For the long-range outlook, guidance from computer forecasting models and information from historical ocean-atmospheric feedbacks lend credence to the general idea that warmth will return to the East Coast for next weekend and beyond. Both the European and American models are in good agreement that a mid-level ridge of high pressure will build over the Southeastern United States six to 10 days from now, which should touch off southwesterly flow aloft and bring above average temperatures to the mid-Atlantic.
This trend is in good agreement with the expected seasonal influence of the El Nino/Southern Oscillation. Currently, the ENSO is in the La Nina phase, with negative sea surface temperature anomalies of two to four degrees Fahrenheit located along the Equatorial Eastern Pacific between 150°E and 120°W. While these anomalies are moderating, they are still strong enough to influence global atmospheric circulation patterns. For the set of analog years in the climatological record for which Pacific sea surface temperature anomalies most closely resemble the current morphology, there is a sharp dichotomy between cooler-than-normal temperatures in March and early April and a warm and fairly dry late April and May for the Eastern United States. These signals suggest increasing likelihood of daily temperature deviations from climatological norms of six to 12 degrees by late next week, with the resulting highs comfortably in the upper 60s to mid 70s and low to nonexistent rain chances.