Wildfire near Lake Okeechobee in Florida

May 30th, 2007 |

GOES + MODIS shortwave IR images

Hot spots on GOES-12 3.9µm and MODIS 3.7µm IR imagery (above) indicated the presence of several wildfires near the northwestern shoreline of Lake Okeechobee in southern Florida on 30 May 2007. The fires were hot enough to saturate the shortwave IR detectors on GOES-12, causing the hottest brightness temperatures (normally appearing as black pixels) to “roll over” and show up as “cold” (white) pixels. An Aqua MODIS true color image (below) showed a smoke plume extending westward from the fires, with the smoke reaching the Gulf Coast of Florida. That region continued to experience extreme drought conditions — in fact, the water levels for the lake set an all time record low (note how much the lake water had receded from the southern, western, and northwestern portion of Okeechobee in the MODIS true color image).

MODIS true color image

TD Alvin and TS Barbara

May 30th, 2007 |


An AWIPS image of the GOES 10.7µm InfraRed (IR) channel (above) shows Tropical Depression Alvin (left) and Tropical Storm Barbara (right) on 30 May 2007 — both disturbances were located near the Intertropical Convergence Zone (ITCZ) over the Eastern Pacific Ocean. The morning NHC discussion pointed out that only twice before (in 1956 and 1984) have there been two named Eastern Pacific basin storms in the month of May. An animation of GOES-12 IR imagery with a different color enhancement (below) indicates that the cold cloud top temperatures (red to white enhancement) associated with Tropical Storm Barbara were increasing in areal coverage during the morning hours.

GOES-12 IR animation

The NHC discussion also made reference to the CIMSS Advanced Dvorak Technique or ADT (below) in their decision to upgrade Tropical Depression Barbara to a Tropical Storm.

CIMSS Advanced Dvorak Technique