GOES-14 SRSO-R: Return flow of Gulf of Mexico moisture in eastern Texas; blowing dust and a wildfire in western Texas

February 1st, 2016

GOES-14 Visible (0.63 µm) images, with surface observations [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with surface observations [click to play MP4 animation]

Day 1 of the 01-25 February 2016 test period of GOES-14 Super Rapid Scan Operations for GOES-R (SRSO-R) revealed some interesting features across the state of Texas. During the morning hours, the northward “return flow” of moisture from the Gulf of Mexico could be seen in the form of widespread fog and low stratus across the eastern part of the state on 1-minute interval GOES-14 Visible (0.63 µm) images (above; also available as a large 83 Mbyte animated GIF). Surface reports showed that dew point temperatures were as high as the 60s F along and just inland of the coast. GOES-13 derived products such as the MVFR Probability, LIFR Probability, and Low Cloud Thickness (FLS product training) showed the northward motion of the fog and low stratus during the preceding overnight hours.

During the afternoon hours, GOES-14 Visible (0.63 µm) images (below; also available as a large 91 Mbyte animated GIF) revealed the hazy signature of areas of blowing dust across southwest Texas, both ahead of and also in the wake of a cold frontal passage (surface analyses). Much of the blowing dust ahead of the cold front originated from dry lake beds in northern Mexico, which was then transported northeastward across Texas by strong southwesterly winds (an enhanced visible MP4 animation which shows the blowing dust better is available here). Blowing dust along and behind the cold front restricted the surface visibility to 1.0 miles at Big Spring (KBPG) and 2.5 miles at Midland (KMAF). Also note that early in the animation — beginning at 1800 UTC — there were small convective bands moving northeastward over the El Paso area, which produced light to moderate accumulating snow that reduced surface visibility to 1.0 miles at El Paso and Biggs Army Air Field (KBIF), and 2.0 miles at Ciudad Juarez, Mexico (MMCS).

GOES-14 Visible (0.63 µm) images, with surface reports [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with surface reports [click to play MP4 animation]

GOES-14 Shortwave Infrared (3.9 µm) images (below; also available as a large 52 Mbyte animated GIF) showed the “hot spot” signature (darker black to red pixels) associated with a large grass fire which developed in the Big Bend National Park area, beginning around 2300 UTC. The hot spot was seen to diminish not long after the arrival of cooler air (lighter shades of gray) behind the cold front. Surface air temperatures were quite warm in Texas ahead of the cold front, with daytime highs of 91º F at Del Rio (KDRT)  and 95º F — the highest temperature recorded for the day in the lower 48 states — farther to the southeast at Cotulla.

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images (below; also available as a large 57 Mbyte animated GIF) showed a broad ascending belt of moisture curving cyclonically over central and eastern Colorado, where moderate snow and significant accumulations were occurring at a number of locations.

GOES-14 Water Vapor (6.5 µm) images, with surface weather symbols [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images, with surface weather symbols [click to play MP4 animation]

A blog post discussing this ascending belt of moisture in more detail can be found here; a YouTube animation of GOES-14 Infrared Window (10.7 µm) images is available here.

===== 02 February Update =====

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

During the subsequent overnight  hours, an undular bore developed along and just ahead of the advancing cold front, as seen in GOES-14 Shortwave Infrared (3.9 µm) images (below; also available as a large 107 Mbyte animated GIF). A detailed view of the undular bore was also captured at 0859 UTC (3:59 AM local time) on Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (below).

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Smog and poor air quality in Beijing, China

November 30th, 2015

Suomi NPP VIIRS true-color images [click to play animation]

Suomi NPP VIIRS true-color images [click to play animation]

The sequence of 5 daily Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images shown above are centered on Beijing in northeastern China — these images (viewed using RealEarth) showed the transition from the Beijing area being sunny and snow-covered on 26 November to enshrouded in dense smog on 30 November 2015. The smog exhibited a distinct gray-colored appearance, in contrast to the brighter white clouds and snow cover. Much of this smog was driven by the burning of coal, both on a local level and by regional power plants (as discussed in this Capital Weather Gang blog post).

