Unusually high temperatures in the Tahoe area have caused concern among authorities, leading to a flood warning due to accelerated snowpack melting.
A flood watch was issued by the National Weather Service and will be in effect from 8 p.m., Thursday, May 18, until 8 p.m., Monday, May 22. The warning addresses the risk of excessive runoff potentially flooding rivers, streams, creeks, and other areas susceptible to flooding. The advisory warns that water bodies may overflow their banks and inundate low-water crossings.
“The unexpected heatwave is causing rapid snowmelt and runoff from higher elevations to lower areas, particularly along the Carson and Walker River basins and eastern Sierra basins,” read the advisory. “As a result, creeks, streams, and main river areas will maintain high, swift, and chilly flows, even after this watch concludes.” The advisory adds that most of the peak flow and heights will occur overnight and in the early morning due to the diurnal melt cycle.
Despite the enticing warmth, the advisory urges caution around the water. The rapid melting keeps the water extremely cold, posing a risk of sudden cold shock that could impair motor function. Additionally, snow bridges, with water flowing beneath, may be present in backcountry areas, and extra caution is advised.
According to the forecast, temperatures will reach their zenith on Friday and Saturday, with highs in the mid-70s. The following week will see a slight decline, with temperatures dropping to the upper 60s. Thunderstorm probabilities are on the rise: from a 15-20% chance on Friday, the likelihood jumps to 30% on Saturday and even 40% on Sunday, particularly in Mono and Mineral counties. In the event of a thunderstorm, gusty winds reaching speeds of 40-50 mph, small hail, and local heavy rainfall could be expected.