Summer Outlook: Temperatures and Precipitation for N. America
The big key for this summer season is the rapid collapse of El Niño, which is currently taking place over the Tropical Pacific. The long range forecast for the summer season calls for above normal temperatures (1.0 to 3.0C or 1.8 to 5.4F) in a large area extending from the Pacific Northwest, eastward across the far northern Rockies, Northern Plains, Great Lakes, and northern New England. Farther south, slightly above normal temperatures (1.0C or about 2.0F) are also expected for a large area extending from the Central Plains, east and southeast across the eastern Gulf Coast to southern Georgia and Florida. As mentioned above, confidence is a bit lower over central and south Texas due to mixed analog signals over this region. Elsewhere across the Lower 48, near normal temperatures are expected across the central and southern Rockies, and from the mid Mississippi Valley to the Atlantic Seaboard from the Carolinas to coastal New England.
Temperature outlook for the summer of 2010. Image: ImpactWeather
The outlook for this summer season calls for above normal rainfall across a large part of the eastern U.S. from the eastern Gulf coast to New England, including the entire length of the Atlantic Seaboard north of the Florida Peninsula. The best chance of above normal rainfall will be across the southeastern U.S. where enhanced tropical activity is expected to occur. Farther west, above normal rainfall is also expected across south Texas. As mentioned above, precipitation anomalies during this period will be strongly dependent on tropical cyclone tracks. One slow moving tropical system could deposit many times the normal amount of rainfall for the entire summer in only a few days. Farther north, below normal precipitation is expected across the Upper Mississippi Valley from northwest Iowa to northern Minnesota and the U.P. of Michigan. Elsewhere, near normal precipitation is expected from the Rocky Mountains to the Great Plains and across the Florida Peninsula.
Precipitation outlook for the summer of 2010. Image: ImpactWeather