A strong upper level trough moved into the Rockies on May 18, with southwest flow aloft over the Missouri Ozarks. A cluster of thunderstorms pushed southeast into portions of central Missouri, bringing heavy rainfall and flash flooding to St.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SGF wrote it up.
A strong upper level trough moved into the Rockies on May 18, with southwest flow aloft over the Missouri Ozarks. A cluster of thunderstorms pushed southeast into portions of central Missouri, bringing heavy rainfall and flash flooding to St. Clair, Benton, and Camden counties. Additionally, a low level jet axis extending from the Gulf through eastern Kansas strengthened overnight into May 19 while interacting with the upper level trough and a surface front. As a result, a second line of thunderstorms formed across northern Kansas, moving into Missouri overnight before exiting the state in the late afternoon hours. With the multiple rounds of heavy rainfall, storm total rainfall observations ranged between 3-7 inches across portions of southeast Kansas and the Missouri Ozarks, with 8.20 inches of rainfall measured in Hickory County. This led to multiple road closures reported from the flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Springfield, MO wrote its last area forecast discussion before the first event at May 18, 12:31 PM CST, 1 hour 55 minutes earlier. Its key messages:
Area Forecast Discussion
National Weather Service Springfield MO
131 PM CDT Mon May 18 2026
.KEY MESSAGES...
- A Moderate Risk (3 out of 4) for thunderstorms with heavy
rainfall that may result in flash flooding this afternoon and
another round overnight. A Flood Watch in effect for an area
north of Interstate 44 towards the Highway 54 corridor.
Additional rainfall amounts of 1-3 inches.
- A Slight Risk (2 out of 5) for a few strong to severe
thunderstorms this afternoon. Primary hazard is damaging wind
gusts and large hail to the size of quarters.
- A Slight Risk (2 out of 5) for severe thunderstorms overnight
tonight into Tuesday. A line of thunderstorms expected to
quickly move through the area, with the primary hazard being
damaging wind gusts. There is a lower chance for a few, brief
tornadoes.
- Additional rainfall chances (40-70%) mid to late week along
with cooler temperatures.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 100 PM CDT Mon May 18 2026
Current Conditions and Synoptic Overview: Water vapor and upper
air analysis shows southwest flow aloft with a strong shortwave
over Colorado. There is a compact shortwave currently moving
into Arkansas. While the low level jet has weakened, it remains
out of the southwest around 35-40kts over the area. An outflow
boundary from overnight storms was beginning to wash out however
it remains west to east from about Barton County east/northeast
to Phelps county. A moist and unstable airmass continues over
the area with the 12Z sounding measuring 2500j/kg MU CAPE and
0-6km shear around 30kts. Thunderstorms continue to develop
along and north of that outflow boundary, especially in the
Flood Watch area. Temperatures varied drastically with 60s
along/north of Highway 54 to lower 80s further south.
Thunderstorm/Flood Threat This Afternoon: Latest meso trends and
12z HREF/REFS supports continued development of scattered
thunderstorms this afternoon over the northern half of the area.
Given the CAPE/Shear combo, a few severe storms are possible
with large hail and damaging winds the most likely hazards.
Flash flooding will be a concern in the Flood Watch area,
especially locations that have received several inches of
rainfall already. There should be a decreasing trend in storm
coverage closer to 6-9pm.
Round of thunderstorms Overnight/Tuesday: Confidence is high
that significant severe storms will develop in Kansas this
afternoon and evening along a cold front and an area of high
shear and high instability. The storms look to quickly grow
upscale into a QLCS and will expand southwest towards Oklahoma.
Latest guidance suggests that the QLCS will move southeast and
enter our southeast Kansas and western Missouri counties shortly
after midnight. ML CAPE around 1500j/kg and 0-3km shear around
30kts will allow for the potential for damaging winds to be the
most likely hazard as this line of storms moves southeast
through the area. We will need to monitor for any line segments
that can surge/pivot to the east-northeast as there will be a
potential for a brief tornado, especially locations west of
Highway 65. There remains uncertainty with respect to the exact
timing of the line as it moves through the area however it
should be along the I-44 corridor in the 4am to 8am time frame.
The instability levels will continue to decrease overnight
therefore an overall weakening trend seems likely as storms move
southeast of I-44 early Tuesday morning. Additional rainfall
amounts of 1-3 inches is possible with the storms overnight. We
did extend the Flood Watch until 18Z Tuesday to account for the
next round of rainfall.
The remainder of Tuesday is uncertain as there are questions
about how fast the front moves through the area during the day.
