Tornado and Flash Flooding in Kansas, May 1, 2018

Name: Tornado and Flash Flooding in Kansas, May 1, 2018
Start: 2018-05-01T14:15
End: 2018-05-01T23:30
Location: Kansas

May 1, 2018 · NWS GID · 24 events in 5 counties and zones

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: $185,000
Crop damage: $600,000
Events: 24

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 GID wrote it up.

Storms produced very heavy rain, localized hail and wind damage, and even a brief tornado over north central Kansas on this Tuesday afternoon and evening. Around 2 PM CST, several thunderstorms rapidly developed southwest-to-northeast across Rooks and Smith counties. These storms merged into a line as they moved east and gradually evolved into two multicell clusters. Each cluster tracked across portions of Jewell, and Osborne and Mitchell counties. The Jewell County storm become a very small bow echo, but with no wind damage reported. However, some wind damage did occur over southeastern Osborne County where wood framing and metal sheeting were blown off an outbuilding on one farm. A hay rake and two empty grain trailers were also blown over. Hail occurred in many places, with the largest 2 inches in diameter over south central Mitchell County. This same storm produced a brief tornado that resembled an elephant trunk. As these storms moved into northeast Kansas, other storms continued to initiate near Interstate 70 and began lifting into southern Osborne and Mitchell counties after 6 PM CST. The axis of storms stopped lifting north and repeated storm development occurred over southern Osborne and Mitchell counties, between 7 and 11 PM CST, resulting in total rainfall amounts between 2.50 and 5.18 inches. The highest amount of 5.18 inches fell just southeast of Tipton. Flash flooding occurred in low-lying spots from southeast Osborne across central Mitchell counties, with water over multiple county roads. Flooding resulted in a washout where bridge work was being performed in Mitchell county on Victor road, between P and Q roads.

A low pressure system was near Lake Superior with a slow-moving cold front extending southwest across Kansas to the Oklahoma Panhandle. In the upper-levels, southwest flow covered most of the U.S., with a trough over the West and a ridge over the Northeast. Just prior to thunderstorm development, temperatures were in the lower to middle 80s with dewpoints in the lower 60s. With mid-level lapse rates near 8 C/km, MLCAPE was 2000-2500 J/kg. Deep layer shear was 40-50 kts, which was more than sufficient for severe thunderstorms.

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 Hastings, NE wrote its last area forecast discussion before the first event at May 1, 1:36 PM CST, 39 minutes earlier.

Area forecast discussion, May 1, 1:36 PM CST, 39 minutes before

Area Forecast Discussion
National Weather Service Hastings NE
236 PM CDT Tue May 1 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 228 PM CDT Tue May 1 2018

Attention is on the severe weather threat this evening/tonight.

A cold frontal boundary stretched from roughly along a line from
near Alma to Blue Hill to York and Shelby at mid day. The boundary
location shows up fairly well on KUEX radar and the front has
meandered a little farther to the north from this morning and areas
along/south of the front and east of the dry line are the areas we
are monitoring for thunderstorms and severe weather heading into
this evening/early tonight. The HRRR seems to have the best handle
on the evolution of convection tonight with development between 4
and 5 pm, and increasing in coverage along our east/southeast zones
through the evening. Instability along/ahead of the boundary is
good, with ML CAPES of 2000-2500 j/kg and there is plenty of shear
with effective values of 40-50kts. Potential exists for supercells
capable of producing very large hail, damaging winds and even
tornadoes, with storms expected to evolve into a line along the
boundary this evening. The brunt of the convection is expected to
impact our region during the evening hours, with the line of storms
exiting our region shortly after dark, but additional development is
possible in SE zones overnight with lift enhanced by a strengthening
low level jet over the front. Locally heavy rainfall may accompany
the storms with precipitable water values averaging near one inch,
or roughly 150 percent of normal for this time of year.

