Tornadoes · United States · Alabama · 2020

EF1 tornado, Tanner Williams to Cottage Hill, Alabama, April 19, 2020

From Tanner Williams to Cottage Hill, this EF1 tornado ran 8.9 miles across Mobile County on April 19, 2020, touching down at 10:55 PM CDT and reaching 100 yards wide. It killed nobody.

The rating scale

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

  1. EF065 to 85 mph

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

  2. EF186 to 110 mphthis tornado

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

  3. EF2111 to 135 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. EF3136 to 165 mph

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

  5. EF4166 to 200 mph

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

  6. EF5over 200 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
EF1
Date
April 19, 2020
Touchdown
10:55 PM CDT (03:55 UTC)
Lifted
11:06 PM CDT (04:06 UTC)
On the ground
11 minutes
Path length
8.9 miles (14.3 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Mobile County
Touchdown point
30.709, -88.378
Lift-off point
30.640, -88.252
Record number
2004192155-01

The damage survey

44 damage points were recorded along this path by NWS LIX and NWS MOB, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 100 mph.

  • Screened in porch detached and flew over house and street.
  • Patchy tree damage on high resolution satellite imagery.
  • Patchy tree damage on high resolution satellite imagery collocated with likely TDS.
  • Patchy tree damage on high resolution satellite imagery. Likely TDS on KMOB radar imagery.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

A powerful storm system swept across the southeast states through the day and into the evening on the 19th. Ahead of this system a warm front brought a very warm, moist and unstable air mass northward across the area. Numerous thunderstorms develop along and south of the warm front and became severe, producing wind damage tornadoes and large hail.

The tornado touched down just west of North Grand Bay Wilmer|Road and continued east-southeast to Eliza Jordan Road South,|then turned toward the southeast crossing over Airport Boulevard.|The most significant damage occurred after the tornado crossed|Airport Blvd. in the Wakefield and Dominion Subdivisions where|many homes suffered damage to roofs, siding, gutters, chimneys,|and porches. Numerous fences were brought down as well. The|tornado continued southeast before finally lifting just south|of Cottage Hill Road. Numerous trees were either snapped or|uprooted along the entire path.

The tornado touched down just east of the Alabama/Mississippi state|line and tracked eastward before quickly lifting after it crossed|Tom Gaston Road. The tornado first toppled an irrigation watering|system, and then passed through two private residential properties|where it destroyed a barn, along with numerous broken branches and|a few snapped trees. The most significant damage occurred shortly|after to a private industrial property where three silos and a barn|were destroyed, three empty semi trailers were tipped over, and one|door of a large metal building was blown in and the other blown out.

The tornado touched down just south of Hitt Road in the Smithfield|Subdivision and tracked southeast, crossing over the intersection of|Cody and Grelot Roads. It continued to move toward the southeast|across Hillcrest Road and Cottage Hill Road, and then finally lifted|just before reaching Knollwood Drive. Mostly tree damage occurred|with this tornado with numerous branches broken, with the most damage|occurring from Hillcrest Road until the tornado lifted where several|trees were snapped or uprooted. Some houses suffered structural damage|that were impacted by falling limbs or trees, and many fences were|brought down as well. Sporadic wind damage occurred from Knollwood|Drive to Government Boulevard after the tornado lifted.

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.

The county was under a tornado watch, issued at 02:39 UTC and running to 05:48 UTC.

Issued (UTC)ExpiredProductOffice
17:00 UTC07:05 UTCWind AdvisoryMOB
02:39 UTC05:48 UTCTornado WatchMOB
02:42 UTC03:01 UTCSevere Thunderstorm WarningMOB
03:38 UTC04:30 UTCSevere Thunderstorm WarningMOB
03:54 UTC04:45 UTCSevere Thunderstorm WarningMOB
04:03 UTC04:30 UTCTornado WarningMOB
04:07 UTC04:45 UTCTornado WarningMOB
04:43 UTC05:30 UTCSevere Thunderstorm WarningMOB
05:28 UTC05:56 UTCSevere Thunderstorm WarningMOB

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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 01:01 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.

Slidell Radar S, LA (KSIL), 00:00Z

3.9 hours before the tornado, 141 km from the path. April 20, 2020.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 00:00Z on 2020-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2097 joules per kilogram, CIN -13, lifted condensation level 819 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, Slidell Radar S, LA at 00:00Z on 2020-04-20The 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 202 square meters per square second, 0 to 6 km bulk shear 65 knots.1939587897Sfc1 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
2097 J/kg
Mixed-layer CIN
-13 J/kg
Surface CAPE
2649 J/kg
Mixed-layer LCL
819 m above ground
0-6 km bulk shear
65 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
202 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
2.5
Supercell composite
9.5
0-3 km lapse rate
6.5 K/km

