Severe Weather

Alabama Hailstone in March Now an Official State Record

At a Glance

Hailstones as big as grapefruits hammered areas near Cullman, Alabama, on March 19.
One of those hailstone was more than 5 inches in diameter, setting a new state record.

Giant hail that was documented in Alabama in March set a new record for the largest hailstone ever observed in the state, upon further review from a team of meteorologists.

Craig Mann holds the hailstone he preserved for the NWS to measure. (Credit: Craig Mann)

Supercell thunderstorms struck northern Alabama and dropped hailstones as big as grapefruits, resulting in significant damage to vehicles, homes and other structures.

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One of the hailstones was collected and preserved in a freezer by Craig Mann, a reporter with the Cullman Tribune in the town of Walter, about 10 miles southeast of Cullman, Alabama.

The National Weather Service (NWS) met with Mann on March 21 to take measurements of the hailstone, finding a peak width of 5.38 inches, weighing 9.8 ounces, just over one-half a pound.

Measurement of the hailstone by the National Weather Service in Huntsville, Alabama. (Credit: NWS - Huntsville)

“Based on federal guidelines and with the coordination of federal and state officials, we established this as the first Alabama hailstone record,” Dr. John Christy, Alabama's state climatologist, told the Cullman Tribune Thursday.

Christy was one of five meteorologists and climatologists of an ad hoc committee that reviewed the hailstone's measurements to certify the state record.

Prior to this event, there was no recognized official state record hail size for Alabama at this time. A search of NOAA's storm database showed the largest known hailstone in the state is 4.25 inches.

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The hail smashed windshields and put holes in the roof of a travel trailer in this parking lot in Cullman. (Credit: NWS - Huntsville)

Only six states have recognized records for the hail category in NOAA's extreme weather database. Why so few states have verified hail records is partly due to the difficulty of collecting and preserving hailstones before they begin to melt so that official measurements can be taken.

Some of the heaviest damage was to the Cullman County Sheriff's office and jail.

"It (the jail) had hailstones go through its roof and into the freezer," Chris Darden, meteorologist in charge of the National Weather Service in Huntsville, Alabama, told the Cullman Tribune.

The largest hailstone verified in any state fell from the sky in Vivian, South Dakota, on July 23, 2010. It had a diameter of about 8 inches and weighed nearly 2 pounds.

Supercell thunderstorms typically produce some of the largest hail on earth due to their vigorous updrafts (upward air motion), which allow hailstones to stay suspended in the storm and grow larger.

Hailstones eventually reach the ground for one of two reasons: They encounter a downdraft (downward air motion) or they grow too large for the storm's updrafts to overcome the force of gravity.

(MORE: Weather 101 - Supercells)