There have been no shortages of weather extremes this summer. Those in the “line of fire” are probably wondering what the root causes of this volatile weather have been – and more importantly, if more is on the way.
The weather analysis firm Planalytics points to the following seven “key factors” that are the biggest influencers of U.S. and global weather this growing season. Many of them are the result of sea surface temperature anomalies, which provide a “great backdrop for summarizing what has been happening to cause our crazy summer weather,” according to the company.
1. La Niña – it’s not official per the strict definitions of the meteorology community, but Planalytics says “La Niña-like” conditions are creating all-to-real warmer, dryer influences on our weather.
2. The Pacific Decadal Oscillation (PDO) has remained warm. This contributes to an enhanced jet stream into the northern Plains.
3. The Gulf of Mexico has relatively warm waters. This fuels upper-level high pressure over the southern Plains and Southeast. The result – more heat and more dry weather in these areas.
4. The eastern Indian Ocean is warming, which helps promote the transition to La Niña and will contribute to warmer temperatures in the southern U.S.
5. In western Canada, upper-level low pressure establishment has led to multiple rounds of thunderstorms in the northern Plains and upper Midwest.
6. In the western Pacific, warm waters combined with upper-level atmospheric conditions are bringing big amounts of moisture to southeast Asia.
7. La Niña development is also promoting drier conditions in the heart of South America, including below-normal precipitation in central Brazil and northern Argentina.