on
Sunday. Thunderstorms enter the picture Saturday night into Sunday
as the surface warm front will lift north, and the upper low will
steepen lapse rates. If that weren't enough, the upper low will
then swing through late Sunday with very large height falls
providing deep ascent for hopefully what will be the system's last
hurrah, heavy precip wise.

Confidence in the general pattern, reaffirmed by decent model
agreement and high relative measure of predictability of the
actual upper low progression, is fairly decent, but the devil is
in the details as far as where each wave's high QPF axis will
setup and how much of the high pwat axis will lift this far north.

Especially given how much rain will fall via convection to our
south that may limit how heavy the rain will get up here. Still,
current suite of guidance suggest we can generally expect qpf
numbers in the Friday through Sunday night period in the 2 to 4
inch range, and locally higher numbers are certainly possible,
with the main swath coming later Saturday into Sunday. Pwat values
in the whole area are at maximum moving average values for late
april, with the 1.6" pw values possible in some areas being at all
time highs recorded for the month of april. After modest rains
early Thursday, these numbers could at least lead to some minor
flooding, and will likely re-aggravate a number of area rivers.

The actual low center will still not be through until Monday
evening, so there will still be some showers around.

Behind the low expect much cooler and breezy conditions, with the
seasonally chilly airmass lingering into mid next week.

Kmd

Aviation
For the 18z tafs...

the summary of the aviation forecast is gusty winds this
afternoon with very gradually lifting cloud bases, and then
gradually lowering clouds Friday afternoon with likely some rain
showers spreading in.

The surface low over northern lake michigan is pulling away from
the area with gusty west-southwest winds and continued cloud
cover. The cold advection pattern will support the gusts through
the afternoon and some occasional lower gusts early this evening.

Confidence is minimal in whether low clouds will continue
tonight, but even if they do they should lift toVFR.

The next weather system approaches on Friday causing clouds to
lower in the afternoon as moisture streams aloft. Support for rain
showers should increase in the afternoon, with an area spreading
northeast from northern missouri/western illinois in the morning.

This may be more of scattered showers, but do think there will be
some around. The lowering of CIGS to MVFR or ifr is likely to not
be until after dark on Friday.

Mtf

Marine
226 am... Broad low pressure over lake michigan early this morning
will consolidate into a smaller/stronger low later this morning
as it lifts northeast to eastern lake superior this afternoon and
then into ontario this evening. As this low lifts north... Winds
are expected to shift west/northwest and increase... Possibly to 30
kts. Depending on how strong the gradient becomes... There could
also be some brief gale gusts. Confidence is only medium and
trends will need to be monitored later this morning. Prior to the
westerly winds increasing... Areas of fog will be possible which
may become dense but confidence is low.

A weak ridge will build across the lakes region tonight into
Friday morning and then slowly lift north Friday night and is
absorbed by a stronger high building across ontario. Low pressure
will move from the southern plains Saturday to the western great
lakes Monday. The gradient will tighten between these two features
with northeast winds increasing to 30 kts. A period of gales is
also possible but confidence is low. Cms

Lot watches/warnings/advisories
Il... None.

In... None.

Lm... Small craft advisory... Nearshore waters
until 7 pm Thursday.

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
FSTI2 2 mi105 min SW 14 46°F
OKSI2 3 mi105 min WSW 6 47°F
CHII2 - Chicago, IL 4 mi45 min WSW 20 G 25 45°F 38°F
CNII2 7 mi15 min WSW 6 G 19 45°F
JAKI2 12 mi105 min W 8.9 46°F
CMTI2 - 9087044 - Calumet, IL 16 mi45 min SW 9.9 G 19 45°F 1002.9 hPa (+3.2)38°F
WHRI2 - Waukegan Harbor, IL 30 mi44 min WSW 16 G 27 45°F
BHRI3 - Burns Harbor, IN 33 mi40 min WSW 18 47°F 1003.7 hPa
45170 38 mi25 min 18 G 23 46°F 48°F5 ft40°F
MCYI3 - Michigan City, IN 41 mi25 min SW 21 G 23 46°F 39°F
KNSW3 - Kenosha, WI 45 mi45 min WSW 16 G 26 44°F 1001.7 hPa (+4.4)

Wind History for Calumet Harbor, IL
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SW13
G20
SW8
G16
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S12
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G16
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G16
S8
G12
W5
G8
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G23
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S11
G16
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G13
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SE9
G14
SE11
G15
SE11
G16
SE10
G15
SE9
G15
SE7
G11
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G11
SE5
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2 days
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N6
N8
N7
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NE4
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G10
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E7
G10
SE8
G12
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G16
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SE9
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G14
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G15
SE10
G15
S9
G14
S11
S9
SE10
G14

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago, Chicago Midway Airport, IL13 mi52 minWSW 15 G 2310.00 miOvercast46°F37°F73%1002.9 hPa
Chicago, Chicago-O'Hare International Airport, IL14 mi54 minW 15 G 2510.00 miOvercast46°F37°F71%1002.2 hPa
Chicago / Wheeling, Pal-Waukee Airport, IL18 mi53 minWSW 13 G 2010.00 miOvercast45°F37°F77%1002.3 hPa

Wind History from MDW (wind in knots)
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Last 24hrSW12
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W10W5W8W5SE3SE5SE6SE10S8S11S10
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G25
SW21
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W23
G32
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SW16
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1 day agoS14
G20
S9
G18
SE14
G21
SE15
G23
SE13
G22
SE13
G20
SE9SE7S5SE6S9S9S11
G18
S11S10S10S11S13
G18
S15
G20
S12S12SW20
G26
SW14
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W18
G25
2 days agoE11
G15
E11E10E11NE9E8E9E8E7SE4SE9SE11SE9SE8S9SE9SE7S9S10
G18
S10S10SE8SE9S13
G19

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 (14,3,4,5)
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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.