Climate Highlight: November 10, 2004

November - December 2004 Outook:

As an attempt to predict temperature and precipitation for the upcoming months of November and December 2004, trends from the summer across the Keystone state were analyzed.  August and September of 2004 were both relatively wet, however had opposite temperature anomalies (one warm and one cold).  In order to parallel this, years in history that had wet Augusts and Septembers while having a cold August and warm September, or vice versa, were found.  These analog years were: 1912, 1926, 1934, 1945, 1955, 1975, 1977, 1993, 1999, and 2003. 

The above years were then used to compile temperature and precipitation departure maps for the upcoming months.  The maps are shown below.

Temperature Prediction for November 2004:

-         Very warm anomaly in the New England and eastern regions
-         Warm anomaly throughout most of the country
-         Cool spots in Washington, Montana, North Dakota, Florida, and western Arizona

Precipitation Prediction for November 2004:

-         Average precipitation for a good portion of the country
-         Very dry in Texas, New Mexico, Arizona, and the surrounding states
-         Very wet in Wisconsin and parts of Michigan and Oregon

Temperature Prediction for December 2004:

-         Colder than average in the east
-         Warmer than average in the west
-         Average temperature in Midwest and Florida

Precipitation Prediction for December 2004:

-         Dry through central U.S. extending from New York, Florida, Nebraska, and Arizona
-         Very wet in Idaho and Wyoming
-         Wet along eastern and western coast, and the northwestern region of the U.S.

Taking a closer look at Pennsylvania, the departures for temperature and precipitation for each of the ten years were found for Climate Divisions 1, 3, 5, 7 and 9.  The departures for the ten analog years for each division were averaged for both November and December.  These tables were compiled to get an approximation of the departures that could be expected this year:

As you can see from the above tables, November's following similar 'lead in' conditions to this November experienced warmer than normal temperatures and be normal to slightly wetter than normal.  December could be expected to have cooler temperatures and somewhat drier than normal precipitation.  These predictions areillustrated on the charts of the entire U.S. as well.