This is a timeline of scientific and technological advancements as well as notable academic or government publications in the area of atmospheric sciences and meteorology during the 21st century. Some historical weather events are included that mark time periods where advancements were made, or even that sparked policy change.
2000s 2001 January – Researchers from the University of Maryland, College Park and McGill University published a numerical case study, funded by the National Science Foundation, on Hurricane Andrew in 1992.
2002 April–September – A Service Assessment Team was formed by the United States government to assess the quality of forecasts and post-tornado assessments conducted by the National Weather Service (NWS) office in Baltimore/Washington for the 2002 La Plata tornado. Their assessment and findings, released in September 2002, found: That the local NWS office failed to indicate the initial findings of F5 damage on the Fujita scale was "preliminary" to the media and public. The Service Assessment Team also recommended the National Oceanic and Atmospheric Administration require local National Weather Service offices to only release "potentially greater than F3" if F4 or F5 damage was suspected and to only release information regarding F4 or F5 damage after Quick Response Team (QRT) had assessed the damage. September – The National Weather Service creates a national Quick Response Team (QRT), whose job is to assess and analyze locations believed to have sustained F4 or F5 damage on the Fujita scale.
2003 August – Researchers at McGill University's Department of Atmospheric and Oceanic Sciences published case study to the American Meteorological Society on Hurricane Earl in 1998.
2004 February – Researchers at the Cooperative Institute for Meteorological Satellite Studies (CIMSS) published a case study to the American Meteorological Society on category 5 Hurricane Isabel in 2003.
2005 June 2005 – January 2006 – A record 27 named storms occurred during the Atlantic hurricane season. The National Hurricane Center runs out of names from its standard list and uses Greek alphabet for the first time.
2006 November – Timothy P. Marshall and Stuart Robinson published a case study to the American Meteorological Society about the 2005 Birmingham tornado.
2007 February – The Enhanced Fujita scale is formally released and put into use across the United States, replacing the Fujita scale. May – The 2007 Greensburg tornado family occurred, producing a tornado family of 22 tornadoes, including the first tornado to receive the rating of EF5 on the Enhanced Fujita scale; the 2007 Greensburg tornado.
2008 August – Timothy P. Marshall, a meteorologist and structural and forensic engineer with Haag Engineering, Karl A. Jungbluth with the National Weather Service, and Abigail Baca with RMS Consulting Group, published a detailed damage survey and analysis for the 2008 Parkersburg–New Hartford tornado. October Leslie R. Lemon with the University of Oklahoma and Mike Umscheid with the National Weather Service published a detailed case study on The Greensburg tornado family. Matthew R. Clark with the United Kingdom's Met Office published a case study on a tornadic storm in southern England on December 30, 2006.
2009 February – Researchers with the University of Mississippi, University at Buffalo, and University of California Riverside published a case study on the relief efforts conducted in response to Hurricane Katrina in 2005.
2010s 2010 June – Richard M. Zoraster, with the Los Angeles County Emergency Medical Services Agency, publishes a case study, through the University of Cambridge, on the population vulnerably during Hurricane Katrina in 2005.
2011 April – The 2011 Super Outbreak occurs across the United States. May – A violent EF5 tornado strikes Joplin, Missouri, killing 158 people, becoming the deadliest modern-day tornado in the United States. October – The Hong Kong Observatory and the U.S. Center for Severe Weather Research publish a joint paper analyzing a rare tornado in Hong Kong on May 20, 2002.
2012 February – Researchers at North Carolina State University's Department of Marine, Earth, and Atmospheric Science published a case study to the American Meteorological Society on category 5 Hurricane Felix in 2007.
2013 April – Environment Canada (EC) adopts a variation of the Enhanced Fujita scale (CEF-scale), replacing the Fujita scale across Canada. May A violent EF5 tornado impacts Moore, Oklahoma, which would be the last tornado to receive the rating of EF5 on the Enhanced Fujita scale until 2025. A violent tornado impacts areas around El Reno, Oklahoma. The University of Oklahoma's RaXPol mobile Doppler weather radar, positioned at a nearby overpass, measured winds preliminarily analyzed as in excess of . These winds are considered the second-highest ever measured worldwide, just shy of the recorded during the 1999 Bridge Creek–Moore tornado. August – The International Federation of Red Cross and Red Crescent Societies publish a report on Tropical Storm Washi in 2011, challenging the official death toll, saying it was 2,546, rather than the 1,292 deaths reported by the World Meteorological Organization.
2014 August – Meteorologist, structural and forensic engineer Timothy P. Marshall, along with the National Weather Service and Texas Tech University's National Wind Institute, published a detailed damage survey and analysis of the 2014 Mayflower–Vilonia, Arkansas EF4 tornado. October Researchers with the Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO), National Weather Service (NWS), National Severe Storms Laboratory (NSSL), and Timothy P. Marshall with Haag Engineering, published a detailed damage survey and analysis on the 2013 Moore, Oklahoma EF5 tornado. Researchers at Lyndon State College and the University of Colorado Boulder published a damage and radar analysis of the 2013 Moore tornado.
