The eastern Pacific hurricane season starts today. Just slightly ahead of schedule tropical storm Aletta formed yesterday well to the southwest of the Mexican coast. The image above uses data captured when the TRMM satellite passed above Aletta on 15 May 2012 at 0253 UTC. TRMM's Microwave Imager (TMI) instrument had a good look at the newly formed storm and showed that Aletta had a large area of light to moderate rainfall north of the storm's center of circulation. The TMI rainfall analysis is shown overlaid on an enhanced infrared image from TRMM's Visible and InfraRed Scanner (VIRS)

Tropical cyclones are more likely to form in the northern hemisphere in May so tropical cyclone 19S is a little unusual. Tropical cyclone 19S attained tropical storm intensity in the Banda Sea on 7 May 2012. 19S is expected to quickly weaken to tropical depression intensity with wind speeds of about 25 kts (~29 mph) as it moves southward into the Timor Sea north of Australia. The TRMM satellite has been useful for monitoring the development of tropical cyclones over the global tropics. TRMM flew above tropical cyclone 19S during the daylight on 8 May 2012 at 0213 UTC. A rainfall analysis from

It has been reported that spring floods with mudslides have resulted in the death of at least 9 people and forced 11,000 people to flee their homes in the Dominican Republic. Data from the TRMM satellite are used to calibrate rainfall data merged from various satellite sources. TRMM-based, near-real time Multi-satellite Precipitation Analyses (TMPA) at the NASA Goddard Space Flight Center are used to monitor rainfall over the global Tropics. TMPA rainfall estimates are shown above for the week from April 19 to April 26, 2012. This analysis shows that extreme rainfall (shown in dark red)

It's springtime in the Plains, which means the increased likelihood that severe weather, including tornadoes, will occur somewhere across the region. After a week of relative quiet, a strong storm system moved out of the southern Rockies and out into the Central Plains. In association with this system, strong southerly winds at low levels drew Gulf moisture up across Texas and into Oklahoma and Kansas while strong jet-stream winds aloft raced northeastward around the base of an upper-level trough over the four-corners region and out over the Plains, setting the stage for a potential severe

By Ellen Gray, NASA Goddard Space Flight Center Original www.nasa.gov Press Release (published 4/3/12) On March 30, the Japan Aerospace Exploration Agency (JAXA) officially handed off a new satellite instrument to NASA at Goddard Space Flight Center, Greenbelt, Md. The Dual-frequency Precipitation Radar (DPR) was designed and built by JAXA and Japan's National Institute of Information and Communications Technology (NTSpace). JAXA DPR Project Manager Masahiro Kojima (seated left) formally signed over the DPR to GPM Project Manager Art Azarbarzin (seated right). Behind from left to right: Minoru

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite provides a look at thunderstorms in three dimensions and shows scientists the heights of the thunderclouds and the rainfall rates coming from them, both of which indicate severity. Powerful thunderstorms that created severe weather were more than 8 miles high. The TRMM satellite passed above northeastern Texas on April 3, 8:33 p.m. CDT and gathered rainfall and cloud height data from a line of thunderstorms moving through the area. The rainfall image above shows a distinct line of tornadic thunderstorms extending from Arkansas through