Wildfire in North Carolina

June 7th, 2008 |

MODIS visible + shortwave IR images (Animated GIF)

AWIPS images of the MODIS visible and 3.7 µm shortwave IR channels (above) showed smoke and a “hot spot” associated with a large wildfire that had burned over 30,000 acres in the Pocosin Lakes National Wildlife Refuge in northeastern North Carolina on 07 June 2008.

The fire was started by lightning about a week earlier — an animation of MODIS true color images (below) revealed the changing shape and direction of the smoke plume during the 02-07 June period. At times the smoke was causing air quality problems as it drifted northward over the urban areas of southeastern Virginia — note the elevated MODIS Aerosol Optical Depth (AOD) values that had spread northward across southeastern Virginia on 06 June.

MODIS true color images (Animated GIF)

A closer view using 250-meter resolution MODIS true color imagery on from the SSEC MODIS Today site (below) shows the thick smoke drifting southeastward across the Outer Banks of North Carolina, then dispersing over the waters of the Atlantic Ocean on 07 June. Note the appearance of small pyrocumulus clouds that had formed over the hottest portions of the fire area, which cast a small shadow onto the smoke plume located below the cloud tops.

MODIS true color image

It was quite warm across the mid-Atlantic region on 07 June, which worsened the already-favorable fire conditions – the MODIS Land Surface Temperature (LST) product (below) indicated widespread LST values of 100-120º F (darker red colors) around 18 UTC (2 PM local time). Surface air temperatures reached 100º F at a few locations in southeastern Virginia (the 101º F at Norfolk and the 100º F at Richmond were record highs for the date).

MODIS Land Surface Temperature product

UPDATE #1: A MODIS Sea Surface Temperature (SST) image from 09 June (below) showed that the water temperatures in the Chesapeake Bay had risen to unusually high values (upper 70s to low 80s F) for early June, as a result of several consecutive days of record or near-record high temperatures. Note that the MODIS SST values in Chesapeake Bay were significantly warmer than those suggested by the High Resolution RTG_SST model analysis.

MODIS Sea Surface Temperature (SST) image

UPDATE #2: The large Pocosin Lakes National Wildlife Refuge fire continued to burn on 13 June, while another fire had started in the Great Dismal Swamp area along the North Carolina/Virginia border. With an easterly flow present, the smoke plumes were now drifting inland toward the west, as seen on GOES-12 visible images (below). A significant amount of smoke had drifted inland across central North Carolina on the previous day (12 June), and was dense enough to restrict surface visibility to 1/2 mile as far to the west as Raleigh; that smoke pall remained thick enough on 13 June to apparently have the effect of inhibiting the formation of cumulus clouds (by reducing the amount of surface heating).

GOES-12 visible images (Animated GIF)

Advection fog over the western Great Lakes

June 7th, 2008 |

MODIS SST image (01 June 2008)

An AWIPS image of the MODIS Sea Surface Temperature (SST) product (above) revealed that the water temperatures were still quite cool across much of the western Great Lakes on 01 June 2008. Several days later, a northward surge of warm and humid air brought daytime temperatures into the 80s F with dew points into the mid-upper 60s F over a good deal of the region on 06 June 2008. As this warm and humid air flowed over the still-cool waters of Lakes Superior, Michigan, and Huron, dense advection fog formed which lasted into the early morning hours on 07 June 2008.

A comparison of the 4-km resolution GOES-12 IR window, fog/stratus product, and Low Cloud Base product images with the 1-km resolution MODIS fog/stratus product image (below) showed the extensive coverage of fog over the lakes just after 08 UTC (3am local time).

MODIS + GOES images (Animated GIF)

250-meter resolution MODIS true color images from the SSEC MODIS Today site (below) show interesting small-scale structure in the fog over Lake Superior on 06 June and over Lake Michigan on 07 June, including “bow shock waves” where the southerly flow of wind and lake fog was interacting with various islands and coastal features.

MODIS true color image

MODIS true color image