2015 September – The European Severe Storms Laboratory along with the Max Planck Institute for Nuclear Physics publish a detailed assessment of the 1764 Woldegk tornado, in which it was assigned a rating of F5 on the Fujita scale, marking the oldest official F5 tornado.
2016 August – The National Oceanic and Atmospheric Administration publishes that a Doppler on Wheels measured for 21 seconds during the 2016 Dodge City EF2 tornado.
2017 March – Researchers at Florida State University, the University of Colorado Denver, the University of Texas at Austin, and the University of Notre Dame, published a case study to the American Meteorological Society on the effects that category 4 Hurricane Gustav in 2008 had on the Bay of St. Louis.
2018 August – Researchers with the University of Oklahoma's School of Meteorology (OU SoM), National Weather Service (NWS), National Severe Storms Laboratory (NSSL), and Ohio University, published a detailed analysis of the multiple-vortex nature of the 2013 El Reno, Oklahoma tornado.
2019 2019–2023 – The Targeted Observation by Radars and UAS of Supercells (TORUS) project, led by the University of Nebraska–Lincoln, along with the NOAA National Severe Storms Laboratory (NSSL), NOAA Office of Marine and Aviation Operations (OMAO), Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO), and Texas Tech University, and the University of Colorado Boulder, occurs.
2020s
2020 March – The European Centre for Medium-Range Weather Forecasts (ECMWF) announced that a worldwide reduction in aircraft flights due to the COVID-19 pandemic could impact the accuracy of weather forecasts, citing commercial airlines' use of Aircraft Meteorological Data Relay (AMDAR) as an integral contribution to weather forecast accuracy. The ECMWF predicted that AMDAR coverage would decrease by 65% or more due to the drop in commercial flights. May – Researchers at Howard University, the Cooperative Science Center for Atmospheric Sciences and Meteorology, and the National Center for Atmospheric Research (NCAR), published a detailed damage survey and analysis on the 2011 Tuscaloosa–Birmingham EF4 tornado. June – The World Meteorological Organization announces new records for the longest lightning bolt (700 km) and the "megaflash" with the longest duration (16.73 s).
2021 April – Typhoon Surigae Forms and strengthens from category two-equivalent to a category five within a single day (April 17). Two days later, while Typhoon Surigae was still a category 4-equivalent, Matthew Cappucci, a meteorologist with The Washington Post, published an analysis linking the rapid-strengthening of Typhoon Surigae to climate change saying it was "bearing the fingerprint of climate change".
2022 March – The National Weather Service publishes a new damage survey and analysis for the 2012 Henryville EF4 tornado, where a "possible EF5 damage" location is identified and discussed. June – A review elucidates the current state of climate change extreme event attribution science, concluding probabilities and of links as well as identifying potential ways for its improvement. July Scientists report that heatwaves in western Europe are increasing "three-to-four times faster compared to the rest of over the past 42 years" and that can explain their increase. A study shows that climate change-related exceptional marine heatwaves in the Mediterranean Sea during 2015–2019 resulted in widespread mass sealife die-offs in five consecutive years. A research team, from the University of Oklahoma, National Severe Storms Laboratory, and University of Alabama in Huntsville was funded by the National Oceanic and Atmospheric Administration to investigate a stretch of the 2019 Greenwood Springs, Mississippi EF2 tornado where the National Weather Service was unable to survey. In their survey, published in Monthly Weather Review, they note that the tornado "produced forest devastation and electrical infrastructure damage up to at least EF4 intensity" and conclude by writing that "the Greenwood Springs event was a violent tornado, potentially even EF5 intensity." August – The National Centers for Environmental Information publish a report called Assessing the Global Climate in July 2022, where they state an all-time record cold temperature occurred in Australia during the month. On October 7, 2022, Zack Labe, a climate scientist for the NOAA Geophysical Fluid Dynamics Laboratory released a statement and a climate report from Berkeley Earth on the average monthly temperature, tweeting, "There are still no areas of record cold so far in 2022." Labe's statement also denied the record cold temperatures in Brazil, reported by the National Institute of Meteorology in May 2022, a month before the official start of winter, was also not record cold temperatures. September Category 5 Hurricane Ian strikes Florida, causing $113 billion in damage, making it the costliest hurricane in Florida history and third costliest hurricane to ever strike the United States. NOAA conducts the first successful launch of the Altius-600 small uncrewed aircraft system into Hurricane Ian, which records winds up to . October – Timothy Marshall, a meteorologist, structural and forensic engineer; Zachary B. Wienhoff, with Haag Engineering Company; Christine L. Wielgos, a meteorologist at the National Weather Service of Paducah; and Brian E. Smith, a meteorologist at the National Weather Service of Omaha, publish a detailed damage survey and analysis of the 2021 Western Kentucky tornado.
2023 January Perseverance provides the first ever detailed weather report on Mars. The 2023 Pasadena–Deer Park tornado prompts the National Weather Service forecasting office in Houston to issue a rare tornado emergency, the first ever issued by the office. February Elizabeth Leitman becomes the first woman to issue a convective watch from the Storm Prediction Center.