NASA tracks Norbert moisture to Arizona's drenching thunderstorms

September 10, 2014 by Hal Pierce, NASA's Goddard Space Flight Center
On Sept. 8 at 5:05 a.m. PDT the TRMM satellite saw a cluster of intense thunderstorms in Arizona directly below the satellite. Rain was falling at a rate of over 62 mm (2.4 inches) per hour in some downpours. Credit: SSAI/NASA, Hal Pierce

Post-tropical storm Norbert may have been centered a couple of hundred miles off the northwestern coast of Mexico's Baja California, but the flow of warm, moist air that spun around it generated drenching thunderstorms over Arizona. NASA's TRMM satellite saw Norbert's remnants and those Arizona thunderstorms dropping rainfall at over 2 inches per hour.

NASA's Tropical Rainfall Measuring Mission or TRMM satellite flew above the post-tropical cyclone remnants of former hurricane Norbert on September 8, 2014 at 0849 UTC (1:49 a.m. PDT). When TRMM passed overhead data gathered from the Microwave Imager (TMI) and Precipitation Radar (PR) instruments showed the occurring in the low pressure area.

TRMM showed only a small amount of light to moderate rainfall was located around Norbert's center of circulation. However, the moisture moving in a huge counterclockwise circulation around Norbert's remnants was transported almost 1,000 miles away where it generated thunderstorms over Arizona. The TRMM image showed very heavy rainfall was being produced over the southwestern United States, including Arizona, southern California and southern Nevada.

Data from TRMM's Precipitation Radar (PR) instrument were used to create a 3-D image at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The 3-D image showed that some showers located to the west of Norbert's center of circulation weren't very high.

The TRMM satellite flew over the southwestern United States again on September 8 at 1205 UTC (5:05 a.m. PDT). At that time a cluster of intense thunderstorms was found in Arizona directly below the satellite. Rain was measured by the TRMM Precipitation Radar (PR) instrument falling at a rate of over 62 mm (2.4 inches) per hour in some downpours.

On Sept. 8, the TRMM satellite captured rainfall in former hurricane Norbert and the thunderstorms over Arizona generated by its moisture. Rainfall data was overlaid on a NOAA GOES-West satellite image of clouds. Credit: SSAI/NASA, Hal Pierce

According to the National Weather Service, 3.29 inches of rain fell at the Phoenix airport breaking the day's record.

For over sixteen years the TRMM's Precipitation Radar (PR) has been providing three dimensional vertical profiles of precipitation from the surface of the earth to heights of about 12 miles (20 kilometers). The 3-D view showed that some thunderstorm tops reached heights of 13.5 km (about 8.4 miles).

This simulated flyby of NASA's TRMM satellite on Sept. 8 saw rain falling at a rate of over 62 mm (2.4 inches) per hour in some downpours over Arizona. Some thunderstorm tops reached heights of 13.5 km (about 8.4 miles). Credit: SSAI/NASA, Hal Pierce

On September 8, the moisture spreading northeastward from tropical storm Norbert caused flooding over inland areas of southern California. By September 9, that moisture generated the strong over Arizona that created widespread flooding led the Governor to declare a state of emergency in the state.

Explore further: NASA sees Dolly's remnants bringing showers to the Rio Grande Valley

Related Stories

NASA sees Tropical Cyclone's Hellen's lively remnants

April 2, 2014

Powerful Tropical Cyclone Hellen rapidly weakened after hitting northwestern Madagascar but Hellen's remnants have recently started to show signs of life. The TRMM satellite flew over these remnants in the Mozambique Channel ...

Recommended for you

On-chip, electronically tunable frequency comb

March 18, 2019

Lasers play a vital role in everything from modern communications and connectivity to bio-medicine and manufacturing. Many applications, however, require lasers that can emit multiple frequencies—colors of light—simultaneously, ...

Alligator study reveals insight into dinosaur hearing

March 18, 2019

To determine where a sound is coming from, animal brains analyze the minute difference in time it takes a sound to reach each ear—a cue known as interaural time difference. What happens to the cue once the signals get to ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.