{"id":40932,"date":"2021-05-21T23:59:14","date_gmt":"2021-05-21T23:59:14","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=40932"},"modified":"2021-05-25T15:36:36","modified_gmt":"2021-05-25T15:36:36","slug":"tropical-invest-90l-becomes-subtropical-storm-ana-in-the-atlantic","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/40932","title":{"rendered":"Tropical Invest 90L becomes Subtropical Storm Ana in the Atlantic"},"content":{"rendered":"

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> and “Clean” Infrared Window (10.35 \u00b5m)<\/em> images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>1-minute\u00a0Mesoscale Domain Sector<\/strong><\/a>\u00a0GOES-16\u00a0(GOES-East)<\/em>\u00a0\u201cRed\u201d Visible (0.64 \u00b5m<\/strong><\/a>) and \u201cClean\u201d Infrared Window (10.35 \u00b5m<\/strong><\/a>) images\u00a0(above)<\/em><\/strong> displayed the exposed low-level circulation of Invest 90L, in the Atlantic Ocean (about 150 miles northeast of Bermuda, TXKF) on 21 May 2021.<\/p>\n

GOES-16 Visible images with plots of Visible Derived Motion Winds<\/strong><\/a> (below)<\/strong> <\/em>revealed a few wind speeds of 50 knots or greater (red wind barbs)<\/em> within its northwest quadrant — but since no organized and sustained deep convection remained in close proximity to the low-level circulation, Invest 90L was not yet considered to be a tropical cyclone.<\/p>\n

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> images, with plots of Visible GOES-16 Derived Motion Winds [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>\n

===== 22 May Update =====<\/strong><\/p>\n

\"GOES-16<\/a>

GOES-16 “Clean” Infrared Window (10.35 \u00b5m)<\/em> images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>During the overnight hours, convection organized and intensified around the low-level circulation of Invest 90L — and as of 0900 UTC it was classified as Subtropical Storm Ana<\/strong><\/a>. GOES-16 Infrared images of Ana are shown above.<\/p>\n

A closer view of GOES-16 Visible images (below)<\/strong> <\/em>indicated that the center of Ana eventually stopped moving southwestward toward Bermuda, performed a counterclockwise loop, then began moving to the northeast.<\/p>\n

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>GOES-16 Visible images with plots of Derived Motion Winds (below)<\/strong><\/em> indicated that the maximum near-surface wind speeds were 39 knots.<\/p>\n

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> images, with plots of Visible GOES-16 Derived Motion Winds [click to play animation |\u00a0MP4<\/a><\/b>]<\/p><\/div>

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> image at 1219 UTC, with plots of Metop-A ASCAT winds [click to enlarge]<\/p><\/div>An overpass of Metop-A at 1219 UTC provided ASCAT surface scatterometer winds centered on Ana (above)<\/strong>,<\/em> with a maximum speed value of 31 knots just northwest of the storm center. In general, Visible GOES-16 Derived Motion Wind speed values were around 5 knots faster than nearby ASCAT winds (below)<\/strong><\/em> — since the former are computed by tracking cloud targets that are above the surface, where winds speeds are greater (due to a lack of surface friction).<\/p>\n

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> image at 1219 UTC, with plots of Visible GOES-16 Derived Motion Winds and Metop-A ASCAT winds [click to enlarge]<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

1-minute\u00a0Mesoscale Domain Sector\u00a0GOES-16\u00a0(GOES-East)\u00a0\u201cRed\u201d Visible (0.64 \u00b5m) and \u201cClean\u201d Infrared Window (10.35 \u00b5m) images\u00a0(above) displayed the exposed low-level circulation of Invest 90L, in the Atlantic Ocean (about 150 miles northeast of Bermuda, TXKF) on 21 May 2021. GOES-16 Visible images with plots of Visible Derived Motion Winds (below) revealed a few wind speeds of 50 knots […]<\/p>\n","protected":false},"author":18,"featured_media":40937,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[74,58,25,2],"tags":[],"class_list":["post-40932","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-goes-16","category-metop","category-satellite-winds","category-tropical-cyclones"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/40932","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=40932"}],"version-history":[{"count":7,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/40932\/revisions"}],"predecessor-version":[{"id":40941,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/40932\/revisions\/40941"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/40937"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=40932"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=40932"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=40932"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}