Signs the El Nino underway in the equatorial Pacific may already be having an impact northern hemispheric weather are growing. While difficult to establish a direct link between the cool temperatures which have dominated the Chicago area over the past few weeks and the developing El Nino between South America and the Australia, it's worth noting cooler than normal September through November periods have been El Nino hallmarks here.
An in-house analysis of 17 El Ninos since 1950 indicates 14 of them have featured below normal temperatures during the three month meteorological fall period. In the past, falls have also displayed a modest tendency toward wetter than normal weather. Each month from September through November has produced precipitation tallies above the long term average during El Ninos. It will be interesting to see if a wetter, more humid weather pattern predicted to begin taking hold late in the upcoming holiday weekend turns out to be the opening salvo of a wetter autumn weather regime.
Other signs that El Nino may already be at work include the limited number of tropical storms and hurricanes which have occurred in the Atlantic at the same time the eastern Pacific hurricane season has been on overdrive. Powerhouse Hurricane Jimena is just the latest tropical cyclone to sweep that region. The storm weakened dramatically as it encountered cool waters off Mexico's Baja Peninsula where it made landfall during the day. Wednesday's 73-degree high was up one degree from the day before. It was only the fourth time since June 1 Chicago has received 100 percent of its possible daily sunshine.
An in-house analysis of 17 El Ninos since 1950 indicates 14 of them have featured below normal temperatures during the three month meteorological fall period. In the past, falls have also displayed a modest tendency toward wetter than normal weather. Each month from September through November has produced precipitation tallies above the long term average during El Ninos. It will be interesting to see if a wetter, more humid weather pattern predicted to begin taking hold late in the upcoming holiday weekend turns out to be the opening salvo of a wetter autumn weather regime.
Other signs that El Nino may already be at work include the limited number of tropical storms and hurricanes which have occurred in the Atlantic at the same time the eastern Pacific hurricane season has been on overdrive. Powerhouse Hurricane Jimena is just the latest tropical cyclone to sweep that region. The storm weakened dramatically as it encountered cool waters off Mexico's Baja Peninsula where it made landfall during the day. Wednesday's 73-degree high was up one degree from the day before. It was only the fourth time since June 1 Chicago has received 100 percent of its possible daily sunshine.