Low clouds settle in behind the front again tonight and the NAM has
been overdone in developing drizzle in this set up and prefer the
drier model forecasts heading into Wednesday morning. The front is
expected to stall in the vicinity of our southeast counties
Wednesday and the location will be key as to whether we see
another round of severe weather tomorrow.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 228 PM CDT Tue May 1 2018

Wednesday night through Thursday evening, the upper trough which has
been over the Rockies for several days finally gets kicked out and
emerges onto, then crosses the Central Plains. Showers and
thunderstorms remain in the forecast as this system moves through.
On Wednesday the surface front may be oriented as far north as a
roughly KHLC/KHYS to KHJH per GFS, or just southeast of our cwa
during peak heating per the NAM. It'll be close to the southeast
edge of our area, with the boundary bringing a continued threat for
severe thunderstorms capable of producing large hail/damaging winds.
If the boundary does settle across our southeast zones, it'll be a
smaller window time wise where storms are possible before convection
shifts eastward.

By Thursday, the main instability axis moves east of our area
while the upper low fills as it crosses the plains. The better
chances for severe weather will be departing our area by Thursday,
however the weather will still be fairly cool/wet with scattered
showers and a few storms as the upper system moves across.
Instability is elevated in nature through the morning, then
diminishes nw/se through the day and precip will end in the
aftn/evening as the upper trough axis departs.

The weather quiets down Friday/Saturday with dry and warmer weather
forecast. Weak upper ridging breaks down as it expands onto the
interior CONUSThe frontal
boundary location will be dependent upon how storms unfold
tonight, with the boundary expected to be located along our
southeast counties Wednesday. to whether or not we will see another
round of storms/severe weather tomorrow. Saturday due to a shortwave translating southeast
from British Columbia. Temperatures trend up, rising above seasonal
normals into the 70s/80s over the weekend. Overall rain/storm
chances look rather minimal until Tuesday, with the arrival of the
next upper trough/front.

.AVIATION...(For the 18Z KGRI/KEAR TAFS through 18Z Wednesday)
Issued at 109 PM CDT Tue May 1 2018

A cold frontal boundary was located south of the terminals with
varying ceiling categories the main challenge for KEAR and KGRI.
Cloud heights are expected to primarily be at MVFR through the
evening, but fall to IFR tonight into Wednesday morning before
increasing again. Rain/thunderstorm chances are not high due to
the frontal position, however a VCTS is included in the TAFs for
few hours.

.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.

SHORT TERM...Fay
LONG TERM...Fay
AVIATION...Fay

Hazardous weather outlook, May 1, 2:09 PM CST, 6 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Hastings NE
309 PM CDT Tue May 1 2018

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-
021200-
Phillips-Smith-Jewell-Rooks-Osborne-Mitchell-Valley-Greeley-Nance-
Sherman-Howard-Merrick-Polk-Dawson-Buffalo-Hall-Hamilton-York-
Gosper-Phelps-Kearney-Adams-Clay-Fillmore-Furnas-Harlan-Franklin-
Webster-Nuckolls-Thayer-
309 PM CDT Tue May 1 2018

This Hazardous Weather Outlook is for south central Nebraska and
portions of north central Kansas.

.DAY ONE...This Afternoon and Tonight.

Thunderstorms are expected to develop and rapidly become severe
through the evening. The storms will be capable of producing
large hail the size of tennis balls, damaging winds over 60 mph as
well as tornadoes. Locally heavy rain in excess of two inches may
accompany the stronger storms which may lead to areas of low land
flooding. The severe weather threat is expected to last until
around 10 PM.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Thunderstorms are also possible Wednesday afternoon into Thursday.
There is a chance storms may become severe Wednesday evening
southeast of a line from Beloit Kansas to Hebron Nebraska. One
inch hail and winds of 50 to 60 mph winds would be the main
hazards.

Slight chances for thunderstorms exist across portions of the
outlook area Saturday night and again Monday.

.SPOTTER INFORMATION STATEMENT...

Spotter will be needed through the evening.

