{"id":63972,"date":"2025-04-08T15:07:44","date_gmt":"2025-04-08T15:07:44","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=63972"},"modified":"2025-04-11T15:58:25","modified_gmt":"2025-04-11T15:58:25","slug":"flooding-along-the-ohio-river","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/63972","title":{"rendered":"Flooding along the Ohio River"},"content":{"rendered":"\n\t\n\t\t\n\t\t\t<\/polyline>\n\t\t\t<\/polyline>\n\t\t\t<\/polyline>\n\t\t\t<\/polyline>\n\t\t\t<\/svg>\n\t\t<\/span>\n\t<\/span>\n<\/div>\n\n\n\n\n\n

Heavy rains during the first week of April have led to significant flooding along the Ohio (and other) Rivers. The slider above compares True-Color imagery from CSPP Geosphere on 24 March<\/a> — long before the rains — and on the morning of 7 April 2025<\/a> — during the floods. The expansion of the Ohio River, a sinuous brown in the image, is apparent, as is the general greening up of the background as Spring progresses. (Click here for an annotated image from 7 April <\/a>that includes local geography, and here for the same annotation from 24 March<\/a>).<\/p>\n\n\n\n

Cloud cover after a rain event can make flood detection from satellites a challenge. SAR data can be used to detect floods underneath clouds (or at night) and imagery is available at this RealEarth-powered website<\/a>. RadarSat imagery from late on 6 April 2025, below, shows the extent of the flooding over southern Illinois and southwestern Indiana. Regions where SAR data suggests flooding is occurring are shown in red.<\/p>\n\n\n\n

\"\"<\/a>
Radarsat-2 estimates of flooding, 2340 UTC on 6 April 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n

Clear Skies over the Ohio River valley on 8 April allowed for excellent coverage from a multitude of satellites that can assess the horizontal extent of flooding. For example, False-color imagery from Sentinel-2 (at this link<\/a>), toggled below with a ‘before’ image from 22 March 2025, shows the obvious increase in flood waters.<\/p>\n\n\n\n

\"\"<\/a>
Sentinel-2A False Color imagery on 22 March 2025 and 8 April 2025 over the lower Ohio River Valley (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

Sentinel-2A horizontal coverage doesn’t cover the entire flooded region — but clear skies on 8 April allowed the VIIRS flood product to create information over the Ohio River Valley and mid-Mississippi River Valley, as shown in the image below (taken from this website<\/a>).<\/p>\n\n\n\n

\"\"<\/a>
1-Day VIIRS Composite of the Flood Product, 08 April 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n

Added, 11 April 2025, below: The CIMSS Flood Product (1-day VIIRS Composites, source<\/a>) during the 4 mostly clear days from 7-10 April 2025 is shown below. Memphis is at the southern edge of the image, where the Mississippi takes a long and lazy southerly to westerly curve<\/a>. Some of the flooded tributaries of the Mississippi in western Tennessee show decreasing flood waters over these 4 days.<\/p>\n\n\n\n

\"\"
VIIRS 1-day Flood Composite imagery, 7-10 April 2025 (Click to enlarge)<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"

Heavy rains during the first week of April have led to significant flooding along the Ohio (and other) Rivers. The slider above compares True-Color imagery from CSPP Geosphere on 24 March — long before the rains — and on the morning of 7 April 2025 — during the floods. The expansion of the Ohio River, […]<\/p>\n","protected":false},"author":19,"featured_media":63983,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[74,16,47,104],"tags":[],"class_list":["post-63972","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-goes-16","category-heavy-rain-flooding","category-other-satellites","category-sar"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/63972","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=63972"}],"version-history":[{"count":10,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/63972\/revisions"}],"predecessor-version":[{"id":64078,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/63972\/revisions\/64078"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/63983"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=63972"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=63972"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=63972"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}