A significant shortwave trough digging across the Four Corners brought strong winds to a large swath of the southern High Plains on 17 Mar 2022, resulting in widespread blowing dust and critical fire weather conditions. GOES-East Water Vapor Imagery combined with RAP Analysis fields allows one to connect features observed in the imagery with those present in SFC/UL charts (Fig 1). In this case, a surface low is analyzed deepening out ahead (east) of the main mid-level cyclonic circulation associated with the mid-level trough. A mid-level (70+ knot) jet streak rounds the base of the trough and is associated with a meridional temperature gradient in the water vapor imagery. The warming in the water vapor imagery here also represents a region of drying/descending air. Deep vertical mixing during the day across the dry/warm region helped to mix down the increasing mid-level winds, resulting in strong surface wind gusts.
As is typically shown, basic split window difference imagery captures lofted dust quite well, and is represented here as darkest shades of gray (Fig 2). The area of lofted dust is coincident with the downward momentum transport and drying observed in water vapor imagery, circling the mid-level circulation.
The SWD is combined with IR and SWIR imagery to yield a Dust-Fire RGB, which shows the blowing dust as bright green, wildfire hot spots as red, and clouds as varying shades of blue (Fig 3).
DEBRA Dust imagery results from a more advanced algorithm that highlights suspected dust, based on the IR techniques, onto visible imagery as shades of yellow (Fig 4). DEBRA Dust is available on CIRA Slider.
Two, GOES-East mesoscale sectors of 1-min imagery each were positioned over the region to capture the widespread wildfire threat. A 3-hr long 1-min animation of Geocolor imagery combined with a hot SWIR range provides a nice depiction of the blowing dust and wildfire development (Fig 5). The Geocolor imagery from GOES-East, especially later in the afternoon (increasing forward scattering), depicts aerosols quite well, including blowing dust as shades of brown/tan, and wildfire smoke as gray. By including only hot (40+C) shortwave IR pixels as an overlay, we are able to capture wildfire hot spots as well (yellow). Click the following 1-min and 30-sec animations for better resolution views. Geocolor is available on CIRA Slider, STAR Image Viewer, and coming soon to every AWIPS.
Because the two GOES-East mesoscale sectors overlapped slightly, 30-second imagery was available (in the overlap region). This partially overlapped meso sector 30-sec imagery can be accessed in AWIPS with some simple configuration additions. Thirty-second Geocolor imagery of early upper-level cloud cover evolution is shown in in Fig 6, while a wildfire hot spot, smoke plume, and blowing dust are shown in Fig 7.
Strong southerly winds within a dry antecedent atmosphere a few days later on 20 March resulted in another day of critical fire weather conditions and blowing dust. A Geocolor + Fire Power derived product + SWD Dust Enhancement AWIPS display captures the evolution of the wildfire hot spots and smoke plumes across Texas, and broad plume of blowing dust across west Texas (Fig 8). By employing the Fire Power product in this type of display, as opposed to the SWIR imagery, one needs not worry about setting thresholds for hot spot detection.
Bill Line, NESDIS and CIRA
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