Warm, dry and windy conditions last week led to the development of numerous wildfires across the region, while some fires were controlled burns prescribed by the National Park Service and the Alabama Forestry Commission. Some of these fires produced sufficient amounts of smoke to be observed by geostationary and polar-orbiting satellites. On Friday, mostly clear sky conditions allowed a view of some of the larger fires and their smoke from the VIIRS instrument aboard the Suomi NPP satellite. The SPoRT True Color RGB product from the VIIRS instrument provided a quick and relatively easy view of the smoke plumes that developed across the area on Friday afternoon.
In particular, note the presence of smoke plumes (white/gray streaks) from fires in the Bankhead Nat’l Forest (northern Alabama) and from firest between Birmingham and Montgomery. Another smoke plume, although a little more difficult to see, was located southwest of Middleton Field (KGZH) in Evergreen, AL and adjacent to the far NW corner of the Florida peninsula. Southwesterly winds pushed smoke from this fire for a several mile stretch along the I-65 corridor northeast of the Mobile area. Persistent SW winds during the afternoon eventually pushed this smoke plume into the Evergreen, AL area affecting Middleton Field (noted on the Google Earth image) with reduced visibility to 5sm (marginal visual flight rule range) by 2143 UTC.
The smoke plume is a little more difficult to see in the last VIIRS image (valid 1945 UTC) as this area was on the far SE corner of the image swath, however, the smoke plume is still visible and has moved closer to Middleton Field. Within two hours, visibility at the airport dropped to 5sm. Given the appearance of the smoke plumes, the one affecting I-65 between Birmingham and Montgomery likely produced much lower visibilities for a stretch of several miles. This type of imagery can be very useful for nowcasting and for forecasting visibility reductions at aiports in terminal aerodrome forecasts. One lingering issue is how to estimate the visibility based on the appearance of the smoke in the satellite imagery. Perhaps future algorithms will be able to address this important issue.