&&

More information may be obtained at the following web page:
   https://www.weather.gov/hastings

In the hours before

Local storm report, May 1, 8:46 AM CST, 5 hours 29 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HASTINGS NE
946 AM CDT TUE MAY 1 2018

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

0700 AM     HEAVY RAIN       6 W ELYRIA              41.68N 99.12W
05/01/2018  M2.85 INCH       VALLEY             NE   COCORAHS

            RAINFALL FROM MONDAY EVENING. OBSERVER ALSO
            REPORTED A CONSIDERABLE AMOUNT OF SMALL
            HAIL, WITH HAIL DRIFTS STILL VISIBLE THIS
            MORNING.

&&

PFANNKUCH

Local storm report, May 1, 11:22 AM CST, 2 hours 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HASTINGS NE
1222 PM CDT TUE MAY 1 2018

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

0923 PM     HAIL             8 WSW ELYRIA            41.65N 99.15W
04/30/2018  E1.00 INCH       VALLEY             NE   PUBLIC

            DELAYED REPORT. A FEW HAILSTONES UP TO
            QUARTER SIZE MOST SMALLER. TIME ESTIMATED
            FROM RADAR.

&&

THIES

The radar

The Grand Island radar (KUEX), 96 km away, was scanning. The volume nearest the first event began at 20:13 UTC.

Open the radar archive at this moment

Event by event

14 hail, 4 heavy rain, 3 thunderstorm wind, 2 flash flood, 1 tornado. Local standard time, as filed.

Hail, Phillips

When: May 1, 2:15 PM CST
Where: Phillips County, 2 mi SSW of Kirwin
Measured: 1.25 in hail
Reported by: Emergency Manager
Coordinates: 39.643, -99.134

Hail, Smith

When: May 1, 2:38 PM CST
Where: Smith County, Kensington
Measured: 1 in hail
Reported by: Public
Coordinates: 39.770, -99.030

Hail, Smith

When: May 1, 2:40 PM CST
Where: Smith County, Athol
Measured: 1.75 in hail
Property damage: $50,000
Crop damage: $150,000
Reported by: Trained Spotter
Coordinates: 39.770, -98.920

Heavy Rain, Mitchell

When: May 1, 3:00 PM CST to 11:00 PM CST
Where: Mitchell County, 4 mi SE of Tipton
Reported by: Mesonet
Coordinates: 39.289, -98.427

A storm total rainfall amount of 5.18 inches was measured.

Heavy Rain, Osborne

When: May 1, 3:00 PM CST to 11:00 PM CST
Where: Osborne County, 11.11 mi ESE of Covert
Reported by: Trained Spotter
Coordinates: 39.200, -98.640

A storm total rainfall amount of 4.84 inches was measured.

Heavy Rain, Mitchell

When: May 1, 3:00 PM CST to 11:00 PM CST
Where: Mitchell County, 8 mi NE of Victor
Reported by: CoCoRaHS
Coordinates: 39.332, -98.174

A storm total rainfall amount of 3.28 inches was measured.

Heavy Rain, Mitchell

When: May 1, 3:00 PM CST to 11:00 PM CST
Where: Mitchell County, 2 mi NNW of Hunter
Reported by: CoCoRaHS
Coordinates: 39.257, -98.414

A storm total rainfall amount of 4.50 inches was measured.

Hail, Smith

When: May 1, 3:12 PM CST
Where: Smith County, 1 mi E of Gaylord
Measured: 0.75 in hail
Reported by: Trained Spotter
Coordinates: 39.650, -98.831

Hail, Jewell

When: May 1, 3:42 PM CST
Where: Jewell County, 3 mi N of Esbon
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.863, -98.430

Hail, Jewell

When: May 1, 3:47 PM CST
Where: Jewell County, 3 mi W of Burr Oak
Measured: 0.88 in hail
Reported by: Trained Spotter
Coordinates: 39.870, -98.357

Thunderstorm Wind, Jewell

When: May 1, 3:48 PM CST to 3:50 PM CST
Where: Jewell County, 1 mi W of Burr Oak to Burr Oak
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 39.870, -98.319

Wind gusts were estimated to be near 60 MPH.

