Tornadoes · United States · Kansas · 1994

F1 tornado, Portis to Downs, Kansas, July 1, 1994

From Portis to Downs, this F1 tornado ran 12.0 miles across Osborne and Mitchell counties on July 1, 1994, touching down at 9:39 PM CDT and reaching 73 yards wide. It killed nobody, and did $50,000 to $500,000 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
July 1, 1994
Touchdown
9:39 PM CDT (02:39 UTC)
Path length
12.0 miles (19.3 km)
Path width
73 yards (67 m)
Deaths
0
Injuries
0
Property damage
$50,000 to $500,000
Counties
Osborne and Mitchell counties
Touchdown point
39.530, -98.700
Lift-off point
39.530, -98.400
Record number
688

What the Weather Service recorded

This tornado broke contact with the ground several times but managed to knock down numerous telephone poles between Portis and Delphos as well as inflicting significant damage to several farm outbuildings just north of Delphos.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
01:57 UTC02:45 UTCSevere Thunderstorm WarningTOP
02:41 UTC03:30 UTCTornado WarningTOP

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 06:07 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.

Dodge City, (KDDC), 00:00Z

2.7 hours before the tornado, 228 km from the path. July 2, 1994.

Skew-T log-pSkew-T log-p diagram, Dodge City, at 00:00Z on 1994-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1432 joules per kilogram, CIN -29, lifted condensation level 3072 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Dodge City, at 00:00Z on 1994-07-02The 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 64 square meters per square second, 0 to 6 km bulk shear 52 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
1432 J/kg
Mixed-layer CIN
-29 J/kg
Surface CAPE
1548 J/kg
Mixed-layer LCL
3072 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
160 m²/s²
Significant tornado parameter
0.0
Supercell composite
9.1
0-3 km lapse rate
9.3 K/km

Open this sounding in Storm Lab

Dodge City, (KDDC), 12:00Z

9.3 hours after it, 228 km from the path. July 2, 1994.

Skew-T log-pSkew-T log-p diagram, Dodge City, at 12:00Z on 1994-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 717 joules per kilogram, CIN -563, lifted condensation level 1261 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Dodge City, at 12:00Z on 1994-07-02The 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 278 square meters per square second, 0 to 6 km bulk shear 42 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
717 J/kg
Mixed-layer CIN
-563 J/kg
Surface CAPE
74 J/kg
Mixed-layer LCL
1261 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
278 m²/s²
0-3 km storm-relative helicity
644 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4
0-3 km lapse rate
2.3 K/km

Open this sounding in Storm Lab

The surface observations

Phillipsburg (PHG), 70 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:00 UTC9661200° 5 kt1005.1
02:00 UTC74.8460350° 20 kt301007.1-TSRA
03:00 UTC6561.88100° 20 kt1009.8TS

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

This ground now

The live radar over the trackEvery 1994 tornado in KansasEvery tornado in Kansas since 1950Warnings in force in Kansas nowThe forecast where you are

The other tornadoes of July 1, 1994

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 111:04 AM EDTF0Aroostook, ME3.030$5,000 to $50,000
July 13:36 PM MDTF0Hooker, NE0.523
July 16:45 PM CDTF1Hamilton, NE0.323
July 17:03 PM CDTF1Clay, NE7.073
July 17:45 PM CDTF0Gove, KS0.120$50 to $500
July 17:45 PM CDTF0Gage, NE0.550$500,000 to $5 million
July 18:55 PM CDTF0Ottawa, KS2.550$500 to $5,000

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.