Marine Forecasts

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7 Day Forecast for Marine Location Near Chicago, IL

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Area Discussion for - Chicago, IL

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Fxus63 klot 191127 afdlot area forecast discussion national weather service chicago romeoville, il 627 am cdt Sun aug 19 2018 Update 627 am cdt goes-e nighttime microphysics rgb imagery shows fog developing and expanding north, mainly between i-39 and the fox river. Sfc obs support satellite imagery with many sites dropping to or even below 1 4sm, so have opted to expand the advisory to include these areas. - izzi 424 am cdt have opted to issue a dense fog advisory for locations south of i-80. Satellite trends and surface obs indicate the fog has expected and become more dense over the south half of the cwa during the past hour or two. Calls around the area confirm this as well. As noted in the short term discussion, this fog should dissipate by mid morning given the lack of clouds aloft. Kluber Short term 302 am cdt through tonight... generally quiet weather is expected through tonight ahead of an approaching strong low pressure system on Monday. Fog has slowly developed across primarily the south half of the CWA early this morning per satellite imagery and area observations. For the most part, locations with visibility less than one mile have been far more isolated than Saturday morning. With no cloud cover aloft, expect any fog to dissipate quickly after sunrise. A surface ridge extending SW across the CWA will keep light NE to se winds across the area today, with some enhanced wind behind an expected lake breeze this afternoon. Some hi-res guidance continues to indicate a few widely isolated showers forming on the lake breeze this afternoon across NW indiana and the chicago metro. Some capping around 700mb should limit the vertical motion of any deeper cumulus to the point that dry air entrainment prevents further cloud growth. With that said, would not be surprised to see some of the deeper cumulus generate sprinkles. Mid to upper-level clouds will gradually increase tonight ahead of the approaching system. Precip should remain SW of the CWA prior to daybreak Monday. The thickening clouds and stronger SE winds should prevent fog development tonight. Kluber Long term 302 am cdt Monday through Saturday... an unseasonably strong low pressure will move across the region Monday into Tuesday, with several rounds of showers and thunderstorms along with a highly conditional severe thunderstorm threat. Monday and Tuesday: guidance continues to develop an anomalously strong surface low for mid late august across the great lakes region as a slow-moving upper low over the central great plains phases with longwave troughing across south-central canada. The surface low is expected to track from between kansas city and omaha late tonight to far NW illinois Monday evening, to northern lake huron Tuesday morning. A swath of precipitable water values around two inches will supply ample moisture to this system. With the time frame now falling into the window of several hi-res models, it is becoming apparent that there may be two main waves of precip Monday and Monday night. The first will quickly shift ne across the CWA Monday morning into the afternoon on an embedded trough axis rotating around the upper-low. This will likely result in a broken line of moderate to sometime heavy showers over a 2-4hr window. The second round will be associated with developing convection as the stacked low nears from the west late Monday

