California's Rainfall Analyzed From Space
It has been very dry in the state of California for the past couple years. The lack of rain in 2013 and 2014 contributed to exceptional drought conditions in the state. Records were set over the past winter for the lowest winter snow packs recorded in a century. Rainfall produced by storms moving into California from the Pacific Ocean has recently brought some very temporary drought relief.
Precipitation data (3B42) from various satellites such as TRMM and recently the GPM core observatory satellite have been collected, merged and archived at the Goddard Space Flight Center since 1998. The long term collection of these data will enable increasingly accurate measurements that will be useful in global precipitation climatology. The rainfall analysis above shows estimates of total precipitation that fell over the western United States during the past month. Northern California received the most precipitation. This analysis indicates that downpours over the past few weeks had dropped totals of over 300 mm (11.8 inches) in some areas. Heavy precipitation that fell at higher elevations will add to snow pack totals.
The two rainfall anomaly analyses shown above were made by comparing rainfall data compiled during the twelve year period from 2001-2012 to "near real-time" Multi-satellite Precipitation Analysis (TMPA-RT 3B42RT) data. The first image shows a rainfall anomaly analysis for rainfall data (3B42) collected a year ago from November 4 to December 4, 2013 and the second image shows a rainfall anomaly analysis for the same period in 2014. Above normal precipitation (wetter) is shown in colors ranging from light green to purple and below normal values (drier) are shown in colors from yellow to dark red. Extensive areas of drier than normal values in 2013 are shown in sheer contrast to the recent wetter conditions.