Wildfire forces closure of Interstate 95 in Florida

February 28th, 2011

 

GOES-13 0.63 µm visible images (click image to play animation)

GOES-13 0.63 µm visible images (click image to play animation)

McIDAS images of GOES-13 0.63 µm visible channel data (above; click image to play animation) showed the large smoke plume from a wildfire that forced the closure of Interstate 95 in eastern Florida on 28 February 2011. A MODIS true color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (below; viewed using Google Earth) offered a closer view of the growing smoke plume at 19:14 UTC. The fire burned several structures and forced evacuations of parts of Scottsmoor, Florida.

MODIS true color Red/Green/Blue (RGB) image (viewed using Google Earth)

MODIS true color Red/Green/Blue (RGB) image (viewed using Google Earth)

A sequence of AWIPS images of 1-km resolution POES AVHRR and MODIS 3.7 µm shortwave IR data (below) revealed the very large “hot spot” (black to red to yellow pixels) associated with the wildfire as it jumped eastward across Interstate 95 after about 23:00 UTC (4 pm local time).

 

POES AVHRR 3.7 µm and MODIS 3.7 µm shortwave IR images

POES AVHRR 3.7 µm and MODIS 3.7 µm shortwave IR images

Fires and blowing dust across western Texas

February 27th, 2011

 

MODIS true color Red/Green/Blue (RGB) image (viewed using Google Earth)

MODIS true color Red/Green/Blue (RGB) image (viewed using Google Earth)

 

High winds (gusting to 69 mph at Amarillo, Texas) downed power lines that ignited a number of grassland wildfires across western Texas on 27 February 2011 — according to media reports, these fires destroyed at least 60 homes, burned more than 140,000 acres, and caused an accident on Interstate 20 near Midland, Texas that killed a 5-year-old child. These high winds were also responsible for widespread areas of blowing dust, which reduced surface visibilities in a number of locations. Laredo, Texas recorded a daily high temperature of 103ºF (the first high temperature of 100º F or greater of the year in the US). A MODIS true color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (above, viewed using Google Earth) showed the areas which were affected by blowing dust and smoke plumes from wildfires.

 

A comparison of AWIPS images of 4-km resolution GOES-13 3.9 µm shortwave IR data with the corresponding 1-km resolution MODIS 3.7 µm shortwave IR data (below) demonstrated the improved fire hot spot (red to yellow color enhancement) detection capability provided by higher spatial resolution. On the MODIS image, some of the fire pixels were so hot that they “wrapped around” on the color scale and appeared as white pixels.

MODIS 3.7 µm + GOES-13 3.9 µm shortwave IR images

MODIS 3.7 µm + GOES-13 3.9 µm shortwave IR images

 

An AWIPS comparison of the MODIS 0.65 µm visible channel and the corresponding MODIS 1.38 µm “cirrus detection channel” image (below) showed the utility of the near-IR cirrus detection channel for highlighting the areal coverage of the blowing dust (which showed up as the slightly brighter areas, since this MODIS channel is sensitive to any particles that are efficient scatters of light). At the time of the MODIS image, winds across this region were gusting as high as 46 knots at Pecos (station identifier KPEQ).

 

MODIS 0.65 µm visible image + MODIS 1.38 µm "cirrus detection" image

MODIS 0.65 µm visible image + MODIS 1.38 µm "cirrus detection" image

 

Farther to the north over the Texas Panhandle region, a similar comparison of the 4-km resolution GOES-13 3.9 µm shortwave IR data with the corresponding 1-km resolution MODIS 3.7 µm shortwave IR data (below) again demonstrated the improved fire hot spot (red to yellow color enhancement) detection capability provided by higher spatial resolution.

MODIS 3.7 µm + GOES-13 3.9 µm shortwave IR images

MODIS 3.7 µm + GOES-13 3.9 µm shortwave IR images

 

A similar AWIPS comparison of the MODIS 0.65 µm visible channel and the corresponding MODIS 1.38 µm “cirrus detection channel” image (below) again showed the utility of the near-IR cirrus detection channel for highlighting the areal coverage of the blowing dust. At the time of the MODIS image, winds across this region were gusting as high as 60 knots at Amarillo (station identifier KAMA), where surface visibility was restricted to 1.5 miles.