There are a few CAMS that suggest that storms intensify during
the afternoon, mainly southeast of I-44. Large hail and damaging
winds would be the most likely hazards if storms
redevelop/intensify Tuesday afternoon. Considerable uncertainty
exists with additional updates likely. Temps will also begin to
fall quickly behind the front with 60s in some areas by late
Tuesday afternoon. Additional post frontal showers look likely
Tuesday evening as additional energy moves through the area.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 100 PM CDT Mon May 18 2026
Additional Rain Chances/Cooler Weather Mid/Late Week: Ensemble
data continues to suggests that the overall upper level pattern
west/southwest with several disturbances moving through the
region. The front that moves through Tuesday looks to stay south
of the area Wednesday however given the flow, additional precip
chances are possible south of I-44. The front does appear to
attempt to lift north into the area Thursday and persist through
Saturday. Precip chances currently from the NBM are rather
pessimistic with chances greater than 50% at times, especially
closer to Thursday and Friday. Currently not seeing a signal for
severe storms or flooding. Temps will remain cooler than
previous days, especially Wednesday with slowly climbing temps
closer to 80 degrees by the weekend.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1230 PM CDT Mon May 18 2026
Scattered showers and thunderstorms will be in and around the
TAF sites this afternoon, especially JLN and SGF. Otherwise
ceilings around 3000ft will be likely this afternoon. Winds will
likely remain out of the south with gusts around 25-30kts. Low
level wind shear is likely at SGF and JLN overnight. There will
be a line of thunderstorms that moves into the area after 08z
and continues through Tuesday morning. Confidence is increasing
that winds will turn west to northwesterly towards the end of
the TAF period along with ceilings dropping into at least MVFR.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...Flood Watch until 7 PM CDT this evening for MOZ055>058-066>071-
078>081.
&&
SHORT TERM...Burchfield
LONG TERM...Burchfield
AVIATION...BurchfieldHazardous Weather Outlook National Weather Service Springfield MO 207 PM CDT Mon May 18 2026 KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-191915- Bourbon-Crawford-Cherokee-Benton-Morgan-Miller-Maries-Vernon- St. Clair-Hickory-Camden-Pulaski-Phelps-Barton-Cedar-Polk-Dallas- Laclede-Texas-Dent-Jasper-Dade-Greene-Webster-Wright-Newton- Lawrence-Christian-Douglas-Howell-Shannon-McDonald-Barry-Stone- Taney-Ozark-Oregon- 207 PM CDT Mon May 18 2026 This Hazardous Weather Outlook is for portions of the Missouri Ozarks and extreme southeast Kansas. .DAY ONE...Today and Tonight. Weather hazards expected... Slight tornado risk. Slight hail risk. Slight thunderstorm wind damage risk. Limited lightning risk. Significant excessive rainfall risk Limited non thunderstorm wind risk. DISCUSSION... - A Moderate Risk (3 out of 4) for thunderstorms with heavy rainfall that may result in flash flooding this afternoon and another round overnight. A Flood Watch in effect for an area north of Interstate 44 towards the Highway 54 corridor. Additional rainfall amounts of 1-3 inches. - A Slight Risk (2 out of 5) for a few strong to severe thunderstorms this afternoon. Primary hazard is damaging wind gusts and large hail to the size of quarters. - A Slight Risk (2 out of 5) for severe thunderstorms overnight tonight into Tuesday. A line of thunderstorms expected to quickly move through the area, with the primary hazard being damaging wind gusts. There is a lower chance for a few, brief tornadoes. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. - A line of thunderstorms will be ongoing on Tuesday morning. There is uncertainty with how quickly the front clears the area and will determine if we see any severe thunderstorm redevelopment Tuesday afternoon. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed this afternoon and again overnight. && More detailed information can be accessed at: http://www.weather.gov/sgf/dsspacket This product in graphical format...along with other weather... hydrological and climate information...at http://www.weather.gov/sgf Burchfield
Preliminary Local Storm Report
National Weather Service Springfield MO
242 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0235 PM Flash Flood 1 S Hastain 38.20N 93.18W
05/18/2026 Benton MO Dept of Highways
State Highway V is closed due to flooding at
Deer Creek.
&&
MBPreliminary Local Storm Report
National Weather Service Springfield MO
245 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0240 PM Flash Flood 1 N Knobby 38.17N 93.10W
05/18/2026 Benton MO Dept of Highways
State Highway DD is closed due to flooding
at Knobby Creek.
&&
MBThe Springfield radar (KSGF), 75 km away, was scanning. The volume nearest the first event began at 20:28 UTC.
9 flood, 4 flash flood, 1 thunderstorm wind. Local standard time, as filed.
De Laporte SE 900 Rd in Collins flooded from the heavy rainfall and started to wash out.
State Highway V was closed due to flooding at Deer Creek.
State Highway DD was closed due to flooding at Knobby Creek.
Missouri State Highway Patrol reported a swift water rescue at the low water crossing bridge.
County Road 363 was flooded due to the heavy rainfall.
Route D was closed due to heavy rainfall.
Both the northbound and southbound of Route BB was closed due to flooding.
Route BB was closed due to water over roadway.
A few reports came in of trees down in McDonald County from the morning round of thunderstorms.
The crossing on SE 550 Rd was flooded and impassable from the heavy rainfall.
Brush Creek was flooded out of its banks at the bridge on SE 1200 Rd. A small crossing before the bridge was damaged from the heavy rainfall.
Water was over the road and bridge at Brush Creek on SE 451 Rd from the heavy rainfall.
State Highway CC was closed due to flooding at Indian Creek.
Southeast 95th road was closed in southern Barton County due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Missouri in 2026Every state in 2026This day in weather historyWarnings in Missouri, May 2026
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1336520, 1336523, 1336524, 1336526, 1336532, 1336533, 1336534, 1336535, 1336540, 1336531, 1336536, 1336537, 1336538, 1336539.