Flash Flood and Hail in North Dakota, July 31, 2001

Name: Flash Flood and Hail in North Dakota, July 31, 2001
Start: 2001-07-31T15:50
End: 2001-07-31T17:30
Location: North Dakota

July 31, 2001 · NWS FGF · 4 events in 2 counties and zones

2 hail, 1 flash flood, 1 thunderstorm wind, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 1 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: $20,000
Crop damage: None recorded
Events: 4

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 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 Grand Forks, ND wrote its last area forecast discussion before the first event at Jul 31, 2:25 PM CST, 1 hour 25 minutes earlier.

Area forecast discussion, Jul 31, 2:25 PM CST, 1 hour 25 minutes before

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
325 PM CDT TUE JUL 31 2001

FORECAST CHALLENGE FOR TONIGHT AND WED IS PCPN. CURRENT SATELLITE
IMAGERY HAS ALL BUT SE CWFA CLOUDY. KMVX HAS SVR TSRA OVER N
CWFA...WITH OTHER TSRA TRYING TO GET ORGANIZED IN FRONTAL ZONE IN E
ND. LATEST MSAS SFC PRESSURE ANALYSIS HAS LOW PRESSURE CENTERED NEAR
MBG...WITH FRONT EXTENDING BET JMS-FAR TO GFK-DVL TO HCO. WHEN
COMPARING INITIALIZATION CONDITIONS TO MODELS...ETA INITIALIZED
BEST...BUT USED COMPROMISE SOLUTION AS NO MODEL HANDING SCENARIO
ENTIRELY. MODEL SOUNDINGS QUITE SATURATED WITH PW'S REMAINING AROUND
2.0 INCHES OVER CWFA THROUGH THE NIGHT. IN ADDITION...SFC LOW TRACKS
THROUGH CWFA OVERNIGHT...WITH GOOD 850 MB LLJ...NICE THETA-E
RIDGE...AS WELL AS A 700MB TROF AND UPPER LEVEL SHORTWAVE...ALL
SETTING SITES ON CWFA TO KEEP HEAVY RAIN AND SVR POTENTIAL TONIGHT.
WITH FFG VALUES FOR MAJORITY OF COUNTIES UNDER 2 INCHES...WILL KEEP
FFA OUT FOR CWFA TONIGHT...BUT WILL LET NIGHT SHIFT DETERMINE IF E
CWFA WILL NEED TO EXTEND FFA INTO WED. THANKS TO BIS AND DLH FOR
COORD.

FORECAST CHALLENGE FOR WED NIGHT AND THU IS TEMPS. STRONG CAA AHEAD
OF SFC HIGH WILL BRING BREEZY CONDITIONS TO CWFA ON WED. HIGH BUILDS
INTO CWFA BY 06Z THU...WITH GOOD 850 MB Q-VECTOR DIVERGENCE AND
WINDS GOING LIGHT AND VARIABLE...EXPECT TEMPS TO FALL INTO 55 TO 65
DEGREE RANGE. THEN ON THU...SFC HIGH MOVES E WITH SE-S RETURN FLOW
SETTING UP...ALLOWING TEMPS TO BUMP BACK INTO THE LOW TO MIDDLE 80S.

EXTENDED RANGE MODELS IN REASONABLY GOOD AGREEMENT IN SFC AND MID
LEVEL FEATURES THROUGH PERIOD IN BUILDING UPPER RIDGE INTO FORECAST
AREA. MODELS CONSISTENT IN SHOWING AREA OF LOW PRESSURE OVR DAKOTAS
WHICH MAY BRING CHC OF MAINLY NIGHTTIME TSRA THIS WEEKEND. FOLLOWING
THIS AN UPPER RIDGE BUILDS...SO WARM TEMPS AT 700MB MAY SQUELCH ANY
CHANCE FOR CONVECTION. FOR NOW WILL KEEP FCST DRY FOR EARLY NEXT
WEEK BECAUSE OF POTENTIAL CAPPING. AT OR ABOVE AVERAGE TEMPS TEMPS
TO CONTINUE WITH WARMEST TEMPS FIRST PART OF NEXT WEEK.

.FGF...FLASH FLOOD WATCH FULL CWFA TONIGHT.