Open this sounding in Storm Lab

Slidell Radar S, LA (KSIL), 12:00Z

8.1 hours after it, 141 km from the path. April 20, 2020.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 12:00Z on 2020-04-20Temperature 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 -90188, lifted condensation level 1340 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Slidell Radar S, LA at 12:00Z on 2020-04-20The 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 -138 square meters per square second, 0 to 6 km bulk shear 61 knots.1939587897117Sfc1 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
-90188 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1340 m above ground
0-6 km bulk shear
61 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
-138 m²/s²
0-3 km storm-relative helicity
-96 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.6 K/km

Open this sounding in Storm Lab

The surface observations

Mobile/Bates Field (MOB), 7 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:50 UTC210° 15 kt1004.1
01:55 UTC210° 15 kt1003.7
01:56 UTC7571210° 13 kt231004.1
02:00 UTC220° 19 kt261004.1
02:05 UTC220° 18 kt1004.4
02:10 UTC220° 16 kt1004.4
02:15 UTC220° 16 kt1004.7
02:20 UTC220° 15 kt1004.7
02:25 UTC230° 15 kt1005.1
02:30 UTC240° 14 kt1005.1
02:35 UTC230° 16 kt221005.4
02:40 UTC230° 14 kt1005.4
02:45 UTC230° 11 kt1005.4
02:50 UTC230° 13 kt1005.1
02:55 UTC220° 11 kt161005.1
02:56 UTC7670220° 11 kt211005.1
03:00 UTC230° 11 kt1005.1
03:05 UTC230° 8 kt1005.1
03:10 UTC230° 10 kt1004.7
03:15 UTC 14 kt1004.4
03:20 UTC230° 11 kt1004.4
03:25 UTC220° 9 kt1004.4
03:29 UTC7670220° 7 kt1004.4
03:30 UTC230° 9 kt1004.4
03:35 UTC230° 8 kt1004.7
03:38 UTC7670230° 7 kt161004.7
03:40 UTC230° 8 kt1004.4
03:45 UTC220° 10 kt1003.7
03:47 UTC7670210° 9 kt151004.1TS
03:50 UTC210° 10 kt1003.7
03:55 UTC 13 kt1004.1
03:56 UTC7571220° 12 kt171004.4
04:00 UTC 11 kt1004.7-RA
04:03 UTC7571260° 12 kt211005.4-TSRA
04:05 UTC 21 kt431006.8RA BR
04:07 UTC7269340° 29 kt441008.5TSRA BR SQ
04:10 UTC6664350° 18 kt441007.5+TSRA BR SQ
04:12 UTC646310° 21 kt441006.1+TSRA BR SQ
04:15 UTC 17 kt1006.1+RA BR
04:18 UTC6463350° 15 kt341006.4+TSRA BR
04:20 UTC350° 14 kt1006.4+RA BR
04:25 UTC330° 11 kt1006.8+RA BR
04:30 UTC360° 8 kt1006.4+RA BR
04:32 UTC636310° 7 kt1006.4+TSRA BR
04:35 UTC330° 4 kt1006.8+RA BR
04:39 UTC636310° 6 kt1006.4+TSRA BR
04:40 UTC20° 8 kt1006.4+RA BR
04:45 UTC20° 11 kt1006.1+RA BR
04:48 UTC636320° 10 kt1006.1+TSRA BR
04:50 UTC20° 8 kt1005.8RA BR
04:55 UTC20° 8 kt1005.8-RA
04:56 UTC636310° 9 kt1005.8VCTS -RA
05:00 UTC360° 5 kt1005.8RA
05:05 UTC30° 7 kt1005.8-RA
05:10 UTC40° 7 kt1005.4RA
05:15 UTC70° 2 kt1005.8-RA
05:20 UTC110° 5 kt1005.8-RA
05:23 UTC6363120° 8 kt1005.8VCTS -RA
05:25 UTC130° 7 kt1005.8RA
05:30 UTC90° 8 kt1005.1-RA
05:35 UTC50° 7 kt1004.4-RA
05:40 UTC30° 7 kt1004.4-RA
05:43 UTC636340° 7 kt1004.7-RA
05:45 UTC50° 7 kt1004.7

