National Discussion
An approach to making a prediction for temperatures and precipitation for November
and December 2004 is to analyze the anomalies of both temperature and precipitation
over the past October.
Using the above temperature and precipitation anomalies, years that matched
both the warm and cool spots and the wet and dry were found by entering the
regions into our anomaly finding database. Then, the 500 mb flow patterns for
October for years that matched above 50% (about 20) were compared to the current
500 mb flow pattern of October 2004. Only two of the 20 years offered a decent
match (2000 and 1991). Bringing these years to the forefront and combining the
other years yielded 2000, 1991, 2001, 1920, 1924, 1963, 1952, 1974, 1978, and
1940 as the years that coincided well.
After putting together a composite map of these years, several predictions can
be made for both November and December.
Anticipated Temperature Anomaly for November 2004
- Cold anomaly in the entire western part of the United States, ranging from
California to the western Great Plains Region
- Very cold anomaly in southern Wyoming
- Very warm anomaly in Northern Michigan
- Warm anomaly through Ohio River Valley, east of the Mississippi River, middle
south (Alabama, Tennessee, Kentucky), and some areas east such as Pennsylvania,
New York, Connecticut and Massachusetts.
- Cool in Southern Florida
Figure 3 Nov Temp Anomaly Prediction
Anticipated Precipitation Anomaly for November 2004
- Mostly average precipitation throughout the U.S.
- Dry anomaly in eastern portions extending from Maine down through Alabama,
and also in Florida
- Dry anomaly in western Oregon and Washington, and part of Nevada, Wyoming,
and Montana.
- Wet anomalies in southern and northern central US, specifically Texas, New
Mexico, Arizona, Oklahoma, Iowa, Minnesota, and Wisconsin.
Figure 4 Nov Precip Anomaly Prediction
Anticipated Temperature Anomaly for December 2004
- Coldest anomalies lie in the Rocky Mountain Region.
- The surrounding area also has cold anomalies extending west to Nevada and
parts of southern California and east to Georgia, Tennessee, and Wisconsin.
- Warm anomalies include most of the eastern seaboard, Pennsylvania, West Virginia,
northern Minnesota and Washington.
- Very warm anomaly in Florida.
Figure 5 Dec Temp Anomaly Prediction
Anticipated Precipitation Anomaly for December 2004
- Very dry anomaly in northwestern and north central United States.
- Dry anomalies are also along the east coast, as well as parts of Pennsylvania,
New York, Illinois, Missouri, Kansas, and Indiana.
- Very wet anomalies in Texas, Nebraska and the eastern part of Colorado.
- Wet anomalies lie in the remainder of the country.
Figure 6 DEC Precip Anomaly Prediction
Pennsylvania Temperature Forecast
Using 15-day medium range forecast temperature guidance and the likely monthly departures based on analog years, the following is a daily temperature forecast for May and June 2004 for western, central and eastern Pennsylvania. This forecast predicts the daily average temperature departure from the 30-year average temperature (dotted line) and the five day running mean of the temperature departure (solid line).
