{"id":17418,"date":"2014-12-25T23:59:18","date_gmt":"2014-12-25T23:59:18","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=17418"},"modified":"2014-12-28T05:47:50","modified_gmt":"2014-12-28T05:47:50","slug":"white-christmas-in-hawaii","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/17418","title":{"rendered":"White Christmas in Hawai’i"},"content":{"rendered":"
\"GOES-15<\/a>

GOES-15 0.63 \u00b5m visible channel images (click to play animation)<\/p><\/div>\n

According to the National Operational Hydrologic Remote Sensing Center, only 35.5% of the Lower 48 states<\/strong><\/a> had snow cover on 25 December 2014. However, a deep cutoff low over the Hawaiian Islands had brought unusually cold air aloft (the 500 hPa temperature on the Lihue rawinsonde report<\/a><\/strong> was as cold as -18\u00ba C, which is extremely cold by Hawaiian standards<\/strong><\/a>) and strong winds, which prompted Blizzard Warnings to be issued for the high elevation summits of the Big Island of Hawai’i on 23-24 December. As the cutoff low departed and skies began to clear, GOES-15 (GOES-West)<\/em> 0.63 \u00b5m visible channel images (above; click image to play animation)<\/strong><\/em> revealed the bright white snow-covered summits of Mauna Kea and Mauna Loa on Christmas Day.<\/p>\n

A toggle between a Suomi NPP VIIRS 0.64 \u00b5m visible channel and a false-color Red\/Green\/Blue (RGB) “snow vs cloud discrimination” image at 23:22 UTC (below)<\/strong><\/em> confirmed that the bright white features seen in the GOES-15 visible images was indeed snow cover — snow (and fully-glaciated ice clouds) appear as darker shades of red on the RGB image. Cloud tops that are partially glaciated appear as lighter shades of pink.<\/p>\n

\"Suomi<\/a>

Suomi NPP VIIRS 0.64 \u00b5m visible channel and false-color “snow vs cloud discrimination” RGB images<\/p><\/div>\n

===== 26 December Update =====<\/strong><\/p>\n

Using the SSEC RealEarth<\/strong><\/a> web map server, the comparison below shows 375-meter resolution Suomi NPP VIIRS true-color RGB images of the Big Island of Hawai’i on 20 December (before the snowfall on the Mauna Kea and Mauna Loa summits)<\/em> and also on 25-26 December (after the snowfall<\/em>). On the 26 December image, you can see that the patches of snow had melted somewhat at the 2 summits; in addition, an increase in hazy volcanic fog (vog) can be seen drifting southeastward off the island; this vog was being generated by the ongoing eruption of the Kilauwea volcano in the Hawai’i Volcanoes National Park.<\/p>\n

\"Suomi<\/a>

Suomi NPP VIIRS true-color RGB images<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

According to the National Operational Hydrologic Remote Sensing Center, only 35.5% of the Lower 48 states had snow cover on 25 December 2014. However, a deep cutoff low over the Hawaiian Islands had brought unusually cold air aloft (the 500 hPa temperature on the Lihue rawinsonde report was as cold as -18\u00ba C, which is […]<\/p>\n","protected":false},"author":18,"featured_media":17420,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[43,53,45,49,48,5],"tags":[],"class_list":["post-17418","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-goes-15","category-real-earth","category-redgreenblue-rgb-images","category-suomi_npp","category-viirs","category-winter-weather"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/17418","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=17418"}],"version-history":[{"count":11,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/17418\/revisions"}],"predecessor-version":[{"id":17441,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/17418\/revisions\/17441"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/17420"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=17418"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=17418"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=17418"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}