{"id":1995,"date":"2009-02-12T20:14:41","date_gmt":"2009-02-12T20:14:41","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=1995"},"modified":"2010-05-20T20:32:27","modified_gmt":"2010-05-20T20:32:27","slug":"hole-punch-clouds-over-texas","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/1995","title":{"rendered":"Aircraft “hole punch” and “distrail” cloud features over Texas"},"content":{"rendered":"
\"GOES-13<\/a>

GOES-13 visible and 3.9 \u00c2\u00b5m shortwave IR images<\/p><\/div>\n

We received the following in an email from the\u00c2\u00a0 National Weather Service forecast office at Fort Worth, Texas<\/strong><\/a>:<\/p>\n

Some of our forecasters noted an interesting feature on visible satellite imagery on Thursday, Feb 12, 2009. I would like to get an expert opinion on what was causing the observed features. There was a layer of ~ 15kft altocumulus along with some scattered-broken areas of cirrus.<\/p><\/blockquote>\n

Excellent question…and we appreciate the heads-up on this event. An animation of GOES-13 visible and 3.9 \u00c2\u00b5m “shortwave IR” images (above; QuickTime animation<\/a>)<\/strong><\/em> showed the evolution of two “hole punch” cloud features that were drifting eastward across northern Texas on 12 February 2009<\/strong><\/a>. The first hole punch cloud feature moved just to the north of Dallas\/Fort Worth (DFW) around 14:45 UTC, while the second feature moved just south of DFW about an hour later (around 15:45 UTC)<\/em>. In addition, an elongated aircraft dissipation trail (or “distrail”)<\/em> could be seen to the west of the first hole punch feature (oriented west-to-east on the 14:15 and 14:32 UTC visible images),<\/em> with a second distrail forming about an hour later (oriented northwest-to-southeast on the 15:15 and 15:32 UTC visible images)<\/em>.<\/p>\n

These aircraft “hole punch” and “distrail” cloud features form when an aircraft ascends or descends through a layer of supercooled water droplet cloud, with the engine exhaust causing the droplets to glaciate — the resulting ice crystals then fall toward the ground, creating a visible hole or trail in the cloud layer. Note that there is a subtle “brighter white” signal evident on the GOES-13 3.9 \u00c2\u00b5m shortwave IR images in the area of the hole punch features — this colder<\/em> signal confirms the idea that the aircraft engine exhaust was causing the supercooled water droplets to glaciate.<\/p>\n

A NOAA-17 false color Red\/Green\/Blue (RGB) composite image using channels 01\/02\/04 (below)<\/strong><\/em> showed the second hole punch cloud as it was moving to the south of DFW at 15:58 UTC. Similar aircraft hole punch and distrail cloud features have been seen in the past: for example, over the southcentral US<\/strong><\/a> and also over Wisconsin<\/strong><\/a>.<\/p>\n

\"NOAA-17<\/a>

NOAA-17 false color RGB image<\/p><\/div>\n

\"GOES-13<\/a>

GOES-13 visible and 10.7 \u00c2\u00b5m IR images<\/p><\/div>\n

GOES-13 10.7 \u00c2\u00b5m IR data (above)<\/strong><\/em> showed cloud top brightness temperatures in the -20 to -30\u00c2\u00ba C range (cyan to dark blue color enhancement)<\/em> over much of the cloud patch where the initial hole punch feature was seen. Rawinsonde data from both Midland and Fort Worth in Texas (below)<\/strong><\/em> displayed a moist layer centered around 425 hPa that corresponded to those temperatures — this indicates that the hole punch and distrail features were at a fairly high altitude (around 20,000 feet or so)<\/em>. Dallas\/Fort Worth METAR reports<\/strong><\/a> listed cloud bases at 15,000 feet during the period.<\/p>\n

\"Midland<\/a>

Midland TX and Fort Worth TX rawinsonde data<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

We received the following in an email from the\u00c2\u00a0 National Weather Service forecast office at Fort Worth, Texas: Some of our forecasters noted an interesting feature on visible satellite imagery on Thursday, Feb 12, 2009. I would like to get an expert opinion on what was causing the observed features. There was a layer of […]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[22,21,11,45],"tags":[],"class_list":["post-1995","post","type-post","status-publish","format-standard","hentry","category-avhrr","category-aviation","category-goes-13","category-redgreenblue-rgb-images"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/1995","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=1995"}],"version-history":[{"count":21,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/1995\/revisions"}],"predecessor-version":[{"id":5737,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/1995\/revisions\/5737"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=1995"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=1995"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=1995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}