Regional Precipitation Summary for April 2019

Minor flooding to due to rainfall and snowmelt runoff occurred on some tributary rivers during the middle of month. Minor April 2019 saw minor to moderate flooding on the Mississippi River for the entire month at Wabasha and Winona MN, La Crosse WI, and McGregor and Guttenberg L/D 10 IA, with 2 crests. Warmer weather along with snow melt and locally heavy rains across portion of central and northern WI on the 17th into the 18th produced minor to major flooding along portions of the Chippewa (just north of the HSA) Trempealeau, Black, Yellow and Wisconsin River in western, central and southwest WI from the 17th to the 24th. These flood flows lead to the second crest on the Mississippi River from the 22nd to 27th. April 2019 in the La Crosse HSA saw below to much above normal precipitation near to much above normal snowfall, and near to below normal temperatures.

Precipitation this month was below to above normal across the southeast half of the HSA to above and much above normal across the northwest half. Light rain and snow fell across mainly the central and south parts of the HSA on the 2nd. Light rain was common across the HAS from the 4th to the 8th. On the 10th and 11th a stronger low brought moderate to heavy snows to the northwest third of the HSA a wintry mix to the central third and moderate to locally heavy rains to the southeast third. Light to locally heavy rain fell across the HSA on the 17th, with the heaviest rain across the northwest half. Light to locally moderate rain fell across much of the HSA on the 22nd and 25th. Light to moderate snow and light rain fell across the southwest half of the HSA on the 27th. Light to moderate rain fell across most of the HSA on the 30th.

Normal April rainfall ranges from around 2.75 inches across the north end of the HSA, to around 3.5 inches across the south end. Totals this month ranged from 70 to 100 percent of normal across the southern third of the HSA to 100 to 175 percent of normal across the northern third. Most totals this April were 90 to 120 percent of normal. Extreme totals recorded for the month ranged from 1.80 inches at Oelwein in Fayette Co. IA and 2.35 inches at Lancaster in Grant Co. WI, to 5.19 inches at Neillsville in Clark Co. WI, and 5.49 inches at Steuben in Crawford Co. WI. Snowfall this April ranged from an inch or less along the Mississippi River south of La Crosse, to 8 to 10 inches across portions of southeast MN into north-central WI. This was below normal to much above normal. Normal April snowfall ranges from 1.5 to 3 inches from south to north across the HSA. Totals this month ranged from around 50 percent of normal in the Mississippi River valley south of La Crosse, to 200 to 400 percent of normal across the northwest two-thirds of the HSA.

April 2019 temperatures averaged 42 to 49 degrees. This was 0.5 degree above to 2.5 degrees below the normals. Temperatures were a few degrees above to below normal on the 1st to 5th, much above normal on the 6th to 8th, above normal on the 9th then below and much below normal from the 10th to the 15th. Above normal temperatures occurred on the 16th, followed by near normal readings on the 17th to 20th. Temperatures were much above normal on the 21st, above normal on the 22nd the back to near normal for the 23rd to 26th. The month ended with below and much below normal temperatures on the 27th to 30th. Extremes for the month ranged from lows in the upper teens to mid 20s on the morning of the 15th, to highs in the mid 70s to mid 80s on the 21st.

Flows in the rivers and streams of the HSA were above to much above normal during April. Even with closer to normal temperatures during April, crop planting and field work were a few days to 2 weeks behind normal at the end of the moth. This due in part to the continued wetness and top soil and sub soil moisture being reported as surplus across some 40 to 50 percent of the HSA on April 30th.