Fire near Lake Tahoe

June 25th, 2007 |

GOES-12 3.9µm IR + visible image

The large “Angora wildfire” began to burn just south of Lake Tahoe in California sometime after 21:00 UTC (1:00 PM local time) on 24 June 2007, eventually destroying 254 homes and burning 3100 acres. Images of the 3.9µm InfraRed (IR) and visible channels from GOES-12 (above; Java animation) and GOES-11 (below; Java animation) revealed a large “hot spot” (black pixels) associated with this fire, as well as a long smoke plume that spread quickly northeastward during the afternoon hours. Dark IR “hot spots” were first evident on GOES-12 imagery at 21:32 UTC and on GOES-11 imagery at 21:41 UTC, with a “processed fire” (red pixel) showing up on the GOES-11 Wildfire ABBA product at 22:00 UTC. Note that the hot fire saturated the 3.9µm detectors on GOES-12, causing the temperature to “roll over” and be falsely displayed as very cold (white) pixels. The saturation temperature of the GOES-11 3.9µm detectors (338.8º K / 66º C / 150º F) was reached as early as 22:30 UTC (2:30 PM local time).

GOES-11 3.9µm IR + visible image

The majority of the smoke was transported rapidly northeastward between Reno, Nevada (KRNO) and Fallon, Nevada (KNFL) by strong winds aloft; however, GOES-12 visible imagery indicated that some smoke at lower altitudes was curving southward away from the main plume and moving toward Fallon (and areas south of Fallon) after about 00:00 UTC on 25 June. The surface meteorogram from Fallon (below) indicates that surface visibility there dropped from 10 miles to 6 miles around 02 UTC as this smoke began to move into the area.

Fallon NV meteorogram

The fire continued to burn for several days; a Terra MODIS true color image from 26 June (below) shows a smaller smoke plume that was continuing to drift northward across the lake.

Terra MODIS true color image