{"id":10512,"date":"2012-06-06T21:54:00","date_gmt":"2012-06-06T21:54:00","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=10512"},"modified":"2012-06-08T21:09:42","modified_gmt":"2012-06-08T21:09:42","slug":"valley-fog-in-the-allegheny-plateau-region-of-the-northeastern-us","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/10512","title":{"rendered":"Valley fog in the Allegheny Plateau region of the northeastern US"},"content":{"rendered":"
\"GOES-13<\/a>

GOES-13 11-3.9 \u00c2\u00b5m legacy "fog\/stratus product" (click image to play animation)<\/p><\/div>\n

AWIPS images of the 4-km resolution GOES-13 11-3.9 \u00c2\u00b5m brightness temperature difference (BTD) or “legacy fog\/stratus product” (above; click image to play animation)<\/strong><\/em> began to display a signal of increasing coverage of fog and\/or stratus across parts of the Allegheny Plateau region of New York and Pennsylvania during the pre-dawn hours of 06 June 2012<\/strong><\/a>. Strong nocturnal radiational cooling — Bradford, Pennsylvania (station identifier KBFD)<\/em>\u00c2\u00a0 dropped to an overnight low temperature of 37 F — was helping to promote the formation of valley fog.<\/p>\n

A more quantitative alternative to the legacy\u00c2\u00a0 BTD “fog\/stratus product” is a new GOES Instrument Flight Rules (IFR) Probability product, developed as part of ASPB\/CIMSS<\/strong><\/a> participation in the GOES-R Proving Ground<\/strong><\/a>. Note that the legacy fog\/stratus product cannot make the distinction between fog and elevated stratus features (such as those found northwest of Lake Ontario, and also in west central Pennsylvania)<\/em> — but the IFR Probability product does accurately make this discrimination. A trend of increasing areal coverage and magnitude of IFR Probability was noted (below; click image to play animation),<\/strong><\/em> especially along the New York\/Pennsylvania border region where locations across southern New York such as Wellville (station identifier KELZ<\/strong><\/a>),<\/em> Elmira (station identifier KELM<\/strong><\/a>),<\/em> and Binghamton (station identifier KBGM<\/strong><\/a>)<\/em> had surface visibilities drop to 1\/4 mile and cloud ceilings drop to 100-200 feet above ground level.<\/p>\n

\"GOES-13<\/a>

GOES-13 IFR Probability product (click image to play animation)<\/p><\/div>\n

A comparison of 4-km resolution GOES-13 and the corresponding 1-km resolution POES AVHRR “fog\/stratus product” images at 07:40 UTC or 3:40 AM local time (below)<\/strong><\/em> demonstrated the importance of improved spatial resolution for the detection of small-scale features such as valley fog.<\/p>\n

\"POES<\/a>

POES AVHRR vs GOES-13 legacy BTD "fog\/stratus product" images<\/p><\/div>\n

Similarly, a comparison of 4-km resolution GOES-13 and the corresponding 375-meter resolution (projected onto a 1-km resolution AWIPS grid)<\/em> “fog\/stratus product” images just after 08:00 UTC or 4:00 AM local time (below)<\/strong><\/em> showed much greater detail associated with the narrow fingers of valley fog.<\/p>\n

\"Suomi<\/a>

Suomi NPP VIIRS vs GOES-13 legacy BTD "fog\/stratus product" images<\/p><\/div>\n

In addition, comparing the Suomi NPP VIIRS “fog\/stratus product” with the VIIRS 0.7 \u00c2\u00b5m Day\/Night Band (DNB) image at that same time (below)<\/strong><\/em> showed that the DNB channel could detect a few of the narrow fingers of valley fog in far southwestern Pennsylvania and far northern Maryland that were obscured by high cirrus clouds (black features)<\/em> on the “fog\/stratus product” image. During periods of strong illumination from moonlight (as was the case on 06 June),<\/em> the DNB can serve as a form of night-time visible channel imagery.<\/p>\n

\"Suomi<\/a>

Suomi NPP VIIRS legacy BTD "fog\/stratus product" vs VIIRS Day\/Night Band image<\/p><\/div>\n

After sunrise, McIDAS images of GOES-13 0.63 \u00c2\u00b5m visible channel data (below; click image to play animation)<\/strong><\/em> showed the widespread valley fog features across parts of New York and Pennsylvania, which subsequently dissipated with daytime heating and boundary layer mixing.<\/p>\n

\"GOES-13<\/a>

GOES-13 0.63 \u00c2\u00b5m visible channel images (click image to play animation)<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

AWIPS images of the 4-km resolution GOES-13 11-3.9 \u00c2\u00b5m brightness temperature difference (BTD) or “legacy fog\/stratus product” (above; click image to play animation) began to display a signal of increasing coverage of fog and\/or stratus across parts of the Allegheny Plateau region of New York and Pennsylvania during the pre-dawn hours of 06 June 2012. […]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[22,13,11,34,26,49,48],"tags":[],"class_list":["post-10512","post","type-post","status-publish","format-standard","hentry","category-avhrr","category-fog-detection","category-goes-13","category-goes-r","category-poes","category-suomi_npp","category-viirs"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/10512","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=10512"}],"version-history":[{"count":12,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/10512\/revisions"}],"predecessor-version":[{"id":10551,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/10512\/revisions\/10551"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=10512"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=10512"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=10512"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}