The corresponding daily time series plots of surface weather data at Beijing Capital International Airport (below) revealed that the surface visibility remained below 1.0 statute miles for extended periods. Although not indicated on the 26 November plot, the surface visibility began at 19 statute miles on that day, before the wind speeds became 4 knots or less beginning at 10 UTC and the visibility eventually began to decrease.

Daily time series plots of Beijing surface data [click to play animation]

Daily time series plots of Beijing surface data [click to play animation]

Grass fire in Colorado

September 19th, 2015

GOES-15 (left panels) and GOES-13 (right panels) Visible (0.63 µm) and Shortwave infrared (3.9 µm) images [click to play animation]

GOES-15 (left panels) and GOES-13 (right panels) Visible (0.63 µm) and Shortwave infrared (3.9 µm) images [click to play animation]

GOES-15 (GOES-West) and GOES-13 (GOES-East) Visible (0.63 µm) and Shortwave infrared (3.9 µm) images (above; click to play animation; also available as an MP4 movie file) showed the smoke plume and “hot spot” (dark black to red pixels) associated with a large and fast-burning grass fire in north-central Colorado on the afternoon of 18 September 2015. The smoke plume was more apparent in the GOES-13 visible images, due a more favorable “forward scattering” sun-satellite geometry. The fire burned an estimated 12,669 acres, and dense smoke forced the closure of Interstate 76 for about an hour in the afternoon.

On the following day, the fire burn scar could be seen in a comparison of Suomi NPP VIIRS  true-color and false-color images from the SSEC RealEarth site (below).

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

Due to the darker color and the lack of vegetation, the grass fire burn scar also exhibited a much warmer signature on the Terra MODIS Land Surface Temperature (LST) product (below) — LST values were as high as 112º F (darker orange color enhancement) within the burn scar, compared to LST values in the 80s and 90s F in surounding areas.

Terra MODIS Land Surface Temperature product [click to enlarge]

Terra MODIS Land Surface Temperature product [click to enlarge]

Eruption of the Cotopaxi volcano in Ecuador

August 14th, 2015

GOES-13 visible (0.63 µm) images [click to play animation]

GOES-13 visible (0.63 µm) images [click to play animation]

GOES-13 visible (0.63 µm) images (above; click to play animation) displayed distinct dark-gray ash plumes from 2 separate daytime eruptions of the Cotopaxi volcano in Ecuador on 14 August 2015 (there was also an initial eruption that occurred during the preceding nighttime hours). The asterisk near the center of the images marks the location of the volcano summit. Volcanic ash fall was observed in the capitol city of Quito (station identifier SEQU, located about 50 km or 30 miles north of the volcano), and some flights were diverted due to the volcanic ash cloud.

The corresponding GOES-13 infrared (10.7 µm) images (below; click image to play animation) showed that cloud-top IR brightness  temperatures were as cold a -53º C (orange color enhancement) at 1915 UTC.

GOES-13 infrared (10.7 µm) images [click to play animation]

GOES-13 infrared (10.7 µm) images [click to play animation]

The volcanic cloud features were also easily tracked on GOES-13 water vapor (6.5 µm) images (below; click image to play animation). In fact, note how the signature in the water vapor imagery is more distinctly seen for a longer period of time than on the 10.7 µm infrared imagery.

 GOES-13 water vapor (6.5 µm) images [click to play animation]

GOES-13 water vapor (6.5 µm) images [click to play animation]

The tan-colored volcanic ash cloud was also evident on Aqua MODIS and Suomi NPP VIIRS true-color Red/Green/Blue (RGB) imagery (below), as viewed using the SSEC RealEarth web map server.

Aqua MODIS true-color images [click to enlarge]

Aqua MODIS true-color images [click to enlarge]

Suomi NPP VIIRS true-color image [click to enlarge]

Suomi NPP VIIRS true-color image [click to enlarge]

A comparison of Suomi NPP VIIRS visible (0.64 µm) and infrared (11.45 µm) images is shown below (courtesy of William Straka, SSEC). The coldest cloud-top IR brightness temperature was -72.7º C.

Suomi NPP VIIRS visible (0.64 µm) and infrared (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS visible (0.64 µm) and infrared (11.45 µm) images [click to enlarge]