|Data: NCEP reanalysis daily geopotential height
(250, 500, and 925 hPa) on a 2.5 x 2.5 deg. lat/lon grid.
Data Source: NCEP
The maps above show 30-day average geopotential height
anomalies with respect to the 1971-2000 climatology (grey contours) at
250 (top), 500 (middle), and 925 hPa (bottom) for the last 30 days.
Positive anomalies are shown in yellow and orange; negative anomalies in
shades of blue. The climatology contour interval in the 250 and 500 hPa
maps is 60 gpm, and is 30 gpm in the 925 hPa map.
NCEP is an acronym
for the National Centers for Environmental Prediction, US.