Cold Blast Behind Winter Storm Wesley May Delay Flooding

Linda Lam
Published: April 12, 2019

A blast of cold air has plunged into the central U.S. behind Winter Storm Wesley and could delay river flooding for at least a few days until temperatures warm up again.

A southward dip in the jet stream, or upper-level trough, will allow colder-than-average temperatures to infiltrate much of the Plains through the weekend.

With temperatures rising only into the 30s and 40s during the day and dipping to near or below freezing overnight, the more than 20 inches of snow the storm dropped in parts of South Dakota this week and the more than a foot of snow the on the ground from the Plains to the upper Midwest won't melt too fast.

Current River Gauges and Snow Depth

Still, even with gradual snow melting, river levels will continue to rise and significant flooding is still a concern. Soil moisture is close to record-high levels from eastern Nebraska to Wisconsin, according to NOAA, and this will exacerbate the flood risk.

River gauges indicating at least minor flooding are shown above and the river forecasts from NOAA expect that number to increase through mid-April, even with the colder temperatures.

Colder-than-average temperatures will persist in parts of the central U.S. due to a southward dip in the jet stream.

Chilly Mid-April Forecast

High temperatures will be 10 to 35 degrees below average into this weekend for most of the Plains.

On Friday, temperatures will top out in the 30s in the northern Plains and upper-Mississippi valley.

Highs in the 30s and 40s are expected on Saturday from the northern Great Lakes into the northern and central Plains and even into the Texas Panhandle. This will be quite a difference in parts of the southern Plains where high temperatures reached the 80s and 90s ahead of Winter Storm Wesley.

(MAPS: 10-Day Forecast

Forecast Highs

Although temperatures will warm into the 60s and 70s on Sunday in the southern Plains, areas from the northern Plains into the Great Lakes will continue to see highs in the 30s and 40s.

Low temperatures will also be 10 to 25 degrees below average into Monday morning for much of the central U.S.

This translates to temperatures dropping into the teens and 20s from the central Plains into the northern Great Lakes. Lows in the 20s and 30s will be found as far south as western Texas and Oklahoma at times.

Forecast Morning Lows

This cooler, drier air will not last, however.

Warmer air, that is, highs in the 60s and 70s will soar as far north as Minneapolis on Tuesday and Wednesday.

Rain, and possibly thunderstorms, will also arrive in much of the Midwest and Great Lakes on Tuesday.

The warmth and the rain will renew the threat of river flooding as snow is melted even in the Upper Midwest.

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