Severe weather and heavy rain was observed across the lower Missouri River Valley region, May 12th through may 13th. Numerous impacts were felt in the region, with heavy rain, wind damage, and hail.
The most severe weather took place in portions of eastern Kansas and western Missouri, as a strong bow echo moved through the area near and just after the midnight hour.  Embedded in this bow echo were small features called meso-vortices, which can often times cause local intensifications of the strong straightline winds, or even produce weak spinnup tornadoes.  One such feature embedded in a smaller bowing storm segment south of the Plattsburg area, led to reports of a damaged greenhouse, tree damage, as well as damage to other nearby structures.  It was determined, that a combination of enhanced straight line winds as well as a very brief and weak (EF0) tornado, produced winds as high as 70 to 85 mph in this area.  Further to the south, strong straight line winds, also blew over trees and caused other forms of property damage, to fences and homes in areas around Kansas City. Several observations of 60 to 70 mph winds were observed in the area.
However, the biggest impact from this event, was the persistent heavy rain due to the training of storms over the same areas.  The hardest hit areas were in the Kirksville and Chillicothe areas, where rainfall totals in the 3 to 6 inch range were common.  Elsewhere, while rainfall amounts may have been lower, the rapid rainfall rates in excess of 2 per hour, caused localized flash flooding in portions of the Kansas City Metropoitan area and elsewhere. The heavy rains caused many rivers and creeks to go out of their banks.

Heavy Rain in LIVINGSTON, MISSOURI
From 12-MAY-10 21:41:00 to 12-MAY-10 21:41:00 (CST-6)
Location: CHILLICOTHE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter measured 2.10 inches of rain in 70 minutes.

Flash Flood in LINN, MISSOURI
From 12-MAY-10 22:08:00 to 13-MAY-10 04:08:00 (CST-6)
Location: MEADVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Numerous streets around Meadville were reported under water.

Hail in CLAY, MISSOURI
From 12-MAY-10 18:55:00 to 12-MAY-10 18:55:00 (CST-6)
Location: NORTH KANSAS CITY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in LINN, MISSOURI
From 12-MAY-10 20:45:00 to 12-MAY-10 20:45:00 (CST-6)
Location: MEADVILLE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in DE KALB, MISSOURI
From 12-MAY-10 18:48:00 to 12-MAY-10 18:48:00 (CST-6)
Location: WEATHERBY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in JACKSON, MISSOURI
From 12-MAY-10 23:01:00 to 12-MAY-10 23:01:00 (CST-6)
Location: BLUE SPGS
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds were estimated to gust up to 65 mph.

Hail in PLATTE, MISSOURI
From 12-MAY-10 18:46:00 to 12-MAY-10 18:46:00 (CST-6)
Location: (MCI)KS CITY INTL AR
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in CALDWELL, MISSOURI
From 12-MAY-10 20:13:00 to 12-MAY-10 20:13:00 (CST-6)
Location: COWGILL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAIR, MISSOURI
From 12-MAY-10 20:10:00 to 12-MAY-10 20:10:00 (CST-6)
Location: BRASHEAR
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in JACKSON, MISSOURI
From 12-MAY-10 22:45:00 to 12-MAY-10 22:45:00 (CST-6)
Location: EAST INDEPENDENCE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Large tree was blown down.

Thunderstorm Wind in GRUNDY, MISSOURI
From 12-MAY-10 23:48:00 to 12-MAY-10 23:48:00 (CST-6)
Location: TRENTON ARPT
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorms winds were reported to have gusted to 70 mph.

Hail in CLINTON, MISSOURI
From 12-MAY-10 19:18:00 to 12-MAY-10 19:18:00 (CST-6)
Location: CONVERSE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CLAY, MISSOURI
From 12-MAY-10 19:34:00 to 12-MAY-10 19:34:00 (CST-6)
Location: MISSOURI CITY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in CHARITON, MISSOURI
From 12-MAY-10 18:30:00 to 12-MAY-10 18:30:00 (CST-6)
Location: TRIPLETT
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in LIVINGSTON, MISSOURI
From 12-MAY-10 21:25:00 to 13-MAY-10 03:25:00 (CST-6)
Location: CHILLICOTHE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Water was reported over the road, at the intersection of Clay Street and Easton Street.

Hail in RAY, MISSOURI
From 12-MAY-10 19:41:00 to 12-MAY-10 19:41:00 (CST-6)
Location: UNION
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in GRUNDY, MISSOURI
From 12-MAY-10 23:48:00 to 12-MAY-10 23:48:00 (CST-6)
Location: TRENTON ARPT
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Two foot diamater tree limbs fell on to a house. A three foot diameter tree was snapped off in the downtown area.

Hail in PLATTE, MISSOURI
From 12-MAY-10 18:39:00 to 12-MAY-10 18:39:00 (CST-6)
Location: LAKE WAUKOMIS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CLAY, MISSOURI
From 12-MAY-10 19:34:00 to 12-MAY-10 19:34:00 (CST-6)
Location: MISSOURI CITY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash Flood in CALDWELL, MISSOURI
From 12-MAY-10 21:55:00 to 13-MAY-10 03:55:00 (CST-6)
Location: CATAWBA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

State Route A between Braymer and Highway 36, was reported under water in several locations.

Flash Flood in CALDWELL, MISSOURI
From 12-MAY-10 20:19:00 to 13-MAY-10 02:19:00 (CST-6)
Location: POLO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flash flooding was observed around the railroad bridge.

Flash Flood in MACON, MISSOURI
From 12-MAY-10 20:11:00 to 13-MAY-10 02:11:00 (CST-6)
Location: ECONOMY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

State Route M was flooded with over a foot of water.

Flash Flood in PLATTE, MISSOURI
From 12-MAY-10 21:05:00 to 13-MAY-10 03:05:00 (CST-6)
Location: PARKVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Bridge was reported flooded near Walnut Creek. Residential evacuations were possible in that area.

Flash Flood in CALDWELL, MISSOURI
From 12-MAY-10 20:13:00 to 13-MAY-10 02:13:00 (CST-6)
Location: COWGILL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Water was reported flowing over Highway 116.

Flash Flood in SCHUYLER, MISSOURI
From 12-MAY-10 22:40:00 to 13-MAY-10 04:40:00 (CST-6)
Location: LANCASTER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash flooding caused pavement over a culvert to give way. This caused the front end of a vehicle, to fall through the roadway. While attempting to get out of the vehicle, a 32 year old male, was swept away by the current and drowned.

Tornado in CLINTON, MISSOURI
From 12-MAY-10 22:52:00 to 12-MAY-10 22:55:00 (CST-6)
Location: PLATTSBURG
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A brief EF0 tornado touchdown at 2252 CST was reported 4 miles south of Plattsburg, around J Highway and Middle Road. The tornado lifted at 2255 CST, with damage reported to two greenhouses/outbuildings. Trees larger than one foot in diamater, were also found snapped off at a height of 14 feet. These trees blocked roads. Power lines were also reported down.