Record high temperatures in the US Desert Southwest
MODIS 0.65 µm visible channel image + MODIS Land Surface Temperature product
A comparison of AWIPS images of 1-km resolution MODIS 0.65 µm visible channel data and the corresponding 1-km resolution MODIS Land Surface Temperature (LST) product at 21:22 UTC on 22 April 2012 (above) depicted marine layer stratus clouds extending inland along much of the California coast — but farther inland most areas were cloud-free, with some of the interior deserts exhibiting very hot LST values (as high as 148º F in the Death Valley region of California, and 139º F in southern Nevada and southwestern Arizona).
An overlay of the 21 UTC METAR surface reports (below) showed that instrument shelter air temperatures were only in the 50s and 60s F beneath the marine layer stratus along coastal California, but many air temperatures were over 100º F in the interior deserts. A number of daily maximum temperature records were set on this day, including 113º F at Furnace Creek in Death Valley, California, 105º F in Phoenix, Arizona, and 99º F in Las Vegas, Nevada (which tied their record for the warmest high temperature for the month of April, and was also the earliest occurrence of a 99º F temperature).
MODIS Land Surface Temperature product + METAR surface reports
===== 23 April Update =====
Following the hot daytime temperatures on 22 April, a night-time MODIS Land Surface Temperature image showed that many of the lower elevations were still quite warm at 09:19 UTC (below). In Death Valley, California LST values were still as warm as 86º F. Lower elevations in the Grand Canyon in Arizona exhibited LST values in the 60s and 70s F, while the higher elevation canyon rims had cooled into the 30s and 40s F. In Arizona, record high minimum temperatures for the date were set at Phoenix (77º F) and Yuma (74º F).
MODIS Land Surface Temperature product