- Showers and thunderstorms are expected this week in parts of the Plains, Midwest and South.
- Flash flooding is possible in parts of those regions this week.
- Many rivers remain in flood.
- Record flooding has occurred along portions of the Arkansas and Missouri rivers.
- Flooding along the Mississippi River may last through the summer.
Multiple rounds of rain and thunderstorms will impact portions of the Plains, Midwest and South this week, potentially contributing to flash flooding, including in areas that were soaked last month.
Scattered thunderstorms, including some overnight thunderstorm clusters, have returned to the Plains. They will continue early this week in parts of the Plains and Midwest as upper-level disturbances interact with moisture returning to those regions.
Then, an area of low pressure will move through the southern tier of the United States later this week while pulling in deep moisture from a tropical disturbance in the western Gulf of Mexico. That setup could trigger more heavy downpours from the southern Plains into the lower Mississippi Valley from Wednesday through late this week.
These thunderstorms could at least bring more localized flash flooding and compound the ongoing long-term river flooding issues.
Many locations from the central and southern Plains into the Mississippi Valley and Ohio Valley could see 1 to 3 inches of rain in the week ahead. Locally up to 5 inches of rain is possible in some areas where clusters of thunderstorms stall for several hours at a time.
Here’s a general look at which areas have the greatest risk of localized flash flooding the next few days.
Monday-Monday Night: West Texas to parts of Kansas, eastern Nebraska and western Iowa.
Tuesday-Tuesday Night: Parts of southwest Texas and southeast New Mexico, as well as from central and northern Missouri into central Illinois.
Wednesday-Wednesday Night: Parts of the southern and central Plains, particularly eastern and central Texas.
The potential for flash flooding will continue through late this week, but details are uncertain at this time.
River Flooding and Record May Rainfall
Heavy rainfall over the past few weeks shattered all-time May records, swelling rivers to record levels in parts of Arkansas, Kansas, Missouri and Oklahoma.
So far, 10 locations have set new record river levels during this prolonged siege of heavy rain.
Hardest hit so far is the Arkansas River, where record levels have been set near Ponca City, Oklahoma, and Van Buren/Fort Smith, Dardanelle, Morrilton, Toad Suck Reservoir and Pendleton, Arkansas. The record at Morrilton, Arkansas, had stood since the Great Flood of 1927.
The river also reached its highest level since the 1986 flood in Tulsa, Oklahoma, putting unprecedented stress on the levee system, and crested at its highest level since 1943 in Muskogee, Oklahoma, due to heavy rain upstream in northern Oklahoma and southern Kansas.
Little Rock, Arkansas, has seen the Arkansas River rise to its highest level at that location since 1945. The river could have its highest crest since 1957 in Pine Bluff, Arkansas, this week. Record flooding isn’t expected in either location, according to the National Weather Service.
Over 250 river gauges in the United States are reporting levels above flood stage, primarily in the nation’s midsection.
(MORE: Latest NWS River Forecasts)
Record river crests were also set in May along Bird Creek in Avant, Oklahoma, Fancy Creek at Randolph, Kansas, and the Chariton River near Prairie Hill, Missouri.
Record or near-record flooding is possible along the Illinois River downstream from Havana, Illinois.
This week, St. Louis will see its second major crest of the Mississippi River in just under a month, a crest topped only by the Great Flood of 1993, possibly a couple of feet higher than the Mississippi River flood of 1973.
(MORE: Why the Midwest, Plains Have Been Most Extreme Weather Regions in 2019)
That volume of water from the upper Mississippi and Arkansas River valleys will then drain downstream, reaching the lower Mississippi Valley in early to mid-June.
If these forecasts hold, the U.S. Army Corps of Engineers will gradually open the Morganza Spillway upriver from Baton Rouge, Louisiana, on June 6 for only the third time in its history, previously done only in 1973 and 2011.
Constructed in 1954, this structure would divert some water from the Mississippi River into Louisiana’s Atchafalaya Basin to minimize stress on Mississippi River levees downstream and avoid overtopping.
Farther downstream, the Bonnet Carré Spillway in St. Charles Parish, Louisiana, has opened twice this year for the first time in its history, and half of its gates remain open, diverting some Mississippi River water into Lake Pontchartrain.
“The current flood fight is historic and unprecedented,” said a U.S. Army Corps statement issued last Monday.
(MORE: Longest-Lasting Mississippi River Flood Since 1927)
Monthly Rain Records
Rainfall amounts have been staggering over parts of the Plains.
A number of locations from Oklahoma and southern Kansas to western Missouri picked up over a foot of rain in May.
(MORE: The Wettest 12 Months in U.S. History)
Kansas City, Missouri, set a new May rainfall record last Tuesday, topping the previous record from 1995 and ranking it among its wettest months of all-time.
Over 15 inches of rain soaked Bartlesville, Oklahoma, tripling its average May rain, crushing its previous May record of a mere 10.31 inches in 2000 and less than 1 inch away from the city’s single wettest-month record of 16 inches in June 1957.
All-time May monthly rain records were just out of reach in Chanute, Kansas (18.35 inches in May 1990), Wichita, Kansas (13.14 inches in 2008), and Enid, Oklahoma (15.85 inches in May 1982), despite each city picking up over a foot of rain.
Chanute, Kansas, picked up more rain in May – 18.01 inches – than it averages from May through July, combined (16.20 inches).
According to an analysis by the NWS’s Arkansas-Red Basin River Forecast Center, parts of southern Kansas picked up over 60 percent of their average yearly precipitation in May alone.
Also setting May rainfall records were Chicago – for the second May in a row – and Paducah, Kentucky.
Read more from source here…