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]

Advection of fog/stratus across western Lake Superior

November 3rd, 2015

GOES-13 Visible (0.63 µm) image, Metop ASCAT and RTMA surface winds, METAR surface reports, and surface frontal analysis [click to enlarge]

GOES-13 Visible (0.63 µm) image, Metop ASCAT and RTMA surface winds, METAR surface reports, and surface frontal analysis [click to enlarge]

A GOES-13 Visible (0.63 µm) image (above) showed a bank of fog and low stratus (FLS) covering much of the western portion of Lake Superior at 1600 UTC on 03 November 2015. Overlays of Metop ASCAT and Real-Time Mesoscale Analysis (RTMA) surface winds showed the long fetch of northeasterly winds that were moving this FLS feature toward the southwest; this southwestward (and eventual inland) advection could be followed on GOES-13 Visible images (below).

GOES-13 Visible (0.63 µm) images with METAR surface reports [click to play animation]

GOES-13 Visible (0.63 µm) images with METAR surface reports [click to play animation]

A more detailed view of the FLS deck was provided by a 375-meter resolution Suomi NPP VIIRS Visible (0.64 µm) image at 1848 UTC, with overlays of METAR surface reports, RTMA surface winds, and surface frontal analysis (below).

Suomi NPP VIIRS Visible (0.64 µm) image with METAR surface reports, RTMA surface winds, and surface frontal analysis [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) image with METAR surface reports, RTMA surface winds, and surface frontal analysis [click to enlarge]

The GOES-R Low Cloud Thickness product shown below (derived using GOES-13 data) indicated that the maximum depth of the FLS feature was around 2200 feet (yellow color enhancement).

GOES-13 Low Cloud Thickness product [click to enlarge]

GOES-13 Low Cloud Thickness product [click to enlarge]

Semi-Truck/School Bus Collision in Fog in Southeast North Dakota

September 25th, 2015
GOES-13 Visible (0.63 µm) imagery and surface observations of visibility; Richland County is outlined [click to play animation]

GOES-13 Visible (0.63 µm) imagery and surface observations of visibility; Richland County is outlined [click to play animation]

Three Semi-Truck/Trailers collided with a school bus in fog in Richland County North Dakota just before 9 AM CDT (1400 UTC) on 25 September 2015. The GOES-13 Visible animation, above, shows an eroding fog bank over southeastern North Dakota. Richland County is outlined in the imagery. The school bus was traveling on Highway 46, which hugs the northern border of Richland County; the accident was about 3 miles west of Interstate 29 (Press Report 1 ; Press Report 2).

Suomi NPP VIIRS "fog/stratus product" IR brightness temperature difference images [click to enlarge]

Suomi NPP VIIRS “fog/stratus product” IR brightness temperature difference images [click to enlarge]

During the preceding nighttime hours, Suomi NPP VIIRS “fog/stratus product” IR brightness temperature difference images at 0756 UTC (2:56 am CDT) and 0937 UTC (4:37 am CDT), above, showed an increasing signal of fog/stratus – yellow to red color  enhancement – over the region during that time period (when surface visibilities also began to rapidly decrease at Wahpeton KBWP, the county seat of Richland County).

GOES-R IFR Probability fields, 1300-1515 UTC on 25 September 2015 [click to play animation]

GOES-R IFR Probability fields, 1300-1515 UTC on 25 September 2015 [click to play animation]

GOES-R IFR Probability fields, above, around the time of the accident, showed a high probability of IFR Conditions over southeast North Dakota. High values were present over the area before sunrise (Sunrise in Fargo on 25 September is at 1318 UTC). Values at 1400 UTC show largest values over northern and western Richland County. The Low IFR Probabilty field for 1400 UTC, below, immediately after the time of the crash, shows a maximum across northern Richland County where the accident occurred.

GOES-R Low IFR Probability field, 1400 UTC on 25 September 2015 [click to enlarge]

GOES-R Low IFR Probability field, 1400 UTC on 25 September 2015 [click to enlarge]

Smoke and Fog in the VIIRS Day/Night Band

July 2nd, 2015
Suomi NPP VIIRS 0.70 µm visible Day/Night Band and 11.45 µm - 3.74 µm Brightness Temperature Difference images, and Ceilings and Visibilities, ~0800 UTC (click to enlarge)

Suomi NPP VIIRS 0.70 µm visible Day/Night Band and 11.45 µm – 3.74 µm IR Brightness Temperature Difference images, and Ceilings and Visibilities, ~0800 UTC (click to enlarge)

July’s first Full Moon occurred at 0219 UTC on 2 July (a second full moon occurs later this month on 31 July). Strong illumination from the moon showed river valley fog in several tributaries of the Mississippi River (for example, the Wisconsin River in southwest Wisconsin; the Upper Iowa River in Iowa) across the Upper Midwest. The Suomi NPP VIIRS Day/Night Band also shows a plume of Canadian wildfire smoke aloft, stretching from central Iowa northwestward to western Minnesota. This smoke (visible on 1 July in Aqua true-color imagery from the MODIS Today site) is not apparent in the IR Brightness Temperature Difference field, although the river valley fog certainly is. Smoke is transparent to most infrared channels and detection at night is very difficult if visible information such as that provided by the Day/Night Band is not present.

The VIIRS Day/Night Band also enabled detection of the dense plume of Canadian wildfire smoke as it moved off the US East Coast and over the adjacent offshore waters of the western Atlantic Ocean at 0614 UTC  (below). Again, note that the smoke aloft does not exhibit a signature on the corresponding VIIRS Infrared imagery.

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

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