Thursday, September21, 2017 L-36.com


Marine Weather and Tides
Niles, 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 6:37AMSunset 6:50PM Thursday September 21, 2017 2:39 PM CDT (19:39 UTC) Moonrise 7:57AMMoonset 7:56PM Illumination 1% Phase: Waxing Crescent; Moon at 1 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
    EDIT      (on/off)   Help
LMZ741 Winthrop Harbor To Wilmette Harbor- Wilmette Harbor To Northerly Island- Northerly Island To Calumet Harbor- 916 Am Cdt Thu Sep 21 2017
Rest of today..South winds 5 to 10 kt becoming southeast around 10 kt. Becoming mostly Sunny. Waves 1 ft or less.
Tonight..South winds 10 to 15 kt. Mostly clear. Waves 1 ft or less.
Friday..South winds 10 to 15 kt becoming southeast in the afternoon. Sunny. Waves 1 ft or less.
Friday night..South winds 10 to 15 kt. Mostly clear. Waves 1 ft or less.
LMZ741 Expires:201709212200;;715714 FZUS53 KLOT 211416 NSHLOT NEARSHORE MARINE FORECAST National Weather Service Chicago/Romeoville IL 916 AM CDT Thu Sep 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>742-212200-

7 Day Forecast for Marine Location Near Niles, IL
   Hourly   EDIT   Help
location: 42, -87.81     debug


Area Discussion for - Chicago, IL
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus63 klot 211924
afdlot
area forecast discussion
national weather service chicago romeoville, il
224 pm cdt Thu sep 21 2017

Short term
224 pm cdt
through Friday...

late september heat remains the main focus of the forecast in the
near term. New record high temp already set today at o'hare with
a 94 degree reading there.

Midwest remains along the periphery of highly amplified upper
level ridge axis, downstream of a deep long wave trough across
western noam. 12z RAOB from dvn indicated 850 mb temp of +20c, and
a 925 mb temp of +26c, resulting in low-mid 90 degree temps across
the region. Residual high cloud cover from decaying MCS over
southeast ia northeast mo has kept temps slightly lower across
western parts of the cwa, though a decrease in the denser cirrus
has temps approaching 90 there as well this afternoon. Of course
the weak surface pressure gradient in the vicinity of the
stationary front just north of the CWA has allowed a lake breeze
to push inland across far northeastern il, keeping temps in the
mid-upper 80's for areas near the lake.

Recent runs of the hrrr indicate the potential for isolated
thunderstorm development across mainly the southern parts of the
cwa late this afternoon. Experimental esrl hrrr also hints at this
though with much lower coverage. It appears these models may be
focusing on a remnant MCV from the ia mo convection, though no
distinct circulation is noted in water vapor imagery. While
current rap mesoanalysis depicts 3000 j kg of MLCAPE and little
cin across the southern tier of CWA counties, weak flow and
fairly shallow CU field per goes-16 vis imagery suggests these
models may be quite overdone with thunderstorm potential.

Maintained less than 20 percent pops through sunset, but may have
to add an isolated mention if CU field becomes more impressive or
something pops.

Another mild night is in store for the region with persistent
light south winds and unseasonably high dew points. Overnight mins
should remain in the 70's in most locations, which will also give
a warm head start for temps on Friday. Less cloud cover and
similar low level thermal field should allow highs in the low
90's in most spots again Friday afternoon, again at or near record
levels for september 22nd. (records for tomorrow are 92 for
chicago, 93 for rockford) weak southeasterly lake breeze should
again keep temps in the 80's right along the lake.

Ratzer

Long term
Friday night through Thursday...

218 pm... The models continue to show slight thermal cooling this
weekend but this will likely have little if any noticeable
affects as overnight lows remain in the 60s... Low 70s
downtown... And highs in the upper 80s near 90 Saturday Sunday.

Bumped temps up a few degrees to near current guidance values.

Lake breezes are possible both days which will keep the immediate
lakeshore areas cooler but confidence is low regarding how strong
these lake breezes may be and how far inland they will move.

Forecast highs are cooler near the lake but trends will need to be
monitored as these time periods approach. Highs may still reach
the upper 80s before temps cool and winds shift off the lake.

There is still some potential that the models are cooling the
airmass too fast and if that were to occur... Highs could still be
a few degrees warmer than currently expected this weekend.

However by early next week it does appear that the entire airmass
will cool enough for highs to remain in the 80s. Additional cloud
cover... Perhaps a more broken afternoon CU field... May also help
put a lid on high temps... Keeping them in the 80s.