NG/AMV

In the hours before

Local storm report, Jul 31, 12:53 PM CST, 2 hours 57 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
153 PM CDT TUE JUL 31 2001

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0350 AM    3 E BUXTON                ND   WIND DAMAGE
07/31/01   TRAILL                         LARGE TREE DOWN

0357 AM    HALSTAD                   MN   67 MPH TSTM GUST
07/31/01   NORMAN

0417 AM    HAWLEY                    MN   .88 INCH HAIL
07/31/01   CLAY

0425 AM    GENTILLY                  MN   WIND DAMAGE
07/31/01   POLK                           4-5 INCH DIAMETER LIMBS
                                          DOWN

0425 AM    CROOKSTON                 MN   WIND DAMAGE
07/31/01   POLK                           4-5 INCH DIAMETER LIMBS
                                          DOWN

0515 AM    1 NE SKIME                MN   WIND DAMAGE
07/31/01   ROSEAU                         LARGE TREES DOWN

0515 AM    4 NW GRYGLA               MN   WIND DAMAGE
07/31/01   MARSHALL                       LARGE TREES DOWN

0600 AM    1 W CLEMENTSON            MN   WIND DAMAGE
07/31/01   LAKE OF THE WOODS              ROOF BLOWN OFF TRAILER
                                          HOME, 20 INCH DIAMETER
                                          TREES DOWN

1000 AM    COOPERSTOWN               ND   WIND DAMAGE
07/31/01   GRIGGS                         6 TO 8 INCH BRANCHES DOWN

1055 AM    COOPERSTOWN               ND   FLOODING
07/31/01   GRIGGS                         CITY PARK FLOODED, STREET
                                          FLOODING 2 FOOT DEEP
                                          DOWNTOWN

1100 AM    15 NE FINLEY              ND   WIND DAMAGE
07/31/01   STEELE                         4 INCH BRANCHES DOWN

1108 AM    HATTON                    ND   WIND DAMAGE
07/31/01   TRAILL                         5 INCH BRANCHES DOWN

1130 AM    GRAND FORKS               ND   WIND DAMAGE
07/31/01   GRAND FORKS                    12 INCH DIAMETER TREES
                                          DOWN

1130 AM    7 SW GRAND FORKS          ND   .75 INCH HAIL
07/31/01   GRAND FORKS

1132 AM    FISHER                    MN   WIND DAMAGE
07/31/01   POLK                           POWER POLES BLOWN DOWN

1150 AM    3 S ANGUS                 MN   WIND DAMAGE
07/31/01   POLK                           NUMEROUS TREES DOWN

1215 PM    1 SW WYLIE                MN   .75 INCH HAIL
07/31/01   RED LAKE

1220 PM    THIEF RIVER FALLS         MN   72 MPH TSTM GUST
07/31/01   PENNINGTON                     NUMEROUS LARGE TREES DOWN,
                                          DAVIS WIND SENSOR REPORT

1223 PM    THIEF RIVER FALLS         MN   .75 INCH HAIL
07/31/01   PENNINGTON

1235 PM    4 W MAVIE                 MN   WIND DAMAGE
07/31/01   PENNINGTON                     SEVERAL LARGE LIMBS DOWN

1245 PM    15 SW GRYGLA              MN   .75 INCH HAIL
07/31/01   PENNINGTON                     ALONG COUNTY LINE

1245 PM    2 NE MAVIE                MN   .75 INCH HAIL
07/31/01   PENNINGTON                     ALONG COUNTY LINE

1245 PM    15 SW GRYGLA              MN   .75 INCH HAIL
07/31/01   MARSHALL                       ALONG COUNTY LINE

The radar

The Fargo/Grand Forks radar (KMVX), 81 km away, was scanning. The volume nearest the first event began at 21:50 UTC.

Open the radar archive at this moment

Event by event

2 hail, 1 flash flood, 1 thunderstorm wind. Local standard time, as filed.

Hail, Cass

When: July 31, 3:50 PM CST
Where: Cass County, Embden
Measured: 0.75 in hail
Reported by: GENERAL PUBLIC
Coordinates: 46.800, -97.433

Hail, Grand Forks

When: July 31, 3:54 PM CST
Where: Grand Forks County, Grand Forks
Measured: 1 in hail
Reported by: NWS EMPLOYEE(OFF DUTY)
Coordinates: 47.917, -97.050

A few one inch hailstones fell in south Grand Forks.

Flash Flood, Grand Forks

When: July 31, 4:52 PM CST to 5:20 PM CST
Where: Grand Forks County, Grand Forks
Property damage: $20,000
Reported by: GENERAL PUBLIC
Coordinates: 47.922, -97.457 (the zone’s center; the record gives no point)

Street flooding was reported in Grand Forks with a few stalled vehicles. Sewer backup occurred in the basement of one house. Underground parking lots were flooded.

Thunderstorm Wind, Cass

When: July 31, 5:30 PM CST
Where: Cass County, 3 mi NE of Argusville
Measured: 52 kt (60 mph)
Reported by: GENERAL PUBLIC
Coordinates: 47.083, -96.883

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

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

The same day elsewhere

Every storm in North Dakota in 2001 Every state in 2001 This day in weather history Warnings in North Dakota, July 2001

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: 5260558, 5260559, 5260560, 5260561.