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The Late-March 2007 Tornado Outbreak was a tornado outbreak that took place across the central United States. It developed in the High Plains from South Dakota to central Texas on March 28, 2007, which produced most of the tornadoes. Several more tornadoes were reported the next three days before the system weakened on March 31. It affected western Nebraska, western Kansas, extreme eastern Colorado, and much of Oklahoma, and Texas. It was the second major outbreak of 2007, four weeks after an outbreak farther east. The outbreak produced at least 81 tornadoes, and at least five deaths and extensive damage was reported. In addition to the tornadoes, widespread hail as large as softballs and destructive straight-line winds as strong as 90 mph (145 km/h) were reported. The activity level was very uncertain for March 29, as it was conditional on the dry line refiring. Despite the squall line remaining intact, several more tornadoes developed. Several more tornadoes developed on March 30 and 31 before the system weakened. ==Meteorological synopsis== A powerful mid and upper level system brought terrifically strong wind fields aloft over the southern and central Great Plains region on May 28. The system was located over the Great Basin and moved eastward into the central Rocky Mountains during this time frame. Ahead of the system, a dry line became organized from a low-pressure area over extreme northeastern Colorado and Nebraska panhandle southwards into western Texas. Increasing south to southeasterly winds close and above the surface allowed for a progressively humid air mass to spread across the western portion of the Great Plains during the afternoon. Unseasonably warm surface temperatures and increased lift ahead of the approaching system supported rapid thunderstorm formation. This altogether allowed for the potential for large hail, damaging winds and tornadoes. That afternoon, the first signs of severe weather developed, and tornado watches were issued from South Dakota south to Texas. The advancing dry line and the cold front moving eastward combined to produce explosive supercell development late in the afternoon. Early that evening, supercells with severe thunderstorms and tornadoes were occurring along a nearly continuous line from near Lubbock, Texas to Rapid City, South Dakota. Before the supercells reformed into a squall line late that evening, at least 63 tornadoes were reported, many of them were very large and potentially destructive.〔(Storm Prediction Center 20070328's Storm Reports )〕 Fortunately, the area is sparsely populated, preventing widespread death and destruction. Still, 5 people were killed.〔 〕 On March 29, the squall line that moved eastward prevented a major outbreak during the daytime hours. Only a slight risk of severe storms was issued. Nonetheless, several tornadoes were reported, with two striking in the Oklahoma City metropolitan area with next to no advance warning before they struck. Significant damage was reported there with at least two people hospitalized when their RV was hit and four others injured during a tornado ten minutes later. Another moderate risk was issued for March 30, this time in south-central Texas into the Mexican state of Coahuila, which was later extended into north Texas and into south-central Oklahoma. At around 2254 UTC, one of the two tornado watches in effect during the day in Texas was lifted, although a watch remained in central and north-eastern Texas. Late in the day, the Oklahoma tornado watch was extended into eastern Kansas. For March 31, a moderate risk was issued for central Texas with the storm line continuing through the state, along with Oklahoma and Kansas in a north-eastern direction. This outlook was later changed to a slight risk as the system continued on with a tornado watch in effect in south-eastern Texas and a thunderstorm watch in Louisiana. The tornado watch was discontinued around 1504 UTC, although tornado warnings were issued in south-eastern Arkansas. Later in the day, the system reached the north-central United States, which caused warnings to be issued in Wisconsin, Illinois and Iowa. As the system continued to move in its north-eastern direction in the early evening, a watch was extended into the north-western portion of Indiana. The system weakened that evening and no tornadoes occurred afterward. However, NWS officials later confirmed a microburst in Carol Stream and Glendale Heights in DuPage County just west of Chicago just before 10:00 PM CDT. Extensive roof and window damage was reported to buildings, including an apartment complex and a church. The damage path was about 0.5 miles (0.8 km) long and 250 yards wide.〔(Carol Stream-Glendale Heights Microburst Storm Survey )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Late-March 2007 tornado outbreak」の詳細全文を読む スポンサード リンク
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