Clouds, Fog Helped Reduce Flood Impact

OMAHA (DTN) -- Well-above-normal temperatures next week after deep freeze conditions and heavy snow in January in parts of central United States, and snowmelt that could lead to possible ice-jams on frozen rivers, has led to some flood concerns.

People think back to the bomb cyclone of 2019 and some of the similar weather factors that created a devastating flood for five Midwest states. (https://www.dtnpf.com/…)

However, even though there are already flash flood warnings and other types of flood advisories popping up from the National Weather Service on Friday and into early next week, DTN Meteorologist Teresa Wells said there are differences, which mean this won't be a repeat of those 2019 floods.

You can thank several factors for some of that: the dreary, cloudy, densely foggy days this week and into next week that helped block the sun and avoided rapid temperature increases during the day; the warm fall we had that helped slow ice buildup on rivers and streams; and even the continued drought in the heart of the country that meant fields and rivers could absorb more moisture. (https://droughtmonitor.unl.edu/…)

Most importantly, as the river levels are expected to peak this weekend and early next week, there isn't any heavy precipitation forecast.

"So that'll really be the saving grace, I think, for a lot of these places -- we're not really expecting any really heavy rainfall here through this weekend and into basically the middle of next week," said Wells. She said there is a clipper system moving through early next week, and "a potentially larger system late next week, but I would have low confidence on details with that just because it is so far out."

FLOOD ADVISORIES ALREADY OUT

Flash flood warnings and flood warnings were already issued Friday by the National Weather Service in parts of northern Illinois, especially along the Illinois River. Recent rainfall and warmer weather are leading to snow melting and levels rising in rivers and streams.

Wells explained there was a mild December in the Midwest, until the Arctic blast hit in early January and started to freeze up the rivers. It especially got cold in the north-central U.S. She said there was still plenty of time for the rivers to ice up; there is now some heavy river ice in some of those areas -- along with the recent snows -- that expect flooding.

On Friday, NWS noted that minor flooding is already happening, and moderate flooding is forecast this weekend in Illinois.

Wells said parts of Illinois have been receiving rain throughout the week since Monday. "Portions of northern Illinois saw anywhere between a half to 1 1/2 inches of rain. So that's definitely contributing to some of that flooding. And, with that rain and the warmer temperatures, that's going to create that risk for more of that snow melting," Wells said.

She said with the frigid weather in January, there was also frozen ground in places leading to "greater risk for that water just running off instead of actually soaking into the ground." Looking at the snow depth, there was still 2-4 inches of snow in northern Illinois and eastern Iowa as of Friday morning, although there are pockets still of 4-8 inches.

OTHER FLOOD WATCHES AND WARNINGS

There have also been flood watches and warnings for this weekend into early next week stretching from Alabama to West Virginia.

Rising temperatures to well-above normal are expected next week in the Midwest, such as eastern Nebraska, and this is also leading the NWS to note the warmer weather and snowmelt runoff "will lead to an increased chance of ice breakup and subsequent jamming along prone stretches of area rivers."

However, Wells explained how weather conditions this winter have helped prevent the floods from being worse.

For example, the rise from some record-low temperatures to much-warmer-than-normal conditions has been gradual. This week, parts of the Midwest saw temperatures increase to the mid-30s Fahrenheit in the afternoons. This helped keep it from a significant snowmelt all at once. There were also "pretty cloudy" conditions for much of the central U.S., and that definitely helped to act as an insulator to keep temperatures moderate but also kept out a bright sun that would have melted the snow too fast.

CONDITIONS COMING UP

As for what's coming up, the weekend will start cool.

"On the weekend, there is going to be a low-pressure system that will be sliding by into the eastern Midwest," Wells said, adding that it is currently in the Southern Plains.

"The western Midwest shouldn't really see any snow out of it," Wells said.

"That'll continue to slide northeast, so portions of Iowa, Illinois, even Nebraska will stay on the cooler side of this low-pressure system as it moves by to the east of those areas, and high temperatures look to be around, say, the mid-30s to low 40s." As for precipitation, the eastern Midwest could see some light rain or light freezing rain.

Then the warmup begins on Monday across the Plains, with portions of Nebraska and Kansas into the low 40s, maybe even low 60s; it will be on the cooler side for Illinois and parts of Iowa with temperatures in the upper 30s to maybe mid-40s.

As for flood risk along the Missouri River, Wells said there doesn't seem to be much potential for floods as the river maintains or even dips a little next week in its levels because it was so low this fall. (https://www.dtnpf.com/…)

See more about the warmer weather next week at https://www.dtnpf.com/….

Elaine Shein can be reached at elaine.shein@dtn.com

Follow her on X, formerly known as Twitter, @elaineshein

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