FORT WAYNE, Ind. (WFFT) — Springtime is a great time to get yourself prepared for thunderstorms and severe weather in general.
Thunderstorms can occur at any point during the year but they are common in the Great Lakes from Spring to early Fall.
Peak severe weather season is March through May.
This is typically when warm, moist air collides with cooler, drier air.
WHAT IS A THUNDERSTORM?
A thunderstorm is a rain-bearing cloud that also produces lightning.
All thunderstorms are dangerous and every thunderstorm produces lightning.
According to the National Weather Service, an average of 300 people are injured and 80 people are killed each year by lightning in the United States.
HOW DO THEY FORM?
Thunderstorms need pretty basic ingredients such as moisture, unstable air and lift.
A thunderstorm forms in three different stages: the developing stage, the mature stage and the dissipating stage.
The development stage starts with a cumulus cloud.
Have you experienced a thunderstorm yet this summer?
A thunderstorm requires three basic ingredients: moisture, unstable air, and lift. Watch to learn all about thunderstorm formation! pic.twitter.com/Sognt2QJt8
— NOAA SciJinks (@scijinks) July 11, 2020
That cloud will get pushed upward by a rising column of air or what is known as an updraft.
The cumulus cloud will then look like a towering cumulus cloud as the updraft continues.
During this phase, there is little to no rain but there can be lightning.
A thunderstorm is in the mature stage when the updraft continues to fuel the storm and precipitation begins to reach the surface creating a downdraft (column of air pushing downward).
— NWS Tallahassee (@NWSTallahassee) March 9, 2018
When the downdraft or rain-cooled air spreads out along the ground it can form a gust front or a line of gusty winds.
During the mature stage, hail, heavy rain, frequent lightning, strong winds and tornadoes can occur.
When the downdraft becomes stronger than the updraft, this will signal the beginning of the dissipating stage.
The rain will decrease in intensity, the storm weakens and eventually ends.
TYPES OF THUNDERSTORMS
There are four types of thunderstorms which are single-cell, multi-cell, squall line and supercell.
A single-cell thunderstorm is your run of the mill storm that develops, grows, and dies.
— Danielle Dozier WPXI (@DanielleDozier) April 22, 2016
They are short lived, and they are commonly referred to as pop-up storms or popcorn storms.
A multi-cell or cluster thunderstorm is multiple single-cell storms that merge together.
Their speed can make a difference in how much rain a particular area receives, and they occasionally produce large hail, damaging winds, brief tornadoes and flooding.
— Charlie ������️�� (@Hoosier_Charlie) June 13, 2018
Multi-cell thunderstorms can move over the same area, dumping large amounts of rain over a short amount of time which is called training.
Squall line storms are an intense line of thunderstorms that can span for hundreds of miles.
A continuous line of thunderstorms, called a "squall line" may form later this afternoon. Here's a little bit more information about this type of thunderstorm formation. pic.twitter.com/EastxKCWgI
— NWS Sioux Falls (@NWSSiouxFalls) September 20, 2018
These are pretty common in the Midwest and it can be found along a strong cold front.
The biggest threat is usually damaging winds.
This is when you can see the bow like feature on a radar which is a good indication of damaging winds.
Lastly, we have the supercell which is responsible for most tornadoes in the United States.
Here is a throw back from 3+ years ago on 6/28/2015. These radar images from 806 pm show the reflectivity & storm relative velocity data from the KLSX WSR-88D of a high-precipitation supercell thunderstorm producing a tornado just north of St. Peters, Missouri. #stlwx #mowx pic.twitter.com/NQiP81S5uJ
— NWS St. Louis (@NWSStLouis) July 26, 2018
A supercell is a long-lived and highly organized storm feeding off an updraft that is tilted and rotating.
The rotation is due to shear, or the change in wind direction and/or speed with respect to height.
WHAT IS A SEVERE STORM
At the end of the day, there are specific requirements to qualify a thunderstorm as severe.
What is a SEVERE STORM?
The National Weather Service issues Severe Warnings (Severe Thunderstorm or Tornado Warnings) for...
�� Hail of 1" or greater, or
�� Strong Winds of 58 mph or greater, or
�� A Tornado
We do not issue Severe Thunderstorm Warnings for frequent Lightning. pic.twitter.com/ggYlYBocpt
— NWS Aberdeen (@NWSAberdeen) May 31, 2020
According to the National Weather Service, a severe thunderstorm is a thunderstorm that produces one-inch sized hail or larger in diameter and/or winds equal to or exceeding 58 miles an hour.
A severe thunderstorm can also produce a tornado.
Lightning does not mean the storm is severe.
The Storm Prediction Center (SPC) in conjunction with the NWS are responsible with issuing severe outlooks.
There are 5 severe risk categories to an outloook which are listed below.
— NWS Mobile (@NWSMobile) October 24, 2017
HAIL AND HOW IT FORMS
For starters, hail can only form in cumulonimbus clouds or in thunderstorms.
It all starts with a particle of dust or dirt that combines with supercooled droplets.
Thunderstorms have what is called an updraft which lifts the hailstone up into the top of the clouds.
Do you know how hail
�� forms inside a thunderstorm ⛈️? It starts with an ice crystal ❄️ being forced upward by rising air. Water freezes to that crystal until it becomes too heavy; then it falls. This video has more info:https://t.co/TKIw67rF7Q#lawx #mswx #SeverePrep pic.twitter.com/GL5OxLCTXN
— NWS New Orleans (@NWSNewOrleans) February 17, 2020
This is where the hailstone will encounter more supercooled water which will cause it to grow. .
It’ll get caught in a cycle until the updraft can no longer support the weight of the hailstone.
At this point, the hail will fall to the ground.
During the next few days there is a threat for severe weather in central #NCwx. If you see hail, here is a size chart to help estimate the size of hail. As always, we love seeing your posts! https://t.co/6yNNtsUpF7 pic.twitter.com/gfYTESJdPP
— NWS Raleigh (@NWSRaleigh) June 5, 2019
If you look at the hailstone and see layers, this is how many times it traveled upward in the storms before falling to the ground.
Fun fact, the largest hailstone ever reported in the United States was an 8-inch ball of ice that fell near Vivian, South Dakota, in 2010.
Stay safe and always remember, "When Thunder Roars, Go Indoors!"
— MILWAUKEE SKYWARN (@MKEskywarn) June 2, 2020