Marine Weather and Tides
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen
|Sunrise 7:01AM||Sunset 4:18PM||Monday December 9, 2019 6:25 PM CST (00:25 UTC)||Moonrise 3:58PM||Moonset 5:11AM||Illumination 96%|
7 Day Forecast for Marine Location Near Dune Acres, INHourly EDIT Help
Area Discussion for - Chicago, IL  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS63 KLOT 092340 AFDLOT
Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 540 PM CST Mon Dec 9 2019
248 PM CST
Through Tuesday .
Main forecast concerns are with the passage of a strong cold front late this afternoon/early this evening. A brief band of low visibility in moderate snow is possible across far northern IL, with gust west winds dropping temperatures quickly this evening.
Early afternoon surface analysis shows 993 mb low across northern lower Michigan. A strong cold front trails from the deepening low, crossing the Mississippi River into western IL. Sharp temperature drop noted across the frontal zone, with mid-40s in place across the cwa as of 2 pm, dropping quickly into the low-mid 20s west of the river across eastern IA. Impressive look to the upper wave on GOES vapor imagery, with the low level frontal zone also a bit more intense than guidance had depicted over the past couple of days. Stronger frontogenetic forcing, focused around 850 mb, has also been producing a narrow but intense band of primarily snow behind the front across IA this afternoon. Rapid drop in visibility within this band to 1/4SM or less had produced many accidents across IA, with a 50-car pileup on I-80 near DSM earlier. While high-res guidance trends continue to indicate a gradual weakening and erosion from the southwest as the band moves east across northern IL late this afternoon, felt it prudent to fill in a winter weather advisory for far northern IL in agreement with DVN and MKX. For simplicity, ran the headline though 6 pm/00Z, though main impacts from snow band look to be only on the order of 30-45 minutes as it moves through any given area. Thus headlines can be cancelled for counties from west to east as band moves through and precip ends. Still some concern especially farther east that shallow moisture/lack of ice nucleation will prevent much in the way of snow have mentioned more of a rain or rain/snow mix into the Chicago metro area and points south.
Otherwise, gusty west winds and strong cold advection are the story tonight, with temperatures dropping into the teens and low 20s across the area. Wind gusts of 30-40 mph during the evening will slowly diminish overnight, though blustery and cold conditions linger into Tuesday. The combination of wind and cold will produce wind chills in the single digits (negative single digits across north central IL) tonight and only in the teens at best Tuesday. Skies do look to clear out late tonight, providing welcome sunshine for Tuesday, with very dry moisture profiles in the arctic air mass.
LONG TERM. 124 PM CST
Tuesday Night through Monday .
Mostly clear skies beginning Tuesday night should allow temps to drop quickly into the teens and single digits across the area. Increasing cloud cover from an approaching weak clipper system early Wednesday morning could limit additional cooling. Despite this, northwest winds will likely result in wind chills values in the single digits to just below zero.
There is a brief period where we could see some flurries/light snow across the area Wednesday morning as the aforementioned weak clipper system moves through. The combination of strong 850 baroclinicity and associated isentropic lift/frontogenesis could support a brief period of light snow, although uncertainty remains on the overall intensity/coverage due to model variability and being under a fairly dry airmass. Currently have a mention of flurries across most of the area by Wednesday morning. If confidence increases, it may be necessary to include some light snow accumulations given that ground temperatures will be sufficiently cold to limit melting. Highs Wednesday will again be in the 20s and lows drop into the teens.
Temperatures begin to rebound Thursday as the surface high and cold air shift to the north and east and southerly flow returns. Highs on Thursday will be near normal in the mid 30s, and slightly above normal by Friday and Saturday with highs in the upper 30s to 40s. The overall pattern remains active during this period, with slight precip chances Friday night through Sunday. Multiple weak upper level disturbances track across the area and appear to blend together in the forecast due to model variability. Will continue to monitor trends as this gets closer to better determine timing of rain/snow potential.
AVIATION. For the 00Z TAFs .
Gusty west-northwest (280-300) expected tonight with the strongest winds likely this evening. A few gusts over 35kt are possible early this evening with gust magnitude and frequency both decreasing late this evening into the overnight hours. MVFR cigs will likely persist through the evening with skies likely to clear after midnight. Otherwise, no weather concerns expected for the remainder of the TAF cycle.
LOT WATCHES/WARNINGS/ADVISORIES. IL . None. IN . None. LM . Gale Warning . Gary to Michigan City IN until 2 AM Tuesday.
Small Craft Advisory . LMZ744-LMZ745 . 2 AM Tuesday to 3 PM Tuesday.
Small Craft Advisory . Winthrop Harbor to Gary IN until 9 AM Tuesday.
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|MCYI3 - Michigan City, IN||18 mi||35 min||WSW 23 G 25||44°F||40°F|
|CHII2 - Chicago, IL||20 mi||95 min||W 26 G 33||47°F||44°F|
|CMTI2 - 9087044 - Calumet, IL||20 mi||157 min||WSW 9.9 G 21||48°F||997.5 hPa||46°F|
|CNII2||22 mi||40 min||W 11 G 15||41°F||34°F|
|SJOM4 - St. Joseph, MI||41 mi||85 min||SSW 16 G 20||44°F||998.6 hPa (+1.6)|
Wind History for Calumet Harbor, IL(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.
|Gary Regional Airport, IN||21 mi||41 min||WSW 12 G 24||10.00 mi||Overcast||45°F||37°F||76%||1000.7 hPa|
|Michigan City Municipal Airport, IN||23 mi||31 min||W 11 G 21||10.00 mi||Overcast||46°F||46°F||100%||1000 hPa|
Link to 5 minute data for KGYY
Wind History from GYY (wind in knots)
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|2 days ago||N||NE||NE||Calm||Calm||Calm||SW||Calm||S||Calm||Calm||Calm||Calm||Calm||S||S||S||S||S||S||S||S||S||SE |
EDIT Weekend mode (on/off) (on/off)  Help
EDIT (on/off)  Help
Weather Map(on/off)  Help Weather Map
GEOS 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.
Link to Loop
Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for Chicago, IL (19,4,5,8)(on/off)  Help
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