TRMM Sees Tropical storm Dorian Forming

Tropical storm Dorian

The image on the left used data captured by the TRMM satellite on July 22, 2013 at 1703 UTC when it passed above a tropical wave in the eastern Atlantic Ocean. The tropical wave had moved from Africa into the eastern Atlantic earlier in the day. The TRMM satellite view on the right shows that the tropical wave's organization had greatly improved when data was again collected on July 23, 2013 at 0253 UTC. Analyses of rainfall from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) are shown overlaid on Visible and InfraRed Scanner (VIRS) data. A combination visible and infrared VIRS image is shown overlaid with precipitation in the early evening 1703 UTC view on the left. An enhanced infrared image alone, from TRMM's VIRS instrument, was used as an underlay in the early morning 0253 UTC view on the right. The area covered by the TRMM PR instrument is shown as a slightly lighter shade.

TRMM Sees Tropical storm Dorian Forming

The National Hurricane Center (NHC) upgraded the low pressure center to tropical depression four (TD04) on July 24, 2013 at 0900 UTC (5 AM EDT) and then to tropical storm Dorian at 1500 UTC (11 AM EDT). Dorian is the fourth named tropical storm in the 2013 Atlantic hurricane season. Dorian is predicted to remain a tropical storm with winds no greater than 40kts (46 mph) while moving into the central Atlantic.
 
On average, the 4th named storm doesn't occur until around August 23rd, an indication that the 2013 season is off to a fast start. The fact that tropical storm Dorian formed near the Cape Verde Islands is also somewhat unusual. Although they can occur in July, Cape Verde-type storms typically don't form until August and September, and 2013 has almost had one earlier in July--Tropical Storm Chantal.

The image on the left used data captured by the TRMM satellite on July 22, 2013 at 1703 UTC when it passed above a tropical wave in the eastern Atlantic Ocean. The tropical wave had moved from Africa into the eastern Atlantic earlier in the day. The TRMM satellite view on the right shows that the tropical wave's organization had greatly improved when data was again collected on July 23, 2013 at 0253 UTC. Analyses of rainfall from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) are shown overlaid on Visible and InfraRed Scanner (VIRS) data. A combination visible and infrared VIRS image is shown overlaid with precipitation in the early evening 1703 UTC view on the left. An enhanced infrared image alone, from TRMM's VIRS instrument, was used as an underlay in the early morning 0253 UTC view on the right. The area covered by the TRMM PR instrument is shown as a slightly lighter shade.