A vigorous upper level low pressure system developed across southern Nevada.  Significant wind shear and instability developed as moisture was drawn north into the Panhandles setting the stage for a very long duration and higher end severe episode.  Initially, elevated supercell storms developed in the NW Texas Panhandles on the cold side of a nearly stationary frontal boundary and moved northeast into the central Oklahoma Panhandle as the first of multiple disturbances moved across the area.  Hail up to golf ball size and wind damage was reported with these storms.
During the afternoon hours, upper level disturbances, daytime heating and the very pronounced frontal boundary stretching from near Amarillo northeast into Beaver County, Oklahoma became the main catalyst for surface based supercells which produced very large hail up to baseball size and several tornadoes.  Most of the tornadoes remained in Texas, however one very large and long tracked tornado  crossed the Texas state line into Beaver county and eventually into Ellis County, Oklahoma. This tornado was rated an EF-2 in Beaver County based on the damage, but it remained in very rural areas throughout its life-cycle.

Hail in BEAVER, OKLAHOMA
From 23-MAY-19 15:15:00 to 23-MAY-19 15:15:00 (CST-6)
Location: BRYANS CORNER
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in BEAVER, OKLAHOMA
From 23-MAY-19 19:30:00 to 23-MAY-19 19:47:00 (CST-6)
Location: SLAPOUT
Tornado F-scale: EF2
Reported by: NWS Storm Survey

The tornado began in Lipscomb County in Texas, crossed into southeast Beaver County Oklahoma and crossed into Ellis and Harper Counties from there. The tornado got stronger and larger with time, but mainly damaged trees, fences and power poles in the area of this survey limiting the EF rating to a 2. The tornado did greater damage (and earned higher rating) as it destroyed a home just feet across the county line. This damage was surveyed by the Norman Weather Forecast Office.

Thunderstorm Wind in TEXAS, OKLAHOMA
From 23-MAY-19 08:06:00 to 23-MAY-19 08:06:00 (CST-6)
Location: GUYMON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Large tree down on car.

Hail in TEXAS, OKLAHOMA
From 23-MAY-19 08:41:00 to 23-MAY-19 08:41:00 (CST-6)
Location: EVA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Golf ball size hail with heavy rain.

Hail in TEXAS, OKLAHOMA
From 23-MAY-19 08:57:00 to 23-MAY-19 08:57:00 (CST-6)
Location: HOUGH
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in TEXAS, OKLAHOMA
From 23-MAY-19 08:58:00 to 23-MAY-19 08:58:00 (CST-6)
Location: (GUY)GUYMON MUNI ARP
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in TEXAS, OKLAHOMA
From 23-MAY-19 09:00:00 to 23-MAY-19 09:00:00 (CST-6)
Location: GUYMON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Large tree down on car.

Hail in BEAVER, OKLAHOMA
From 23-MAY-19 15:13:00 to 23-MAY-19 15:13:00 (CST-6)
Location: BRYANS CORNER
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in BEAVER, OKLAHOMA
From 23-MAY-19 15:09:00 to 23-MAY-19 15:09:00 (CST-6)
Location: GRAY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in BEAVER, OKLAHOMA
From 23-MAY-19 15:55:00 to 23-MAY-19 15:55:00 (CST-6)
Location: FLORIS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager