Southern Wisconsin’s flooding could get worse before it gets better, as more heavy rain is expected again on Monday, according to forecasters.
Officially, 1.52 inches of rain was recorded at the Dane County Regional Airport on Sunday, setting a record for Madison for Sept. 2. That boosted Madison’s September and meteorological fall (September through November) precipitation total to 1.64 inches, 1.41 inches above normal. The 2018 total rose to 37.67 inches, 12.62 inches above normal.
Labor Day dawned with some locally dense fog that could continue through mid-morning, mainly west of a Monroe to Madison to Fond du Lac line, the National Weather Service said.
Thunderstorms are forecast to spread north through southern Wisconsin mainly Monday afternoon, delivering locally heavy rain with frequent lightning, although severe weather is not anticipated. Another 1.5 to 2 inches is possible, with some locales perhaps seeing 3 inches.
The heavy rain could worsen the significant river flooding that continues along the Baraboo River, while new flooding is expected to occur across the Rock River and Crawfish River basins, and street flooding will continue in the east side of Madison’s Isthmus where the Yahara River connects Lake Mendota and Lake Monona, the Weather Service said.
Additional rain prompts officials to increase the flow between Mendota and Monona and that increases street flooding in the area. Details of street impacts are in the list at the city of Madison’s website.
The state reports that about 75 Wisconsin National Guard soldiers were mobilized to place sandbags overnight along a nearly mile-long stretch of eastbound Interstate 90/94 near Highway 33 in Columbia County. The sandbags aim to keep rising floodwaters from overtopping I-90/94, causing lane closures.
Floodwaters are above pavement level on southbound I-39 in Columbia County near Cascade Mountain Road, but pumps, sandbags and berms are holding back the water there.
See our comprehensive coverage of the flooding here.
In Madison on Monday, there’s an 80 percent chance for showers and storms during the day and 60 percent at night, with a quarter- to half-inch of rain possible in both periods, a high near 73 and low around 68, the Weather Service said.
The chance for showers and storms falls to 20 percent Tuesday, then rises back to 50 percent Tuesday night and 60 percent Wednesday, with a quarter- to half-inch of rain possible Wednesday. Skies should be partly sunny Tuesday and cloudy Wednesday, with highs near 83 and 75 sandwiching a low around 69.
The Weather Service said chances for showers and storms continue at 30 percent Wednesday night, 20 percent Thursday through Friday, 40 percent Friday night, 50 percent Saturday, 40 percent Saturday night, and 20 percent Sunday.
Skies over Madison are predicted to be mostly cloudy Thursday and Friday, cloudy Saturday, and partly sunny Sunday, with highs near 69, 70, 69 and 73, and lows Wednesday night through Saturday night around 59, 57, 58 and 57.
27 Storm Track meteorologist Branden Borremans forecasts scattered showers and thundershowers Monday and Monday night, isolated late day storms Tuesday, a few storms Tuesday night, scattered showers and storms Wednesday, dry weather Thursday and Friday, a few showers and storms late Saturday, and dry again Sunday and next Monday.
Borremans said skies over Madison should be cloudy Monday, partly sunny Tuesday, mostly cloudy Wednesday, partly sunny Thursday and Friday, increasingly cloudy Saturday, and partly sunny Sunday and next Monday, with highs near 77, 86, 77, 72, 72, 70, 74 and 75, and overnight lows around 70, 71, 57, 55, 57, 60, 57 and 60.
Sunday’s high in Madison was 82 at 2:04 p.m., 5 degrees above the normal high and 16 degrees below the record high of 98 for Sept. 2, set in 1953.
Sunday’s low in Madison was 68 at 6:15 a.m., 12 degrees above the normal low and 31 degrees above the record low of 37 for Sept. 2, set in 1976.