Through this week, the heatwave in the US has been continuing, allowing more September records to fall. Salt Lake City in Utah saw its September temperature record broken, with each day hotter than the last, until the current highest ever September temperature was recorded on Wednesday. The new September record is now 107F or 41.7C, which astonishingly is also tied as the all-time temperature record for Salt Lake City. It is extraordinary to record a tied record high temperature in meteorological autumn.
Farther south earlier this week, the tropical storm off the west coast of Mexico, previously Twelve-E, developed into a category 2 hurricane, bringing sustained winds of 100mph, and was named Hurricane Kay. The hurricane brought intense flooding all the way up the west coast of Mexico, from Oaxaca to Nayarit by Thursday 8 September. In the last 48 hours, Kay has weakened into a tropical storm, but continues to bring extreme rain in its path, across the Baja California Peninsula and up towards the US state of California.
This weekend, the remnants of the hurricane are expected to reach closer to California than any other hurricane in 25 years, since Hurricane Nora in 1997. However, one key difference is that Nora advanced inland through California, whereas the remnants of Hurricane Kay are forecast to remain offshore, although still with a high risk of flash flooding expected for southern parts of California after their baking heatwave. Despite a few other tropical storms and hurricanes in the Atlantic, these currently are not looking to pose a threat of landfall in the coming days.
Looking even farther south, in South America earlier this week there was a short wave of intense heat, this unusual for early spring. From Uruguay, up to Paraguay and southern Bolivia, temperatures reached up to 10C above the climatological average on Thursday afternoon. Maximum temperatures reached the mid to high-30sC through the afternoon, but were very short-lived compared with the heatwave in the US. Only 24 hours later, on Friday, some areas that reached the high 30sC on Thursday were a chilly 19C.
