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Summary - large scale and model trends

• A classic nor’easter storm affected the eastern U.S. on March 14th .
• Large-scale factors included coupled jets, phasing short-waves and rapid low-level deepening.
• GEFS ensemble was much too far east and did not capture the storm within its envelope until the 14th.
• The ECMWF was initially too far east, but trended correctly to the west sooner than the GEFS.
• The NAM and NAM had mostly good forecasts leading up the storm. An exception was the 00z March 13 run of the 4 km NAM, which was too far east with the low track and too dry for our area, however the 3 km NAMX was much wetter.
• The NAM was consistently farther west with the track of the 700 mb low and associated frontogenesis than the GFS. The GFS trended toward the NAM but remained too far east through the 00z March 14th run.
• The SREFs were highly dispersive, with mean forecasts trending in the right directly prior to the storm.
• WPC forecasts had less snow than what was observed but still forecast heavy snow and trended in the right direction leading up to the storm.