Severe Weather
North Texas is known for its ever-changing weather conditions. Violent thunderstorms may strike in an instant. All thunderstorms should be considered dangerous and everyone in our community should understand, respect and know how to protect themselves from the effects of severe weather. Lightning, tornadoes, downbursts, hail, and flooding rainfall are all dangerous by-products of thunderstorms that pose a significant threat to Ennis.
It is important to understand the difference between a severe weather “watch” versus a “warning.” Either can be issued by the National Weather Service (NWS) for a specific amount of time and designated area when atmospheric conditions are ripe for the development of a possible thunderstorm and/or tornado.
A “watch” means "watch the sky" as conditions are right for possible development of severe weather. Keep an eye on developing weather and stay tuned to a local radio or television station in case conditions worsen.
A “warning” indicates a severe thunderstorm and/or tornado has been spotted or is indicated on the NWS radar. All those within the designated warning area should take cover immediately and remain there until the danger passes. The City of Ennis will activate the Outdoor Warning Sirens when severe weather, such as a tornado, threatens the community. If severe weather is approaching Ennis and the warning sirens are heard, seek shelter immediately and monitor TV and radio for further instructions.
TORNADOES
A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm and typically produced when cool air overrides a layer of warm air, forcing the warm air to rise rapidly leading to rotational winds, and thus a tornado. The damage from a tornado is a result of high wind velocity and wind-blown debris. Tornadoes strike with incredible velocity with wind speeds approaching up to 300 miles per hour. These winds are capable of uprooting trees and structures, and turning harmless objects into deadly missiles.
When a tornado is approaching, there are only minutes to make life-and-death decisions. Advances in weather radar technology have improved forecasters' ability to identify storms likely to spawn tornados. The City of Ennis has 7 strategically placed Outdoor Warning Sirens throughout the city to alert citizens when severe weather threatens to strike Ennis.
If a tornado warning is issued, go to a predetermined area where family members can safely gather and take shelter. Such an area could be a center hallway, bathroom, basement or closet on the lowest floor of the home. If in a multi-story building or a shopping mall, there may not be time to get to the lowest floor. In that case, go to the center of the building and find an area in a hallway far away from windows. If outside, hurry to the lowest floor of a sturdy building or lie flat in a ditch or low-lying area. If inside a mobile home, get out immediately and head to one of the above-named areas. Turn on a TV or radio and listen for additional instructions, Channel 4-KDFW; Channel 5-KXAS; Channel 8-Wfaa; Channel 11-KTVT; Weather apps are also available for your phone or pad.
Tornado Safety Actions:
THUNDERSTORMS
The National Weather Service issues Severe Thunderstorm Warnings for a particular county, or portions of it, when dangerous winds and damaging hail are likely to exceed the thresholds known to cause significant damage to well-built structures or cause bodily harm. These storms produce hail 3/4-inch or greater and have winds in excess of 58 miles per hour.
Large hail is created by strong rising wind currents (updrafts) that carry water droplets into the upper regions of a thunderstorm where they freeze. These frozen water droplets descend back down only to be carried back up high into the storm system where they refreeze into larger frozen drops. Finally, the cycle repeats itself enough times that the hail becomes so heavy it falls to the earth. Hail that is dime size or greater can produce dents in the tops of vehicles, damage roofs, break windows and cause significant bodily injury. Hailstones can form to softball size and fall at speeds in excess of 100 mph.
Damaging winds are another dangerous ingredient that make up the thunderstorm. Two types of dangerous winds are produced by thunderstorms: Tornadoes and Downbursts. Tornadoes, which have already been mentioned, are rotational winds. Downbursts, also known as straight-line winds, are more prominent in thunderstorms. Downburst (straight-line) winds can produce widespread damage similar to that of a tornado. In fact, downburst winds have been measured in excess of 120 miles per hour or equivalent to an F2 Tornado.
Thunderstorm Safety Actions:
FLOODS & FLASH FLOODING
Most communities in the United States experience some form of flooding after spring rains or heavy thunderstorms. Frisco is no exception. Flood waters can rise quickly or slowly but typically develop over a period of days. Flash floods usually result from intense storms dropping large amounts of rain within a brief period.
Flood waters can be extremely dangerous. The force of just six inches of swiftly moving water can knock a person off their feet. The best protection during a flash flood is to leave the flooding area and move to higher ground.
Flash Flooding Safety Actions: