{"id":32608,"date":"2019-03-26T23:59:57","date_gmt":"2019-03-26T23:59:57","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=32608"},"modified":"2019-03-29T17:03:13","modified_gmt":"2019-03-29T17:03:13","slug":"strong-cyclone-near-antarctica","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/32608","title":{"rendered":"Strong cyclone near Antarctica"},"content":{"rendered":"

\"Composites<\/a>

Composites of geostationary and polar orbiter Infrared<\/strong> imagery [click to play animation]<\/p><\/div>Composites of Infrared imagery (above)<\/strong><\/em> and Water Vapor imagery (below)<\/strong><\/em> from the AMRC<\/strong><\/a> site showed an anomalously strong (MSLP<\/strong><\/a> | 925 hPa winds<\/strong><\/a> | source<\/strong><\/a>) cyclone that was moving southeastward across the South Pacific Ocean toward the coast of Antarctica on 26 March 2019. These composites blend images from both geostationary and polar orbiting satellites; the storm is located in the upper right quadrant of the images. On the Infrared imagery, brighter white shades over much of the middle of Antarctica indicated a very cold surface — in fact, surface air temperatures<\/a><\/strong> were as cold as -84\u00baF over the interior of the continent at 23 UTC.<\/p>\n

\"Composites<\/a>

Composites of geostationary and polar orbiter Water Vapor<\/strong> imagery [click to play animation]<\/p><\/div>The storm was evident along the southern limb of GOES-16 Full Disk scans, as seen on Mid-level Water Vapor (6.9 \u00b5m<\/strong><\/a>) and “Red” Visible (0.64 \u00b5m<\/strong><\/a>) images (below)<\/strong><\/em>. The location of AMRC AWS<\/strong><\/a> station 8930 (Thurston Island)<\/strong><\/a> near the coast of Ellsworth Land<\/strong><\/a> in West Antarctica is indicated in red.<\/p>\n

\"GOES-16<\/a>

GOES-16 Mid-level Water Vapor (6.9 \u00b5m)<\/em> images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>This storm was also evident at the bottom center of a GOES-17 + GOES-16 composite of north-to-south True Color Red-Green-Blue (RGB) swaths of 15-minute illumination at local solar noon — beginning at 12 UTC in the east, and ending at 03 UTC in the west — combined and displayed in a Mollweide projection (below<\/strong>; courtesy of Rick Kohrs, SSEC)<\/em>.<\/p>\n

\"GOES-17<\/a>

GOES-17 + GOES-16 True Color RGB image [click to enlarge]<\/p><\/div>A time series of surface observation data from AWS station 8930 on Thurston Island (below)<\/strong><\/em> showed that southeasterly winds peaked at 113 knots (58 m\/s) late in the day on 26 March as the strong low pressure system approached. According to AMRC staff, this particular AWS is located on a nunatak near Parker Peak in the Walker Mountains (map<\/strong><\/a>) — such an exposure is prone to periods of strong winds, requiring a recent retrofitting of special instrumentation designed to withstand and measure higher wind speeds.<\/p>\n

\"Tiime<\/a>

Time series of surface observation data from AWS station 8930 Thurston Island [click to enlarge]<\/p><\/div>A closer look with GOES-16 Visible and Low-level Water Vapor (7.3 \u00b5m<\/strong><\/a>) images (below)<\/strong><\/em> revealed small wave perturbations in the cloud field and the eventual formation of a banner cloud as Peter I Island<\/strong><\/a> was acting as an obstacle to the strong boundary layer winds south of the storm center.<\/p>\n

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m. left)<\/em> and Low-level Water Vapor (7.3 \u00b5m, right)<\/em> images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>A timely overpass of the Landsat-8 satellite provided a 30-meter resolution Landsat-8 False Color RGB image, viewed using RealEarth<\/strong><\/a> (below)<\/strong>,<\/em> of these orographically-induced cloud perturbations.<\/p>\n

\"Landsat-8<\/a>

Landsat-8 False Color RGB image [click to enlarge]<\/p><\/div>The orographic wave clouds downwind of Peter I Island could also be seen on 375-meter resolution Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 \u00b5m) images at 19 UTC and 21 UTC (below)<\/strong><\/em>.<\/p>\n

\"Suomi<\/a>

Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 \u00b5m)<\/em> images at 19 UTC and 21 UTC [click to enlarge]<\/p><\/div>

<\/p>\n
\n

#GOESWest<\/a> is watching a hurricane-force low that’s headed toward the Antarctic Peninsula. This loop uses what’s known as Air Mass RGB Imagery, which helps distinguish polar from tropical air masses. More imagery: https:\/\/t.co\/3SWkPqjxr9<\/a> pic.twitter.com\/nUOKrYtfm1<\/a><\/p>\n

\u2014 NOAA Satellites (@NOAASatellites) March 26, 2019<\/a><\/p><\/blockquote>\n