April 2029 tornado outbreak sequence

The April 2029 tornado outbreak sequence was a deadly four-day tornado outbreak sequence primarily affecting a region from the Southern Plains through the eastern Midwest, but also affecting the Southeast and Mid-Atlantic states. The tornado outbreak sequence lasted four days, from Tuesday, April 24th through Friday, April 27th.

Meteorological synopsis
Signs of a major tornado outbreak became evident up to a week prior to the first day of the outbreak. Starting on April 17, multiple weather models (including the GFS and European models) began to depict a major tornado outbreak occurring in the region of Oklahoma and Missouri on the 24th. Consequently, the Storm Prediction Center issued a Day 7 outlook which included the states of Oklahoma, Kansas, Missouri, and Arkansas.

As the outbreak drew closer, the weather models began to depict a second storm forming over the Central Plains a day after the first storm moved into the Midwest. While there were concerns with respect to adequate moisture return in the wake of the first system, these concerns were quickly extinguished, and the SPC expected that two simultaneous tornado outbreaks would occur on April 25: one over the eastern Midwest (also extending into the interior Mid-Atlantic and Northeast) with the first storm system, and a second over the Southern Plains with a rapidly strengthening storm centered over Kansas. On April 24, SPC issued an almost-unprecedented Day 2 High Risk for Ohio, with a Day 2 Moderate for the Southern Plains.

Prior to the initiation of the outbreak, a Bermuda High fueled an intense early-season moist heat wave across the Southeastern states, from southern Louisiana all the way up to central Virginia. High temperatures reached well into the 90s across this entire zone, with dewpoints generally in the mid-70s, although lower 80s dewpoints were present along the immediate Gulf and Atlantic coasts of Louisiana, Mississippi, Alabama, Florida, Georgia, and southern South Carolina. Moisture transport over the Appalachians also extended the mid-70s dewpoints into the southern and central Appalachian regions, which helped to fuel the intensity of the outbreak, especially on the 25th and 26th. The Bermuda High then retreated offshore on the 27th, breaking down the upper-level ridge over the Southeast and allowing for the final day of the outbreak to take place over South Carolina, North Carolina, and Virginia.

Midwest and interior Mid-Atlantic
On April 25th, a highly-unstable airmass was in place, even in the morning hours, from eastern Illinois all the way to western Pennsylvania. Dewpoints across this entire area were generally in the upper 60s to lower 70s throughout the day. Dewpoints in the lower 70s reached the I-70 corridor by mid-morning, and would extend as far north as northern Ohio by the early afternoon. Actual air temperatures into eastern Indiana and Ohio were in the lower-to-mid 80s (with the highest temperatures further east into Ohio) prior to storms moving into or developing in this area. A strong SW-to-NE-oriented upper-level jet stream and a SSW-to-NNE low-level jet, in combination with southerly winds, provided intense wind shear and helicity in an already highly-unstable atmosphere (with surface-based CAPE exceeding 4,000 J/kg in central Ohio), fueling a particularly-intense tornado outbreak. A mid-level elevated mixed layer (EML) advected in from the southern Plains would provide a cap, which would prevent storm formation across most of the outbreak area until the afternoon hours, although this EML was not present in western Indiana and eastern Illinois, allowing for supercell formation and tornadic activity even in the late-morning hours. Intense wind shear prevented any storms which formed from merging into a linear squall line, meaning that most storms would be in the form of tornadic supercells. Once the cap broke in the late afternoon, additional tornadic supercells explosively formed over western and central Ohio, in addition to those already ongoing in eastern Indiana. Accounting for this possibility, the SPC was able to issue a 60% hatched tornado risk (the highest possible) across central Ohio well in advance.

Southern Plains
Meanwhile, another highly-unstable airmass was present in Texas, with a strong storm system over the central High Plains quickly advecting moisture northwards into both central and northwest Oklahoma, even reaching southwestern Kansas at its peak. A SSE-to-NNW-oriented low-level jet (becoming S-to-N-oriented with time) provided spin in the lower portions of the atmosphere, in conjunction with SE-to-NW surface winds. Dewpoints in the low 70s were already present in the morning hours over north-central Texas, and mid-to-upper 60s dewpoints advected into central Oklahoma by mid-afternoon. As the possibility of intense tornadic supercells across this region become more apparent with time, SPC upgraded north-central Texas in the area of the Dallas-Fort Worth Metroplex from a moderate risk to a high risk (due to the addition of a 30% hatched tornado risk), meaning that two separate high risk areas were delineated on the same day, the first time this happened in SPC history. Central Oklahoma and western north Texas would remain at a moderate risk.

Both outbreak areas saw the same upper-level jet stream (oriented from SW-to-NE) spreading over the warm sectors.

New Albany, Ohio
See 2029 New Albany, Ohio tornado for information on this tornado.

Bridgeport, West Virginia
A particularly-strong tornado that pierced the statistical "tornado hole" over West Virginia, and was somewhat similar damage-wise to the 1944 Shinnston tornado that occurred nearby. This was only the second violent tornado to occur in West Virginia history (after Shinnston in 1944), and the worst in WV state history in terms of economic damage (although still surpassed by the Shinnston tornado for fatalities). The high fatality rate (47 total) was partially attributable to this tornado striking in populated areas, during the afternoon commute, which were generally unprepared for tornadoes.

The tornado quickly strengthened after touching down, becoming an EF3 wedge southwest of Clarksburg, with a tornado emergency promptly issued 10 minutes prior to a direct hit on Clarksburg. The tornado continued to strengthen as it moveed to the northeast, producing high-end EF4 damage north of Bridgeport, just northwest of the Meadowbrook Mall, at the Bridgeport Country Club and the (fortified) FBI CJIS facility. Cars parked at both the Meadowbrook Mall and at CJIS were thrown skywards, and the wreckage landed on the ground up to 2000 feet away. *That said, the worst damage may have been underestimated as a result of the strongest winds occurring at the FBI CJIS facility (and not only due to said facility's fortification); when combined with the inability to survey the damage at the CJIS facility over security concerns, the true strength of this tornado may never be known. If not for this "unfortunate" turn of events, this may have been an EF5.

Otherwise, the tornado weakened slightly after hitting Bridgeport, producing EF3 damage with a direct hit to Colfax, and further weakened to an EF1 as it suddenly turned north-northwestward and approached Morgantown (and when the supercell began to cycle, although Morgantown is still placed under a tornado emergency). The most destructive tornado in West Virginia history (in terms of monetary costs) finally lifted just southwest of the Mountaineer Mall, in the vicinity of Dorseys Knob Park. This was the third-deadliest tornado of the day.

Southlake, Texas
This tornado first touched down in north Fort Worth, causing minor damage to two warehouses near the I-35W/I-820 interchange. It then rapidly strengthened and widened across the north Fort Worth suburbs, producing EF2 damage to homes and businesses west of U.S. Highway 377. Crossing into Watauga, the tornado strengthened to an EF3, tearing roofs and walls off of homes and schools in its path. After entering the northernmost portion of North Richland Hills, the tornado started producing EF4 damage at the intersection of Rufe Snow Drive and Ridgetop Road. The EF4 damage swath continued into Colleyville, just NW of McPherson Park. Around the same time, an anticyclonic rotation to the SE produces EF1 damage near State Highway 26 and Hall-Johnson Road.

Upon entering Southlake near the intersection of Continental and White Chapel, the tornado strengthened into an EF5, leveling many well-built (and large) homes along its path down to their foundations. Shortly afterwards, the tornado achieved its maximum width of 1.5 miles, as it crossed the northern Timarron neighborhood. At roughly the same time, tragically 6 children in after-school activities at Rockenbaugh Elementary are killed, despite Carroll ISD's implementation of a safe room program.

