Flash floods coming Monday. We’ll show you where and when.

August 20, 2018

Heavy rain and thunderstorms are expected to produce flash flooding conditions in southern Wisconsin on Monday, in pretty much the same areas where heavy rain caused flash flooding last week.

The National Weather Service issued a flash flood watch in effect from Monday afternoon to Tuesday morning, including Dane, Columbia, Green, Iowa, Rock, Sauk and Lafayette counties.

Periods of moderate to heavy rainfall is expected from late Monday afternoon into Tuesday morning, with 1 to 3 inches expected, and some localized amounts could reach 4 inches or more.

Flash flooding in urban areas is possible if 2 to 4 inches of rain falls in a short period of time, and rural areas soaked by rain last week could also get flooded.

In Madison, the heaviest rainfall will happen Monday night, with up to 2 inches of rain possible.

The rain is coming in with a cold front that should keep high temperatures in the mid-70s all week.

27 Storm Track meteorologist Branden Borremans said highs should top out at 76 on Monday, 75 on Tuesday, 76 on Wednesday, 78 on Thursday and 74 on Friday, with sunshine Wednesday and Thursday.

Showers and thunderstorms could return on Friday, with hot and humid conditions forecast for the weekend.

Borremans said highs could hit 87 on Saturday, 89 on Sunday and 87 next Monday.

Sunday’s high of 83 was 4 degrees above normal and 14 degrees below the record high of 97 for Aug. 19, set in 1983.

The low of 58 was 1 degree below normal and 15 degrees above the record low of 43 for the date, set in 1981.

No rain fell at the airport on Sunday, keeping the August rainfall total at 4.52 inches, 1.83 inches above normal.

The record rainfall on Aug. 19 was 2.74 inches in 2016.

For the meteorological summer of June through August, Madison has received 13.31 inches of rain, 1.90 inches above normal.

Since Jan. 1, Madison has received 30.15 inches of precipitation (rain and melted snow), 6.91 inches above normal.

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