Satellite signatures of moist soil (and patches of snow cover) across IowaThe southeastern 2/3 of Iowa received precipitation during the 24 to 48 hours preceding 12 UTC on 19 March 2022 — and GOES-16 (GOES-East) Day Snow-Fog RGB images (above) showed (1) a signature of the resultant moist soil (darker shades of green) across central and southeastern Iowa, along with (2) isolated patches of fresh snow cover (darker shades of red) in southeastern Nebraska, southwestern Iowa, northeastern Iowa and southwestern Wisconsin. The area of deeper (and thus slower-melting) snow cover over southwestern Iowa was enhanced by a period of thundersnow, where 3.0 inches fell at Audubon (KADU) and 2.1 inches fell at Atlantic (KAIO). There was a sharp boundary separating this recently-moistened soil from the very dry soil across northwestern Iowa — an area which had received less than 50% of normal precipitation during the previous 90 days, and was experiencing abnormally dry to severe drought conditions.
The corresponding hourly Land Surface Temperature (LST) derived product displayed a similarly sharp contrast between the dry and moist soil — with the dry soils exhibiting late-morning to mid-afternoon LST values that were 15-25ºF warmer than adjacent moist soils (since the energy of incoming solar radiation was acting to evaporate water from the moist soil, rather than warm it). For example, in the Land Surface Temperature product at 1901 UTC (below) the LST along the 40-mile Baseline segment A-A’ varied from 88ºF in dry soil (at Point A) to 63ºF in moist soil (at Point A’). The radar-derived 24-hour total precipitation showing Baseline A-A’ can be seen here.