{"id":332,"date":"2007-01-04T23:23:21","date_gmt":"2007-01-04T23:23:21","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/2007\/01\/04\/foehn-gap-and-mountain-waves-in-colorado\/"},"modified":"2007-01-06T00:10:37","modified_gmt":"2007-01-06T00:10:37","slug":"foehn-gap-and-mountain-waves-in-colorado","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/332","title":{"rendered":"&#8220;Foehn gap&#8221; and mountain waves in Colorado"},"content":{"rendered":"<p><a target=\"_blank\" title=\"AWIPS MODIS water vapor channel image\" href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2006\/12\/070104_modis_wv_foehn.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"480\" height=\"461\" align=\"middle\" alt=\"AWIPS MODIS water vapor channel image\" title=\"AWIPS MODIS water vapor channel image\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2006\/12\/070104_modis_wv_foehn.jpg\" \/><\/a><\/p>\n<p>AWIPS  MODIS  water vapor channel imagery <em><strong>(above)<\/strong><\/em> shows a well-defined (but cloud-free) variant of a <strong><a target=\"_blank\" title=\"Foehn gap\" href=\"http:\/\/amsglossary.allenpress.com\/glossary\/search?p=1&#038;query=foehn+gap&#038;submit=Search\">&#8220;Foehn gap&#8221;<\/a><\/strong> over central Colorado on 04 January 2007. This  Foehn gap was oriented roughly north-south, just to the lee of the highest terrain of the Front Range of the Rocky Mountains <em><strong>(below)<\/strong><\/em>, and formed as  <a title=\"MODIS water vapor image + NAM 500 hPa winds\" target=\"_blank\" href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2007\/01\/070104_modis_wv_nam500winds.jpg\"><strong>60-70 knot winds at 500 hPa<\/strong><\/a> were flowing from west to east over that region (winds at Boulder CO KBJC  were westerly at 21 gusting to 37 mph around  the time of the MODIS image). A <a target=\"_blank\" title=\"MODIS\/GOES water vapor imagery\" href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2007\/01\/070104_modis_goes_wv_compare.html\"><strong>comparison of MODIS and GOES water vapor imagery<\/strong><\/a>  reveals that, due to <a title=\"parallax\" target=\"_blank\" href=\"http:\/\/apollo.lsc.vsc.edu\/classes\/remote\/graphics\/satellite_images\/parallax_cloud_schem.gif\"><strong>parallax<\/strong><\/a> error with the GOES-12 image, this Foehn gap incorrectly appears to the <strong>west<\/strong> of the highest terrain.\u00c2\u00a0 Also evident on the 1-km resolution MODIS water vapor image is a series of mountain waves further downwind of the Foehn gap (these mountain waves were not apparent on the 4-km resolution GOES-12 water vapor imagery). There was only one isolated pilot report of turbulence in the area around the time of the MODIS water vapor image, but <a title=\"KDEN air traffic plot\" target=\"_blank\" href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2007\/01\/kden.jpg\"><strong>air traffic is generally at a minimum<\/strong><\/a> during that time of day.<\/p>\n<p><a target=\"_blank\" title=\"AWIPS topography image\" href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2006\/12\/070104_topo_foehn.jpg\"><img decoding=\"async\" align=\"middle\" alt=\"AWIPS topography image\" title=\"AWIPS topography image\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2006\/12\/070104_topo_foehn.jpg\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>AWIPS MODIS water vapor channel imagery (above) shows a well-defined (but cloud-free) variant of a &#8220;Foehn gap&#8221; over central Colorado on 04 January 2007. This Foehn gap was oriented roughly north-south, just to the lee of the highest terrain of the Front Range of the Rocky Mountains (below), and formed as 60-70 knot winds at [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[21,19,12],"tags":[],"class_list":["post-332","post","type-post","status-publish","format-standard","hentry","category-aviation","category-goes-12","category-modis"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/332","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=332"}],"version-history":[{"count":0,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/332\/revisions"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}