Chicago Weather Forecast (O'Hare Official) MON JUN 18, 2018 0:35 AM CT with Forecast Discussion


Overnight: Partly cloudy, with a low around 78. South southwest wind 5 to 10 mph.

Monday: Showers and thunderstorms likely, mainly after 4pm. Mostly sunny, with a high near 94. Heat index values as high as 101. West southwest wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Monday Night: Showers and thunderstorms likely, mainly before 7pm. Mostly cloudy, with a low around 65. West northwest wind 5 to 10 mph becoming north northeast after midnight. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

Tuesday: A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 77. Northeast wind around 5 mph.

Tuesday Night: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 63. North northeast wind around 5 mph.

Wednesday: A 30 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 76.

Wednesday Night: Mostly cloudy, with a low around 62.

Thursday: A chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 77.

Thursday Night: A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 62.

Friday: A chance of showers and thunderstorms. Mostly cloudy, with a high near 77.

Friday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 64.

Saturday: A chance of showers and thunderstorms. Partly sunny, with a high near 81.

Saturday Night: Partly cloudy, with a low around 65.

Sunday: Mostly sunny, with a high near 84.

Area Forecast Discussion below ad ...


AREA FORECAST DISCUSSION
National Weather Service Chicago/Romeoville, IL
GO Current Forecast Discussion

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National Weather Service Chicago/Romeoville, IL 1225 AM CDT Mon Jun 18 2018

.UPDATE... 804 PM CDT

Quiet but humid, warm evening across the CWA. Rain-cooled outflows from earlier did push some temperatures down (e.g. 82 in Morris), but also nudged up dew points in these areas. Can`t rule out some shallow fog in these areas overnight if it clears of cirrus. As for the prolonged effects of the heat, the urban heat island of Chicago and adjacent suburbs are doing well to retain the heat, with downtown, O`Hare, and Midway all at 88 degrees as of 8 pm.

Early evening satellite imagery and 00Z upper air raobs indicate a series of short waves from the central Plains into northern Wisconsin with multiple areas of convection. One wave with a 1007 mb surface low is moving eastward in northern Wisconsin, and convection ahead of this has shown some cold pool push. Corfidi vectors for this activity are oriented more south-southeast, and there continues to be good surface and low-level moist flow into this so expecting to see that trend gradually play out. Some of this convection itself, or isolated convection developing ahead of this on outflow, could reach southeast Wisconsin after midnight. In addition, more convective activity favored across the Minnesota/Iowa border region late this evening could also advance into southern Wisconsin late tonight per analysis and support of convective-allowing models. This poses some concern for at the least outflow reaching into northern Illinois including Chicago into Monday morning, and even the possibility to bubble isolated storms. For now have just slightly expanded southward the early morning slight chance of storms, as confidence on this is low, but would at least expect some convective activity late tonight/very early tomorrow morning in southern Wisconsin.

Forecast for Monday continues to look in good shape with the points noted in below AFD. Concerns for heavy rain potential Monday evening into the overnight are certainly there with 00Z raobs at MPX and OAX indicating over two inches of precipitable water, and a potential for west-to-east training setup with generally light propagating vectors off that development corridor. Uncertainties remain on just how quickly the frontal and post- frontal convection work their way into the CWA from the north on Monday evening, as well as some potential for pre-development with RAP soundings for tomorrow afternoon indicating the cap likely being close to being breached.

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Arlingtoncardinal.com/uvindex
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Arlingtoncardinal.com/sun
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Arlington Heights Weather Forecast
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allergy.chgowx.com
Chicago allergy weather

arthritis.chgowx.com
Chicago arthritis weather

respiratory.chgowx.com
Chicago respiratory weather

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