Severe Weather & Flooding of May 4, 2021

Overview

Rain and thunderstorms affected the NWS Birmingham forecast area from morning to evening on Tuesday, May 4th, resulting in significant flooding, widespread straight-line wind damage, and at least 3 low-end tornadoes.

Initially, batches of rain and thunderstorms were most focused near and north of Interstate 20 from morning to early afternoon. As this activity repeatedly moved over the same areas, flooding began to develop. A few storms produced sporadic wind damage. This large area of rain and storms caused an instability gradient to set up across Central Alabama, and a very unstable air mass became established south of Interstate 20. Wind shear values were on the increase, with an upper-level system moving into the region. This set the stage for even more active weather during the hours ahead.

An intense cluster of thunderstorms formed in Mississippi and congealed into a line, which then swept across counties south of Interstate 20 where conditions were most favorable for severe storms. This line produced widespread straight-line winds that took down trees, caused some structural damage, and resulted in lengthy power outages in some communities. The Montgomery Airport recorded a wind gust to 58 mph, with other reports of high winds as well. Curly-Q signatures developed on the front edge of the storms once near and east of Interstate 65, yielding one EF-1 tornado and two EF-0 tornadoes.

Farther north, steady rain continued to fall with several pockets of embedded heavy storms. This exacerbated the flooding situation as rain totals reached five to seven inches in and surrounding Shelby / Jefferson counties. A rare Flash Flood Emergency was issued to highlight the life-threatening nature of the flooding. Many roads were closed, some structures were flooded, and water rescues were performed.

Calmer weather conditions took hold through the night. Flood water gradually subsided overnight / into Wednesday, May 5th across affected urban, suburban, and rural areas, though runoff pushed some rivers into minor flood stage.

Interactive Tornado Map

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**The data below are considered PRELIMINARY.**

Location/Clickable Detailed Summary Link	Damage Rating/Estimated Maximum Wind Speeds	Injuries/Fatalities	Damage Path Length/Width	Starting Point/Time	Ending Point/Time
Hwy 183 Tornado (Perry/Chilton Counties)	EF-0 80 mph	None	25.11 miles 620 yards	4 N Sprott 32.7381/-87.2159 5:19 pm CDT	4 N Pletcher 32.7651/-86.7926 5:44 pm CDT
Prattville-Millbrook Tornado (Autauga/Elmore/Montgomery Counties)	EF-1 100 mph	None	10.73 miles 330 yards	1 NNE Prattville 32.4707/-86.4421 6:17 pm CDT	1 NNE Montgomery Zoo 32.4263/-86.2686 6:28 pm CDT
Chubahatchee Tornado (Macon County)	EF-0 80 mph	None	2.17 miles 50 yards	2 SSW Shorter 32.3667/-85.9491 6:46 pm CDT	2 SSE Hayden 32.3525/-85.9159 6:49 pm CDT

Hwy 183 EF-0

Hwy 183 EF-0 Tornado (Perry/Chilton Counties)
May 4, 2021

Event Summary

Rating: (Click for EF Scale)	EF-0
Estimated Maximum Wind:	80 mph
Injuries/Fatalities:	None
Damage Path Length:	25.11 miles
Maximum Path Width:	620 yards
Approximate Start Point/Time:	4 N Sprott 32.7381/-87.2159 at 5:19 pm CDT
Approximate End Point/Time:	4 N Plecher 32.7651/-86.7926 at 5:44 pm CDT

National Weather Service meteorologists surveyed the damage in northeastern Perry County into western Chilton County and determined it was the result of an EF-0 tornado.

Amongst common occurrences of straight-line wind damage associated with a line of severe thunderstorms, an EF-0 tornado track was confirmed from northeast Perry County to southwest Chilton County. The tornado began along J Mitchell Road and moved east-northeastward before taking a right-hand jog and ending just south of Maplesville. Damage primarily consisted of snapped and uprooted trees, with a few TDS signatures noted along its path.

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Reflectivity (left) and velocity (right) of the circulation before the tornado moved into Maplesville. Images are from KBMX at 5:36 pm CDT.

Prattville-Millbrook EF-1

Prattville-Millbrook EF-1 Tornado (Autauga/Elmore/Montgomery Counties)
May 4, 2021

Event Summary

Rating: (Click for EF Scale)	EF-1
Estimated Maximum Wind:	100 mph
Injuries/Fatalities:	None
Damage Path Length:	10.73 miles
Maximum Path Width:	330 yards
Approximate Start Point/Time:	1 NNE Prattville 32.4707/-86.4421 at 6:17 pm CDT
Approximate End Point/Time:	1 NNE Montgomery Zoo 32.4263/-86.2686 at 6:28 pm CDT

National Weather Service meteorologists surveyed the damage from near Prattville east-southeastward into northern Montgomery County and determined it was the result of an EF-1 tornado.

