EF1 tornado in Pontotoc County, Oklahoma

The Allen Tornado initially developed about 4.5 miles southwest of Allen where a mobile home, a barn and trees were damaged. The tornado moved northeast and produced home and other buildings on the north side of Allen.

An intense upper-level trough impacted the WFO Norman Forecast Area during the late evening of the 3rd through the 4th. Initial thunderstorm development occurred along an attendant cold front, moving west to east across the area early in the period. These initial thunderstorms produced reports of large hail and wind damage across western Oklahoma. A few hours later, during the predawn hours of the 4th, a maturing mesoscale convective system (MCS) swept across portions of south-central into southeastern Oklahoma, producing several tornadoes and widespread damaging winds.

Finally, during daytime hours on the 4th, a strong pressure gradient and low-level jet axis promoted a widespread synoptic high wind episode across the forecast area. As a note, the first, last and highest magnitude wind gusts are those included in this episode for a particular zone (county).