{"id":23008,"date":"2017-01-19T20:59:30","date_gmt":"2017-01-19T20:59:30","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=23008"},"modified":"2017-01-21T02:38:22","modified_gmt":"2017-01-21T02:38:22","slug":"cold-temperatures-in-alaska-2","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/23008","title":{"rendered":"Cold temperatures in Alaska"},"content":{"rendered":"<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_1916utc_noaa18_avhrr_infrared_surface_air_temperatures_AK_large_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_1916utc_noaa18_avhrr_infrared_surface_air_temperatures_AK_large_anim.gif\" alt=\"NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image, with surface air temperatures and corresponding station identifications [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image, with surface air temperatures and corresponding station identifications [click to enlarge]<\/p><\/div>A NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image<em><strong> (above)<\/strong><\/em> showed the signature of cold air<em> (violet colors)<\/em> settling into river valleys and other low-elevation terrain areas across the cloud-free interior of Alaska at 1916 UTC (10:16 am local time) on 18 January 2017. Note that there was a layer of clouds<em> (warmer<\/em> <em>cyan colors)<\/em> over much of the North Slope of Alaska; these clouds were acting to limit strong surface radiational cooling, with resulting surface air temperatures only as cold as the -20s F. This AVHRR image was about 1 hour before the low temperature at Fairbanks International Airport (PAFA) dropped to -51\u00baF (-46\u00baC) &#8212; the first low of -50\u00baF or colder at that location since 31 December 1999 (-53\u00baF). While these were certainly cold temperatures, in general most were several degrees warmer than the daily record lows for 18 January:<\/p>\n<p><center><\/p>\n<blockquote class=\"twitter-tweet\" data-lang=\"en\">\n<p dir=\"ltr\" lang=\"en\">It&#8217;s cold over parts of Alaska, but it&#8217;s not approaching record low levels. Many of these records were set in 1947. <a href=\"https:\/\/twitter.com\/hashtag\/akwx?src=hash\">#akwx<\/a> <a href=\"https:\/\/twitter.com\/Climatologist49\">@Climatologist49<\/a> <a href=\"https:\/\/t.co\/ssWq0ZhV09\">pic.twitter.com\/ssWq0ZhV09<\/a><\/p>\n<p>\u2014 Rick Thoman (@AlaskaWx) <a href=\"https:\/\/twitter.com\/AlaskaWx\/status\/821938371693940741\">January 19, 2017<\/a><\/p><\/blockquote>\n<p><script async src=\"\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script><\/p>\n<p><\/center><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_1916utc_noaa18_avhrr_infrared_surface_air_temperatures_AK_PABT_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_1916utc_noaa18_avhrr_infrared_surface_air_temperatures_AK_PABT_anim.gif\" alt=\"NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image centered on Bettles (PABT), with surface air temperatures and corresponding station identifications [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image centered on Bettles (PABT), with surface air temperatures and corresponding station identifications [click to enlarge]<\/p><\/div>Closer views centered on Bettles <em><strong>(above)<\/strong><\/em> and on Tanana <em><strong>(below)<\/strong><\/em> further highlighted the influence of terrain on the pattern of surface infrared brightness temperatures.<\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_1916utc_noaa18_avhrr_infrared_surface_air_temperatures_AK_PATA_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_1916utc_noaa18_avhrr_infrared_surface_air_temperatures_AK_PATA_anim.gif\" alt=\"NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image centered on Tanana (PATA), with surface air temperatures and corresponding station identifications [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image centered on Tanana (PATA), with surface air temperatures and corresponding station identifications [click to enlarge]<\/p><\/div>A comparison of re-mapped 1-km resolution NOAA-18 and &#8220;4-km&#8221; resolution GOES-15 <em>(GOES-West)<\/em> Infrared Window imagery <em><strong>(below)<\/strong><\/em> demonstrated the spatial resolution advantage of &#8220;Low Earth Orbit&#8221; (Polar-orbiting) satellites over Geostationary satellites, especially for high-latitude regions such as Alaska. As <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/goes_ir_pixel_size_vs_zenith_angle.jpeg\"><strong>this<\/strong><strong> plot<\/strong><\/a> shows, the true spatial resolution of a &#8220;4-km&#8221; GOES-15 Infrared image pixel over the interior of Alaska &#8212; where that satellite&#8217;s viewing angle or &#8220;zenith angle&#8221; from the Equator is about 74 degrees &#8212; is actually closer to 16 km. For the &#8220;2-km&#8221; Infrared imagery that will be provided by the <a href=\"http:\/\/www.goes-r.gov\/\"><strong>GOES-R<\/strong><\/a> series <a href=\"http:\/\/www.goes-r.gov\/spacesegment\/abi.html\"><strong>ABI<\/strong><\/a> instrument, the spatial resolution over the interior of Alaska will be closer to 8 km.