{"id":27626,"date":"2018-04-03T17:58:09","date_gmt":"2018-04-03T17:58:09","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=27626"},"modified":"2018-04-03T17:58:09","modified_gmt":"2018-04-03T17:58:09","slug":"surface-cold-front-over-the-high-plains-of-texas","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/27626","title":{"rendered":"Surface Cold Front over the High Plains of Texas"},"content":{"rendered":"
\"\"<\/a>

Hourly GOES-16 ABI Low-Level Water Vapor Infrared (7.34 \u00b5m) Imagery, and hourly observations, 0700-1600 UTC on 3 April 2018 (Click to enlarge)<\/p><\/div>\n

A cold front<\/a> moving southward along the western Great Plains showed a distinct signature in GOES-16 Water Vapor Imagery.\u00a0 The hourly animation above, with surface observations, shows the front in the Low-Level Water Vapor passing over stations where winds shift from westerly and southwesterly to strong northerly.\u00a0 The feature is far more trackable in GOES-16 ABI Imagery with a 5-minute cadence as is typical over CONUS, as shown below for both low-level water vapor infrared imagery (Band 10, 7.34\u00a0\u00b5m) and upper-level water vapor infrared imagery (Band 8, 6.19 \u00b5m). The infrared imagery allowed a precise determination of when the cold front would reach a location. (In fact, because a GOES-16 Mesoscale Sector was placed over west Texas, the time of arrival could be observed down to the minute, as shown in this animation<\/a> of the clean window (10.3 \u00b5m) infrared imagery from GOES-16).<\/p>\n

\"\"<\/a>

GOES-16 ABI Low-Level Water Vapor Infrared Imagery (7.34 \u00b5m), 0832-1637 UTC on 3 April 2018 (Click to animate)<\/p><\/div>\n

\"\"<\/a>

GOES-16 ABI Upper-Level Water Vapor Infrared Imagery (6.19 \u00b5m), 0832-1637 UTC on 3 April 2018 (Click to animate)<\/p><\/div>\n

Visible Imagery after sunrise (below) shows that some surface cloudiness was associated with this feature — but other parts were clear.<\/p>\n

\"\"<\/a>

GOES-16 ABI “Red” Visible Imagery (0.64 \u00b5m), 1252-1637 UTC on 3 April 2018 (Click to animate)<\/p><\/div>\n

It is not common for surface features to appear in the Upper-Level Water Vapor Imagery, even when the surface is near 900 mb, as over the High Plains of west Texas. Weighting Functions<\/a> show from which layers in the atmosphere energy detected by the satellite originates. The Weighting function from Amarillo TX at 1200 UTC on 3 April is shown below.\u00a0 The low-level water vapor weighting function — shown in magenta — shows contributions from the surface, but the upper-level water vapor weighting function — shown in green, shows contributions ending about 200 mb above the surface, at around 700 mb.\u00a0 A conclusion might be that the depth of the cold air quickly increases to around 200 mb behind the front.\u00a0 Thus is can appear in the Upper-Level water vapor imagery. \u00a0 The cold front passes Amarillo (here is a meteorogram<\/a>) shortly before 1200 UTC (and before the Radiosonde was launched).\u00a0 The radiosonde from Dodge City Kansas, however, at 1200 UTC<\/a>, shows a cold layer about 200 mb thick.\u00a0 (Here is the Amarillo Sounding<\/a> for the same time;\u00a0 it’s shown in the Weighting Function plot below as well).<\/p>\n

\"\"<\/a>

Clear-Sky Weighting Functions from Amarillo TX, 1200 UTC on 3 April 2018 (Click to enlarge)<\/p><\/div>\n

Interpretation of water vapor imagery is simplified if you use information from weighting functions to understand the three-dimensional aspect of the water vapor imagery.<\/p>\n","protected":false},"excerpt":{"rendered":"

A cold front moving southward along the western Great Plains showed a distinct signature in GOES-16 Water Vapor Imagery.\u00a0 The hourly animation above, with surface observations, shows the front in the Low-Level Water Vapor passing over stations where winds shift from westerly and southwesterly to strong northerly.\u00a0 The feature is far more trackable in GOES-16 […]<\/p>\n","protected":false},"author":19,"featured_media":27634,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[10,74],"tags":[],"class_list":["post-27626","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-general-interpretation","category-goes-16"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/27626","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=27626"}],"version-history":[{"count":6,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/27626\/revisions"}],"predecessor-version":[{"id":27645,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/27626\/revisions\/27645"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/27634"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=27626"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=27626"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=27626"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}