Hail and Damaging Winds in Iowa, June 4 to 5, 2020

Name: Hail and Damaging Winds in Iowa, June 4 to 5, 2020
Start: 2020-06-04T21:52
End: 2020-06-05T01:10
Location: Iowa

June 4 to 5, 2020 · NWS FSD · 19 events in 7 counties and zones

A strong jet streak moved across Montana and North Dakota during the afternoon and early evening, providing enough lift to overcome a lid of warmer temperatures aloft across central South Dakota. Storms progressed east and southeast and utilized drying within the elevated layer to generate enough cooling to produce hail, and environmental deep-layer shear of 45 to 55 knots to organize into short…

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: $3,000
Crop damage: $176,000
Events: 19

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 FSD wrote it up.

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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Jun 4, 6:08 PM CST, 3 hours 44 minutes earlier.

Area forecast discussion, Jun 4, 6:08 PM CST, 3 hours 44 minutes before

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Sioux Falls SD
708 PM CDT Thu Jun 4 2020

.UPDATE...
Issued at 642 PM CDT Thu Jun 4 2020

Scattered storms continue to develop in the vicinity of a frontal
boundary from Sheldon to Sioux Rapids and locally enhanced
instability. Thus far the main threats with storms in this region
have been small hail, gusty winds, and frequent lightning amidst
weaker mid level lapse rates, but cannot rule out brief large hail
up to 1 inch diameter in a strongly sheared environment in this
small region through sunset.

Further west across central SD, will continue to monitor isolated
severe storms as they track eastward toward the forecast area.

&&

.SHORT TERM...(This Evening through Friday)
Issued at 337 PM CDT Thu Jun 4 2020

The concern in the short term will be the convection chances
overnight.

A weak upper level wave continues to move east and has moved into
northwestern South Dakota per GOES-16 hi-level water vapor image.
Convection has begun to develop along the North and South Dakota
border as well as in the northern Black Hills. Effective shear
remains more than adequate to support supercells with values of
40-50 kts. The problem is the lack of instability due to limited
moisture. As temperatures have approached 90 degrees east of the
James River, dry air just above the surface has mixed out leaving
dew points in the 50s over southwestern Minnesota, east central
South Dakota, and northwestern Iowa. This is combined with 700-500
mb lapse rates that are generally from 6.5 - 7 C/km. As a result
MLCAPES are generally less than 1000 J/kg except in the Missouri
Valley where lapse rates are near 7 C/km and dew points are in the
lower 60s. With limited instability and the lack of any
significant boundary in the area, it is unlikely severe
thunderstorms will develop over the area. Rather, the expectation
is that storms that develop in the vicinity of the Black Hills
will need to propagate into the area following the high MLCAPE
axis from western South Dakota into south-central South Dakota.
For this reason the best chance for severe storms remains in south
central South Dakota where hail up to golf ball size will be
possible with any supercells than can move into the area after
sunset. DCAPE values are less than 1000 J/kg in this area so while
60 mph wind gusts will be possible, wind will be a lesser threat.
Similarly, a weak low level wind field has resulted in 0-1 km
shear of less than 10 kts so that tornadoes appear unlikely. As
these storms move east toward Sioux City, the atmosphere does
become more stable and inflow into the storms will be lacking due
to the absence of any low level jet so that updrafts will slowly
weaken. Maximum hail size should be closer to 1 or 1.25 inches.
The storms are expected to exit the area prior to sunrise on
Friday. That will leave Friday dry with above average
temperatures. While cooler than today, highs will again be from 80
to 85.

.LONG TERM...(Friday Night through Thursday)
Issued at 337 PM CDT Thu Jun 4 2020

The forecast challenge going into the weekend and early next
weekend will be the development and subsequent evolution of a deep
upper trough that will set up over the western US this weekend and
move into the plains early next week.