<\/p>\n<div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_0915utc_noaa18_goes15_infrared_Alaska_cold_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118_0915utc_noaa18_goes15_infrared_Alaska_cold_anim.gif\" alt=\"NOAA-18 vs GOES-15 Infrared Window images [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-18 vs GOES-15 Infrared Window images [click to enlarge]<\/p><\/div>\n<p style=\"text-align: center;\"><strong>=================================================================<\/strong><\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170119_1518utc_noaa19_avhrr_infrared_surface_air_temperatures_AK_LARGE_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170119_1518utc_noaa19_avhrr_infrared_surface_air_temperatures_AK_LARGE_anim.gif\" alt=\"NOAA-19 AVHRR Infrared Window (10.8 \u00b5m) image, with surface air temperatures and corresponding station identifications [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-19 AVHRR Infrared Window (10.8 \u00b5m) image, with surface air temperatures and corresponding station identifications [click to enlarge]<\/p><\/div>The cold continued across much of Alaska on 19 January, as seen on a NOAA-19 AVHRR Infrared Window (10.8 \u00b5m) image at 1519 UTC or 4:19 am local time<em><strong> (above)<\/strong><\/em>. However with a lack of cloud cover over the central portion of the North Slope, surface air temperatures were much colder (in the -40s F) compared to the -20s F that were seen there on the previous day.<\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170119_1518utc_noaa19_avhrr_infrared_surface_air_temperatures_AK_PABT_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170119_1518utc_noaa19_avhrr_infrared_surface_air_temperatures_AK_PABT_anim.gif\" alt=\"NOAA-19 AVHRR Infrared Window (10.8 \u00b5m) image centered on Bettles (PABT), with surface air temperatures and corresponding station identifications [click to enlarge\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-19 AVHRR Infrared Window (10.8 \u00b5m) image centered on Bettles (PABT), with surface air temperatures and corresponding station identifications [click to enlarge]<\/p><\/div>As was shown on the previous day, closer views centered on Bettles<em><strong> (above)<\/strong><\/em> and on Tanana <em><strong>(below)<\/strong><\/em> further highlighted the influence of terrain on the pattern of surface infrared brightness temperatures. On this day a layer of clouds <em>(highlighted by<\/em> <em>the warmer cyan colors)<\/em> covered the far eastern portion of the Tanana image below &#8212; note that surface temperatures in the Fairbanks area beneath these clouds were only as cold as the -30s F. Farther to the west, which remained cloud-free, the minimum temperature at Tanana was -59\u00baF.<\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170119_1518utc_noaa19_avhrr_infrared_surface_air_temperatures_AK_PATA_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170119_1518utc_noaa19_avhrr_infrared_surface_air_temperatures_AK_PATA_anim.gif\" alt=\"NOAA-19 AVHRR Infrared Window (10.8 \u00b5m) images centered on Tanana (PATA), with surface air temperatures and corresponding station identifications [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-19 AVHRR Infrared Window (10.8 \u00b5m) images centered on Tanana (PATA), with surface air temperatures and corresponding station identifications [click to enlarge]<\/p><\/div>Time series plots of surface weather conditions at Fairbanks, Tanana and Bettles during the 18-19 January period are shown below. Note that the surface visibility was periodically restricted 1 statute mile or less, due to ice fog, at all 3 locations.<\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118-19_PAFA_SFCMG.GIF\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118-19_PAFA_SFCMG.GIF\" alt=\"Surface weather conditions at Fairbanks [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">Surface weather conditions at Fairbanks [click to enlarge]<\/p><\/div><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118-19_PATA_SFCMG.GIF\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118-19_PATA_SFCMG.GIF\" alt=\"Surface weather conditions at Tanana [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">Surface weather conditions at Tanana [click to enlarge]<\/p><\/div><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118-19_PABT_SFCMG.GIF\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/01\/170118-19_PABT_SFCMG.GIF\" alt=\"Surface weather conditions at Bettles [click to enlarge]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">Surface weather conditions at Bettles [click to enlarge]<\/p><\/div><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A NOAA-18 AVHRR Infrared Window (10.8 \u00b5m) image (above) showed the signature of cold air (violet colors) settling into river valleys and other low-elevation terrain areas across the cloud-free interior of Alaska at 1916 UTC (10:16 am local time) on 18 January 2017. Note that there was a layer of clouds (warmer cyan colors) over [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":23013,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37,22,34,26,5],"tags":[],"class_list":["post-23008","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-arctic","category-avhrr","category-goes-r","category-poes","category-winter-weather"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/23008","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=23008"}],"version-history":[{"count":12,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/23008\/revisions"}],"predecessor-version":[{"id":23021,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/23008\/revisions\/23021"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/23013"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=23008"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=23008"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=23008"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}