Winter 08/09 to Be Warm in Midwest, Dry in South
NOAA Forecast Sees Variability in Conditions Across the USA
Nov 20, 2008
The forecast is produced by the NOAA Climate Prediction Center, and looks at conditions from the December 2008 to February 2009 period. Whereas AccuWeather's winter forecast attempts to predict specifics, NOAA gives their forecasts in terms of percentage probabilities.
Conditions Contributing to NOAA's Winter Forecast
"Equal chances" are assigned when there is no prevailing sign whether conditions would be warmer than normal or colder then normal. This is also assigned to areas where conditions are expected to remain near normal as well. For the forecast to be assigned a specific description - for example "warmer" or "drier" - there must be a indication that is greater than 33.3% probability.
NOAA forecasters seem to indicate that rather than La Nina or El Nino deciding the winter weather fate of the country, it will be climate patterns over the Arctic and North Atlantic that would play a part. However, these patterns are much more variable than La Nina and El Nino are, forecasters warn.
"These patterns are only predictable a week or two in advance and could persist for weeks at a time," CPC deputy director Michael Halpert said. “Therefore, we expect variability, or substantial changes in temperature and precipitation across much of the country."
Eastern Winter Temperatures Average, Drier Across Southeast
Across the East Coast, NOAA has issued equal chances as to what temperatures could do, according to the forecast. However, inland east of the Mississippi there is a greater chance for warmer than normal temperatures, with the highest chances the furthest west.
The best signals for precipitation look to be in the southeastern US, where it is expected to be drier than normal. Highest chances for below normal precipitation appear to extend from southeast North Carolina to the Florida panhandle.
Midwest Looks To Be General Warmer and Wetter this Winter
Across the Midwest, there seems to be the greatest signals for anomalous weather. NOAA says there is more than a 50/50 chance of above normal temperatures across the central Plains, with a better than 40 percent chance of above normal precipitation across generally the same area.
Overall, the entire Midwest save for the Dakotas look to have a better than equal chance of being warmer than normal this year. Other notable anomalies appear across Southern Texas, where there is the slight possiblity of drier than normal conditions.
No Clear Signals Across the West
The West appears to be an unknown right now, according to NOAA. Both the precipitation and temperature forecasts have been assigned "equal chances." Forecasters may be having a problem here due to the El Nino-La Nina being in a "neutral" phase, and during those events it seems as if the West sees the most pronounced abnormal effects.
Across Alaska, temperatures are expected to be above normal, although precipitation looks to be near normal. Across Hawaii, cooler temperatures should occur over the east with warmer than normal temperatures in the west.
NOAA did not give any data on projected snowfall: it says that accurate predictions can only be made "days in advance."
