{"id":38286,"date":"2020-09-15T14:20:45","date_gmt":"2020-09-15T14:20:45","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=38286"},"modified":"2020-09-17T15:31:12","modified_gmt":"2020-09-17T15:31:12","slug":"hurricane-sally","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/38286","title":{"rendered":"Hurricane Sally"},"content":{"rendered":"
\"\"<\/a>

GOES-16 Clean Window Infrared (10.3 \u00b5m) Imagery over Sally, 1113 \u2013 1312 UTC 14 September 2020. GLM Flash Density (1-minute observations) are also plotted (Click to animate)<\/p><\/div>\n

Hurricane Sally was moving very slowly in the north-central Gulf of Mexico at sunrise on 15 September 2020. A GOES-16 Mesoscale sector placed over the storm allowed for 1-minute imagery, and the Clean Infrared window animation, above, for the 2 hours centered on Sunrise, show a compact storm south of Mobile Bay and east of the Mississippi River delta. Geostationary Lightning Mapper (GLM) data overlain on the ABI imagery show active lightning in a feeder band to the east of the storm, but little lightning in the storm center.<\/p>\n

\"\"<\/a>

GOES-16 Upper Level (6,19 \u00b5m) and Lower Level (7.34 \u00b5m) water vapor imagery, 1311 UTC on 15 September 2020 (Click to enlarge)<\/p><\/div>\n

Intensification of Sally has been affected by dry air near the storm (as mentioned in this discussion<\/a>, for example). The toggle above of GOES-16 infrared upper-level<\/a> and lower-level<\/a> water vapor imagery (observed at 6.19 \u00b5m<\/a> and 7.34 \u00b5m<\/a>, respectively), shows warm brightness temperatures to the west of the storm.\u00a0 These warm temperatures (yellow in the 7.34 \u00b5m image, blue in the 6.19 \u00b5m image) are regions of mid-level dryness:\u00a0 the top of the moist layer is farther down in the atmosphere in these regions.<\/p>\n

Morphed microwave imagery, below, (from this site<\/a>), shows the effect of dry air on the storm structure.\u00a0 The eyewall almost forms — but it is eroded along its southern edge by dry air.<\/p>\n

\"\"<\/a>

Morphed Microwave imagery following the center of Hurricane Sally for the 24 hours ending 1300 UTC on 15 September (Click to enlarge)<\/p><\/div>\n

The 1200 UTC MIMIC Total Precipitable Water (TPW) field, below (from this site<\/a>) suggests that dryer Continental air might be affecting the storm.\u00a0 Advected Layer Precipitation Water from 1200 UTC (here<\/a>, from this site<\/a>), tells a similar tale.<\/p>\n

\"\"<\/a>

Microwave-derived Total Precipitable Water, 1200 UTC on 15 September 2020 (Click to enlarge)<\/p><\/div>\n

Visible imagery, below, at sunrise shows a thick clouds over the center of the storm.\u00a0 The appearance is similar to yesterday’s. A visible animation (from 1130-1313 UTC) without the GLM overlay is available here<\/a>.<\/p>\n

\"<\/a>

GOES-16 visible imagery (0.64 \u00b5m) with 1-minute GLM Flash Density overlain, 1145 – 1311 UTC 15 September (Click to animate)<\/p><\/div>\n

===== 21 UTC Update =====<\/strong><\/p>\n

\"GOES-16<\/a>

GOES-16 \u201cRed\u201d Visible (0.64 \u00b5m)<\/em> and \u201cClean\u201d Infrared Window (10.35 \u00b5m)<\/em> images (with and without an overlay of GLM Flash Extent Density) [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\u00a0\u201cClean\u201d Infrared Window (10.35 \u00b5m<\/strong><\/a>) images \u2014 with and without an overlay of\u00a0GLM<\/strong><\/a>\u00a0Flash Extent Density<\/strong><\/a>\u00a0(above)<\/strong><\/em> showed a series of convective bursts that rotated around the center of Category 1 Hurricane Sally during the daylight hours. Minimal GLM-detected lightning activity was seen with these convective bursts.<\/p>\n

A toggle between Suomi NPP VIIRS Visible (0.64 \u00b5m) and Infrared Window (11.45 \u00b5m) images (below)<\/strong> <\/em>showed Sally at 1806 UTC. The coldest cloud-top infrared brightness temperature northwest of the eye was -86\u00baC.<\/p>\n

\"Suomi<\/a>

Suomi NPP VIIRS Visible (0.64 \u00b5m)<\/em> and Infrared Window (11.45 \u00b5m)<\/em> images at 1806 UTC [click to enlarge]<\/p><\/div>For the latest information on Hurricane Sally, refer to the pages of the National Hurricane Center<\/a>.\u00a0 (Direct link to Sally<\/a>)<\/p>\n","protected":false},"excerpt":{"rendered":"

Hurricane Sally was moving very slowly in the north-central Gulf of Mexico at sunrise on 15 September 2020. A GOES-16 Mesoscale sector placed over the storm allowed for 1-minute imagery, and the Clean Infrared window animation, above, for the 2 hours centered on Sunrise, show a compact storm south of Mobile Bay and east of […]<\/p>\n","protected":false},"author":19,"featured_media":38291,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[76,74,30,79,49,2,48],"tags":[],"class_list":["post-38286","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-glm","category-goes-16","category-lightning","category-microwave","category-suomi_npp","category-tropical-cyclones","category-viirs"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/38286","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=38286"}],"version-history":[{"count":21,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/38286\/revisions"}],"predecessor-version":[{"id":38331,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/38286\/revisions\/38331"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/38291"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=38286"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=38286"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=38286"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}