Dan Shapley

💧 The data is in: May 2024 was the moistest May on record for the planet... This continues a run of record-moist months that dates back to last year. 🤔 Wondering why it's been really rainy where you are? 65% of Earth had above normal moisture content during the month, which is being strongly influenced by excessive ocean heat across the global tropics, whereby the jet stream transports warmth and moisture out of the tropics and toward the poles. The tail end of El Niño and record global ocean heat content contributed to regional rainfall extremes, like those experienced in the UK, France, Germany, Belgium, the Netherlands, Italy, southern Brazil, the U.S. Gulf Coast, Indonesia, Papua New Guinea, and Fiji during May. Regional dry patches can and do still exist, forced by other oscillations and modes, but recently they have been more of the exception rather than the rule. The western U.S., Mexico, Chile, Argentina, New Zealand, parts of southern Australia, and eastern Europe were dry zones during May. ⚠️ In my opinion, this moistening trend is just as important as the warming trend as it relates to the potential increase in flood frequency and/or intensity into the future. 🌋 Note: the anomalies shown here are indicative of tropospheric patterns where the vast majority of the atmosphere's water is located and not the stratosphere where the Tongan volcanic moisture anomalies were most pronounced. Extra water vapor in the stratosphere can contribute to a slight warming effect on the ground, but it doesn't come back to the ground in the form of massive dumps of rain. While the eruption led to a substantial wetting of the stratosphere, very little water vapor exists there to begin with. Despite a large percent increase in water vapor there, actual amounts remain very small.