Iowa Flood Watch: 2-4 Inches of Rain Possible Through Thursday

MASON CITY, Iowa — A flood watch will take effect Tuesday evening for Mason City and much of north-central and central Iowa as forecasters warn of a prolonged stretch of heavy rain, according to the National Weather Service in Des Moines.

The watch is in effect from Tuesday evening through late Thursday night. The weather service said Monday afternoon that confidence is increasing for heavy rainfall from Tuesday night through Thursday, with totals of 2 to 4 inches and locally higher amounts likely.

Rain is expected to move into parts of Iowa Tuesday night, with periodic precipitation continuing through at least Thursday. The most likely period for heavy rainfall is Wednesday.

The National Weather Service’s Weather Prediction Center has placed much of the region, including the Mason City area, under a Level 2 of 4 “slight risk” for excessive rainfall Wednesday and Wednesday night. The category means scattered flash floods are possible, with at least a 15% probability of excessive rainfall leading to flash flooding within 25 miles of a point.

Forecasters said significant ponding of water is expected, especially in low-lying areas and places with poor drainage, along with rises on rivers and streams. Flash flooding concerns are limited, but the highest risk is in urban areas, according to the weather service. Urban and street flooding and rising rivers and streams are the primary threats.

Probability forecasts through 7 a.m. Thursday show Mason City has a 77% chance of receiving at least 2 inches of rain and a 29% chance of at least 4 inches. Estherville has a 53% chance of at least 2 inches and a 5% chance of at least 4 inches. Decorah has a 73% chance of at least 2 inches and an 18% chance of at least 4 inches.

The weather service urged residents to prepare now. Recommended steps include clearing downspouts and storm drains of leaves and debris, making sure sump pumps are working properly and having a plan in place if flooding is a risk.

“Should you encounter flooding, turn around, don’t drown,” the weather service said.