Developing winter storm over Colorado

March 19th, 2020 |

GOES-16 Mid-level Water Vapor (6.9 um) images, with hourly plots of surface wind barbs and gusts (knots) [click to play animation | MP4]

GOES-16 Mid-level Water Vapor (6.9 um) images, with hourly plots of surface wind barbs and gusts (knots) [click to play animation | MP4]

As a winter storm began to organize over Colorado on 19 March 2020, GOES-16 (GOES-East) Mid-level Water Vapor (6.9 um) images (above) showed the developing  middle tropospheric cyclonic circulation across the Colorado/Kansas/Nebraska border area. Peak wind gusts included 60 mph in Colorado and Nebraska, and 62 mph in Kansas (WPC Storm Summary).

As a result of the strong winds, several areas of blowing dust were seen in GOES-16 “Red” Visible (0.64 um), Split Window Difference (10.3-12.3 um) and Dust Red-Green-Blue (RGB) images (below): (1) a well-defined plume that originated in southeastern Colorado and moved northeastward across western Kansas, (2) a smaller plume originating north/northwest of Lamar, Colorado which moved eastward toward the Colorado/Kansas border, (3) a small plume that originated over the burn scar from the 07 March “Beaver Fire” in the Oklahoma Panhandle, and (4) multiple narrow plumes of dust in the wake of a cold front that moved southeastward across the region late in the day (which reduced the surface visiblity to 2 miles in southwestern Kansas).

GOES-16

GOES-16 “Red” Visible (0.64 um), Split Window Difference (10.3-12.3 um) and Dust RGB images [click to play animation | MP4]

A NOAA-20 True Color RGB image as viewed using RealEarth (below) provided a more detailed view of the dust plume north of Lamar, Colorado as well as the longer plume which stretched from southeastern Colorado into western Kansas.

NOAA-20 True Color RGB image at 18:40 UTC [click to enlarge]

NOAA-20 True Color RGB image at 18:40 UTC [click to enlarge]

GOES-16 Visible images with plots of GLM Groups (below) revealed a few clusters of lightning associated with convective elements that were likely producing thundersnow across northeastern Colorado and near the Colorado/Nebraska border. Where warmer air was still present near the Colorado/Kansas border, a more longer-lived thunderstorm was producing rainfall at the surface.

GOES-16

GOES-16 “Red” Visible (0.64 um) images, with GLM Groups plotted in red and hourly surface weather type plotted in yellow [click to play animation | MP4]



===== 20 March Update =====

GOES-16 Day Cloud Phase Distinction RGB images [click to play animation | MP4]

GOES-16 Day Cloud Phase Distinction RGB images [click to play animation | MP4]

On the following day, GOES-16 Day Cloud Phase Distinction RGB images (above) showed the large swath of fresh snow cover (shades of green) produced by this storm as it moved northeastward across the Upper Midwest. Clouds persisted over much of eastern Colorado, masking the extent of the snow cover there.

===== 21 March Update =====

Landsat-8 False Color RGB image, with and without labels [click to enlarge]

Landsat-8 False Color RGB image at 1724 UTC, with and without labels [click to enlarge]

On 21 March, a decrease in cloudiness over eastern Colorado allowed much of the snow cover (shades of cyan) to be seen in a swath of 30-meter resolution Landsat-8 False Color imagery as viewed using RealEarth (above). The effects of terrain were evident, with a lack of snow cover seen in areas where downslope flow was prevalent during the winter storm.

Wildfire in the Oklahoma Panhandle

March 7th, 2020 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), Fire Power (bottom left) and Fire Temperature (bottom right) [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images along with 5-minute Fire Power and Fire Temperature products (which are components of the GOES Fire Detection and Characterization Algorithm (SHyMet | ATBD) showed the rapid northeastward run (as fast as 103 feet per minute) of the 13,000 acre “Beaver Fire” (also known as the “412 Fire”) in the Oklahoma Panhandle on 07 March 2020. An elevated thermal signature on Shortwave Infrared imagery first began to appear southwest of Beaver, OK around 1546 UTC  — and 3.9 µm infrared brightness temperatures eventually peaked around 139ºC. Maximum Fire Power and Fire Temperature values exceeded 3100 MW and 2900 K, respectively. Fire Warnings were issued, with residents of Beaver and Forgan being advised to evacuate as the fire rapidly approached. In Visible imagery, the dark signature of a long, narrow vegetation burn scar was evident — and pyrocumulus clouds were seen developing over the fire.


