Winter Storm in South Dakota, May 11, 2002

Name: Winter Storm in South Dakota, May 11, 2002
Start: 2002-05-11T05:30
End: 2002-05-11T08:45
Location: South Dakota

May 11, 2002 · NWS UNR · 3 events in 3 counties and zones

A late season winter storm system moved across the Northern Plains. Abundant moisture combined with sufficiently cold air and wind to produce winter storm conditions throughout the Black Hills.

Where it happened

Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. 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: 3

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 UNR wrote it up.

A late season winter storm system moved across the Northern Plains. Abundant moisture combined with sufficiently cold air and wind to produce winter storm conditions throughout the Black Hills. Most locations received four to six inches of snow in just a few hours during the morning. Several areas received eight to ten inches of snowfall.

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 Rapid City, SD wrote its last area forecast discussion before the first event at May 11, 1:15 AM MST, 4 hours 15 minutes earlier.

Area forecast discussion, May 11, 1:15 AM MST, 4 hours 15 minutes before

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY
215 AM MDT SAT MAY 11 2002

CURRENT SURFACE MAP HAS LOW PRESSURE OVER EASTERN COLORADO...WITH
INVERTED TROF INTO EXTREME EASTERN WYOMING. WIDESPREAD RAIN FALLING
ACROSS THE CWA...WITH SNOW IN THE BLACK HILLS. SOME ELEVATED
CONVECTION APPROACHING SOUTH CENTRAL SOUTH DAKOTA. AS 700MB LOW
MOVES ACROSS EASTERN SOUTH DAKOTA THIS AFTERNOON...DRIER AIR WILL
WORK IN FROM THE NORTHWEST...BRINGING AN END TO THE PRECIPITATION.
SNOW IN THE BLACK HILLS MAINLY ABOVE 5000. WILL MENTION LOCAL
ACCUMULATIONS OF 3 TO 5 INCHES.

FOR SUNDAY...QUICK WARMUP IN STORE AS RIDGE BUILDS OVER THE NORTHERN
ROCKIES. FORECAST SOUNDINGS SUGGEST SOME BROKEN CU ACROSS THE
NORTHWEST IN THE AFTERNOON.

UPPER LEVEL RIDGE REMAINS OVER THE AREA FOR MONDAY AND TUESDAY.
TEMPERATURES WILL WARM INTO THE 70S. HOWEVER...WITH RECENT MOISTURE
AND GREENUP OCCURRING...THAT WILL KNOCK A FEW DEGREES OF THE HIGHS.

UPPER LOW MOVES INTO NORTHERN ROCKIES WEDNESDAY...WITH COLD FRONT
MOVING THROUGH CWA EARLY WEDNESDAY. CHANCE OF SHOWERS/THUNDERSTORMS
LOOKS GOOD FOR WEDNESDAY/THURSDAY. AS UPPER LOW MOVES OVER
FRIDAY...EXPECTING COOLER TEMPERATURES AND A FEW SHOWERS.

.UNR...NONE.
07

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

3 winter storm. Local standard time, as filed.

Winter Storm, Central Black Hills

When: May 11, 5:30 AM MST
Where: Central Black Hills forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 43.841, -103.137 (the zone’s center; the record gives no point)

Winter Storm, Northern Black Hills

When: May 11, 5:37 AM MST to 8:45 AM MST
Where: Northern Black Hills forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 44.310, -103.111 (the zone’s center; the record gives no point)

Winter Storm, Southern Black Hills

When: May 11, 5:37 AM MST to 8:30 AM MST
Where: Southern Black Hills forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 43.678, -103.451 (the zone’s center; the record gives no point)

What these are

Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.

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

The same day elsewhere

Every storm in South Dakota in 2002 Every state in 2002 This day in weather history Warnings in South Dakota, May 2002

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 2026-09-24. Each event’s entry at NCEI: 5291560, 5291559, 5291561.