With the upper trough digging into the western US Friday night,
strong southerly flow will develop across the plains in the
lowest 500 mb of the atmosphere. This will bring very warm air
into South Dakota at and above 700 mb by Saturday morning. The
result will be increasingly steep lapse rates along and west of
the James River toward sunrise. With strong warm air advection at
700 mb and steep lapse rates, there will be a chance for high-
based convection from late Friday night into Saturday morning -
primarily west of the James River although a few cells could
approach I-29. These storms are not expected to be severe. As the
day continues, warmer and more moist air will move in at 850 mb
over much of South Dakota. While the atmosphere will become
increasingly unstable west of I-29, there will be a large cap in
place as 700 mb temps warm to +12 or +14. If the warming aloft is
slower and moisture comes in more quickly around 850 mb, there is
the potential for storms to develop over portions of eastern South
Dakota as a strong upper level short wave/jet streak moves into
the northern High Plains. Should storms develop, effective shear
is around 40 kts so could not rule out some large hail from
elevated supercells. The best chance will be west of the James
River. Any storms that manage to develop should move north of the
area late Saturday night.

On Sunday and Monday, both the NAEFS and ECMWF ensemble are
showing unusually warm air at 700 mb - amongst the warmest seen
for this time of year. The warm anomaly is not as significant at
850 mb. The combination argues that a significant cap is likely to
be in place Sunday and Monday. This will make thunderstorm
development increasingly unlikely as the surface low and front
remain over western South Dakota. Instead, very warm temperatures
in the 90s with dew points climbing well into 60s can be expected.
The surface low and upper trough look to approach the area Monday
night and Tuesday. There remains a lot of uncertainty on the
timing of the frontal passage but when it does go through there
will be a threat of heavy rainfall as there could be training
storms in the deep southerly flow. After the frontal passage,
cooler air with temperature at or even below seasonal averages
can be expected by the middle of next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 642 PM CDT Thu Jun 4 2020

MVFR ceilings and vsby are possible this evening through early
Friday morning as scattered thunderstorms move through the
region. Storms across western and central SD and NE will track
east, first near KHON this evening and then perhaps reaching near
KFSD and KHON after midnight. Other than with storms, expect VFR
conditions through the period.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

UPDATE...BP
SHORT TERM...Schumacher
LONG TERM...Schumacher
AVIATION...BP

Hazardous weather outlook, Jun 4, 8:05 PM CST, 1 hour 47 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Sioux Falls SD
905 PM CDT Thu Jun 4 2020

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-SDZ038>040-056-051200-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Beadle-Kingsbury-Brookings-Moody-
905 PM CDT Thu Jun 4 2020

This Hazardous Weather Outlook is for northwest Iowa, west central
Iowa, southwest Minnesota and east central South Dakota.

.DAY ONE...Tonight.

Isolated strong to severe thunderstorms are expected to pass through
portions of the region late tonight. The strongest storms may
produce hail up to quarter size and wind gusts up to 60 mph.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Another round of scattered strong to severe thunderstorms are
possible Saturday evening into the overnight hours.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is possible through 4 AM Friday morning.

NEZ013-014-SDZ050-052>055-057>071-051200-
Dixon-Dakota-Gregory-Jerauld-Sanborn-Miner-Lake-Brule-Aurora-Davison-
Hanson-McCook-Minnehaha-Charles Mix-Douglas-Hutchinson-Turner-
Lincoln-Bon Homme-Yankton-Clay-Union-
905 PM CDT Thu Jun 4 2020

This Hazardous Weather Outlook is for northeast Nebraska, central
South Dakota, east central South Dakota, south central South Dakota
and southeast South Dakota.

.DAY ONE...Tonight.

Scattered strong to severe thunderstorms are expected to pass
through portions of the region through 2 AM tonight. The strongest
storms may produce hail up to golf ball size and wind gusts up to 60
mph.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Another round of scattered strong to severe thunderstorms are
possible Saturday evening into the overnight hours.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed this evening.

In the hours before

Local storm report, Jun 4, 8:47 PM CST, 1 hour 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
947 PM CDT THU JUN 4 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0939 PM     TSTM WND GST     6 NNE WHITE             44.52N 96.60W
06/04/2020  E60 MPH          BROOKINGS          SD   TRAINED SPOTTER

            LEAVES FROM TREES SPLATTERED ON WINDOWS AND
            SIDING OF HOUSE.

