Kyle's Weather School...Derecho!

Hello this is Junior Meteorologist Kyle Elliott with another lesson in "weather school"...so hope ya'll were better able to understand the concept of warm air aloft and what it does to precipitation type as a result of my last lesson...but I think it's time I move on to my next lesson: that of the derecho! I figured because we're in the bleak damp chill of winter that I'd post a topic in my "school" that has to do with spring and summer...and the derecho is just that. I'm sure many of you have heard the term "derecho" before, but do you really know what that term means and what a derecho causes? Possibly, but I'm sure many of you have not...so let me elaborate by giving ya'll this lesson on the derecho. First, before I even describe a derecho or go into details about what it causes, I must begin by giving you some background on the conditions necessary to spark the formation of a derecho, or widespread short-term straight-line damaging wind event. Their are several ingredients that must be present to back the formation of these damaging multi-state wind events...so let me give them to you now. First, there MUST be strong upward motion and much instability across many states at a time to result in a derecho. If this ingredient is not present across a large area, forget it...a derecho just WILL NOT FORM. Plus, you must have a boundary somewhere around where the derecho is riding...a derecho must ride along or near a boundary where sharp contrast in both temperature and humidity are present. There are other more minor ingredients that must be present for the formation of a derecho, but those are the two basic ingredients, so I think I have given enough background on the conditions that must be present for the formation of a derecho...so now I will describe what happens as a result of this phenomenon. Derechos, or widespread straight-line wind events, are most common in the months of May and June anywhere from the Midwest to the Northeast and Mid-Atlantic as warm and cool air set up a battleground across those areas during those months. Derechos normally begin in either Iowa, Nebraska, Wisconsin, or Illinois and then race eastward the entire way to the Eastern Seaboard between southern Virginia and Massachusetts depending on the location of boundaries. Normally, derechos that form in the Midwest one evening reach the East Coast in 24 hours or less as these severe squall lines of thunderstorms race eastward at up to speeds of 50-70 MPH. As you can imagine, storms that are moving this fast must have EXTREME wind energy with them...and you are 100% right as derechos commonly have sustained winds to 70 + MPH across a north-south area of hundreds of miles along with wind gusts up to 100-110 MPH in certain given areas depending on the strength of the derecho. As you can imagine, winds of this magnitude must do some pretty darn severe damage, and you would be more than right as derechos commonly level entire forests and level mobile homes. Loss of life is not uncommon with these violent wind events as trailers and mobile homes cave in and destroy any life that is inside. The greatest threat from a derecho is property damage along with the threat of shingles and rooves being torn from your home. Although these are not the only things that can result as a derecho, they are the main threats that one will deal with with these events, so I will not go into more precise detail. Basically, if you are forecast to have a derecho come through your area with severe winds within the next few hours or less, remember to tie down lose furniture and then take cover when the storm bears down in the most interior room of your home or your basement if you are fortunate enough to have one. The best offense against derechos is defense as you should secure any lose items and then take cover until the storm has passed. Remember, if a derecho approaches, seek shelter immediately and stay away from windows or lose objects as they could become "flying tools of death" due to them being hurled around in the strong winds. So the bottom line is this: STAY SAFE and ACT SMART if a derecho approaches!! So that's about all I have for this lesson on derechos in "weather school"...so hope ya'll have a great rest of your evening and I'll talk to ya'll tomorrow in my discussion. If you have any questions on this lesson or would like to know my forecast for the weather in your area of the country for any day in the next two weeks or less, please, feel free to e-mail me at akstormtracker17@yahoo.com or kyleae@earthlink.net! This has been Junior Meteorologist (Storm Tracker) Kyle Elliott with a "lesson" in weather!