DECEMBER DAY OUTLOOK
400 PM EDT Mon. Dec. 1, 2003


Atmospheric patterns, 700 MB and 500 MB height anomalies, statistical data,
ECMWF, and Canonical Correlation analysis, observed cases from past such months
were used in this forecast.

Oceanic and atmospheric indices indicate a weak El Nino may be developing in
the tropical Pacific. The impact on the circulation is expected to be minimal.
Equatorial surface sea surface temperatures were warmer than normal throughout
the Pacific, with anomalies greater than 1°F observed in most areas along the
equator between Indonesia and the South American coast. However, the 850 zonal
wind indices in the central and western equatorial Pacific values near zero,
and the OLR index were also near zero, 200 zonal wind index were also near
zero, along with the SOI were near zero, indicating weak ENSO conditions.
Statistical and computer models forecasts indicate near neutral conditions for
the remainder of 2003 and early 2004.

There are various atmospheric oscillations and indices such as NAO and AO.
Currently both are in a positive phase and are mostly expected to remain
positive through mid month. The exception will be NAO which is forecast to go
slightly negative by that time. There is a large block over Europe and the
middle and high latitudes of the central Atlantic. Usually, this block will
retrograde across the North Atlantic and into Canada and will cause NAO to be
negative. The PNA has been long negative and is forecast to remain so through
the mid-month period. The upper pattern is forecast to be amplified across
North America with a ridge in the central Pacific, a trough along the west
coast, a ridge in the Southwest. Another trough will be off the East coast.
Blocking will be evident in the high latitudes.

Above normal temperatures are expected across much of the Southwest, the
central Rockies westward. The probability of above normal temperatures in this
region is 57 percent. Below normal temperatures are expected from the eastern
Plains eastward. The probability of above normal temperatures in this area is
58 percent. The remainder of the nation is likely to average near normal with
no significant deviation from normal climatology.

Above normal precipitation is expected across the Northwest into western
Montana. The probability of below normal precipitation in this region is 58
percent. Blow normal precipitation is expected across the central and southern
Plains westward. The probability of below normal precipitation in this region
is 56 percent. Above normal precipitation is expected from the central gulf
coast northeastward. The probability of below normal precipitation in this
region is 58 percent. The remainder of the nation is expected to average near
normal with no significant deviation from normal climatology.

Jim Munley Jr.
http://www.geocities.com/jimmunleywx