The weather of March 2011 came in like the proverbial lion in the United States, with strong storm systems bringing destruction and heavy rains to the Southeast, Mid-Atlantic, and eventually New England. Snow associated with this system was forecast for eastern states including Ohio, West Virginia, and eastern Pennysylvania, and also northern Vermont, New Hampshire, and Maine. The Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA-RT) data product provides data which allow observations of precipitation events like these as they are happening. The rains were expected to cause flooding as rain fell on the snowpack in the Northeast.
The first image below (Figure 1) shows total rainfall accumulation for the period 00Z March 8 to 00Z March 10 (7:00 PM EST March 7 to 7:00 PM EST March 9). The heaviest rain fell in central Mississippi and Alabama, with rain exceeding 240 mm (9.5 inches) in some places. Tornado damage was reported in Alabama.
Figure 1: Giovanni-generated TMPA-RT image of accumulated rainfall for the period 00Z March 8 to 00Z March 10, 2011.
Update, March 11:
The second image below (Figure 2) shows the TMPA-RT accumulated rainfall for the period 03Z March 10 to 03Z March 11, 2011 (10:00 PM EST March 9 to 10:00 PM EST March 10). Looking at this image, and knowing that areas around Baltimore received about 2 inches of rain on March 10, it might appear that the satellite totals are off. The third image (Figure 3) is an image of the rainfall recorded for March 10 by the National Weather Service Advanced Hydrologic Prediction Service. This image shows heavier rainfall amounts over Virginia and Pennsylvania than in the Washington-Baltimore metro area. The reason for the difference may be related to the actual time the TRMM satellite instruments observe a particular area and the acquired data are utilized to calculate rain rate and accumulated rainfall.
Figure 2: Giovanni-generated TMPA-RT image of accumulated rainfall for the period 03Z March 10 to 03Z March 11, 2011.
Figure 3: NWS AHPS precipation map for March 10, showing heavier rainfall over central and southern Virginia and central Pennsylvania. consistent with the TMPA-RT data for this date.