NASA Remasters Nearly 20 Years of Global Rain

2015-2016 Precipitation Accumulation 2015-2016 Precipitation Anomalies featuring El Nino. This visualization of the precipitation from IMERG, averaged over 90 days, shows how the broad patterns of global precipitation fluctuate during this particular time period. Unlike the climatology, the vigorous, relatively small-scale precipitation systems create a very "lumpy", continually evolving pattern. Most notably here, the 2015-2016 El Niño is one of the strongest on record. The changes in the atmospheric circulation shift the rainfall that typically falls in the western Pacific—over Southeast Asia and northern Australia—to the central or eastern Pacific. The anomalies show the deviation from the normal seasonal cycle of precipitation. These maps help interpret the accumulation maps by isolating attention on the changes. Most notably here, the 2015-2016 El Niño is one of the strongest on record. The changes in the atmospheric circulation shift the rainfall that typically falls in the western Pacific—over Southeast Asia and northern Australia—to the central or eastern Pacific. As well, there are dry conditions across the Caribbean, tropical Atlantic, and northern South America. This display reduces the welter of "ordinary" precipitation and focuses attention on the systematic changes that are persistent, but not necessarily large enough to be readily noticed in the accumulations. Related pages

Continental United StatesThis IMERG visualization depicts the average amount of rainfall every 30 minutes around the day during the summer months of June, July and August. This detailed information on the diurnal cycle of precipitation over the globe can help improve numerical weather and climate models by providing a reliable dataset based on observations. Florida and SoutheastThis IMERG visualization depicts the average amount of rainfall every 30 minutes around the day during the summer months of June, July and August. The heat from the Sun builds up over the course of a day, culminating in afternoon thunderstorms over land. Near the coast, this is further accentuated by coastal breezes, feeding the rainfall systems over land with moisture from the sea. This detailed information on the diurnal cycle of precipitation over the globe can help improve numerical weather and climate models by providing a reliable dataset based on observations. NortheastThis IMERG visualization depicts the average amount of rainfall every 30 minutes around the day during the summer months of June, July and August. The heat from the Sun builds up over the course of a day, culminating in afternoon thunderstorms over land. This detailed information on the diurnal cycle of precipitation over the globe can help improve numerical weather and climate models by providing a reliable dataset based on observations. Midwest and Great PlainsThis IMERG visualization depicts the average amount of rainfall every 30 minutes around the day during the summer months of June, July and August. Over the Great Plains, thunderstorms flare up east of the Rocky Mountains in the late afternoon and roll eastwards over the night across the central U.S. This detailed information on the diurnal cycle of precipitation over the globe can help improve numerical weather and climate models by providing a reliable dataset based on observations. West Coast (winter)This IMERG visualization depicts the average amount of rainfall every 30 minutes throughout the day during the winter months of December, January and February. The average precipitation varies weakly over the course of a day, but the coastal regions generally receive similar amounts of precipitation at any hour, day or night. During the winter, precipitation systems in this region are driven less by the daily cycle of heating from the Sun and more by atmospheric rivers coming in from the Pacific Ocean. This detailed information on the diurnal cycle of precipitation over the globe can help improve numerical weather and climate models by providing a reliable dataset based on observations. The daily cycle of weather, also known as the diurnal cycle, shapes how and when our weather develops and is fundamental to regulating our climate. These animations show the most detailed view of the diurnal cycles over the United States. They were created using NASA's newest extended precipitation record known as the Integrated Multi-satellitE Retrievals for GPM, or IMERG analysis.The IMERG analysis combines almost 20 years of rain and snow data from the Tropical Rainfall Measuring Mission (TRMM) and the joint NASA-JAXA Global Precipitation Measurement mission (GPM).Learn more at NASA.gov. Related pages

Example composite showing the daily climatology along with the appropriate month and colorbar. Daily Climatology with a 30 day trailing average. Colorbar for IMERG Daily Climatology. Cooler colors are areas that receive very little precipitation. Warmer colors receive more precipitation. Alternative IMERG daily climatology colorbar. Text and colorbar outline are white. Blank Earth Map used for compositing. Month overlay layer for compositing. The daily climatology dataset covers January 2001 to December 2018, computed as a trailing 30-day average to reduce the random noise due to isolated big events. Notable features include the annual cycle of the InterTropical Convergence Zone (ITCZ) following the motion of the Sun (with a time lag) over both land and ocean, the seasonal shift of the Asian Monsoon between South Asia in the boreal summer and Australia in the boreal winter, the North American Monsoon in the late boreal summer in northern Mexico and southwestern U.S., and the dry summer/wet winter pattern in the Mediterranean Sea area and the west coast of the U.S. Related pages