The Weather Prediction Center (WPC),located in College Park,Maryland,is one of nine service centers under the umbrella of the National Centers for Environmental Prediction (NCEP),a part of the National Weather Service (NWS),which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. Government. Until March 5,2013 the Weather Prediction Center was known as the Hydrometeorological Prediction Center (HPC). The Weather Prediction Center serves as a center for quantitative precipitation forecasting,medium range forecasting,and the interpretation of numerical weather prediction computer models.
A widespread,destructive tornado outbreak affected Iowa,Kansas,Missouri,and Nebraska on April 27,2002,and Illinois,Indiana,Kentucky,Maryland,New York,Ohio,Pennsylvania,Tennessee,Virginia,and West Virginia on the following day,April 28. Generally,tornado reports were widely scattered in each state,but significant to severe damage was noted in multiple states. Overall,48 tornadoes were confirmed along with 6 deaths,256 injuries,and $224 million in damage,with wind and hail adding to the damage total.
A flash flood warning is a severe weather warning product of the National Weather Service that is issued by national weather forecasting agencies throughout the world to alert the public that a flash flood is imminent or occurring in the warned area. A flash flood is a sudden,violent flood after a heavy rain,or occasionally after a dam break. Rainfall intensity and duration,topography,soil conditions,and ground cover contribute to flash flooding.
Tropical Storm Grace was a weak tropical storm that struck Texas in the 2003 Atlantic hurricane season. The eleventh tropical depression and the seventh tropical storm of the season,Grace was also the weakest storm of the season. On August 30 the storm developed from a long-track tropical wave in the western Gulf of Mexico. Grace remained disorganized throughout its lifetime due to an upper-level low to its west. The weak storm moved northwestward and made landfall on southeastern Texas. Grace quickly weakened over land,and dissipated on September 2 as it merged into a cold front.
In weather forecasting in the United States,"particularly dangerous situation" (PDS) is enhanced wording used by the National Weather Service to convey special urgency in some watch or warning messages when there is a significant risk of extreme weather,most commonly from types of weather events that are usually less severe by comparison,such as a severe thunderstorm outbreak or flash flooding. It is used in the format "This is a particularly dangerous situation..." at the discretion of the issuing forecaster. A watch or warning bearing the phrase is referred to as a PDS watch or PDS warning as shorthand jargon.
Floods in the United States (2000–present) is a list of flood events which were of significant impact to the country during the 21st century,since 2000. Floods are generally caused by excessive rainfall,excessive snowmelt,storm surge from hurricanes,and dam failure.
The tornado outbreak of October 17–19,2007 was a widespread tornado outbreak that took place across much of the eastern half of North America starting on October 17,2007,and continuing into the early hours of October 19. The outbreak was also responsible for five deaths;three in Michigan and two in Missouri,plus many injuries. At least 64 tornadoes were confirmed including 16 on October 17 across six states including Texas,Oklahoma,Arkansas,Louisiana,Mississippi and Missouri with wind damage reported in Oklahoma,Kansas,Illinois,Iowa,Arkansas and Mississippi. On October 18,at least 48 tornadoes were confirmed across eight states including Florida,Alabama,Mississippi,Tennessee,Kentucky,Illinois,Indiana and Michigan,plus widespread straight line wind damage. Until 2010,this event held the record for largest tornado outbreak ever recorded in the month of October according to NOAA.
The March 2008 Midwest floods were a massive flooding event in the Southern Midwest and portions of the Southern Plains. Cape Girardeau,Missouri officially reported 11.48 inches (29.2 cm) between March 18 and 19. At least 17 people died as a result of the flooding. Levee breaks were observed in several areas,most notably in Southeastern Missouri,where levee breaks occurred through mid-April.