Extreme fire behavior was aided by anomalously-strong winds across the southern Plains. The peak wind gust at Beaver, Oklahoma was 46 mph; south of the fire, surface winds were gusting to 43 mph at Perryton (in far the northern Texas Panhandle), and west of the fire winds gusted to 42 mph at Guymon (in the Oklahoma Panhandle). A large-scale animation of 1-minute GOES-16 Visible images from the AOS site (below) indicated that the smoke plume was transported northeastward across Kansas and eventually moved over south-central Nebraska. Smoke reduced the surface visibility to 6 miles at Dodge City as it moved across southwestern Kansas.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

Shortwave Infrared images from MODIS (3.7 µm) and VIIRS (3.74 µm) (below) displayed three snapshots of the 10-15 mile long thermal anomaly (elongated cluster of black pixels) associated with the wildfire.

Shortwave Infrared images from MODIS (3.7 µm) and VIIRS (3.74 µm) [click to enlarge]

Shortwave Infrared images from MODIS (3.7 µm) and VIIRS (3.74 µm) [click to enlarge]

===== 08 March Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 0857 UTC [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 0857 UTC [click to enlarge]

During the subsequent overnight hours, a comparison of NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 0857 UTC or 3:57 am local time (above) revealed the dark southwest-to-northeast oriented burn scar, with isolated small fires still burning along the northwestern periphery of the burn scar. Note: the NOAA-20 images are incorrectly labelled as Suomi NPP.

===== 09 March Update =====

GOES-16 Land Surface Temperature product and

GOES-16 Land Surface Temperature product and “Red” Visible (0.64 µm) image [click to enlarge]

A toggle between a GOES-16 Land Surface Temperature product and the corresponding Visible image (above) showed the fire burn scar at 2101 UTC on 09 March. Land Surface Temperature values were 10ºF warmer within the burn scar (middle 80s F, shades of yellow to orange) compared to areas immediately adjacent to the burn feature.

Blowing dust across the Canary Islands and Atlantic Ocean

February 23rd, 2020 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with plots of hourly surface reports [click to play animation | MP4]

GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the onset of a 2-day event of dense plumes of blowing sand/dust (known locally as a Calima) — with Western Sahara and Morocco being the primary source regions — which moved across the Canary Islands and the adjacent East Atlantic Ocean on 22 February 2020. Along the coast of Morocco, surface visibility was reduced to 1/8 mile at Tan-Tan (GMAT); over the Canary Islands, visibility dropped to 1/4 mile at Gran Canaria (GCLP).

GOES-16 Dust Red-Green-Blue (RGB) images spanning the period 0800 UTC on 22 February to 2100 UTC on 23 February (below) provided a continuous day/night visualization of the first dust plume (shades of pink/magenta). During the day on 23 February, a second dust plume could be seen emerging from below a patch of mid/high-altitude clouds. The RGB images were created using Geo2Grid.

GOES-16 Dust RGB images [click to play animation | MP4]

GOES-16 Dust RGB images [click to play animation | MP4]

VIIRS True Color RGB images from Suomi NPP and NOAA-20 as viewed using RealEarth (below) revealed orographic waves in the airborne sand/dust downwind (northwest) of some of the Canary Islands on 23 February.

VIIRS True Color RGB images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS True Color RGB images from Suomi NPP and NOAA-20 [click to enlarge]

This sand/dust was being lofted by anomalously strong lower-tropospheric winds — which were up to 5 standard deviations above the mean at the 925 hPa pressure level (below).

925 hPa wind speed anomaly during the period 00 UTC on 22 February to 00 UTC on 24 February [click to enlarge]

925 hPa wind speed anomaly during the period 00 UTC on 22 February to 00 UTC on 24 February [click to enlarge]

===== 24 February Update =====

GOES-16 Dust RGB images [click to play animation | MP4]

GOES-16 Dust RGB images [click to play animation | MP4]

GOES-16 Dust RGB images on 24 February (above) showed the second major pulse of sand/dust curling around the northern periphery of the offshore cutoff low pressure system. Toward the end of the animation, another minor pulse could be seen streaming northwestward off the coast of Western Sahara. A longer Dust RGB animation from 08 UTC on 22 February to 18 UTC on 24 February is available here.