A cold front will move across the area Tuesday night into
Wednesday next week. While an isolated shower is possible any
afternoon from Sunday onward next week... This front will be the
next best chance of rain for the entire area. However... Not
confident on how widespread precip will become and its possible
just scattered precip in a narrow time window moves across the
area ahead of the front. Though a slower front... That arrives
later into Wednesday could allow for more daytime heating and
thus better precip coverage. This front will allow much cooler air
to spread across the area with highs back into the 70s. A second
push of colder air is possible late next week. Cms

Aviation
For the 18z tafs...

weak surface pressure gradient across the area this afternoon will
allow a lake breeze to move close to ord mdw and go through gyy,
with current variable winds expected to become east-southeast less
than 10 kt. Direction becomes a bit uncertain with little push to
the lake breeze, though southeast appears to be most likely for
ord mdw. Winds will become more southerly again this evening with
loss of lake breeze circulation. Slightly stronger low level flow
Friday should keep lake breeze east of the chicago metro
airports.

Otherwise,VFR conditions will prevail with gradually decreasing
high cloud cover associated with dissipating thunderstorms over
southeast ia northeast mo. Some patchy shallow MVFR fog is
possible toward sunrise primarily for dpa in the fox river valley.

Ratzer

Marine
218 pm... A weak cold front has stalled over south central
portions of lake michigan this afternoon. This front will lift
back north as a warm front tonight... Shifting light winds back
southerly. A large trough of low pressure will remain nearly
stationary over the plains through early next week maintaining
southerly winds over the lake. This trough front will move across
the great lakes region Tuesday night into Wednesday shifting winds
northwest with a period of 15-25 kts expected. Cms

Lot watches warnings advisories
Il... None.

In... None.

Lm... None.

Visit us at http: weather.Gov chicago (all lowercase)
follow us on facebook... Twitter... And youtube at:


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
FSTI2 9 mi100 min S 1.9 75°F
OKSI2 12 mi100 min E 4.1 89°F
45174 12 mi30 min ENE 7.8 G 7.8 74°F 71°F1 ft71°F
CHII2 - Chicago, IL 14 mi50 min SE 14 G 14 87°F 64°F
JAKI2 20 mi100 min SSE 1.9 83°F
CMTI2 - 9087044 - Calumet, IL 24 mi52 min SE 6 G 9.9 89°F 1015.6 hPa64°F
WHRI2 - Waukegan Harbor, IL 25 mi60 min NE 8 G 9.9 74°F
KNSW3 - Kenosha, WI 41 mi40 min NNW 1.9 G 5.1 73°F 1015.9 hPa (-0.7)
BHRI3 - Burns Harbor, IN 43 mi40 min SW 8.9 G 11 87°F 1016.6 hPa (-1.0)
45170 48 mi30 min N 3.9 G 3.9 77°F 75°F74°F

Wind History for Calumet Harbor, IL
(wind in knots)    EDIT      (on/off)   Help
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
Last
24hr
S10
G14
S14
G21
S11
G16
S10
G16
SE6
G10
SE8
G12
S8
G15
S6
G12
S6
S4
S5
G9
S4
SW2
S1
S3
S5
S5
SW5
SW6
S5
S4
SE4
E4
G7
NE8
1 day
ago
N7
N8
G11
NE7
G10
N5
G9
NE6
NE4
NE3
NE3
E3
E3
SE3
S2
G5
SE4
S3
S2
SE2
S2
SE6
G10
SE5
S6
G11
SE9
S7
G11
S10
SW8
G15
2 days
ago
NE7
NE8
N7
G10
N7
N6
G9
N5
G9
N5
NE7
G10
NE8
NE4
NE5
NE3
N1
N3
NE4
N2
N6
NE4
NE3
NE4
N4
NE4
NE7
NE8
G11

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago, Chicago-O'Hare International Airport, IL5 mi49 minSSW 810.00 miMostly Cloudy93°F62°F36%1015.1 hPa
Chicago / Wheeling, Pal-Waukee Airport, IL9 mi48 minENE 910.00 miMostly Cloudy89°F71°F55%1015.7 hPa
Chicago, Chicago Midway Airport, IL15 mi47 minSSW 710.00 miPartly Cloudy93°F61°F34%1014.4 hPa
Chicago / West Chicago, Dupage Airport, IL24 mi48 minSSW 610.00 miA Few Clouds90°F64°F42%1015.3 hPa

Wind History from ORD (wind in knots)
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
Last 24hrS15S18
G23
S17S20
G23
S11S9S10SW6SW8S8SW8CalmS5S3SW5S5SE3S5S4SW4SE4S5S4S8
1 day agoE8E7E9E9E7NE6E4E3E5E5SE4SE4SE4SE3SE4SE6SE6SE8SE10S9S9S10SW9
G18
S12
G18
2 days agoE6E7NE9E9NE8NE8NE8E9NE8NE6NE7NE5N3N5N5N5N6N4NW3N4NE54NE6NE11

Tide / Current Tables for
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help
Tide / Current Tables for
   EDIT      (on/off)   Help
Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Midwest    EDIT
Geos

Wind Forecast for Chicago, IL (15,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Chicago, IL
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.