Thunderstorms Across the Southeast U.S.; Elevated to Locally Critical Fire Weather in Colorado

A few strong to marginally severe thunderstorms are possible across the Southeast U.S. Friday. A Marginal Risk (Level 1 of 5) outlook has been issued. Strong winds and hail will be the main threats. Elevated to locally critical fire weather conditions will persist across south-central Colorado today due to dry conditions and gusty winds. Read More >

LOADING...

Overview

A large, and slow-moving upper level storm system brought heavy rain and tornadoes to the Four State Region during the night of March 19, 2012, before exiting the area during the evening hours of March 21, 2012. The upper level trough dove south across the Pacific Coast and moved east across the Desert Southwest. By Monday, this large upper trough became "cut off" from the main upper level jet stream. With no main flow steering the trough, it moved very slowly eastward into West Texas and near the Red River between Texas and Oklahoma. Southerly flow aloft and at the surface ahead of the low provided a rich stream of moisture from the Pacific Ocean and the Gulf of Mexico. The abundant moisture, combined with the slow moving storm system set the stage for a long-duration heavy rain event over much of the Four State Region beginning late Monday, March 19.

Rainfall began first across portions of Northeast Texas where several inches fell during the late night of Monday, March 19. By mid morning on Tuesday, March 20, heavy rain had spread into adjacent portions of Northwest Louisiana and Southwest Arkansas. The strongest thunderstorms within the main convective band continually occurred south of Interstate 20 and along and just east of Interstate 49, particularly in Natchitoches Parish. Flash flooding occurred through Northwest Louisiana with several roads being closed. There were also a few swift water rescues. Flooding was very severe around Natchitoches and Nachez. Some schools were closed due to the flooding in Natchitoches Parish. Rainfall amounts in excess of 8" were common in Central and Southern Natchitoches Parish. An automated RAWS observation site at Natchitoches recorded over 10" of rain!

The high amounts of rain made the soil so soft that the ground was not able to support the weight of heavy trees and relatively light winds were able to uproot the trees. In one case, a very large pine tree fell onto a house and into the bedroom of a person who was sleeping at the time. The effects of the heavy rainfall will continue to be felt for several days and weeks as rivers and stream around the area have also begun to flood. Despite the damage and flooding, this rainfall will go a long way to easing the effects of the drought that has plagued the area over the last couple of years.

Composite map of rainfall amounts from 12am on 3/19/2012 through 12am on 3/21/2012. Map was produced by combining rain gage reports and radar estimates. Data was compiled by the NWS River Forecast Centers.

In addition to the flooding threat, a high amount of low-level wind shear contributed to produce a few tornadoes with the strongest storms on Tuesday and Wednesday, March 21. Several reports of suspected tornado damage were received from various locations in Northwest and North Central Louisiana Tuesday and early Wednesday. Meteorologists from the National Weather Service in Shreveport conducted surveyed the damage on March 21, 2012. The report is presented in chronological order of when the tornadoes occurred.

TOTAL TORNADO COUNT = 5

EF0 = 4

EF1 = 1

Tornado Table

Damage Map

TOR. #	START POINT	RATING	START TIME	END TIME	LENGTH/ WIDTH	FATALITIES/ INJURIES	REMARKS
MARCH 20, 2012
#1	5 miles E of Zwolle, Sabine Parish, LA	EF0	11:36am CDT	11:41am CDT	3 miles/ 50 yards	None	This tornado touched down along Highway 1215. Several trees were snapped and uprooted and a few power lines were downed. The tornado continued northeast crossing Highway 120 near Belmont snapping more trees and downing more power lines before lifting.
#2	2.3 miles SE of Goldonna, Natchitoches Parish, LA	EF0	1:15pm CDT	1:18pm CDT	2.1 miles/ 75 yards	None	This tornado touched down along State Route 156. Several trees were snapped on both sides of the road with power lines downed. More trees were downed on railroad tracks east of Highway 156.
#3	2 miles E of Natchitoches, Natchitoches Parish, LA	EF0	9:28pm CDT	9:29pm CDT	1 mile/ 20 yards	None	This tornado touched near the Cedar Grove Mobile Home Park. A tree was snapped along Highway 484 leading east into the mobile home park. Three homes sustained damage with one sustaining moderate roof damage. Debris was scattered east as the tornado crossed a field and lifted.
MARCH 21, 2012
#4	2 miles S of Sikes, Winn Parish, LA	EF0	3:14am CDT	3:15am CDT	0.4 miles/ 50 yards	None	This tornado briefly touched down along Highway 499. A few trees were snapped on the west side of the highway near the intersection of Highway 499 and Parish Road 1134. The tornado was moving northeast and lifted in a clearing before reaching the community of Sikes
#5	2 miles W of Grayson, Caldwell Parish, LA	EF1	8:30am CDT	8:38am CDT	4.1 miles/ 400 yards	None	An EF1 tornado touched down along State Route 845 snapping a few trees. The tornado crossed Highway 126 along McCrary Road where most of the damage occurred. Twenty homes were damaged and one mobile home was destroyed. Damage was primarily due to fallen trees. Several sheds were also destroyed from falling trees. Other damage occurred to homes and structures along Highway 165 due to straight-line winds or the rear-flank downdraft east of the tornado track.

Coming Soon

Back to Top

Follow us on Twitter

Follow us on Facebook

Follow us on YouTube

SHV RSS Feed

Thunderstorms Across the Southeast U.S.; Elevated to Locally Critical Fire Weather in Colorado

March 19-21, 2012: Flooding and Tornadoes