In addition to the Dust RGB, signatures of the airborne sand/dust were also evident in GOES-16 Split Window Difference (10.3-12.3 µm) and Split Cloud Top Phase (11.2-8.4 µm) imagery (below). This arises from the fact that silicates (sand/dust particles) have different energy absorption characteristics at varying wavelengths.

GOES-16 Dust RGB, Split Window Difference (10.3-12.3 µm) and Split Cloud Top Phase (11.2-8.4 µm) [click to play animation | MP4]

GOES-16 Dust RGB, Split Window Difference (10.3-12.3 µm) and Split Cloud Top Phase (11.2-8.4 µm) images [click to play animation | MP4]

A comparison of TROPOMI Aerosol Index, TROPOMI Aerosol layer height (meters), Meteosat-11 Natural Color RGB and Meteosat-11 Dust RGB images at 1515 UTC is shown below (credit: Bob Carp, SSEC). Note that the height of the center of the aerosol layer near the western tip of the plume was generally in the 500-1000 meter range (shades of blue to cyan).

Panel 1: TROPOMI Aerosol Index Panel 2: TROPOMI Aerosol layer height (meters) Panel 3: Meteosat-11 Natural Color RGB Panel 4: Meteosat-11 Dust RGB [click to enlarge]

TROPOMI Aerosol Index (top left), TROPOMI Aerosol layer height in meters (top right), Meteosat-11 Natural Color RGB (bottom left) and Meteosat-11 Dust RGB (bottom right) [click to enlarge]

GOES-16 Split Window Difference image, with plots of available NUCAPS profile points [click to enlarge]

GOES-16 Split Window Difference (10.3-12.3 µm) image, with plots of available NUCAPS profile points [click to enlarge]

A GOES-16 Split Window Difference (10.3-12.3 µm) image with plots of available NUCAPS profile points at 1600 UTC (above) denoted the locations of a sequence of 9 consecutive north-to-south sounding points through the western tip of the dust plume. Profiles of NUCAPS temperature and dew point data for those 9 points are shown below — the strong temperature inversion and dry air below 1 km at Points 6, 7 and 8 showed the presence of this dry, dust-laden air (and the Total Precipitable Water value dropped to a minimum value of 0.34 inch at Point 7).

Profiles of NUCAPS temperature and dew point data for Points 1-9 [click to enlarge]

Profiles of NUCAPS temperature and dew point data for Points 1-9 [click to enlarge]

Widespread fires across the Deep South

November 19th, 2019 |

GOES-16 Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products [click to play animation | MP4]

GOES-16 Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products [click to play animation | MP4]

A sequence of GOES-16 (GOES-East) Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products (above) displayed signatures of widespread fires — a combination of prescribed burns and agricultural fires — across parts of the Deep South on 19 November 2019. Fire Temperature, Fire Power and Fire Area products are components of the GOES Fire Detection and Characterization Algorithm (SHyMet | ATBD).

GOES-16 “Red” Visible (0.64 µm) images, with and without plots of surface observations, are shown below. While most of the fires were too small/brief to produce large smoke plumes, a prominent plume was associated with one of the hottest and most long-lived fires — which was likely a prescribed burn — in the Chickasawhay State Wildlife Management Area (located east of Hattiesburg/Laurel Airport KPIB) in southeastern Mississippi.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with and without plots of surface observations [click to play animation | MP4]

There were no surface stations downwind of that Mississippi fire; however, one small smoke plume drifted over Lafayette in southern Louisiana (KLFT) near the end of the day, briefly reducing the visibility to 6 miles at 22 UTC (below).

Time series of surface observation data from Lafayette Regional Airport in Louisiana [click to enlarge]

Time series of surface observation data from Lafayette Regional Airport in Louisiana [click to enlarge]

For the hot fire in southeastern Mississippi, GOES-16 Shortwave Infrared, Fire Temperature, Fire Power and Fire Area values are shown for the same hot fire pixel at 1716, 1731 and 1806 UTC (below). Note that the individual parameter trends can be different for a given fire pixel — for example, even though the hottest 3.9 µm brightness temperature value was 58.8ºC at 1806 UTC, the peak Fire Temperature value was 1373.1 K at 1731 UTC. However, the time of the maximum Fire Power value of 213.6 MW coincided with the time of the hottest 3.9 µm brightness temperature value (1806 UTC).

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1716 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1716 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1731 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1731 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1806 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1806 UTC [click to enlarge]