Flooding and Tornadoes Strike the
Four State Region March 19-21, 2012

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.
500 mb map from 00z on 3/20/2012
Upper-air map at 500mb from 00z on 3/20 (7pm CDT on 3/19) showing the large upper trough near the Four Corners.  Map provided by the Storm Prediction Center.
 
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.
 
Observed Rainfall from 3/19/2012 thru 3/20/2012
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 amounts low-level wind shear contributed to produce a few tornadoes with the strongest storms on Tuesday and continued into Wednesday, March 21, when the storms began to exit the region.  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. Below is a preliminary report from the findings of the survey.  The report is presented in chronological order of when the tornadoes occurred.  Click here to see a Google Map of confirmed tornado tracks.  More information may be added to this page in the coming days as it becomes available.

TOTAL TORNADO COUNT = 5

EF-0 = 4
EF-1 = 1

 

MARCH 20, 2012

  1. Location:  5 miles east of Zwolle, LA, in Sabine Parish
    Rating:  EF0
    Time:  11:36 AM CDT through 11:41 AM CDT
    Maximum Width:  50 yards
    Length:  3 miles
    Injuries:  0
    Fatalities:  0
    Details:  An EF0 tornado touched down along Highway 1215.  Several trees were snapped and uprooted and a few powerlines were downed.  The tornado continued northeast crossing Highway 120 near Belmont snapping more trees and downing more powerlines before lifting.

  2. Location:  2.5 miles southeast of Goldonna, LA, in Natchitoches and Winn Parishes
    Rating:  EF0
    Time:  1:15 PM CDT through 1:18 PM CDT
    Maximum Width:  75 yards
    Length:  2.1 miles
    Injuries:  0
    Fatalities:  0
    Details:  An EF0 tornado touched down along State Route 156.  Several trees were snapped on both sides of the road with powerlines downed.  More trees were downed on railroad tracks east of Highway 156.

  3. Location:  2 miles east of Natchitoches, LA, in Natchitoches Parish
    Rating:  EF0
    Time:  9:28 PM CDT through 9:29 PM CDT
    Maximum Width:  20 yards
    Length:  1 mile
    Injuries:  0
    Fatalities:  0
    Details:  An EF0 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. Location:  2 miles south of Sikes, LA, in Winn Parish
    Rating:  EF0
    Time:  3:14 AM CDT through 3:15 AM CDT
    Maximum Width:  50 yards
    Length:  0.4 miles
    Injuries:  0
    Fatalities:  0
    Details:  An EF0 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. Location:  2 miles west of Grayson, LA, in Caldwell Parish
    Rating:  EF1
    Time:  8:30AM CDT through 8:38 AM CDT
    Maximum Width:  400 yards
    Length:  4.1 miles
    Injuries:  0
    Fatalities:  0
    Details:  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.
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Disclaimer
This survey data is preliminary and subject to change as more information becomes available.  Road accessibility and inconsistencies between mapping and GPS software may limit the accuracy of the tracks plotted on this map. Line widths are not representative of actual tornado widths.  The information plotted on this map is intended for general reference use only.

For official post-storm information, use Storm Data from the National Climatic Data Center.
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