So now we have to worry about something called a Derecho...
I have never heard this term until today. Apparently, it is a sustained wind out front of a line of thunderstorms.
All day long they have been warning us of a night full of storms and this Derecho.
Anyway, I got something more to worry about now with this elevated weather event.
= new reply since forum marked as read
I would try to be informed about what it might mean to my environment, and plan accordingly.
Like, more cheese on that pizza...
Is that what happened near you?
I'm not sure if all parts of the country call these by the same name. Here's a picture and some details. I don't know if we've had them or not:
A shelf cloud along the leading edge of a derecho photographed in Minnesota
derecho (/dəˈreɪtʃoʊ/, də-reh-choh, from Spanish: derecho [deˈɾetʃo], "straight" is a widespread, long-lived, straight-line wind storm that is associated with a fast-moving band of severe thunderstorms. Generally, derechos are convection-induced and take on a bow echo (backward "C" form of squall line, forming in an area of wind divergence in the upper levels of the troposphere, within a region of low-level warm air advection and rich low-level moisture. They travel quickly in the direction of movement of their associated storms, similar to an outflow boundary (gust front), except that the wind is sustained and increases in strength behind the front, generally exceeding hurricane-force. A warm-weather phenomenon, derechos occur mostly in summer, especially during June and July in the Northern Hemisphere, within areas of moderately strong instability and moderately strong vertical wind shear. They may occur at any time of the year and occur as frequently at night as during the daylight hours.
Organized areas of thunderstorm activity reinforce pre-existing frontal zones, and can outrun cold fronts. The resultant mesoscale convective system (MCS) forms at the point of the best upper level divergence in the wind pattern in the area of best low level inflow.[3] The convection then moves east and toward the equator into the warm sector, parallel to low-level thickness lines with the mean tropospheric flow. When the convection is strong linear or curved, the MCS is called a squall line, with the feature placed at the leading edge of the significant wind shift and pressure rise.[4]
Derechos are squall lines that are bow- or spearhead-shaped on radar and, thus, also are called bow echoes or spearhead radar echoes. Squall lines typically bow out due to the formation of a mesoscale high pressure system which forms within the stratiform rain area behind the initial line. This high pressure area is formed due to strong descending motion behind the squall line, and could come in the form of a downburst.[5] The size of the bow may vary, and the storms associated with the bow may die and redevelop.
During the cold season within the Northern Hemisphere, derechos generally develop within a pattern of southwesterly winds at mid levels of the troposphere in an environment of low to moderate atmospheric instability (caused by heat and moisture near ground level or cooler air moving in aloft and measured by convective available potential energy) and high values of vertical wind shear (20 m/s (45 mph) within the lowest 5 kilometres (16,000 ft) of the atmosphere). Warm season derechos in the Northern Hemisphere form in west to northwesterly flow at mid levels of the troposphere with moderate to high levels of instability. Derechos form within environments of low-level warm air advection and significant low-level moisture.[6]
Its common definition is a thunderstorm complex that produces a damaging wind swath of at least 250 miles (400 km),[7] featuring a concentrated area of convectively-induced wind gusts exceeding 50 knots (58 mph; 93 km/h).[8] According to the National Weather Service criterion, a derecho is classified as a band of storms that have winds of at least 50 knots (93 km/h; 58 mph) along the entire span of the storm front, maintained over a time span of at least six hours. Some studies add a requirement that no more than two or three hours separate any two successive wind reports.[9] Derechos typically possess a high or rapidly increasing forward speed. They have a distinctive appearance on radar (known as a bow echo) with several unique features, such as the rear inflow notch and bookend vortices, and usually they manifest two or more downbursts.
A typical multi-bow serial derecho
A typical progressive derecho
There are three types of derechos:
* Serial derecho — This type of derecho is usually associated with a very deep low.
* Single-bow — A very large bow echo around or upwards of 250 miles (400 km) long. This type of serial derecho is less common than the multi-bow kind. An example of a single-bow serial derecho is the derecho that occurred in association with the October 2010 North American storm complex.
* Multi-bow — Multiple bow echoes are embedded in a large squall line typically around 250 miles (400 km) long. One example of a multi-bow serial derecho is a derecho that occurred during the 1993 Storm of the Century in Florida.[10] Because of embedded supercells, tornadoes can spin out of these types of derechos. This is a much more common type of serial derecho than the single-bow kind. Multi-bow serial derechos can be associated with line echo wave patterns on weather radar.
* Progressive derecho — A line of thunderstorms take the bow-shape and may travel for hundreds of miles along stationary fronts. An example of this is the Boundary Waters-Canadian Derecho of 4–5 July 1999. Tornado formation is less common in a progressive than serial type.[why?][citation needed]
* Hybrid derecho — A derecho with characteristics of both a serial and progressive derecho. Similar to serial derechos and progressive derechos, these types of derechos are associated with a deep low, but are relatively small in size. An example is the Late-May 1998 tornado outbreak and derecho that moved through the central Northern Plains and the Southern Great Lakes on 30–31 May 1998.
