Severe Weather Samples

The following maps were plotted with WeatherGraphix, using data taken from the Surface Archives and Upper Archives CD-ROM disk packs that we sell.

Some Canadian upper-air data is missing from these charts during the 1960s and early 1970s, since Canada was using 72xxx block WMO identifiers at the time and WeatherGraphix doesn't have these old identifiers in its tables. However the data does exist.

April 11, 1965

Palm Sunday tornado outbreak

A very dynamic weather system produced at least 31 tornadoes, which in turn claimed 256 lives across much of the Midwest and Great Lakes states.

See surface or 500 mb for 1200Z (7 am CDT).

May 11, 1970

Lubbock, Texas tornado

Shortly after the valid time on these maps, a retreating dryline set the stage for a tornado that tore through Lubbock in west Texas. It killed 26, injured over 500, and caused at least $135 million in damage.

See surface or 500 mb for 0000Z (7 pm CDT).

September 3, 1970

Coffeyville, Kansas hailstone

A severe thunderstorm near Coffeyville, KS was responsible for what's generally held to be the largest hailstone. It measured 1.67 pounds, 7.5" in diameter, and 17.5" in circumference.

See surface or 500 mb for 0000Z (7 pm CDT).

May 24, 1973

Union City, Oklahoma tornado

This tornado, which nearly levelled Union City, southwest of Oklahoma City, was one of the most widely photographed and studied tornadoes in Oklahoma history.

See surface or 500 mb for 1200Z (7 am CDT).

April 3, 1974

Ohio Valley tornado outbreak

The most deadly outbreak in modern history occurred on this date. At least 148 tornadoes touched down across the east central United States, killing 337. Kentucky, Ohio, Tennessee, Pennsylvania, and Indiana were especially hard hit.

See surface or 500 mb for 1200Z (7 am CDT).

January 19, 1977

Florida snowfall

An exceptionally cold outbreak of arctic air slammed through the southeast United States, causing snowfall as far south as Tampa and Miami. Snow was on the ground at all 50 states on this day. On the day before, South Carolina set its all-time record low of -20F at Long Creek.

See surface or 500 mb for 1200Z (6 am CST).

January 26, 1978

Record-low barometric pressure

A deep winter storm moved through the Great Lakes, sending the pressure down to 28.21" in Sarna, Ontario. Hurricane-force winds resulted in blizzard conditions across the Ohio River valley and the Great Lakes.

See surface or 500 mb for 1200Z (6 am CST).

April 10, 1979

Wichita Falls & Seymour, Texas tornadoes

A series of violent tornadoes raked northwest Texas during the afternoon, touching down near Seymour and in downtown Wichita Falls. Property damage was tremendous.

See surface or 500 mb for 1200Z (7 am CDT).

July 16, 1979

Cheyenne, Wyoming tornado

One of the worst tornadoes in Wyoming history struck on this day. Especially hard-hit was the Shannon Heights trailer park where 17 trailers were damaged. The damage was rated an F4.

See surface or 500 mb for 1200Z (7 am CDT).

December 25, 1983

Record-cold Christmas Day

Temperatures reached record lows across the eastern third of the United States. Over 125 cities reported broken records.

See surface or 500 mb for 1200Z (6 am CST).

May 31, 1985

Northeast tornado outbreak

At least 43 tornadoes developed across Pennsylvania, New York, Ohio, and southern Ontario, killing 87 and causing widespread damage. Barrie, northwest of Toronto, was especially hard-hit.

See surface or 500 mb for 1200Z (7 am CDT).

June 26, 1990

Record summer heat in Arizona

The official temperatures soared to over 120 degrees in Arizona on this day, setting an all-time record high for Phoenix. This chart is valid for 2300Z, in the heat of the afternoon.

See surface or 500 mb for 2300Z (5 pm MST).