WEBVTT FILE 1 00:00:00.030 --> 00:00:04.010 Favorable environmental conditions and warm waters in the Gulf allowed tropical storm Harvey to restructure and strengthen over several days. 2 00:00:04.030 --> 00:00:08.040 3 00:00:08.060 --> 00:00:12.060 On August 25, Harvey became a category 4 hurricane. 4 00:00:12.080 --> 00:00:16.100 5 00:00:16.120 --> 00:00:20.120 The Global Precipitation Measurement (GPM) Core Observatory saw several passes. 6 00:00:20.140 --> 00:00:24.140 GPM captured the hurricane continuously over land and ocean, observing the storm beyond the reach of land-based radars. 7 00:00:24.160 --> 00:00:28.160 8 00:00:28.180 --> 00:00:32.190 As Harvey slowly moved southeast, GPM showed an asymmetric rainfall pattern 9 00:00:32.210 --> 00:00:36.210 10 00:00:36.230 --> 00:00:40.260 11 00:00:40.280 --> 00:00:44.320 with a massive swath of rain reaching north and east of the hurricane’s center. 12 00:00:44.340 --> 00:00:48.410 13 00:00:48.430 --> 00:00:52.460 14 00:00:52.480 --> 00:00:56.490 NASA's Integrated Multi-satellite Retrievals for GPM estimated over 30 inches of rain from August 21 to 29. 15 00:00:56.510 --> 00:01:00.570 16 00:01:00.590 --> 00:01:04.610 The rainfall has lead to catastrophic flooding and difficult relief efforts. 17 00:01:04.630 --> 00:01:08.660 18 00:01:08.680 --> 00:01:12.700 19 00:01:12.720 --> 00:01:14.967