Blowing dust in northeastern Arkansas

April 12th, 2016 |

GOES-13 Visible (0.63 um) images [click to play animation]

GOES-13 Visible (0.63 um) images [click to play animation]

Strong southwesterly winds (gusting as high as 39 knots or 45 mph) created areas of blowing dust that reduced visibility to near zero and caused 2 incidents of multiple-vehicle accidents (NWS Local Storm Reports) near Portia in northeastern Arkansas on 10 April 2016. GOES-13 (GOES-East) Visible (0.63 um) images (above) showed the faint hazy signature of a few narrow plumes of blowing dust moving northeastward, one of which moved across Lawrence County and between Portia (denoted by the red * symbol) and Walnut Ridge (station identifier KARG). The blowing dust plumes are perhaps a bit easier to see on these images without county outlines and highways, though they are still somewhat difficult to identify with the patches of thin cirrus and contrails drifting from west to east overhead. Video of the conditions on the ground can be seen here.

Time series plots of surface data for Walnut Ridge (KARG) located just to the northeast and Newport (KM19) located farther to the south-southwest are shown below. Surface reports indicated that the visibility was reduced to less than 1 mile at 1756 UTC at Newport, and less than 3 miles at 1735 UTC at Walnut Ridge.

Time series plot of surface data for Walnut Ridge, Arkansas [click to enlarge]

Time series plot of surface data for Walnut Ridge, Arkansas [click to enlarge]

Time series plot of surface data for Newport, Arkansas [click to enlarge]

Time series plot of surface data for Newport, Arkansas [click to enlarge]

On the previous day, a comparison of the 1849 UTC Aqua MODIS Visible (0.65 µm) image and the corresponding Normalized Difference Vegetation Index (NDVI) product (below) showed that there were many areas upwind (to the southwest of) Portia and Walnut Ridge — in both southern Lawrence and northern Jackson counties — that exhibited low NDVI values (tan color enhancement), indicative of recently-plowed and/or unplanted agricultural fields within that part of the Mississippi Alluvial Plain. It is possible that field plowing activities on that windy day may have been the catalyst for the some of the  blowing dust plumes.

Aqua MODIS Visible (0.65 um) and Normalized Difference Vegetation Index (NDVI) product [click to enlarge]

Aqua MODIS Visible (0.65 um) and Normalized Difference Vegetation Index (NDVI) product [click to enlarge]

Similarly, a comparison of the 1849 UTC Aqua MODIS NDVI and Land Surface Temperature (LST) products (below) showed that the land surface in areas with less vegetation were warming up more quickly, with some LST values in excess of 90º F (darker red enhancement).

Aqua MODIS Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature products [click to enlarge]

Aqua MODIS Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature products [click to enlarge]

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