Severe storms produced numerous reports of hail and 3 brief, weak tornadoes on this Tuesday afternoon and evening. Between 230 and 330 PM CST, scattered fairly small supercell thunderstorms developed along a line from Red Cloud to Grand Island to Columbus.
Every event with a place to put it. Tap one for its entry below.
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.
The episode as NWS GID wrote it up.
Severe storms produced numerous reports of hail and 3 brief, weak tornadoes on this Tuesday afternoon and evening. Between 230 and 330 PM CST, scattered fairly small supercell thunderstorms developed along a line from Red Cloud to Grand Island to Columbus. They were not mini-supercells, though, as cloud tops were near 40,000 ft. The storms generally remained along that line except for one storm that moved east into Clay County and another small multicell cluster that moved east along the Nebraska-Kansas border. Nearly 30 occurrences of severe hail were reported with most of between the sizes of quarters and golf balls. The largest hail reported was 2 inches in diameter in the town of Roseland. Three brief EF-0 tornadoes also occurred. The storms from Grand Island to Columbus formed along a slow-moving cold front. One tornado was associated with a supercell located on or very close to the front just west of Aurora. Another tornado formed near Doniphan as a north-northeastward-moving storm crossed the front. The third tornado occurred with the storm that moved east along the Nebraska-Kansas border. This storm evolved from a small bow echo and exhibited a spiral shape as it produced a brief tornado near Chester. The storms dissipated or moved out of south central Nebraska by 6 PM CST.
A low pressure system was near Lake Superior with a slow-moving cold front extending southwest across Nebraska 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 80s with dewpoints in the upper 50s to near 60. 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 supercell convective mode.
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, 1 hour 24 minutes earlier.
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...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
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.
&&
THIESPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HASTINGS NE
339 PM CDT TUE MAY 1 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0315 PM HAIL 2 SSW KIRWIN 39.64N 99.15W
05/01/2018 E1.25 INCH PHILLIPS KS EMERGENCY MNGR
REPORT OF NICKEL TO HALF DOLLAR SIZE HAIL.
&&
PFANNKUCHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HASTINGS NE
340 PM CDT TUE MAY 1 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0338 PM HAIL KENSINGTON 39.77N 99.03W
05/01/2018 E1.00 INCH SMITH KS PUBLIC
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HASTINGS NE
350 PM CDT TUE MAY 1 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0340 PM HAIL ATHOL 39.77N 98.92W
05/01/2018 M1.75 INCH SMITH KS TRAINED SPOTTER
PEA TO QUARTERS WITH GOLF BALLS MIXED IN.
&&The Omaha radar (KOAX), 91 km away, was scanning. The volume nearest the first event began at 21:02 UTC.
17 hail, 3 tornado. Local standard time, as filed.
Quarter to golf ball size hail was reported.
Half dollar to golf ball size hail was reported.
A nearly stationary landspout tornado occurred northwest of Aurora. This EF-0 tornado had a maximum wind speed estimated to be 70 MPH, which was based upon damage to a center irrigation pivot which was overturned. Several people witnessed this tornado.
This tornado touched down approximately 2 miles south of Doniphan and moved north before lifting on the south edge of Doniphan. The tornado was rated an EF-0 with a maximum wind speed estimated to be 75 MPH. This rating was based on damage to an outbuilding and nearby home. The damage to the home was caused by flying debris from the outbuilding. Other structures in the area sustained minor damage, such as broken windows, damage to soffits and garage doors.
The path was determined from a combination of storm survey information, video, radar data, and other reports. Several reports indicate the possibility of other small circulations near the parent tornado, but the most reliable path information is related to the main parent circulation as given.
Quarter to golf ball size hail was reported.
This EF-0 rated tornado moved in from Republic County, Kansas. The tornado was captured on video by a local farmer. The video and radar was used to determine the time. This tornado did not cause any significant damage as it moved through an open field, and the maximum wind speed was estimated to be 70 MPH.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2018Every state in 2018This day in weather historyThe tornado archive for Nebraska, 2018Warnings in Nebraska, May 2018
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: 755175, 755183, 755184, 755185, 755186, 755171, 755188, 755189, 753012, 755190, 753011, 755191, 755192, 755169, 755167, 755193, 755194, 755195, 755196, 753016.