Wind damage was prevalent along a line of storms that moved through Autauga and Elmore counties, making it hard to distinguish between straight-line wind damage and tornadic damage; however, a corridor of enhanced damage, co-located with a rotational radar signature, was apparent along a path from Prattville to Millbrook. This was associated with an EF-1 tornado. Structural damage caused directly by wind consisted of some shingle loss, including: many residences, the Bass Pro Shop on the west side of I-65, and several hotels on the east side of I-65 at exit 179. A Chevron also had many metal panels blown from the gas pump canopy. Some homes were very heavily damaged by large, fallen trees. There were a few locations where the number / density of snapped hardwood and softwood trees increased, which pushed the rating to EF-1. Uprooted trees were plentiful as well.

The tornado began in a large residential area between Cobbs Ford Road and Alabama State Route 14 / Fairview Avenue. The tornado was at peak intensity along a short segment from S Old Farm Lane on the west side of I-65 to near the intersection of S Cobb Loop Road and Cobb Ford Road on the east side of I-65. The tornado continued southeastward, causing additional timber damage and sporadic minor structural damage before dissipating near the intersection of Alabama River Parkway and Highway 152 on the north side of Montgomery.

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Reflectivity (left) and velocity (right) of the circulation just as the tornado crossed I-65. Images are from KMXX at 6:21 pm CDT.

Tree Damage	Gas Station Damaged

Chubahatchee Creek EF-0

Chubahatchee Creek EF-0 Tornado (Macon County)
May 4, 2021

Event Summary

Rating: (Click for EF Scale)	EF-0
Estimated Maximum Wind:	80 mph
Injuries/Fatalities:	None
Damage Path Length:	2.17 miles
Maximum Path Width:	50 yards
Approximate Start Point/Time:	2 SSW Shorter 32.3667/-85.9491 at 6:46 pm CDT
Approximate End Point/Time:	2 NW Cross Keys 32.3525/-85.9159 at 6:49 pm CDT

National Weather Service meteorologists surveyed the damage in Macon County and determined it was the result of an EF-0 tornado.

An EF-0 tornado path was apparent along Crosskeys Road at Chubahatchee Creek where multiple softwood trees were uprooted. Most of the path was in an inaccessible wooded area to the northwest of the road, where a small, faint TDS is apparent on radar. In all, radar evidence suggests the tornado was brief in duration.

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Reflectivity (left) and velocity (right) of the brief touchdown. Images are from KMXX at 6:48 pm CDT.

Flooding

Canterbury United Methodist Church Mountain Brook, AL Courtesy Beth Hamer	Little Shades Creek at McCallum Park Vestavia, AL Courtesy Jerry Griffies	Oporto Madrid Blvd Birmingham, AL Courtesy ABC3340
Rue Maison Rd Homewood, AL Courtesy Homewood FD	Hwy 119 at Leeds Memorial Park Leeds, AL Courtesy Lori Davidson	Hwy 31 at Stonehaven Trail Pelham, AL Courtesy Pelham FD
Homewood, AL Courtesy Homewood FD	County 52 at County Road 33 Pelham, AL Courtesy Pelham PD	Mountain Brook, AL Courtesy Josh Stone
Hwy 31N at Hwy 150 Hoover, AL Courtesy @torcmatrix	County Road 13 Helena, AL Courtesy Nicole Fochtmann	Dolly Ridge Rd Cahaba Heights, AL Courtesy Nicole Tingle
Dickey Springs Road Bessemer, AL Courtesy Wayne Campbell (Jeff Co Rd & Transportation Dept.)	Laurel View Estates Hoover, AL Courtesy Natalie Garner	Clairmont Ave Birmingham, AL Courtesy Alex Skinner & @mpreaves
Jemison Trail Mountain Brook, AL Courtesy Cynthia Gould (ABC3340)

Outlooks & Reports

Local Day 3 Outlook May 2 at 120 pm	Local Day 2 Outlook May 3 at 250 pm	Local Day 1 Outlook May 4 at 1150 am
Storm Reports May 4

Surface Charts

Surface Analysis May 4 at 7 am	Surface Analysis May 4 at 10 am	Surface Analysis May 4 at 4 pm
Surface Analysis May 4 at 7 pm	Surface Analysis May 4 at 10 pm	Surface Analysis May 5 at 1 am

Upper Air Charts

250 mb Analysis May 4 at 7 am	500 mb Analysis May 4 at 7 am	850 mb Analysis May 4 at 7 am
250 mb Analysis May 4 at 7 pm	500 mb Analysis May 4 at 7 pm	850 mb Analysis May 4 at 7 pm
KBMX Sounding May 4 at 7 am	KJAN Sounding May 4 at 7 am