{"id":67286,"date":"2025-10-09T14:59:00","date_gmt":"2025-10-09T14:59:00","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=67286"},"modified":"2025-10-10T23:00:29","modified_gmt":"2025-10-10T23:00:29","slug":"1-minute-goes-18-imagery-to-monitor-the-potential-of-flash-flooding-in-american-samoa","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/67286","title":{"rendered":"1-minute GOES-18 imagery to monitor the potential of flash flooding in American Samoa"},"content":{"rendered":"<p><div style=\"width: 3004px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/10\/251009_goes18_infrared_totalPrecipitableWater_glmFlashPoints_American_Samoa.mp4\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/10\/251009_0450utc_g18_ir_tpw_glm.png\" width=\"2994\" height=\"1672\" \/><\/a><p class=\"wp-caption-text\">1-minute GOES-18 Infrared images with an overlay of the Total Precipitable Water derived product (in cloud-free areas) and GLM Flash Points (white), along with plots of METAR surface reports (cyan), from 0401-1400 UTC on 09 October [click to play MP4 animation]<\/p><\/div>Due to a lack of radar coverage over American Samoa, <a href=\"https:\/\/www.weather.gov\/ppg\/?lang=english\"><strong>WSO Pago Pago<\/strong><\/a> requested a 1-minute <a href=\"https:\/\/www.nco.ncep.noaa.gov\/status\/satellite\/\"><strong>Mesoscale Domain Sector<\/strong><\/a> over the islands to monitor convective development and the potential for flash flooding. GOES-18 <em>(GOES-West)<\/em>\u00a0Clean Infrared Window (10.3 \u00b5m) images <em><strong>(above)<\/strong><\/em> showed rain showers that developed in the general vicinity of the American Samoa island of Tutuila (where Pago Pago International Airport NSTU is located) on 09 October 2025. <a href=\"https:\/\/www.goes-r.gov\/spacesegment\/glm.html\"><strong>GLM<\/strong><\/a> Flash Points indicated that intermittent lightning occurred very near the island of Tutuila \u2014 although no thunderstorms or lightning were explicitly reported during that particular 10-hour period at NSTU. The northwest-to-southeast orientated band of deep convection was aligned along a <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/10\/251009_0300utc_0600utc_surface_analyses_anim.gif\"><strong>trough of low pressure<\/strong><\/a> that was located across the islands.<\/p>\n<p>A <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/10\/251009_nstu_ffw.text\"><strong>Flash Flood Warning<\/strong><\/a> was issued at 0335 UTC (25 minutes prior to the start of the animation shown above), which was valid until 0700 UTC &#8212; 0.60&#8243; of rainfall was recorded during the 6-hour period ending at 0600 UTC, but there no reports of flooding on Tutuila that were received by WSO Pago Pago.<\/p>\n<p>GOES-18 Total Precipitable Water derived product values in the vicinity of American Samoa were generally in the 2.0-2.4 inch range &#8212; and a toggle between Pago Pago rawinsonde data at 0000 UTC and 1200 UTC <em><strong>(below)<\/strong><\/em> indicated that Precipitable Water (PW) increased from 2.19 inches to 2.40 inches during that 12-hour period. In addition, after 1200 UTC the coldest cloud-top infrared brightness temperatures associated with some of the rain showers and thunderstorms across the region were around -80\u00baC (darker shades of purple embedded within brighter white areas) &#8212; which represented a small overshoot of the Most Unstable (MU) air parcel&#8217;s Equilibrium Level (EL).<\/p>\n<div style=\"width: 3004px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/10\/251009_ntsu_raobs_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/10\/251009_ntsu_raobs_anim.gif\" width=\"2994\" height=\"1672\" \/><\/a><p class=\"wp-caption-text\">Plots of rawinsonde data from Pago Pago (NSTU) at 0000 UTC and 1200 UTC on 09 October [click to enlarge]<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Due to a lack of radar coverage over American Samoa, WSO Pago Pago requested a 1-minute Mesoscale Domain Sector over the islands to monitor convective development and the potential for flash flooding. GOES-18 (GOES-West)\u00a0Clean Infrared Window (10.3 \u00b5m) images (above) showed rain showers that developed in the general vicinity of the American Samoa island of [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":67287,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[76,114,16,30],"tags":[],"class_list":["post-67286","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-glm","category-goes-18","category-heavy-rain-flooding","category-lightning"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/67286","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\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=67286"}],"version-history":[{"count":19,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/67286\/revisions"}],"predecessor-version":[{"id":67308,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/67286\/revisions\/67308"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/67287"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=67286"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=67286"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=67286"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}