afternoon into the evening. A severe weather threat highly conditional on the ability to generate sufficient instability between these rounds of precip exists with this activity. Poor mid- level lapse rates will limit the upper bound of MLCAPE to around 1200 j kg, but this should be sufficient for strong to severe storms given the impressive dynamics and shear profiles normally expected in early fall versus late summer. While there is a damaging wind threat, low lcls and notable backing of the low-level wind profile supports a conditional tornado threat. Again, this remains very conditional on at least some clearing Monday afternoon between the two rounds of precip. Lastly, while there is some flooding risk, the progressive nature of the waves of precip should limit the areal extent of any excessive rains. After the evening convection, the area will likely fall under a dry slot for a period of time before the upper low passes overhead late Monday night into Tuesday morning, at which time more showers will be possible. Strong cyclonic flow behind the system will result in gusty NW winds and isolated to scattered showers Tuesday. Wednesday through Saturday: high pressure will slowly move across the region Wednesday and Thursday, bringing dry conditions and seasonable temperatures. A potent shortwave trough will then cross the region Friday afternoon into Saturday. While there will be a chance of showers and some storms, better forcing will remain north of the cwa. Kluber Aviation For the 12z tafs... ground fog this morning has largely developed away from the taf sites and what vsby restrictions there are should quickly improve in the next hour or so. Otherwise, no significant weather expected with E to NE winds picking up near and immediately down wind of the lake later this morning through the afternoon. Some showers and t-storms could begin to affect mdw and ord toward the end of the 30 hours taf. - izzi Marine 214 am cdt primary marine concern will be the unseasonably strong storm system progged to move across the region early in the week. First, should see increasing east to southeast winds Monday as the low deepens and approaches the region. The low is progged to track across southern lake michigan late Monday night early Tuesday morning with northerlies increasing later Monday night over northern portions of the lake with the stronger winds spreading south across the remainder of the lake during the day Tuesday. Given increasing model consensus and likelihood of significant instability with the somewhat cooler air on the back side of the system moving over the very warm lake, have introduced a period of gales into the forecast for Tuesday into Tuesday evening. Very strong lake induced instability should set the stage for lake effect showers and thunderstorms Tuesday night into Wednesday morning, so while synoptic winds will ease Tuesday night, there will likely be some localized winds in squalls in association with the stronger lake effect showers and storms. In addition, lake induced instability looks sufficient for a waterspout risk, especially later Tuesday night into Wednesday morning. - izzi Lot watches warnings advisories Il... Dense fog advisory... Ilz003-ilz004-ilz005-ilz008-ilz010-ilz011- ilz012-ilz019-ilz020-ilz021-ilz022-ilz023-ilz032-ilz033- ilz039 until 9 am Sunday. In... Dense fog advisory... Inz001-inz002-inz010-inz011-inz019 until 9 am Sunday. Lm... None. Visit us at http: weather.Gov chicago (all lowercase) follow us on facebook... Twitter... And youtube at:

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Weather Reporting Stations

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Stations	Dist	Age	Wind	Air Temp	Water Temp	Waves	Pressure	DewPt
CNII2	1 mi	22 min	ENE 4.1 G 7	76°F				66°F
45177	3 mi	127 min			76°F	1 ft
JAKI2	5 mi	127 min	ENE 2.9 G 6	76°F
CHII2 - Chicago, IL	5 mi	37 min	NE 8 G 9.9	75°F				67°F
FSTI2	9 mi	127 min	NNE 4.1	75°F
CMTI2 - 9087044 - Calumet, IL	9 mi	37 min	N 4.1 G 6	76°F			1015.2 hPa	69°F
45174	20 mi	27 min	NE 5.8 G 7.8	74°F	76°F	2 ft		71°F
BHRI3 - Burns Harbor, IN	28 mi	37 min		75°F			1016.3 hPa
45170	34 mi	27 min	SE 1.9 G 3.9	73°F	77°F	2 ft		69°F
WHRI2 - Waukegan Harbor, IL	37 mi	27 min	NNE 6 G 7	73°F
MCYI3 - Michigan City, IN	37 mi	47 min	SE 2.9 G 4.1	72°F				67°F
45186	37 mi	27 min	NNE 5.8	74°F	76°F	1 ft
45187	45 mi	27 min		73°F	76°F	1 ft

Wind History for Calumet Harbor, IL

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
Chicago, Chicago Midway Airport, IL	9 mi	74 min	NE 3	10.00 mi	A Few Clouds	75°F	69°F	82%	1014.4 hPa
Chicago, Chicago-O'Hare International Airport, IL	18 mi	76 min	NNE 4	6.00 mi	A Few Clouds with Haze	73°F	66°F	81%	1014.7 hPa
Gary Regional Airport, IN	19 mi	82 min	N 0	10.00 mi	A Few Clouds	64°F	64°F	100%	1015.6 hPa
Lansing Municipal Airport, IL	22 mi	72 min	N 0	10.00 mi	Fair	69°F	68°F	99%	1015.6 hPa
Chicago / Wheeling, Pal-Waukee Airport, IL	24 mi	75 min	N 3	9.00 mi	Fair	72°F	66°F	82%	1015.5 hPa

Wind History from MDW (wind in knots)

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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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GOES Local Image of    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.
target = "new">Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East

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Wind Forecast for Chicago, IL (10,2,3,4)

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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.