Damaging wind and hail producing storms: formation and safety tips
Central Missouri has another chance of observing severe weather on Friday evening and overnight hours. Today's severe weather preparedness week topic, hail and wind safety, goes perfectly with the type of potential hazards expected tomorrow.
The type of system that will eventually enter our area is known as a QLCS, or a quasi-linear convective system. It is a family of storms moving as a line, and it can happen any time of the year. As for how it forms, it can be expected that since it can happen any time of the year, it forms from many different processes.
In these systems, a formation called bowing segments can occur, which makes the storm system as a whole look like an arch. Meteorologists look for these specific characteristics, like bowing segments on radar, to determine the intensity of the storm. For example, a low amount of reflectivity behind the main line of storms means there is most likely strong downdraft winds. Or, for areas of low reflectivity ahead of the main line of storms, that means there could be potential updrafts of storms. These storm types are also known for producing short-lived spin-ups or tornadoes, so meteorologists often carefully investigate the leading edge of these storm lines to find any features that may be indicative of circulation. All of this information is put together in order to produce the most accurate warnings for a specific area, where damaging winds, hail, or tornadoes are most likely.
These QLCS storms form due to a few main features. The first main feature is that warm air ahead of the storm is rising, most commonly due to a cold front passing through an area. This warm air rises ahead of an already preexisting storm due to the much cooler air associated with the cold front, allowing new storms to develop just ahead of the previous storm. This process can repeat for miles and can be sustained by the emergence of the low-level jet stream, a fast-flowing river of air in the lower levels of the atmosphere. This process forces cold air from the upper levels of the storm down to the surface, causing potentially damaging winds along the leading edge of the system, but on occasion, tornadoes can form along the line of storms.
Hail can also form in these storm systems. As hailstones are carried up and down inside the storm cloud, they grow by colliding with supercooled water droplets and ice particles. This allows the hailstones to grow until they are too heavy for the storm to keep them up or when the force keeping them up, known as the updraft, weakens.
With any type of storm system, it is important to take the proper measures to ensure the safety of yourself and others. First, it is essential to know your safe place in case of damaging or impactful conditions, and it is also important to have multiple ways to receive warnings so that you know if these hazardous conditions are heading your direction. Prepare protective gear in case your safe place is not enough, and know what way you are going to go about alerting first responders after the storm has moved out of the area. Finally, take pictures of belongings and valuables in case of any losses or damages to personal property.