The tornado then roared into Southlake Town Square (an outdoor shopping mall) with the full fury of 250 mph winds, catching many shoppers off-guard. All in all, 10 people were killed at the Southlake Town Square.

As the tornado crossed State Highway 114, 2 motorists were killed by the tornado's winds, just before the storm roared across the grounds of Gateway Church. Around the same time, EF3-to-EF4 damage hit Carroll Middle School, killing an additional 2 Carroll ISD students participating in after-school activities. In the Southlake Glen neighborhood, some of the worst damage took place; 3 residents were killed as their homes were completely leveled.

The tornado then crossed into Grapevine city limits, producing a final bout of EF5 damage along Panhandle Drive and Mesa Verde Drive, just before EF4 damage hit the Grapevine Fire Department's Station 2 on Dove Road. The tornado continued producing EF4 damage to neighborhoods in northern Grapevine, adjacent to Grapevine Lake and Oak Grove Park. After crossing the eastern portion of Grapevine Lake, EF4 damage occurred at the Grapevine Recreational Area just prior to the tornado leaving the Grapevine city limits.

The tornado then clipped the SE corner of Flower Mound, destroying warehouses at EF4 intensity as it crosses into Lewisville. Around the same time, 10 fatalities occurred at the Creekside mobile home park in SW Lewisville. The EF4 damage continued into a neighborhood near Business 121 and Round Grove Road as the tornado weakened slightly to an EF3, which then destroys businesses along the I-35E corridor.

Crossing into northernmost Carrollton, the tornado continued to produce EF3 damage in the neighborhoods of Indian Creek and Northwest Carrollton before weakening further into an EF2. The tornado then left Carrollton, and continued to produce EF2 damage in the Castle Hills neighborhood, before roping out and lifting near Parker Road and Josey Lane. The supercell then quickly cycled, proceeding to drop an EF3 tornado in Frisco and McKinney.

This was the fourth-deadliest tornado of the day.

Pontiac, Illinois-Leslie, Michigan
An extremely long-track tornado that produced EF5 damage over South Bend, IN, including at the campus of the University of Notre Dame. This tornado was the ground for nearly 250 miles, and was considered one of the most impressive tornadic events of the entire outbreak sequence (rivaling the previous day's tornado in New Albany, OH in this respect, which was only 1/5 the length of this tornado). It is considered the "Tri-State Tornado" of the 21st century both due to its track length and from having impacted parts of three different states.

101 deaths occurred along the entire track of this tornado.

Columbus, Ohio
This EF4 tornado formed over the Columbus metro area (near Galloway) well ahead of the main area of storms over Illinois, Indiana, and southwestern Lower Michigan (though it was still within the SPC High Risk). It took a path slightly northwest of the previous day's tornado, striking the main campus of the Ohio State University, Easton Town Center, and even the far northwest side of New Albany (which had dodged the prior day's 2.75 mile wide tornado). The tornado hit the northwest side of Johnstown before dissipating near Appleton. This tornado reached a width of one mile wide over Easton Town Center, and killed 28 people in all.

Huntsville-Reidsville, North Carolina
EF5 tornado impacted the Winston-Salem metropolitan area.

Non-tornadic effects
On April 26, the cold side of the low pressure over the Plains produced blizzard conditions from Denver to Minneapolis.

A hybrid derecho formed over Southern Ontario on the evening of April 26, extending overnight into the early morning hours of April 27, producing 70+ mph straight-line wind gusts along a stationary front positioned from Toronto to Boston. Over upstate New York, a few of the supercells responsible for the tornado outbreak merged with the advancing derecho, leading to extreme downburst winds from the dying supercells. One such supercell merged with the derecho over Albany, NY, producing wind gusts in excess of 100 mph over the city. Additional 100+ mph wind gusts occurred near Boston, MA. The derecho also generated destructive waves along the southeast shore of Lake Ontario and on the east shore of Cape Cod Bay. Both Oswego, NY and Provincetown, MA suffered damage to their shorelines.