Tropical Storm Maria upgraded to Hurricane Maria in the central Atlantic

September 16th, 2017 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to animate]

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing *

On 16 September 2017, GOES-16 “Clean” Infrared Window (10.3 µm) images (above) showed the early stages of development of Tropical Storm Maria in the central Atlantic Ocean (located at 12.3 ºN latitude, 52.6 ºW longitude at 2100 UTC). Convective bursts exhibited cloud-top infrared brightness temperatures in the -77 ºC to -79 ºC range (brighter white enhancement). The hourly surface report from TBPB (along the left edge of the images) is Bridgetown in Barbados.

Unfortunately, the initial National Hurricane Center forecast track (below) takes Maria to Major Hurricane intensity over or near islands that were recently heavily impacted by Hurricane Irma. Maria is forecast to remain in an environment of low wind shear and move over waters characterized by warm SST and high OHC values (source), which all favor intensification.

Initial NHC forecast track [click to enlarge]

Initial NHC forecast track [click to enlarge]

===== 17 September Update =====
GOES-16 Visible (0.64 µm, left) and Infrared Window (10.3 µm, right) images [click to animate]

GOES-16 Visible (<strong0.64 µm, left) and Infrared Window (10.3 µm, right) images [click to animate]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Widow (10.3 µm) images (above) revealed a steady trend of organization during the day on 17 September, which allowed Maria to intensify to Category 1 Hurricane status at 2100 UTC. Note the large convective burst which expanded just west of the center of circulation after 1700 UTC — cloud-top infrared brightness temperatures were impressively cold, in the -80ºC to -89ºC range (violet shades of color enhancement).

===== 18 September Update =====
GOES-16 Visible (0.64 µm, left) and Infrared Window (10.3 µm, right) images [click to animate]

GOES-16 Visible (0.64 µm, left) and Infrared Window (10.3 µm, right) images [click to animate]

A GOES-16 Mesoscale Sector was positioned over Hurricane Maria, providing imagery at 1-minute intervals — Visible (0.64 µm) and Infrared Window (10.3 µm) images (above) captured the formation of an obvious eye feature beginning around 1615 UTC. Maria rapidly intensified (CIMSS SATCON) from a Category 1 to a Category 4 Hurricane east of Le Lamentin, Martinique (TFFF) during this daylight sequence of 1-minite images, as the eye then approached the small island of Dominica (TDCF is the identifier of their Canefield Airport) — and in fact Maria was upgraded to Category 5 intensity as the eye was just east of Dominica at 00 UTC on 19 September (NHC advisory). AWIPS imagery of the 1-minute GOES-16 Infrared data is available here.

This small-diameter “pinhole eye” was also evident earlier in the day on DMSP microwave imagery at 1040 UTC, and again at 1843 UTC.

Increase in Gulf of Mexico water turbidity in the wake of Hurricane Irma

September 11th, 2017 |

Suomi NPP VIIRS true-color RGB images on 07 September and 11 September [click to enlarge]ep

A comparison of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images on 07 September (before Irma) and 11 September (after Irma) revealed a marked increase in turbidity of the shallow Continental Shelf waters off the coast of southern/southwestern Florida and the Florida Keys. Irma moved through that region on 10 September as a Category 3 hurricane — and even though the center of Irma moved northward off/along the west coast of Florida (with a wind gust to 75 mph at Key West) , the strongest winds were recorded along/near the east coast of Florida: wind gusts to 92 mph and 109 mph and 142 mph — stirring up particulates within the shallow Continental Shelf waters.

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing *

Large-scale (CONUS) VIIRS true-color before-Irma and after-Irma images are available here and here. Note that the cloud shield of Irma had expanded as far westward as Kansas, Texas and Oklahoma on 12 September ( GOES-16 true-color images) — in addition to large areas of dense smoke from wildfires in the Pacific Northwest (blog post) which was drifting eastward across the northern US.

Hurricane Harvey makes landfall

August 26th, 2017 |

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing *

As Hurricane Harvey moved across warm waters in the northwestern Gulf of Mexico (SST | OHC), it continued to intensify (ADT | SATCON) to a Category 4 hurricane just before making landfall (which occurred around 03 UTC on 26 August 2017, or 10 pm local time on 25 August). A GOES-16 Mesoscale Sector had been positioned over Harvey, providing images at 30-second intervals; some of these are shown with “Red” Visible (0.64 µm) images prior to sunset (below). A GOES-16 vs GOES-13 (GOES-East) Visible image comparison is available here.