The May 2009 Southern Midwest Derecho was an extreme progressive derecho and mesoscale convective vortex (MCV) event that struck southeastern Kansas,southern Missouri,and southwestern Illinois on May 8,2009. Thirty-nine tornadoes,including two of EF3 strength on the Enhanced Fujita Scale,were reported in addition to high non-tornadic winds associated with the derecho and MCV. Due to the abnormal shape of the storm on radar and the extremely strong winds,many called this an "inland hurricane." A new class of storm,the Super Derecho,has been used to describe this event after analysis in 2010. Embedded supercells produced hail up to baseball size in southern Missouri,a rare event in a derecho. A wind gust of 106 mph (171 km/h) was recorded by a backup anemometer at the Southern Illinois Airport after official National Weather Service equipment failed. This derecho was the last of a series of derechos that occurred at the beginning of May.
From May 3 to May 11,2003,a prolonged and destructive series of tornado outbreaks affected much of the Great Plains and Eastern United States. Most of the severe activity was concentrated between May 4 and May 10,which saw more tornadoes than any other week-long span in recorded history;335 tornadoes occurred during this period,concentrated in the Ozarks and central Mississippi River Valley. Additional tornadoes were produced by the same storm systems from May 3 to May 11,producing 363 tornadoes overall,of which 62 were significant. Six of the tornadoes were rated F4,and of these four occurred on May 4,the most prolific day of the tornado outbreak sequence;these were the outbreak's strongest tornadoes. Damage caused by the severe weather and associated flooding amounted to US$4.1 billion,making it the costliest U.S. tornado outbreak of the 2000s. A total of 50 deaths and 713 injuries were caused by the severe weather,with a majority caused by tornadoes;the deadliest tornado was an F4 that struck Madison and Henderson counties in Tennessee,killing 11.
On August 4,2009,a flash flood occurred and impacted Louisville and portions of the surrounding Kentuckiana region as a cold front and mesoscale convective system moved across the Midwestern United States. The National Weather Service estimated that between three and six inches of rain fell across the city in less than one hour,breaking all previous one-hour rainfall records in the area. Most of the downtown area was underwater,with the deluge reaching four feet (1.2 m) deep in places.
A significant and destructive tornado outbreak that affected parts of the Midwestern United States and lower Great Plains in mid-May 2013. This event occurred just days after a deadly outbreak struck Texas and surrounding southern states on May 15. On May 16,a slow moving trough crossed the Rockies and traversed the western Great Plains. Initially,activity was limited to scattered severe storms;however,by May 18,the threat for organized severe thunderstorms and tornadoes greatly increased. A few tornadoes touched down that day in Kansas and Nebraska,including an EF4 tornado near Rozel,Kansas. Maintaining its slow eastward movement,the system produced another round of severe weather nearby. Activity significantly increased on May 19,with tornadoes confirmed in Oklahoma,Kansas,Iowa,Missouri,and Illinois. In Oklahoma,two strong tornadoes,one rated EF4,caused significant damage in rural areas of the eastern Oklahoma City metropolitan area;two people lost their lives near Shawnee. The most dramatic events unfolded on May 20 as a large EF5 tornado devastated parts of Moore,Oklahoma,killing 24 people. Thousands of structures were destroyed,with many being completely flattened. Several other tornadoes occurred during the day in areas further eastward,though the majority were weak and caused little damage.
On November 17,2013,the deadliest and costliest November tornado outbreak in Illinois history took shape,becoming the fourth-largest for the state overall. With more than 30 tornadoes in Indiana,it was that state's largest tornado outbreak for the month of November,and the second largest outbreak recorded in Indiana. Associated with a strong trough in the upper levels of the atmosphere,the event resulted in 77 tornadoes tracking across regions of the Midwest United States and Ohio River Valley,impacting seven states. Severe weather during the tornado outbreak caused over 100 injuries and eleven fatalities,of which eight were tornado related. Two tornadoes—both in Illinois and rated EF4 on the Enhanced Fujita scale—were the strongest documented during the outbreak and combined for five deaths. In addition to tornadoes,the system associated with the outbreak produced sizeable hail peaking at 4.00 in (10.2 cm) in diameter in Bloomington,Illinois,as well as damaging winds estimated as strong as 100 mph (160 km/h) in three locations.
The April 2016 North American storm complex was a major storm system that resulted from an upper-level low in the United States stalling and producing record-breaking rain in and around Houston,Texas,resulting in severe flooding,as well as a major snowstorm in the Rocky Mountains. There were more than 17 inches of rain in one day in parts of the city,and up to 4 inches of rain per hour that morning at George Bush Intercontinental Airport. It is described as the wettest April in the city on record.
