Nocturnal heat in the Desert Southwest

July 6th, 2007 |

AWIPS MODIS IR image

Unusually hot conditions developed across parts of the Desert Southwest during the first week of July 2007 — daily maximum temperatures on 05 July included 127º F (53º C) at Death Valley, California, 122º F (50º C) at several locations within the Lake Mead/Lake Mohave basin region of Nevada/Arizona, 120º F (49º C) at Needles, California, and 116º F (47º C) at Las Vegas, Nevada (1º F shy of their all-time record high temperature). Following such hot daytime temperatures, a nighttime AWIPS image of the MODIS 11.0µm InfraRed (IR) channel (above) showed that nocturnal temperatures remained rather warm — IR brightness temperatures at 09:22 UTC (2:22 AM local time) were still 30º C / 86º F or warmer (orange to red enhancement) over a good deal of the Death Valley and Lake Mead/Lake Mohave basin regions. In fact, the official cooperative weather observation site at Death Valley (DEVC1) reported an overnight minimum temperature of 95º F (35º C), while a nearby mesonet site at Death Valley National Park (CQ162) only dropped to 105º F (41º C) at 7:00 AM local time (14:00 UTC).

AWIPS MODIS + GOES IR images

An AWIPS comparison of MODIS IR, GOES imager IR, and GOES Sounder Skin Temperature (above) revealed brightness temperatures in the lowest elevations of Death Valley were still as warm as 86-96º F (30-36º C) at 09 UTC. In addition, an AWIPS image of the MODIS sea surface temperature product (below) indicated that water temperatures were as warm as 87-89º F (31-32º C) (dark red enhancement) in portions of Lake Mead and Lake Mohave.

MODIS sea surface temperatures

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