MODIS 0.65 µm visible image + MODIS 1.38 µm "cirrus detection" image

MODIS 0.65 µm visible image + MODIS 1.38 µm "cirrus detection" image

 

 

High winds and wildfire activity over the Mid-Atlantic region

February 19th, 2011
GOES-13 6.5 µm water vapor channel imagery (click image to play animation)

GOES-13 6.5 µm water vapor channel imagery (click image to play animation)

AWIPS images of 4-km resolution GOES-13 6.5 µm “water vapor channel” data (above; click image to play animation) revealed an extensive “mountain wave signature” across much of the Mid-Atlantic region of the US on 19 February 2011. Strong winds (gusting to 71 mph in Virginia and 63 mph in Maryland and Pennsylvania) in the wake of a cold frontal passage were interacting with the terrain of the Appalachian Mountains to create the widespread mountain waves — and some of the mountain waves were responsible for pilot reports of moderate to severe turbulence.

1-km resolution MODIS 6.7 µm water vapor images (below) offered a more detailed view of the mountain wave structure.

MODIS 6.7 µm water vapor images

MODIS 6.7 µm water vapor images

On occasion, these mountain waves appear in “clear air’ with no clouds present — this can be seen from Virginia to the Delmarva Peninsula in a comparison of a MODIS 0.65 µm visible image with the corresponding MODIS 6.5 µm water vapor image (below). Aircraft sometimes encounter “clear air turbulence” under such circumstances.

MODIS 0.65 µm visible image + MODIS 6.5 µm water vapor image

MODIS 0.65 µm visible image + MODIS 6.5 µm water vapor image

It is interesting to note that the MODIS 2.1 µm near-IR “snow/ice channel” image (below) displayed  a signature of what appeared to be the effect of atmospheric gravity waves over the adjacent offshore waters. A similar signature was discussed on the MODIS Image of the Day site off the coast of New Zealand on 21 December 2010.

MODIS near-IR 2.1 µm "snow/ice channel" image

MODIS near-IR 2.1 µm "snow/ice channel" image

The combination of strong winds and dry vegetation (MODIS Normalized Difference Vegetation Index) created an environment favorable for wildfire activity — and on this day there were more than 100 wildfires reported across the state of Virginia alone. The “hot spots” signatures (black to yellow to red color enhancement) from many of the larger fires could be seen on 4-km resolution GOES-13 3.9 µm imagery, with many more of the smaller fires exhibiting such signatures on the corresponding 1-km resolution POES AVHRR 3.7 µm shortwave IR image (below).

GOES-13 3.9 µm shortwave IR image + POES AVHRR 3.7 µm shortwave IR image

GOES-13 3.9 µm shortwave IR image + POES AVHRR 3.7 µm shortwave IR image

A MODIS “true color” Red/Green/Blue (RGB) image (below; displayed using Google Earth) showed a few of the longer smoke plumes that were emanating from the largest fires located from western Virginia to the Washington, DC area.

MODIS true color RGB image (displayed using Google Earth)

MODIS true color RGB image (displayed using Google Earth)

Mountain wave turbulence in the western US

February 14th, 2011

GOES water vapor images with pilot reports of turbulence (click image to play animation)

GOES water vapor images with pilot reports of turbulence (click image to play animation)

Strong southwesterly winds aloft interacting with the rugged terrain of the Sierra Nevada mountain range resulted in a number of pilot reports of mountain waves which were producing moderate turbulence over parts of the western US on 14 February 2011. AWIPS images of a composite of 8-km resolution GOES-11 (GOES-West) and 4-km resolution GOES-13 (GOES-East) water vapor imagery (above) revealed a classic mountain wave signature just downwind of the Sierra Nevada. The “seam” between GOES-11 and GOES-13 is fairly evident on the AWIPS water vapor image composite, mainly due to the difference in spatial resolution.

A comparison of the mountain waves on the 8-km resolution GOES-11 6.5 µm water vapor image versus the corresponding 1-km resolution Terra MODIS 6.5 µm water vapor image (below) demonstrates the clear advantage of improved spatial resolution for detecting the areal coverage of such features.

GOES water vapor image + MODIS water vapor image (with pilot reports of turbulence)

GOES water vapor image + MODIS water vapor image (with pilot reports of turbulence)

About 1.5 hours later, a similar comparison of the mountain waves on the 8-km resolution GOES-11 6.5 µm water vapor image versus the corresponding 1-km resolution Aqua MODIS 6.5 µm water vapor image can be seen below. Note that there is less “striping” (due to detector degradation) on the Aqua MODIS water vapor image — Aqua is a newer satellite , launched in 2002 (Terra was launched in 1999) .

GOES water vapor image + MODIS water vapor image (with pilot reports of turbulence)

GOES water vapor image + MODIS water vapor image (with pilot reports of turbulence)