Both Philadelphia and Washington, D.C saw temperatures 20+ degrees above average for three straight days from March 8-10. How does this warmth compare to previous March extremes through the first half of the month? Below are a few memorable examples. The gold standard is March 12-16, 1990 where five straight days of 80+ degrees were recorded in in both cities.
The maps valid back on Wednesday night, March 9th, show the features in place for record warmth. All the cold air is displaced in far northern/Western Canada and Alaska. A deep trough over the Gulf of Alaska and a cutoff upper-level low over Mexico and Texas caused a massive ridge to develop over the Eastern U.S. A deep trough downstream has to form an upstream ridge of similar strength, i.e. Newton's 3rd law of every action has an equal and oppsite reaction.
Philadelphia March 8th - 75 degrees March 9th - 82 degrees (Record) March 10th - 82 degrees (Record) Washington, D.C. March 8th - 79 degrees March 9th - 79 degrees March 10th - 79 degrees (Tied Record)
The images below are 500mb Composite Anomalies taken from the 20th Century Reanalysis Datasets. The data is provided by the Earth System Research Laboratory. The temperature records were provided by the National Climate Data Center and local NWS offices.
March 8th Philadelphia--> 80 degrees (Record) Washington, D.C.--> 85 degrees (Record) March 9th Philadelphia--> 73 degrees Washington, D.C.--> 79 degrees (Record)
Philadelphia March 12th - 83 degrees (record) March 13th - 84 degrees (record) March 14th - 85 degrees (record) March 15th - 81 degrees (record) March 16th - 80 degrees Washington, D.C March 12th - 89 degrees (record) March 13th - 87 degrees (record) March 14th - 86 degrees (record) March 15th - 81 degrees March 16th - 81 degrees
Philadelphia March 13th - 76 degrees March 14th - 74 degrees March 15th - 58 degrees Washington, D.C March 13th - 81 degrees March 14th - 81 degrees March 15th - 82 degrees (record)
Philadelphia March 16th - 82 degrees (record) March 17th - 86 degrees (record) Washington, D.C March 16th - 87 degrees (record) March 17th - 88 degrees (record)