Utilizing Remote Sensing & NASA SPoRT Land Information System-Alaska to Improve Flood & Landslide Situational Awareness from Heavy Precipitation

Southeast Alaska is an area with limited surface observations along with poor radar coverage. The region is the largest temperate rainforest in the world and receives annual precipitation from 40 to 140 inches per year. Identifying and tracking heavy precipitation is difficult in data void areas like Southeast Alaska. Utilizing satellite based microwave moisture and rain rate data is beneficial to NWS forecasters in Juneau, Alaska. The data assists in identifying periods and locations of heavy precipitation. The NASA Global Precipitation Mission (GPM) constellation rain rate product (distributed by NASA SPoRT) is available to NWS forecasters in Alaska. This product has proven to be very useful as a situational awareness tool. Information from the near real time GPM rain rate product, used in conjunction with the experimental NASA SPoRT Land Information System-Alaska (LIS-AK), can provide forecasters with actionable information for providing Impact Decision Support Services (IDSS) to partners identifying the risk of landslides from heavy precipitation.

We present the December 1-2 2020, strong rain on snow atmospheric river (AR) event as a case study to demonstrate the utility of these products. The event produced widespread flooding, numerous landslides and set all-time daily precipitation records at multiple locations across Southeast Alaska.