Marine Hail in Lake Superior, May 5, 2009

Name: Marine Hail in Lake Superior, May 5, 2009
Start: 2009-05-05T15:25
End: 2009-05-05T16:30
Location: Lake Superior

May 5, 2009 · NWS DLH · 2 events in 1 county or zone

Strong thunderstorms moved out over the head of Lake Superior, producing large hail.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 2

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS DLH wrote it up.

Strong thunderstorms moved out over the head of Lake Superior, producing large hail.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Duluth, MN wrote its last area forecast discussion before the first event at May 5, 3:10 PM CST, 15 minutes earlier.

Area forecast discussion, May 5, 3:10 PM CST, 15 minutes before

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Hazardous weather outlook, May 5, 4:00 AM CST, 11 hours 25 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DULUTH MN
500 AM CDT TUE MAY 5 2009

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-061030-
KOOCHICHING-NORTHERN ST. LOUIS-NORTHERN COOK/NORTHERN LAKE-
NORTHERN ITASCA-CENTRAL ST. LOUIS-SOUTHERN LAKE/LAKESHORE-
SOUTHERN COOK/LAKESHORE-NORTHERN CASS-SOUTHERN ITASCA-
SOUTHERN CASS-CROW WING-NORTHERN AITKIN-SOUTHERN AITKIN-
CARLTON/SOUTHERN ST. LOUIS-PINE-DOUGLAS-BAYFIELD-ASHLAND-IRON-
BURNETT-WASHBURN-SAWYER-PRICE-
500 AM CDT TUE MAY 5 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS MAY DEVELOP TUESDAY ACROSS THE REGION...MAINLY
DURING THE AFTERNOON AND EARLY EVENING. SOME STORMS MAY PRODUCE GUSTY
WINDS AND SMALL HAIL...ESPECIALLY OVER THE ST CROIX RIVER VALLEY
VALLEY AND ADJACENT NORTHWEST WISCONSIN.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AND THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

LSZ121-140>148-061030-
BAYFIELD TO OAK POINT WI-GRAND PORTAGE TO GRAND MARAIS MN-
GRAND MARAIS TO TACONITE HARBOR MN-
TACONITE HARBOR TO SILVER BAY HARBOR MN-
SILVER BAY HARBOR TO TWO HARBORS MN-TWO HARBORS TO DULUTH MN-
DULUTH MN TO PORT WING WI-PORT WING TO SAND ISLAND WI-
SAND ISLAND TO BAYFIELD WI-OAK POINT TO SAXON HARBOR WI-
500 AM CDT TUE MAY 5 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NEARSHORE WATERS OF
WESTERN LAKE SUPERIOR.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS MAY DEVELOP TUESDAY ACROSS THE REGION...ESPECIALLY
NEAR THE SOUTH SHORE DURING THE AFTERNOON. SOME STORMS MAY
PRODUCE GUSTY WINDS AND SMALL HAIL.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AND THURSDAY.

CANNON

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB ADDRESS:
HTTP://WWW.WEATHER.GOV/DULUTH (ALL LOWER CASE)

In the hours before

Special weather statement, May 5, 2:57 PM CST, 28 minutes before

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Local storm report, May 5, 3:07 PM CST, 18 minutes before

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Local storm report, May 5, 3:09 PM CST, 16 minutes before

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Local storm report, May 5, 3:11 PM CST, 14 minutes before

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Local storm report, May 5, 3:14 PM CST, 11 minutes before

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Local storm report, May 5, 3:25 PM CST, 0 minutes before

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The radar

The Duluth radar (KDLH), 9 km away, was scanning. The volume nearest the first event began at 21:26 UTC.

Open the radar archive at this moment

Event by event

2 marine hail. Local standard time, as filed.

Marine Hail, Two Hbrs to Duluth Mn

When: May 5, 3:25 PM CST
Where: Two Hbrs to Duluth Mn forecast zone, Duluth
Measured: 0.75 in hail
Reported by: Amateur Radio
Coordinates: 46.800, -92.100

Marine Hail, Two Hbrs to Duluth Mn

When: May 5, 4:30 PM CST
Where: Two Hbrs to Duluth Mn forecast zone, Duluth
Measured: 0.75 in hail
Reported by: Amateur Radio
Coordinates: 46.800, -92.100

What these are

Marine Hail: Hail three-quarters of an inch or larger over water.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Lake Superior in 2009 Every state in 2009 This day in weather history

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 171934, 171933.