User:CO9000/2011 Anchor–Okolona–Wren tornado
 | This is not a Wikipedia article: It is an individual user's work-in-progress page, and may be incomplete and/or unreliable. For guidance on developing this draft, see Wikipedia:So you made a userspace draft. Find sources: Google (books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
 The tornado near its peak width. | |
| Meteorological history | |
|---|---|
| Date | April 27, 2011 |
| Formed | 2:48 p.m. CDT (UTC–05:00) |
| Dissipated | 3:40 p.m. CDT (UTC–05:00) |
| Duration | fifty-two minutes |
| EF3 tornado | |
| on the Enhanced Fujita scale | |
| Highest winds | ≥150 mph (240 km/h)[1] |
| Overall effects | |
| Casualties | 29 overall |
| Fatalities | 4 |
| Injuries | 25 |
| Areas affected | Webster County, Calhoun County, Chickasaw County, Monroe County, Mississippi, United States |
Part of the 2011 Super Outbreak | |
On the afternoon of April 27, 2011, during a major tornado outbreak, a large and extremely powerful EF3 tornado[a] affected rural Webster, Calhoun, Chickasaw, and Monroe counties in Mississippi.[1][2] It was a part of a long-lived, very powerful supercell thunderstorm that would go on to produce an EF5 tornado that devastated the town of Smithville nearly an hour later. Despite being given an EF3 rating with maximum sustained winds of 150 miles per hour (240 km/h), Jen Narramore and Millersville University undergraduate Nelson Tucker reported that the National Weather Service missed some crucial damage indicators indicative of a violent (EF4-EF5) tornado. The tornado in total had 29 casualties, with 4 fatalities, and 25 injuries.[2][b]
Meteorological synopsis
[edit]This section is excerpted from 2011 Smithville tornado § Meteorological synopsis
The environmental conditions leading up to the April 2011 Super Outbreak were among the "most conducive to violent tornadoes ever documented".[3] On April 25, a vigorous upper-level shortwave trough moved into the Southern Plains states.[4] Ample instability, low-level moisture, and wind shear fueled a significant tornado outbreak from Texas to Tennessee; at least 64 tornadoes touched down on this day.[3] An area of low pressure consolidated over Texas on April 26 and traveled east while the aforementioned shortwave trough traversed the Mississippi River and Ohio River valleys.[5] Another 50 tornadoes touched down on this day.[3] The multi-day outbreak culminated on April 27 with the most violent day of tornadic activity since the 1974 Super Outbreak. Multiple episodes of tornadic activity ensued with two waves of mesoscale convective systems in the morning hours followed by a widespread outbreak of supercells from Mississippi to North Carolina during the afternoon into the evening.[3]
Activity on April 27 was precipitated by a 995 mbar (hPa; 29.39 inHg) surface low situated over Kentucky and a deep, negatively tilted (aligned northwest to southeast) trough over Arkansas and Louisiana. A strong southwesterly surface jet intersected these systems at a 60° angle, an ageostrophic flow that led to storm-relative helicity values in excess of 500 m2s−2—indicative of extreme wind shear and a very high potential for tornadic supercells. Ample moisture from the Gulf of Mexico was brought north across the Deep South, leading to daytime high temperatures of 77 to 81 °F (25 to 27 °C) and dewpoints of 66 to 72 °F (19 to 22 °C). Furthermore, convective available potential energy (CAPE) values reached 2,500–3,000 J/kg−1.[3]
The supercell that produced this, and later the Smithville tornado existed along a thermal boundary in northeastern Mississippi. This was an east–west oriented outflow boundary left behind by the morning squall line. This boundary is also assumed to be the same boundary that the Hackleburg tornado developed on. Conditions were locally enhanced by more easterly surface winds generated along the residual boundary, allowing for a corridor of enhanced tornado potential.[3]
The storm first developed at roughly 11:43 a.m. CDT (1643 UTC) near Rayville, Louisiana. Within its first hour, the storm struggled to separate itself from convection, but began producing rotation around the same time.[6]
Tornado summary
[edit]The tornado first touched down on Mississippi Highway 9 at 2:48 p.m. CDT. Damage in Webster County was limited to trees, before it crossed into Calhoun County. The tornado underwent slow intensification after crossing into Calhoun County, a residence suffered damage, and a barn was destroyed.
See also
[edit]- Tornadoes of 2011
- 2011 Smithville tornado – An EF5 tornado produced minutes after this one dissipated by the same storm.
- 2023 Egypt–New Wren–Amory–Smithville tornado – Another powerful, high-end EF3 tornado that affected ajacent areas 12 years later.
Notes
[edit]References
[edit]- ^ a b US Department of Commerce, NOAA. "National Weather Service - Memphis, TN - New Wren, MS Tornado". www.weather.gov. Retrieved 2024-12-22.
- ^ a b Tucker, Jen Narramore-Nelson (2021-04-23). "Anchor-Okolona-Chapel Grove-Wren, MS EF3 Tornado – April 27, 2011 – Tornado Talk". Retrieved 2024-12-22.
- ^ a b c d e f Kevin R. Knupp; et al. (July 2014). "Meteorological Overview of the Devastating 27 April 2011 Tornado Outbreak". Bulletin of the American Meteorological Society. 95 (7). American Meteorological Society: 1, 041–1, 062. Bibcode:2014BAMS...95.1041K. doi:10.1175/BAMS-D-11-00229.1. S2CID 22335326.
- ^ Ryan E. Jewell (April 25, 2011). Apr 25, 2011 0600 UTC Day 1 Convective Outlook (Report). Norman, Oklahoma: Storm Prediction Center. Retrieved May 15, 2016.
- ^ Ryan E. Jewell (April 26, 2011). Apr 26, 2011 0600 UTC Day 1 Convective Outlook (Report). Norman, Oklahoma: Storm Prediction Center. Retrieved May 15, 2016.
- ^ Jackson, Justyn (2011-05-17). "Justyn Jackson's Weather Blog: Initiation to Dissipation -- Smithville, MS Tornadic Supercell". Justyn Jackson's Weather Blog. Retrieved 2024-12-24.