Hail, Osborne

When: May 1, 4:17 PM CST
Where: Osborne County, 9 mi S of Covert
Measured: 1.75 in hail
Property damage: $25,000
Crop damage: $150,000
Reported by: Law Enforcement
Coordinates: 39.150, -98.810

Thunderstorm Wind, Osborne

When: May 1, 4:20 PM CST
Where: Osborne County, 13.12 mi SE of Covert
Measured: 56 kt (64 mph) estimated gust
Reported by: Public
Coordinates: 39.160, -98.630

Some minor outbuilding damage was reported in the area.

Hail, Osborne

When: May 1, 4:25 PM CST
Where: Osborne County, 12.3 mi SE of Osborne Muni Arpt
Measured: 1 in hail
Reported by: Public
Coordinates: 39.310, -98.510

Hail, Mitchell

When: May 1, 4:45 PM CST
Where: Mitchell County, 1 mi N of Hunter
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.245, -98.400

Quarter size hail was accompanied by estimated 60 MPH wind gusts.

Thunderstorm Wind, Mitchell

When: May 1, 4:45 PM CST
Where: Mitchell County, 1 mi N of Hunter
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 39.245, -98.400

Wind gusts were estimated to be near 60 MPH and were accompanied by quarter size hail.

Hail, Osborne

When: May 1, 4:54 PM CST
Where: Osborne County, 11.11 mi ESE of Covert
Measured: 1.25 in hail
Reported by: Trained Spotter
Coordinates: 39.200, -98.640

Tornado, Mitchell

When: May 1, 5:09 PM CST to 5:10 PM CST
Where: Mitchell County, 7.12 mi E of Victor to 7.13 mi E of Victor
Rating: EF0
Path length: 0.01 mi
Path width: 25 yd
Reported by: NWS Storm Survey
Coordinates: 39.250, -98.147

This tornado was captured by video and photograph by a storm chaser. The tornado was rated an EF-0, moving over an open field with an estimated wind speed of 75 MPH.

Hail, Mitchell

When: May 1, 5:10 PM CST
Where: Mitchell County, 9 mi NE of Victor
Measured: 2 in hail
Property damage: $25,000
Crop damage: $150,000
Reported by: Social Media
Coordinates: 39.342, -98.161

Flash Flood, Osborne

When: May 1, 8:00 PM CST to 11:30 PM CST
Where: Osborne County, 12.65 mi SE of Osborne Muni Arpt to 17.6 mi SSE of Covert
Cause: Heavy Rain
Property damage: $30,000
Reported by: Emergency Manager
Coordinates: 39.321, -98.490

Ground-truth rainfall of 3 to 6 inches were recorded, though radar estimates in some locations were at least a few inches higher. The main impact from this heavy rain was water running over multiple county roads.

Flash Flood, Mitchell

When: May 1, 8:00 PM CST to 11:30 PM CST
Where: Mitchell County, 0.84 mi SW of Tipton to 4.85 mi NE of Asherville
Cause: Heavy Rain
Property damage: $30,000
Reported by: Emergency Manager
Coordinates: 39.321, -98.490

Hail, Mitchell

When: May 1, 8:02 PM CST
Where: Mitchell County, Hunter
Measured: 1.75 in hail
Property damage: $25,000
Crop damage: $150,000
Reported by: Trained Spotter
Coordinates: 39.230, -98.400

Hail, Mitchell

When: May 1, 8:14 PM CST
Where: Mitchell County, 10 mi SSW of Simpson
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.246, -98.002

Hail, Mitchell

When: May 1, 8:35 PM CST
Where: Mitchell County, 4 mi NE of Victor
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.291, -98.227

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
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.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
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.

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

The same day elsewhere

Every storm in Kansas in 2018 Every state in 2018 This day in weather history The tornado archive for Kansas, 2018 Warnings in Kansas, May 2018

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: 755198, 755199, 755200, 755218, 755219, 755220, 755221, 755201, 755202, 755203, 755213, 755204, 755215, 755205, 755206, 755216, 755207, 753031, 755208, 758936, 758937, 755210, 755211, 755212.