TRMM: Extreme Weather
Hurricane Iselle weakened to a tropical storm while approaching the island of Hawaii on Thursday August 7, 2014. As a tropical storm Iselle contained some heavy rain showers and strong winds when it hit the big island. Iselle later dropped some heavy rain over Maui and scattered showers extended to Kauai and Oahu. The TRMM satellite had an excellent view of tropical storm Iselle as it neared the Hawaiian islands on August 8, 2014 at 0152 UTC ( August 7 at 3:52 PM HST). A rainfall analysis from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) instruments is shown overlaid on a 0200 UTC GOES-WEST image. TRMM's TMI collected data showing that rain was falling at a rate of over 39 mm (1.5 inches) per hour near Iselle's center. After crossing the island of Hawaii, Iselle is predicted to continue weakening as it's center of circulation passes to the south of the other Hawaiian Islands.
The TRMM satellite also had a very good view earlier of hurricane Julio on August 8, 2014 at 0017 UTC. Julio was still a very powerful intensifying hurricane with winds of over 90 kts (about 104 mph). Rainfall derived from TRMM's TMI and PR are shown overlaid on a GOES-WEST 0030 UTC Visible/Infrared image. Julio's nearly clear circular eye was evidence of the powerful winds within the category 2 hurricane.
TRMM's Precipitation Radar (PR) instrument measured rain falling at a rate of almost 89 mm (about 3.5 inches) per hour in powerful storms south of Julio's center. A 3-D view using data from TRMM PR shows that Julio was apparently undergoing an eye wall replacement at the time of this view. A moat like gap is shown separating an inner eye wall from the replacement outer eye wall. A hurricane usually weakens when this is happening but when the outer eye wall replaces the inner one the storm can intensify again.
Hurricane Julio is predicted to weaken to a tropical storm when passing to the north of the Hawaiian islands in about three days.