The regional consensus climate outlook for the September to December 2015 rainfall season indicates increased likelihood of above normal to near
normal rainfall over most of the equatorial parts of the GHA.
Percent of
normal rainfall over the U.S. West between September 10 - 16, 2013.
Not exact matches
WMO said the abnormal weather was caused by a persistent ridge of high pressure
over western and central Europe, blocking more
normal patterns of
rainfall and temperature.
The stronger trade winds during La Nina do not extend past 130E on average, and are met
over the western Pacific by stronger than
normal westerlies coming from the east Indian Ocean, causing strong convergence and above -
normal rainfall in the western Pacific and around the Maritime Continent.
In contrast,
rainfall anomalies in December 2015 show a clear north - south divide, with many parts of Northern England and Southern Scotland experiencing
over three times
normal monthly
rainfall, while in Southern England
rainfall was closer to
normal.