Tornadoes · United States · Nebraska · 1999

F1 tornado, Morse Bluff to North Bend, Nebraska, April 8, 1999

From Morse Bluff to North Bend, this F1 tornado ran 1.5 miles across Saunders and Dodge counties on April 8, 1999, touching down at 1:07 PM CDT and reaching 400 yards wide. It killed nobody, and did $380,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mphthis tornado

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating
F1
Date
April 8, 1999
Touchdown
1:07 PM CDT (18:07 UTC)
Path length
1.5 miles (2.4 km)
Path width
400 yards (366 m)
Deaths
0
Injuries
0
Property damage
$380,000
Counties
Saunders and Dodge counties
Touchdown point
41.380, -96.780
Lift-off point
41.480, -96.770
Record number
250

What the Weather Service recorded

Of the 12 tornadoes reported over eastern Nebraska and southwest Iowa on 4/08/99 this tornado probably caused damage to the most individual buildings. In Morse Bluff, damage was sustained to 10 buildings including one business that was nearly destroyed. This tornado then tracked north/northeast and crossed the Platte River just south of North Bend and then continued into Dodge county causing damage in North Bend before lifting.

This tornado, which caused extensive damage to Morse Bluff in Saunders county crossed the Platte River just south of North Bend and damaged 14 houses in North Bend, 2 heavily.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

25 minutes of warning. NWS OAX issued a tornado warning for this county at 17:42 UTC, 25 minutes before the tornado touched down, in force until 18:15 UTC.

Issued (UTC)ExpiredProductOffice
17:42 UTC18:15 UTCTornado WarningOAX
18:21 UTC18:40 UTCTornado WarningOAX

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Moderate Risk. The outlook in force was issued at 17:13 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Omaha, NE (KOAX), 00:00Z

5.9 hours after it, 36 km from the path. April 9, 1999.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 1999-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -152, lifted condensation level 2143 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Omaha, NE at 00:00Z on 1999-04-09The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -14 square meters per square second, 0 to 6 km bulk shear 16 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-152 J/kg
Surface CAPE
889 J/kg
Mixed-layer LCL
2143 m above ground
0-6 km bulk shear
16 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
-100 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

The surface observations

Fremont Municipal Arp (FET), 21 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
16:12 UTC57.253.6110° 13 kt18996.3
16:28 UTC57.253.6120° 16 kt21995.6
16:50 UTC57.255.4110° 17 kt24994.9
17:10 UTC5955.4120° 17 kt23993.6
17:30 UTC5957.2110° 20 kt25991.5
17:50 UTC62.659110° 22 kt30989.5
18:10 UTC62.659110° 22 kt27988.5
18:30 UTC62.659110° 23 kt36988.1
18:50 UTC66.260.8200° 17 kt31987.8
19:10 UTC69.846.4220° 22 kt35988.5
19:30 UTC71.642.8210° 21 kt30988.5
19:50 UTC71.637.4220° 26 kt35988.1
20:10 UTC69.833.8220° 25 kt31988.5

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Omaha radar (KOAX), 36 km away, was scanning. The volume nearest the touchdown began at 18:08 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

This ground now

The live radar over the trackEvery 1999 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

The other tornadoes of April 8, 1999

46 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 811:00 AM CDTF1Hamilton, NE4.050$300,000
April 811:54 AM CDTF1Merrick, NE3.040$200,000
April 811:56 AM CDTF0Nance, NE1.010$10,000
April 812:22 PM CDTF0Boone, NE1.040$10,000
April 81:06 PM CDTF1Colfax, NE4.0150$540,000
April 81:12 PM CDTF0Saunders, NE3.570$40,000
April 81:33 PM CDTF1Story, IA2.002$800,000
April 81:48 PM CDTF0Washington, NE0.130$10,000
April 82:08 PM CDTF0Fremont, IA0.040
April 82:18 PM CDTF0Pottawattamie, IA0.360
April 82:22 PM CDTF1Page, IA5.070$10,000
April 82:30 PM CDTF1Andrew, MO13.502$750,000
April 82:36 PM CDTF1Page, IA8.04401$100,000
April 82:38 PM CDTF1Montgomery, IA8.060$40,000
April 82:48 PM CDTF1Page, IA9.0100$20,000
April 82:54 PM CDTF0Montgomery, IA5.080$10,000
April 82:54 PM CDTF4Taylor, IA49.01,0003$2.7 million
April 83:48 PM CDTF4Union, IA56.01,2501$2.4 million
April 84:20 PM CDTF2Carroll, MO53.52802$1.9 million
April 84:20 PM CDTF1Livingston, MO7.00$250,000
April 85:00 PM CDTF0Polk, IA0.230$40,000
April 85:13 PM CDTF2Warren, IA32.00$120,000
April 85:18 PM CDTF3Lucas, IA39.005$1.4 million
April 85:25 PM CDTF2Macon, MO17.0270$1.0 million
April 85:30 PM CDTF1Cooper, MO4.00$750,000
April 85:55 PM CDTF2Boone, MO4.01205
April 86:05 PM CDTF2Lewis, MO16.01502$2.1 million
April 86:05 PM CDTF2Boone, MO10.0120
April 86:15 PM CDTF3Davis, IA16.0300$650,000
April 86:25 PM CDTF0Jefferson, IA0.110
April 86:25 PM CDTF0Jefferson, IA0.110
April 86:30 PM CDTF1Audrain, MO10.0100
April 86:30 PM CDTF1Cole, MO12.0200
April 86:35 PM CDTF3Hancock, IL7.5200$15 million
April 87:36 PM EDTF0Barnwell, SC0.550$1,000
April 87:47 PM EDTF1Allendale, SC9.050$30,000
April 87:00 PM CDTF1Osage, MO8.0200$1.0 million
April 87:15 PM CDTF0Webster, MO0.10$20,000
April 87:34 PM CDTF2Pike, MO to IL27.3120$150,000
April 87:35 PM CDTF0Henderson, IL20.010
April 88:10 PM CDTF1Scott, IL4.0120$100,000
April 88:27 PM CDTF1Morgan, IL9.5200
April 88:45 PM CDTF1Morgan, IL9.333316$1.8 million
April 810:18 PM CDTF1Madison, IL1.001
April 810:35 PM CDTF1Piatt, IL3.510013$150,000
April 811:32 PM CDTF0Cumberland, IL0.30$100,000

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.