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

The radar

The Mobile radar (KMOB), 7 km away, was scanning. The volume nearest the touchdown began at 03:54 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
03:55 UTCTORNADO1 Ssw Tanner WilliamsMobile, ALTHE EF-1 TORNADO TOUCHED DOWN JUST WEST OF NORTH GRAND BAY WILMER ROAD AND CONTINUED EAST-SOUTHEAST TO ELIZA JORDAN ROAD SOUTH, THEN TURNED TOWARD THE SOUTHEAST CROSSING OVER AIRPORT BOULEVARD. THE MOST SIGNIFICANT DAMAG
04:05 UTCTORNADO3 Wnw DeesMobile, ALTHE TORNADO TOUCHED DOWN JUST EAST OF THE ALABAMA/MISSISSIPPI STATE LINE AND TRACKED EAST FOR APPROXIMATELY 1.3 MILES, PRODUCING EF-0 AND EF-1 DAMAGE BEFORE LIFTING JUST EAST OF TOM GASTON ROAD SOUTH. THE TORNADO TIPPED
04:06 UTCTORNADO2 Ese Mobile Regional AMobile, ALTHE TORNADO TOUCHED DOWN JUST SOUTH OF HITT ROAD IN THE SMITHFIELD SUBDIVISION AND TRACKED SOUTHEAST FOR APPROXIMATELY 3.1 MILES BEFORE LIFTING JUST SOUTHEAST OF THE INTERSECTION OF HILLCREST RD AND COTTAGE HILL RD. THE
04:07 UTCTSTM WND DMG2 Sw Mobile Regional AiMobile, ALTREES AND POWER LINES DOWN. TREE DAMAGED A BOAT TRAILER. LIMBS AND LEAF DEBRIS NOTED ALL ALONG MCFARLAND RD/SNOW RD AREA. SIMILAR DAMAGE IN THE SPRING GROVE NEIGHBORHOOD. REPORTS VIA HAM RADIO OPERATORS AND PICTURES VIA
04:07 UTCTSTM WND DMG3 S Mobile Regional AirMobile, ALTREES AND POWER LINES DOWN. FENCE BLOWN DOWN.
04:17 UTCTSTM WND DMG1 Ene Spanish FortBaldwin, ALSEVERAL TREES DOWN AND DAMAGE TO A RESIDENCE.
04:21 UTCTSTM WND DMG1 Ene Spanish FortBaldwin, ALNWS STORM SURVEY FOUND THE DAMAGE IN THE SPANISH FORT AREA ALONG AND JUST NORTH OF HIGHWAY 31 WAS FROM STRAIGHT LINE WINDS OF 70-80 MPH. SEVERAL TREES WERE DOWNED IN THE AREA, INCLUDING ONE LARGE TREE ON AN APARTMENT COM
04:21 UTCTSTM WND DMGIrvingtonMobile, ALGAZEBO DESTROYED. TREES DOWN IN THE IRVINGTON AREA. REPORTS AND PICTURES VIA SOCIAL MEDIA.
04:21 UTCTSTM WND DMGIrvingtonMobile, ALSEVERAL TREES DOWN IN IRVINGTON.
04:22 UTCMARINE TSTM WIND 431 Ne Hollingers IslandMobile, ALMESONET STATION ON THE DOG RIVER MEASURED A MARINE THUNDERSTORM WIND GUST OF 43 MPH.
04:26 UTCTSTM WND DMG1 N DaphneBaldwin, ALMULTIPLE TREES DOWN. TREE ON RESIDENCE.
04:33 UTCTSTM WND GST 742 Ne LoxleyBaldwin, ALUSA CHILI MESONET SITE IN LOXLEY MEASURED WINDS OF 74 MPH.
04:38 UTCTSTM WND DMG1 E Battles WharfBaldwin, ALA NWS STORM SURVEY FOUND STRAIGHT LINE WIND DAMAGE IN IN THE POINT CLEAR/FAIRHOPE AREA. SEVERAL TREES WERE DOWNED IN THE BATTLES RD/OLD BATTLES ROAD AREAS WITH SPORADIC TREE DAMAGE NOTED FURTHER EAST ALONG COUNTY ROAD 32
05:32 UTCTSTM WND GST 60CodenMobile, AL60 MPH WINDS ESTIMATED BY HAM RADIO OPERATOR IN CODEN, AL.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2020 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

The other tornadoes of April 19, 2020

20 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 192:17 PM CDTEF1Grant Parish, LA2.0500
April 194:50 PM CDTEF1Vernon Parish, LA5.3500$300,000
April 197:09 PM CDTEF4Sandy Hook–Camp Shelby tornado, MS53.82,27511$700,000
April 199:50 PM CDTEF1Pearl River, MS4.475
April 1910:13 PM CDTEF1Saint Tammany Parish, LA3.0300
April 1910:28 PM CDTEF0Jackson, MS1.825
April 1910:47 PM CDTEF0Jackson, MS0.510
April 1910:49 PM CDTEF2Covington, AL1.2300
April 1910:53 PM CDTEF0Jackson, MS2.0150
April 1911:03 PM CDTEF0Coffee, AL4.450$50,000
April 1911:05 PM CDTEF1Mobile, AL1.375
April 1911:06 PM CDTEF1Mobile, AL3.275
April 1911:20 PM CDTEF1Dale, AL24.4150$200,000
April 1911:32 PM CDTEF0Geneva, AL1.8100
April 1911:40 PM CDTEF2Henry, AL5.23001
April 1911:42 PM CDTEF1Houston, AL0.750$50,000
April 1911:45 PM CDTEF1Henry, AL1.5500$250,000
April 1911:46 PM CDTEF1Baldwin, AL0.5300
April 1911:46 PM CDTEF1Henry, AL6.5100$5,000
April 1912:07 AM CDTEF0Santa Rosa, FL0.250

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.