Characteristics[edit]
Winds in a derecho can be enhanced by downburst clusters embedded inside the storm. These straight-line winds may exceed 100 miles per hour (160 km/h), reaching 130 miles per hour (210 km/h) in past events.[11] Tornadoes sometimes form within derecho events, although such events are often difficult to confirm due to the additional damage caused by straight-line winds in the immediate area.[12]
With the average tornado in the United States and Canada rating in the low end of the F/EF1 classification at 85 to 100 miles per hour (137 to 160 km/h) peak winds and most or all of the rest of the world even lower, derechos tend to deliver the vast majority of extreme wind conditions over much of the territory in which they occur.[citation needed] Data compiled by the United States National Weather Service and other organizations, shows that a large swath of the north-central United States and presumably at least the adjacent sections of Canada and much of the surface of the Great Lakes, can expect winds above 85 mph to as high as 120 mph (135 to 190 km/h) over a significant area at least once in any 50-year period, including both convective events and extra-tropical cyclones and other events deriving power from baroclinic sources. Only in 40 to 65 percent or so of the United States resting on the coast of the Atlantic basin, and a fraction of the Everglades, are derechos surpassed in this respect — by landfalling hurricanes, which at their worst may have winds as severe as EF3 tornadoes.[13]
Certain derecho situations are the most common instances of severe weather outbreaks which may become less favourable to tornado production as they become more violent;[clarification needed] the height of the 30–31 May 1998 upper Middle West-Canada-New York State derecho and the latter stages of significant tornado and severe weather outbreaks in 2003 and 2004 are only three examples of this. Some upper-air measurements used for severe-weather forecasting may reflect this point of diminishing returns for tornado formation, and the mentioned three situations were instances during which the rare but quite possible particularly dangerous situation severe thunderstorm variety of severe weather watches were issued from the Storm Prediction Center of the U.S. National Oceanic & Atmospheric Administration.[citation needed]
Derechos in North America form predominantly from April to August, peaking in frequency from May into July.[11] During this time of year, derechos are mostly found in the Midwestern United States most commonly from Oklahoma and across the Ohio Valley.[7] During mid-summer when a hot and muggy airmass covers the north-central U.S., they will often develop farther north into Manitoba or Northwestern Ontario, sometimes well north of the U.S.-Canadian border. North Dakota, Minnesota and upper Michigan are also vulnerable to derecho storms when such conditions are in place. They often occur along stationary fronts on the northern periphery of where the most intense heat and humidity bubble exists. Late-year derechos are normally confined to Texas and the Deep South, although a late-summer derecho struck upper parts of the New York State area after midnight on 7 September 1998. Warm season derechoes have greater instability than their cold season counterpart, while cool season derechoes have greater shear than their warm season counterpart.
Although these storms most commonly occur in North America, derechos can occur elsewhere in the world, although infrequently. Outside North America, they sometimes are called by different names. For example, in Bangladesh and adjacent portions of India, a type of storm known as a "Nor'wester" may be a progressive derecho.[8] One such event occurred on 10 July 2002 in Germany: a serial derecho killed eight people and injured 39 near Berlin. They have occurred in Argentina and South Africa as well, and on rarer occasions, close to or north of the 60th parallel in northern Canada. Primarily a mid-latitudes phenomenon, derechos do occur in the Amazon Basin of Brazil.[14] On 8 August 2010, a derecho struck Estonia and tore off the tower of Väike-Maarja Church.[15]
Trees felled by downbursts in the Boundary Waters – Canadian derecho of 1999
Unlike other thunderstorms, which typically can be heard in the distance when approaching, a derecho seems to strike suddenly. Within minutes, extremely high winds can arise, strong enough to knock over highway signs and topple large trees. These winds are accompanied by spraying rain and frequent lightning from all directions. It is dangerous to drive under these conditions, especially at night, because of blowing debris and obstructed roadways. A derecho moves through quickly, but can do much damage in a short time.
Since derechos occur during warm months and often in places with cold winter climates, people who are most at risk are those involved in outdoor activities. Campers, hikers, and motorists are most at risk because of falling trees toppled over by straight-line winds. Wide swaths of forest have been felled by such storms. People who live in mobile homes are also at risk; mobile homes that are not anchored to the ground may be overturned from the high winds. Across the United States, Michigan and New York have incurred a significant portion of the fatalities from derechos. Prior to Hurricane Katrina, the death toll from derechos and hurricanes were comparable for the United States.[7]
Derechos may also severely damage an urban area's electrical distribution system, especially if these services are routed above ground. The derecho that struck Chicago, Illinois on 11 July 2011 left more than 860,000 people without electricity.[16] The June 2012 North American derecho took out electrical power to more than 3.7 million customers starting in the Midwestern United States, across the central Appalachians, into the Mid-Atlantic States during a heat wave.[17]
http://en.wikipedia.org/wiki/Derecho
This somehow seems less predictable and as dangerous as a tornado. They seem to form for the same reasons, just without the funnel.
Be careful guys. WC and Kath, take care when the weather is like this. We're not getting enough warmth for anything like this here yet. I've heard of these described as freak winds. It's still pretty cool here, no fronts hitting each other like this. I've seen clouds like these but passing through going quickly inland many times.
He said to me, where? and then ran to the window to look out. 
I hope you don't lose power.
These can be pretty serious
http://en.wikipedia.org/wiki/June_2012_North_American_derecho
i had to look it up, and now it's happening. I don't wanna live in this world anymore.
one hit last year. The area my sister was in got messed up pretty bad. Good luck to you, stay safe.
I'm in the red zone