&&

TRM

Local storm report, Jun 4, 9:02 PM CST, 50 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1002 PM CDT THU JUN 4 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0941 PM     TSTM WND GST     HENDRICKS               44.51N 96.43W
06/04/2020  E65 MPH          LINCOLN            MN   TRAINED SPOTTER

            PEA SIZED HAIL AND BRIEF HEAVY RAIN FOLLOWED
            THE STRONG WINDS.

&&

TRM

Local storm report, Jun 4, 9:18 PM CST, 34 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1018 PM CDT THU JUN 4 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 PM     HAIL             6 SE ALCESTER           42.96N 96.54W
06/04/2020  E0.70 INCH       UNION              SD   TRAINED SPOTTER

            GROUND COVERED WITH PEA TO DIME SIZED HAIL.

&&

TRM

Local storm report, Jun 4, 9:24 PM CST, 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1024 PM CDT THU JUN 4 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0945 PM     TSTM WND GST     3 S HENDRICKS           44.46N 96.44W
06/04/2020  M70 MPH          LINCOLN            MN   MESONET

            70 MPH PEAK WIND GUST REPORTED AT MN030
            MESONET SITE.

&&

Local storm report, Jun 4, 9:28 PM CST, 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1028 PM CDT THU JUN 4 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0856 PM     HAIL             5 SE WOLSEY             44.36N 98.40W
06/04/2020  E1.00 INCH       BEADLE             SD   TRAINED SPOTTER

            DIME TO QUARTER SIZED HAIL NEAR WOLSEY MN.

&&

Local storm report, Jun 4, 9:31 PM CST, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1031 PM CDT THU JUN 4 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1022 PM     HAIL             1 NNW FLORENCE          44.24N 96.05W
06/04/2020  E0.70 INCH       LYON               MN   LAW ENFORCEMENT

            DIME SIZED HAIL REPORTED NEAR FLORENCE MN.

&&

The radar

The Sioux Falls radar (KFSD), 83 km away, was scanning. The volume nearest the first event began at 03:49 UTC.

Open the radar archive at this moment

Event by event

15 hail, 4 thunderstorm wind. Local standard time, as filed.

Hail, Sioux

When: June 4, 9:52 PM CST to 9:54 PM CST
Where: Sioux County, 1.66 mi WNW of Newkirk
Measured: 0.75 in hail
Reported by: Public
Coordinates: 43.080, -95.980

Hail, O'Brien

When: June 4, 10:18 PM CST to 10:20 PM CST
Where: O'Brien County, 1.01 mi E of Sanborn
Measured: 1 in hail
Reported by: Public
Coordinates: 43.180, -95.650

Hail, O'Brien

When: June 4, 10:20 PM CST to 10:22 PM CST
Where: O'Brien County, 0.5 mi E of Sanborn
Measured: 1 in hail
Reported by: Public
Coordinates: 43.180, -95.660

Hail, O'Brien

When: June 4, 10:27 PM CST to 10:29 PM CST
Where: O'Brien County, Hartley
Measured: 1.75 in hail
Reported by: Social Media
Coordinates: 43.180, -95.480

Hail, Cherokee

When: June 4, 10:43 PM CST to 10:44 PM CST
Where: Cherokee County, 3.43 mi SW of Cleghorn
Measured: 1 in hail
Reported by: Public
Coordinates: 42.780, -95.740

Hail, Dickinson

When: June 4, 10:51 PM CST to 10:53 PM CST
Where: Dickinson County, 1.38 mi S of Fuller Fld Arpt
Measured: 1.75 in hail
Crop damage: $65,000
Reported by: Emergency Manager
Coordinates: 43.310, -95.150

Hail varied in size from quarters to golf balls. Crop damage is an estimate from insured losses. Information provided by the United States Department of Agriculture.

