Got this Severe Weather Awareness Week thing from Wunderground.
... Continuing severe weather awareness week in Oklahoma...
Louisiana and Texas...
This afternoons topics are damaging winds and hail...
Oklahoma... Louisiana and Texas are affected by thousands of
thunderstorms every year. The strongest and most dangerous of these
thunderstorms are defined as severe thunderstorms. Severe
thunderstorms are thunderstorms which produce damaging winds... large
hail and tornadoes. A thunderstorm is severe when it produces winds
of at least 58 mph... hail 1 inch in diameter or larger... or a
tornado. Severe thunderstorms can occur during any time of the year
in our four state region... but are most common during the Spring and
autumn months.
Thunderstorms are capable of producing very strong winds... but it is
important to remember that not all damaging thunderstorm winds are
caused by a tornado. Straight line winds refer to winds that are not
associated with rotating winds in a tornado. Rather... they move
forward along the ground in unidirectional fashion.
One form of straight line winds... the downburst... is a strong
downdraft of air that accelerates toward the ground in a
thunderstorm. Once near the ground... the downdraft can no longer
descend and therefore radiates outward in all directions... producing
a sudden rush of damaging winds at the surface. Two types of
downbursts exist... the microburst and the macroburst. The microburst
is a short lived event and of great concern to the aviation
community. It produces strong winds in an area less than 2.5 miles in
diameter. In contrast... macrobursts are longer lived and capable of
producing extensive wind damage across areas several miles in
diameter.
Straight line thunderstorm winds occasionally reach speeds in excess
of 100 mph. These winds may be intense enough to uproot trees and
produce substantial damage... if not complete destruction... to
buildings. If these winds occur in conjunction with large hail... the
damage will likely be even more extensive.
Hail that is 1 inch in diameter (as big around as a quarter) or
larger is considered severe. Hail is defined as precipitation in the
form of lumps or chunks of ice that develop inside stronger
thunderstorms. Hailstones are usually Oval shaped or round... but can
be also be spiky in appearance. Hail can range in size from pea
size... to greater than softball size. The largest hailstone on record
in the United States fell at Vivian... South Dakota on July 23... 2010.
This massive stone measured 18.625 inches in circumference... and 8
inches in diameter. This massive hail stone weighed nearly 2 pounds.
Hail falls to Earth at speeds approaching 100 mph and can cause
immense damage to buildings... automobiles and vegetation. Annually...
hail storms cause more than one billion dollars in damage across the
entire United States. No part of the four state region is immune to
the dangers of large hail. Although being struck by hail is rarely
fatal... several dozen people are seriously injured each year in
hailstorms.
To protect yourself and your property from damaging winds and hail
associated with a thunderstorm... it is important to stay abreast of
the latest weather conditions. Staying updated through NOAA Weather
Radio from the National Weather Service... as well as monitoring
television... radio and the internet... will help you be better
prepared for the dangers associated with any severe thunderstorms in
your area.
Treat straight line wind events the same as you would an approaching
tornado. Seek shelter in a reinforced building... preferably on the
lowest floor... in an interior room or closet and away from any
windows. Always cover your head to protect against the impact of
flying debris. If you encounter hail while driving... turn around. You
may be driving into the core of a thunderstorm... which is where
tornadoes form. Report hail or wind damage to law enforcement as soon
as it is safe to do so and seek an alternate Route.
The National Weather Service would like to thank everyone involved in
making severe weather awareness week a Success.
&&
For more details on some of the significant severe weather events
across the four state region dating back to the 1978 Shreveport F4
tornado... please visit...
www.Srh.NOAA.Gov/shv/events/
For more information on severe weather awareness week... please
visit...
www.NWS.NOAA.Gov/om/severeweather/
For data on the 1978 Shreveport/Bossier City tornado...I found this on Wikipedia.
The Bossier City, Louisiana Tornado is a tornado that occurred during the early morning hours of December 3, 1978 in Louisiana. An F4 tornado touched down on the eastern bank of the Red River in Bossier City, Louisiana at approximately 1:50 a.m. CST.
The twister cut a path a .5 miles (0.8 km) wide and nearly 4 miles (6.4 km) long through the heart of Bossier City. Extensive damage was done to the Heart of Bossier Shopping Center, the Airline Drive corridor, the now-defunct Highway 80 entertainment district, and the Meadowview and Swan Lake subdivisions. The only two deaths to occur in Bossier City were two young girls who were killed when a car was thrown through their bedroom wall.
