A closed upper low pressure system continued to spin across New Mexico during the afternoon and evening of May 18th, ejecting a shortwave trough northeast across Northeast Texas into Southeast Oklahoma. A very moist and unstable air mass had developed during the afternoon over these areas, with the trough enhancing large scale forcing for a complex of showers and thunderstorms which shifted northeast across Northeast Texas, Southeast Oklahoma, and Southwest Arkansas. Given the extent of instability and adequate wind shear, some of these storms became severe, producing damaging winds which downed trees and power lines across portions of Western Bowie County into Southeast McCurtain County Oklahoma. These storms weakened during the early evening, before dissipating by mid-evening.
Another shortwave trough ejecting northeast across Central and Southeast Texas ahead of the trough promoted the development of another mesoscale convective system across these areas during the evening, which shifted east northeast across Southeast Texas and portions of East Texas. While the northern extent of this system weakened over East Texas due to a more stable air mass in place from the earlier thunderstorms which moved through the area during the afternoon, locally heavy rain did fall over already saturated grounds, with rainfall amounts of two to four inches falling over Smith, Cherokee, Western and Southern Nacogdoches, and Angelina Counties, with isolated higher amounts between five and six inches falling over Southwest Smith County near Lake Palestine. This heavy rainfall resulted in rapid runoff and flash flooding across much of these areas during the late evening through the early morning hours of May 19th. The heavy rainfall and flash flooding ended by daybreak across much of East Texas.

Thunderstorm Wind in BOWIE, TEXAS
From 18-MAY-21 15:15:00 to 18-MAY-21 15:15:00 (CST-6)
Location: DE KALB
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

A tree was blown down onto power lines on Church Street in De Kalb.

Flash Flood in ANGELINA, TEXAS
From 19-MAY-21 02:30:00 to 19-MAY-21 07:00:00 (CST-6)
Location: POLLOK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Green Sanders Road near Pollok was closed due to flooding.

Thunderstorm Wind in CHEROKEE, TEXAS
From 18-MAY-21 20:10:00 to 18-MAY-21 20:10:00 (CST-6)
Location: CRAFT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A tree was blown down onto a vehicle along Highway 69 just southeast of Jacksonville.

Flash Flood in CHEROKEE, TEXAS
From 19-MAY-21 03:00:00 to 19-MAY-21 04:00:00 (CST-6)
Location: STRIKER CREEK RES
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

High water covered FM 2274 just south of Highway 79.

Flash Flood in SMITH, TEXAS
From 19-MAY-21 01:00:00 to 19-MAY-21 04:00:00 (CST-6)
Location: KIRKPATRICK ADDITION
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A portion of County Road 47 north of Highway 64 was washed out.

Flash Flood in CHEROKEE, TEXAS
From 19-MAY-21 02:00:00 to 19-MAY-21 04:00:00 (CST-6)
Location: REKLAW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

FM 343 east of Rusk was closed due to flooding.

Flash Flood in CHEROKEE, TEXAS
From 19-MAY-21 01:00:00 to 19-MAY-21 04:00:00 (CST-6)
Location: CUNEY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

FM 855 north of Highway 175 northeast of Cuney was closed due to flooding.

Flash Flood in ANGELINA, TEXAS
From 19-MAY-21 03:30:00 to 19-MAY-21 07:00:00 (CST-6)
Location: HUNTINGTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

FM 328 northeast of Huntington was closed due to flooding.

Flash Flood in CHEROKEE, TEXAS
From 19-MAY-21 01:00:00 to 19-MAY-21 04:00:00 (CST-6)
Location: CIRCLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

FM 1857 southwest of Rusk was closed due to flooding.

Flash Flood in ANGELINA, TEXAS
From 19-MAY-21 03:00:00 to 19-MAY-21 07:00:00 (CST-6)
Location: PEAVY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

FM 2497 was closed due to flooding.

Flash Flood in SMITH, TEXAS
From 19-MAY-21 01:00:00 to 19-MAY-21 04:00:00 (CST-6)
Location: NEW HARMONY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A portion of FM 724 was closed due to flooding.