Hail, Dickinson

When: June 4, 10:52 PM CST to 10:54 PM CST
Where: Dickinson County, Fuller Fld Arpt
Measured: 1 in hail
Reported by: Social Media
Coordinates: 43.330, -95.150

Thunderstorm Wind, Dickinson

When: June 4, 10:52 PM CST to 10:54 PM CST
Where: Dickinson County, 1.47 mi NNW of Spirit Lake Lake
Measured: 56 kt (64 mph) estimated gust
Property damage: $1,000
Reported by: Emergency Manager
Coordinates: 43.490, -95.130

A large tree, 2.5 feet in diameter, was uprooted and blocked most of County Road M49 on the northwest side of Big Spirit Lake. Property damage costs are rough estimates.

Thunderstorm Wind, Dickinson

When: June 4, 10:55 PM CST to 10:57 PM CST
Where: Dickinson County, 4.27 mi NW of Terril
Measured: 56 kt (64 mph) estimated gust
Property damage: $1,000
Reported by: Emergency Manager
Coordinates: 43.350, -95.030

A two-foot diameter tree was snapped near the base. Property damage costs are rough estimates.

Thunderstorm Wind, Dickinson

When: June 4, 10:57 PM CST to 10:58 PM CST
Where: Dickinson County, 4.02 mi E of Fuller Fld Arpt
Measured: 52 kt (60 mph) estimated gust
Crop damage: $5,000
Reported by: Emergency Manager
Coordinates: 43.330, -95.070

Strong winds flattened crops 3 to 4 miles east of Milford. Crop damage is an estimate from insured losses. Information provided by the United States Department of Agriculture.

Hail, Cherokee

When: June 4, 11:09 PM CST to 11:11 PM CST
Where: Cherokee County, 1.71 mi SE of Cherokee Muni Arpt
Measured: 1.25 in hail
Reported by: Public
Coordinates: 42.710, -95.530

Thunderstorm Wind, Osceola

When: June 4, 11:21 PM CST to 11:23 PM CST
Where: Osceola County, 2.13 mi SSE of May City
Measured: 52 kt (60 mph) estimated gust
Property damage: $500
Crop damage: $106,000
Reported by: Trained Spotter
Coordinates: 43.290, -95.470

Tree limbs two to four inches in diameter were snapped. Property damage costs are rough estimates. Crop damage is an estimate from insured losses. Information provided by the United States Department of Agriculture.

Hail, Ida

When: June 5, 12:53 AM CST to 1:05 AM CST
Where: Ida County, 1.23 mi SW of Ida Grove
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 42.340, -95.490

Hail, Ida

When: June 5, 12:57 AM CST to 1:04 AM CST
Where: Ida County, 0.69 mi S of Ida Grove
Measured: 1.75 in hail
Reported by: Social Media
Coordinates: 42.340, -95.470

Hail, Ida

When: June 5, 12:59 AM CST to 1:05 AM CST
Where: Ida County, 0.69 mi S of Ida Grove
Measured: 1.5 in hail
Reported by: Broadcast Media
Coordinates: 42.340, -95.470

Hail, Ida

When: June 5, 12:59 AM CST to 1:04 AM CST
Where: Ida County, 0.86 mi SW of Ida Grove
Measured: 2.5 in hail
Reported by: Social Media
Coordinates: 42.340, -95.480

Hail, Ida

When: June 5, 1:02 AM CST to 1:05 AM CST
Where: Ida County, 0.69 mi N of Arthur
Measured: 1 in hail
Reported by: Public
Coordinates: 42.340, -95.350

Hail, Buena Vista

When: June 5, 1:04 AM CST to 1:07 AM CST
Where: Buena Vista County, 1.67 mi ESE of Alta
Measured: 1.25 in hail
Reported by: Social Media
Coordinates: 42.660, -95.270

Hail, Ida

When: June 5, 1:06 AM CST to 1:10 AM CST
Where: Ida County, 0.51 mi E of Ida Grove
Measured: 1 in hail
Reported by: Public
Coordinates: 42.350, -95.460

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
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 Iowa in 2020 Every state in 2020 This day in weather history Warnings in Iowa, June 2020

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: 903640, 903642, 903643, 903644, 903645, 903646, 903647, 903651, 903653, 903654, 903648, 903656, 905134, 905139, 905142, 905143, 905144, 905145, 905148.