IRI Climate Information Digest - November 1998
Issued 13 December 1998,Next Issue 15 January 1999
Global Temperatures - It is almost certain that 1998 will enter the record books as the warmest year in the instrumental record. The temperature pattern, for the 11 months (January through November) shows all of the continents with above average temperatures except for the northern sections of Eurasia. North America experienced the largest area of mean departures well above the 1960 to 1990 normals. Over the oceans, the slowly fading El Niño and unprecedented warmth of the Indian Ocean contributed to this record warm year. In contrast, during November much of Europe experienced extremely cold conditions, which spread eastward through Siberia and into Korea and the northern sections of Japan by the end of the month. The concentration of warmer than average temperatures over North America and colder than average temperatures over Eurasia is not typical of the global patterns over the past several years.
La Niña Continues to Evolve- Colder than normal sea surface conditions characterized the equatorial Pacific in November. The greatest relative equatorial cooling extends from the dateline to 120 W. Numerical model and empirical prediction tools are in general agreement suggesting that the La Niña will remain at current levels for the next 2 to 3 months and then begin to diminish in magnitude. Most predictions continue with at least weak cool conditions in the mid-1999. Currently, tropical rainfall patterns have adjusted to La Niña conditions with heavy amounts experienced during November over the far western Pacific and covering much of Indonesia, Malaysia and Northern Australia. Dry equatorial conditions were experienced from 135 E to east of the dateline including the areas from Nauru and the Solomon Islands eastward through Kiribati.
Mid-latitude Rainfall Patterns - Much of eastern North America from the Florida northward into southern Canada has experienced an extremely dry November. Dry conditions have been dominant over most parts of the Mid-Atlantic region through Georgia since mid-May to June 1998. In Europe, heavy rains returned to the central Mediterranean through Turkey while portions of the Iberian Peninsula southward through Morocco and Algeria experienced their second consecutive month of dry conditions.