By Wally Kennedy

wkennedy@joplinglobe.com

On May 10, three National Weather Service (NWS) stations were watching Southeast Kansas and eastern Oklahoma for the possibility of severe thunderstorms. When the storms materialized and rotation was detected, instant messaging relayed the information between meteorologists at Tulsa, Okla.; Wichita, Kan.; and Springfield, Mo.

“Sometimes, you see rotation on radar 15 minutes before the actual tornado touches down,’’ said Steve Piltz, a severe-weather expert at the NWS station at Tulsa. “The tornado that hit Picher (Okla.) was not like that. It developed extremely quickly. It all happened within a five-minute window,’’ he said.

When Tulsa radar observed rotation in the storm, it received instant messages from Wichita and Springfield that they, too, had detected rotation.

“That was at 5:23 p.m. It then took about 60 to 90 seconds to generate the text and the (geographic) box for the tornado warning,’’ he said.

While issuing that alert, the Tulsa station also was monitoring five other tornadic storms and two severe storms in the state developing about the same time.

The NWS warning for Picher was issued at 5:26 p.m. At the same time the warning was issued, the Tulsa station was getting on-the-ground confirmation from spotters.

The Picher Fire Department got a jump on the warning, possibly by as much as six minutes, when it sounded its siren at 5:20 p.m. after hearing radio traffic from spotters near Welch that indicated a tornado was heading east along the state line. Though the exact time has not been pinned down, it is believed the tornado hit Picher at 5:39 p.m.

The residents of Picher had a 19-minute warning when the siren was sounded; they had a 13-minute warning from the NWS.

The five-year national average for tornado warnings in terms of lead time is 12.5 to 14 minutes, according to NWS records. In the 1990s, the lead time was even less. The average then was 7.5 to 11 minutes.

The NWS at Springfield issued a tornado warning for Newton and Jasper counties at 5:35 p.m. The tornado from Picher, which was traveling at about 40 mph, crossed into Newton County at 5:59 p.m. The lead time there was 24 minutes.

Piltz said the reason for the additional lead time in Missouri is a simple one: “The closest place to the touchdown gets the least warning. Those at the end of the track get the most warning. The difference is travel time.’’