Weather

Earth’s climate is changing. The accumulation of greenhouse gases has affected the oceans and ice systems as well as the atmosphere, which in turn impacts the water cycle. To predict future changes in weather and climate and estimate environmental variables, scientists use sophisticated computer models. These models rely on available global data to describe the conditions that exist today to project how conditions may change in the future. GPM’s Weather, Climate, and Land Surface Modeling Applications area promotes the use of precipitation measurements from GPM satellites to help model future behavior of precipitation patterns and climate. 

Map of IMERG precipitation estimates from recent flooding rainfall in Greece.
On Sept. 4, 2023, a low-pressure system developed over southeastern Europe that would lead to devastating floods over Greece and other parts of the region. The system was given the name “Daniel” by local meteorological agencies. Daniel was dynamically driven by strong cyclonic flow in the upper-level winds over southeastern Europe. The upper-levels winds combined with low-level winds from the northeast which supplied moisture from the unusually warm waters of the Aegean and Black Seas to central Greece. According to satellite infrared and microwave estimates from NASA's MUR and NOAA’s OISST v2
IMERG Precipitation Anomalies
Rain gauges are plentiful around the United States, but that’s not the case elsewhere in the world – particularly over oceans and sparsely populated areas. That means scientists and other data users have to rely on satellite measurements – such as those provided by NASA’s Global Precipitation Measurement (GPM) mission – to fill in the gaps. The list of data users now includes the U.S. Air Force’s 557th Weather Wing. For the first time, the Air Force meteorology unit has integrated the Integrated Multi-satellite Retrievals for GPM (IMERG) algorithm into its operational weather forecasts and
Screenshot of the High-Impact Weather Assessment Toolkit (HIWAT),
Bangladesh has a long history of deadly and costly storms. Because these storms are so localized, they can be notoriously difficult to forecast, especially without access to the most advanced weather prediction technology. Researchers have created a new tool to boost the country’s ability to forecast severe weather. The SERVIR program - a joint initiative of NASA, USAID, and leading geospatial organizations in Asia, Africa, and Latin America - and the Bangladesh Meteorological Department ( BMD ) recently launched the High-Impact Weather Assessment Toolkit ( HIWAT ), a web-based tool that
IMERG rainfall totals in South Africa, April 5 - 18, 2022.
An upper-level area of low pressure tapped into the warm waters of the South Indian Ocean to bring heavy rains and flooding to parts of South Africa during the second week of April. The event unfolded when an upper-level trough of low pressure embedded within the midlatitude westerlies traversed the southern part of Africa from west to east. As the trough approached the east coast of South Africa, an area of low pressure became detached from the main flow, this “cut off” low then drifted over the warm waters of the Agulhas Current, which channels warmer waters from the tropical Indian Ocean
IMERG Rainfall Totals from Australian :"Rain Bomb" in March 2022
The below animation shows surface rainfall estimates from NASA’s IMERG multi-satellite precipitation product for the week starting on Feb. 22, 2022 at 0000 UTC and ending on Feb. 28, 2022 at 2330 UTC. Areas shaded in blue and yellow show three-hour average snapshots of IMERG rain rates every half-hour overlaid on cloudiness (shown in white/gray) based on geosynchronous satellite infrared observations. Below the rain rates and cloudiness data, IMERG rainfall accumulations are shown in green and purple. Tropical Cyclone Anika’s track is shown with a gray line based on data from the U.S. Navy-Air
GPM Overpass of Typhoon Surigae
Although it was only the 2nd named storm of the 2021 Pacific typhoon season, Typhoon Surigae became not only the first super typhoon of the season, but also the strongest tropical cyclone of 2021 worldwide. The majority of storms in the Northwest Pacific region form between June and Nov., but the season runs yearlong, as storms can form in any month in this region, which stretches from 100 degrees East to 180 degrees East, north of the equator. Surigae originated from an area of low pressure about 700 miles south of Guam. Persistent thunderstorm activity resulted in the formation of a tropical
IMERG rainfall totals from the Nov. 2021 atmospheric river.
The Pacific Northwest coast saw two atmospheric rivers (ARs) bring heavy rains from Nov. 10-16, 2021, resulting in severe flooding, landslides, and damage to infrastructure in the British Columbia province of Canada. ARs are long, narrow corridors of water vapor that travel vast distances above the ocean from warm, tropical regions to higher latitudes, where they often release their moisture as rainfall when they reach land areas. While ARs occur across the globe, this year has been notable for several strong events that have impacted the Pacific Northwest coast. The two atmospheric rivers in
2021 average daily rainfall June, July August.
The Indian summer monsoon, also known as the southwest monsoon, falls within the South Asian monsoon and is the strongest and perhaps best-known of the world’s monsoons. During summer months when the Asian landmass heats up, warm, moist air flows northward from the Indian Ocean towards the Himalayas, bringing abundant showers and thundershowers to India. The summer monsoon is a regular event that occurs every year and is responsible for roughly 80% of India’s annual rainfall. The summer monsoon typically starts in early June, peaks in July and August and winds down during September and early
IMERG rainfall totals from recent atmospheric river.
The Pacific Northwest experienced a memorable series of storms in late Oct. 2021 as several low-pressure systems rolled in from the northeast Pacific Ocean. One of the systems was classified by meteorologists as a “bomb cyclone”, meaning that its central pressure (an indication of storm strength) had dropped particularly rapidly in a short time period. At its minimum pressure (highest strength), the system was reported by the National Weather Service to have had the lowest pressure of a system over the northeastern Pacific Ocean since reliable observations began in 1974. The system was notable
Hurricane Ida IMERG Totals
All eyes were on Hurricane Ida as it made landfall in Louisiana on Aug. 29, 2021, but many people were taken by surprise by the power of Hurricane Ida's remnants when they reached Virginia during the day on Sept.1 and New York City late at night on Sept. 1 into early morning on Sept. 2. The below animation shows the precipitation that fell during the entire lifecycle of Ida from before landfall in Louisiana through the impacts on New York City. Download this video (right-click -> "Save As") This animation uses data from the near real-time version of NASA's IMERG algorithm, a data product that