Preliminary data indicates that the statewide average temperature in March was 42.6°F, which is 1.2°F below the 1981-2010 mean value of 43.8°F (Figure 1). This places March 2019 temperatures in the middle one-third of monthly values since 1895.
Delaware’s statewide precipitation for March 2019 averaged 3.93 inches, 0.34 inches below the 1981-2010 mean (Figure 2). Snowfall was slightly above normal during the month across northern Delaware with 3.4 inches of snow recorded at the Wilmington – New Castle County Airport (normal is 3.2 inches). Two snowfall events dropped more than an inch of snow across the northern half of the State on March 1st and again on the 3rd.
Statewide Spatial Anomalies
Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were below normal across the entire state (Figure 3), while precipitation departures varied depending upon location (Figure 4) with above normal precipitation in the north, and below normal precipitation in the south.
Most of the United States, except for the southwest, saw negative temperature anomalies during March. Specifically, the Dakotas and Montana saw extreme cold with temperatures up to 10°F below normal for the month (Figure 5). The Great Plains and the interior west were all wetter than normal while the eastern United States generally saw below normal precipitation (Figure 6).
The 500 hPa height pattern for March showed no strong jet stream ridging or troughing over our region (Figure 7).