The tornado outbreak sequence of May 2019 was a prolonged series of destructive tornadoes and tornado outbreaks affecting the United States over the course of nearly two weeks,producing a total of 402 tornadoes,including 53 significant events (EF2+). Eighteen of these were EF3 tornadoes,spanning over multiple states,including Nebraska,Kansas,Texas,Missouri,Oklahoma,Indiana,Iowa,and Ohio,with additional tornadoes confirmed across a region extending from California to New Jersey. Two EF4 tornadoes occurred,one in Dayton,Ohio,and the other in Linwood,Kansas. Four tornadoes during this outbreak were fatal,causing a total of eight fatalities. The deadliest of these occurred on May 22 near Golden City,Missouri,where an EF3 tornado took three lives,including an elderly couple in their eighties. The damaging series of tornadoes that occurred in Indiana and Ohio on the evening of May 27 during this event is sometimes locally referred to as the Memorial Day tornado outbreak of 2019,which became the 4th costliest weather event in Ohio history.
A deadly late-season tornado outbreak,the deadliest on record in December,produced catastrophic damage and numerous fatalities across portions of the Southern United States and Ohio Valley from the evening of December 10 to the early morning of December 11,2021. The event developed as a trough progressed eastward across the United States,interacting with an unseasonably moist and unstable environment across the Mississippi Valley. Tornado activity began in northeastern Arkansas,before progressing into Missouri,Illinois,Tennessee,and Kentucky.
During the late evening of Friday,December 10,2021,a violent,long-tracked EF4 tornado moved across Western Kentucky,producing severe to catastrophic damage in numerous towns,including Mayfield,Princeton,Dawson Springs,and Bremen. Crossing through eleven counties of the Jackson Purchase and Western Coal Field regions during its almost three-hour lifespan,the tornado was exceptionally long-tracked,traveling 165.6 miles (266.5 km) while at times becoming wrapped in rain. It was the deadliest and longest-tracked tornado in an outbreak that produced numerous strong tornadoes in several states;57 fatalities were confirmed in the tornado. The second significant tornado in an exceedingly long-tracked tornado family,this tornado began just inside northern Obion County,Tennessee,a few miles after another long-tracked tornado –which traveled through northeast Arkansas,the Missouri Bootheel,and northwest Tennessee –dissipated in western Obion County.
Beginning on July 24,2022,and lasting for a week,many flash flooding events hit several areas of the United States. These areas included parts of Missouri and Illinois,especially Greater St. Louis,Eastern Kentucky,Southwest Virginia,parts of West Virginia,and the Las Vegas Valley. Several rounds of severe thunderstorms began in Missouri on July 24,culminating during July 25 and 26,when St. Louis broke its previous 1915 record for the most rainfall in a span of 24 hours. Governor Mike Parson declared a state of emergency on July 26. Over one hundred people were rescued from floods,and two people were killed. Late on July 27 and into July 28,historic flooding began in central Appalachia,particularly in Kentucky,where a state of emergency was declared. A total of 38 people were killed in Kentucky as a direct result of flooding,with a 39th fatality occurring days later during cleanup efforts and a 40th coming in September during cleanup efforts in Pike County.
In a three-day period from August 2–4,2023,significant flooding occurred across northwestern Tennessee,southwestern Kentucky,and southeastern Missouri in the United States. Two flash flood emergencies were issued,and water rescues and evacuations were prompted,including rescues at a mobile home park in Union City,Tennessee. Downtown Hickman,Kentucky,was impacted by a mudslide which led to a road closure for a road leading to the town.
On September 29,2023,heavy rainfall led to flooding across portions of the New York metropolitan area and areas in New York City,United States. New York governor Kathy Hochul declared a state of emergency for five boroughs in New York,including portions of Hudson Valley and Long Island,and New York City mayor Eric Adams declared a state of emergency for the city. New Jersey governor Phil Murphy declared a state of emergency for all 21 counties in the state,and Hoboken,New Jersey mayor Ravinder Bhalla also declared a state of emergency.