GOES-16 Visible (0.64 µm) images, with hourly surface ports plotted in yellow (Click to play MP4 animation)

GOES-16 “Red” Visible (0.64 µm) images, with hourly surface ports plotted in yellow [click to play MP4 animation]

Hurricane Harvey had a large eye on GOES-16 “Clean” Infrared Window (10.3 µm) images at landfall, which persisted — albeit becoming smaller with time — for many hours after it moved inland (below). A longer-term animation of 5-minute GOES-16 Infrared Window images (covering the period 23-27 August) is available here.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly surface reports plotted in yellow [click to play MP4 animation]

A sequence of 4 Infrared Window images, from Suomi NPP VIIRS and Terra/Aqua MODIS, covering the period 0419-0851 UTC (below) showed the shrinking eye and the erratic path of Harvey once it moved inland.

Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) Infrared Window images [click to enlarge]

Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) Infrared Window images [click to enlarge]

A recap of the torrential rainfall amounts and maximum wind gusts caused by Hurricane Harvey can be seen in the WPC Storm Summary.

Total solar eclipse of 21 August 2017 – a satellite perspective

August 21st, 2017 |

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing*

GOES-16 CONUS Sector images (at 5-minute intervals)

GOES-16

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

During the total solar eclipse of 21 August 2017,  the lunar umbra was evident on imagery from the GOES-16  0.5 km resolution (at satellite sub-point) “Red” Visible band (0.64 µm) (above) and 1.0 km resolution Near-Infrared “Vegetation” band (0.86 µm) (below).

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Vegetation” (0.86 µm) images [click to play animation]

The shadow was also prominent in other Visible and Near-Infrared bands, as shown in a 4-panel comparison of GOES-16 “Blue” Visible (0.47 µm, upper left), “Red” Visible (0.64 µm, upper right), “Vegetation” (0.86 µm, lower left) and “Snow/Ice” (1.61 µm, lower right) images (below).

GOES-16

GOES-16 “Blue” Visible (0.47 µm, upper left), “Red” Visible (0.64 µm, upper right), “Vegetation” (0.86 µm, lower left) and “Snow/Ice” (1.61 µm, lower right) images [click to play animation]

GOES-16 true-color Red/Green/Blue (RGB) images from the SSEC Geostationary Satellite site (below) showed another view of the shadow. A GOES-16 Full-Disk true-color animation (courtesy of  Kaba Bah, CIMSS) is available here.

GOES-16 true-color RGB images [click to play animation]

GOES-16 true-color RGB images [click to play animation]

The 3.9 µm Shortwave Infrared band is also sensitive to reflected solar radiation — particularly that which is reflected from land surfaces and cloud tops composed of small spherical supercooled water droplets (and to a lesser extent, small ice crystals) — which causes this band to sense warmer (darker gray to black) brightness temperatures compared to the other ABI infrared bands. Therefore, a loss of sunlight within the eclipse shadow will lead to cooling (lighter shades of gray) 3.9 µm brightness temperatures (below).

GOES-16 Shortwave Infrared (3.9 µm) images [click to play animation]

GOES-16 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

Taking a closer look at eastern Missouri and southern Illinois as the solar eclipse shadow was passing over that region shortly after 1800 UTC (1:00 pm local time), GOES-16 “Red” Visible (0.64 µm) images (below) revealed that the pronounced decrease of incoming solar radiation appeared to temporarily suppressed the development of widespread boundary layer cumulus clouds. Note that increase in hourly surface temperatures was also halted, with some locations even experiencing a slight cooling (1-3 ºF) due to reduction of heating within the lunar umbra.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Shortwave Infrared (3.9 µm) images (below) also showed a slight cooling — seen as a lighter shade of red enhancement — across the region.

GOES-16 Shortwave Infrared (3.9 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Shortwave Infrared (3.9 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Mesoscale Sector images (at 1-minute intervals)

GOES-16 "Red" Visible (0.64 µm) images, with station identifiers plotted in yellow [click to play animation]

1-minute GOES-16 “Red” Visible (0.64 µm) images, with station identifiers plotted in yellow [click to play animation]

A “floating” Mesoscale Sector provided 1-minute imagery during the eclipse (above).

Polar-orbiting satellite images (Terra MODIS, and Suomi NPP VIIRS)

Terra MODIS Visible (0.65 µm). Land Surface Temperature product, Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Terra MODIS Visible (0.65 µm), Land Surface Temperature product, Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

A toggle between Terra MODIS Visible (0.65 µm), Land Surface Temperature product, Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images (above) showed the eclipse shadow as it was centered over western Nebraska around 1748 UTC. Without a time series of MODIS Land Surface Temperature product images, it is difficult to gauge the exact amount of surface cooling brought about within the shadow of totality. A large-scale high resolution Terra MODIS Visible image is available here (courtesy of Liam Gumley, SSEC).

Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (above) showed the shadow center over eastern Tennessee around 1833 UTC. A closer comparison of Day/Night Band and Infrared images (below) revealed the  presence of cloud features that made it difficult to see a signature of any city lights that may have come on in the Nashville TN (KBNA) metropolitan area.

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

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