On Monday, November 27, 1978, a cold front moved through Northwest Louisiana. By Friday, December 1, a positively-tilted trough was present in the upper atmosphere from the High Plains to the Desert Southwest. This allowed Gulf moisture to return to the lower part of the atmosphere Friday night. The placement of the upper atmospheric trough allowed very little movement of the associated front from Thursday to Saturday. At this time, the front stretched over north Texas, Southern Missouri, Southwestern Arkansas, and Southeast Oklahoma. This front was unusually strong for the month of December. Also at this time, a low pressure system had developed over Northeast Texas. This caused increased low level wind shear which enabled the development of thunderstorms.
In deep East Texas, a series of supercell thunderstorms developed ahead of a squall line. As thunderstorms approached the area, a severe thunderstorm warning was issued at 1:27 a.m. CST for northern Caddo and Bossier Parishes. The supercell which spawned the tornado tracked over the town of Deadwood, Texas, Southwood High School, Pierremont Mall, and the VA Hospital in Shreveport with no reports of tornadic activity. The NWS office in Shreveport clocked the supercell's winds at 52 mph. Due to radar indication of possible rotation, the NWS issued a Tornado Warning at 1:33 a.m. CST. At 1:50 a.m. the tornado developed over the Central Park subdivision in western central Bossier City.
Once on the ground, the tornado crossed Interstate 20 and then Barksdale Blvd making its way into the Heart of Bossier Shopping Center causing extensive damage. It continued northeast across Old Minden Road destroying a power substation, the Port-au-Prince apartments, the Sheraton Hotel, and Rusheon Junior High School. It continued parallel to Interstate 20 into the Airline Drive Business District. Numerous businesses were damaged or completely leveled including Pizza Hut, the Best Western, the Master Hosts Inn, Whataburger, Thrifty Liquor and K-Mart. After crossing U.S. Route 80, the twister moved through a sparsely populated area and then into the Meadowview and Swan Lake subdisions destroying substantial parts of the neighborhood. Meadowview Elementary School suffered extensive damage with one wing of the school being completely destroyed. The storm continued to track northeastward until it dissipated over the Red Chute area.
The tornado caused minor damage in the Central Park neighborhood which amounted to some roof damage and fallen trees. As it touched down near the Heart of Bossier Shopping Center, it destroyed Christmas decorations, street lights, and sign posts. Baskin Robbins and Pancho's were among the businesses in the Heart of Bossier Shopping Center which sustained major damage. The tornado's track across Old Minden Road brought it through the SWEPCO power substation creating a tangle of power lines and connectors. Two buildings at the Port-au-Prince Apartments lost their roofs and cars throughout the parking lot were piled on top of each other. The Sheraton hotel and Rusheon Junior High School also sustained roof damage and broken windows. As the tornado traveled along Interstate 20, several 18-wheelers were toppled by the F4 winds.
The tornado made its way into the Airline Drive business district leveling or nearly leveling the Best Western, the Master Hosts Inn, Pizza Hut and Thrifty Liquor. One noted anomaly was the minor damage caused to the Whataburger. It was later speculated that the position of the Whataburger situated between two suction vortices. The tornado made its way through K-Mart and the intersection of Airline Drive and U.S. Highway 80 throwing several mobile homes out into the middle of U.S. 80. Traveling into the Meadowview neighborhood, the tornado tore through several streets of housing. It was in this neighborhood that the only two deaths occurred from this tornado. On La Don Drive, Lisa and Jana Currington, ages 13 and 8, were killed when a car was thrown through the wall of the bedroom they were sleeping in. The tornado completely leveled one wing at Meadowview Elementary while causing extensive roof damage to other parts of the school.
My parents remember that. The 1:27 AM warning woke them up. And the tornado missed their old house in Bossier City by one/tenths of a mile! But i still think the tornado AndyWS went through was worse.
t beat out of it by 2.00" hail. A storm with hail of 0.25"-0.50" hail is expected to head into Bossier City by 1:25-1:30 PM.
There is a 20% chance of thunderstorms for Monday Night and Tuesday, But no severe weather expected. It could change...