EF1 tornado, Princeton to Grays Chapel, Alabama, November 29, 2016

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.

Rating

EF1

Date

November 29, 2016

Touchdown

10:02 PM CST (04:02 UTC)

Lifted

10:07 PM CST (04:07 UTC)

On the ground

5 minutes

Path length

0.9 miles (1.4 km)

Path width

40 yards (37 m)

Deaths

0

Injuries

0

County

Jackson County

Touchdown point

34.920, -86.140

Lift-off point

34.920, -86.130

Record number

1611292202-01

38 damage points were recorded along this path by NWS HUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 107 mph.

• Snapped large branches observed on ridge from valley.
• numerous trees snapped going into the valley
• valley inflow likely into tor. downed hunting stand and snapped trees
• numerous downed and snapped trees coming down slope

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

A tornado outbreak occurred during the evening hours of the 29th into the early morning hours of the 30th. A very mild and unstable air mass was in place along with a strong southwesterly upper level jet. These ingredients combined with a cold front and pre-frontal trough sweeping from west to east across the area sparked scattered supercell thunderstorms during the evening, a few of which were tornadic. This was followed by a quasi-linear convective system (QLCS) that occurred with the trough, which also was responsible for severe weather. Beneficial rainfall occurred with this system with 2-5 inches reported. Some of the rainfall fell fast enough to produce brief flash flooding in the Florence area during the evening.

DEC 2 2016 Update...|NWS and UAH survey team determined that the Monte Sano EF-2 tornado|tracked into Western Jackson County and crossed over Putnam|Mountain. The team observed mainly EF-1 and EF-0 damage. Numerous|hardwood trees were either snapped or uprooted as the tornado|crossed the western slope of Putnam Mountain along with a homestead|sustaining minor roof damage and damage to a small shed. Near the ridge |top, significant tree damage was reported near a small camp ground. Several|camper trailer sustained damage from the downed trees. Additional|ridge top tree damage was observed slightly further to the WSW along CR-303|but was rated lower to slight beetle rot. The tornado continued downslope |where more hardwood trees were snapped or uprooted along with a camper trailer|that destroyed in the valley.

The parent supercell thunderstorm that produced the Monte Sano EF-2 tornado also produced a separate area of rotation that caused the EF-1 Estillfork tornado. The National Weather Service and University of Alabama in Huntsville surveys found significant softwood tree damage in the form of healthy and snapped pine trees along CR-9, east of the CR-9 and CR-141 intersection. The convergence of the down trees was evident at several locations along CR-9 and in the Estillfork area. Peak winds were determined to be 95 MPH.

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

21 minutes of warning. NWS HUN issued a tornado warning for this county at 03:41 UTC, 21 minutes before the tornado touched down, in force until 04:18 UTC.

The county was under a tornado watch, issued at 00:48 UTC and running to 04:28 UTC.

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 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 00:51 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 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.

The Northeast Alabama radar (KHTX), 5 km away, was scanning. The volume nearest the touchdown began at 04:01 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.

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

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

The live radar over the trackEvery 2016 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

21 more were confirmed in the United States that day.

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.

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