Update: Conditions improved -Dense Fog Advisory is no longer in effect this morning

Update 7:30AM CDT…

Fog conditions improved rapidly from west to east this morning. While there is still some patchy fog in northwest Indiana, the Dense Fog Advisory is no longer in effect.

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Dense Fog Advisory will be in effect until 10AM CDT this Tuesday morning extending roughly from the Fox River Valley east through and south of Chicago into northwest Indiana (see gray-shaded area on the highlighted map). Visibility will drop to a quarter-mile or less prior to sunrise and then improve from west to east – first to clear will likely be the Fox River Valley area (follow the visibility across our area on the current visibility chart below).  The morning commute and travel in general will be hazardous due to the poor visibility in the area under the Dense Fog Advisory, so those traveling should take appropriate precautions.

The low pressure system that triggered the severe thunderstorms and widespread rains Monday has moved east into Lower Michigan and the associated cold front is well east of our area. However a trough of low pressure extends west out of the low pressure center back over Lake Michigan into and west of Chicago, and fog/low stratus clouds have formed in the trough with little spread between the temperatures and dewpoints (see current maps below). As high pressure slowly builds into the area and winds pick up from the west/northwest this morning, the temperature-dewpoint spread should widen and conditions subsequently improve from west to east.

Current Metro-area Visibility in tenths of a mile…

Current Metro-area temperatures…

Current Metro-area Dewpoints…