Storm Hilary Threatens Severe Flooding in Unprecedented California Landfall
Tropical Storm Hilary, with maximum sustained wind gusts of 130mph (210km/h) and a central air pressure of 943mb, has made a historic landfall in California. This event marks the first tropical storm to hit California in 84 years. Originally a category 4 hurricane, Hilary approached the Baja California peninsula over the weekend and eventually reached southern California as a tropical storm late on Sunday. The last recorded instance of a tropical storm making landfall in southern California dates back to 1939, a disaster that resulted in devastating floods in Los Angeles and claimed nearly 100 lives.
Hilary’s impact has prompted California’s inaugural tropical storm warning, extending from the Mexican border to just north of Los Angeles. Initial estimates indicate rainfall totals ranging from 70-150mm (3-6in) across southern California. Such a deluge poses a serious threat of life-threatening flooding and is equivalent to over a year’s worth of rainfall in certain areas of California and Nevada.
President Joe Biden announced last week that the Federal Emergency Management Agency (FEMA) has positioned personnel and supplies to respond to the affected regions. Simultaneously, the Mexican army deployed nearly 14,000 soldiers to Mexicali and the states of Baja California Sur, Jalisco, and Colima.
While Hilary advances north-northwestward through California, Nevada, Oregon, and Idaho in the coming days, it is expected to gradually weaken into a depression but will still bring heavy rain to these regions. Central and southwest Idaho typically receives around 15mm of rainfall in August, but cumulative totals of 30-50mm are anticipated over the next few days.
Meanwhile, extensive portions of the Midwest, central, and southern Plains in the United States are under excessive heat warnings for the upcoming week. Temperatures are soaring 5-10C above the climatological average. Last Friday, over 65 million people received heat alerts, many of which extend into Friday or Saturday this week. Widespread temperatures exceeding 38C (100F) are anticipated, with some areas experiencing peak temperatures in the low to mid-40Cs (104-112F).
In Europe, heat originating from northern Africa will migrate northward this week, with Spain and Portugal bearing the brunt of the impact. Southwest Spain and southern Portugal are expected to experience temperatures reaching the low 40Cs. Parts of Italy and southern France can also anticipate temperatures around 40C. However, this heat is expected to dissipate as low-pressure systems bring cooler westerly winds by the weekend.