GOES-16 Visible 0.64 µm Imagery, 1144-1243 UTC on 5 September 2017 (Click to animate)

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

Hurricane Irma, northeast of Antigua and Barbuda in the Lesser Antilles, achieved Category 5 status on 5 September, based on aircraft reconnaissance. The symmetric storm with a clear eye (that includes mesoscale vortices) is shown above with 1-minute imagery from GOES-16.

GOES-16 Geostationary Lightning Mapper data, below, shows lightning occurring in the outer bands of the storm. Two-hour animations, updated every 15 minutes, of GLM data superimposed over Visible (0.64 µm) or over Infrared (10.3 µm) imagery. are available at the links (Imagery courtesy Dave Santek, SSEC).

Note that a slightly later animation, ending at 1500 UTC, (here), shows considerable lightning activity in the eye of Irma, as does the animation ending at 1915 UTC (here). It is not unusual for strengthening tropical systems to support electrical activity in the eyewall.

GOES-16 ABI Visible (0.64 µm) every 15 minutes, 1100-1315 UTC 5 September 2017, with 3-minute increments of GLM Group data plotted (Yellow Points: oldest; Red Points: Latest) (Click to enlarge)

Suomi NPP overflew Irma near 0600 UTC on 5 September, when Irma was still a Category 4 storm. Two views of the storm are shown below, both toggling between the Day Night Band visible image (0.7 µm) that has excellent illumination from a near-Full Moon and the 11.45 µm Infrared Imagery.

Suomi NPP Day Night Band Visible (0.7 µm) and VIIRS Infrared (11.45 µm) imagery, 0554 UTC 5 September 2017 (Click to enlarge)

Suomi NPP Day Night Band Visible (0.7 µm) and VIIRS Infrared (11.45 µm) imagery, 0554 UTC 5 September 2017, over the eye of Hurricane Irma (Click to enlarge)

A GOES-16 late in the day on 5 September, below, shows a well-developed storm with a distinct eye

GOES-16 Infrared Imagery (10.3 µm, upper left; 6.19 µm, upper right, 7.34 µm, lower right) and Visible Imagery (0.64 µm, lower right), 2057-2143 UTC on 5 September 2017 (Click to animate)

Interests throughout the Greater Antilles, the northern Lesser Antilles, the Bahamas and the southeastern United States including Florida should be monitoring this storm closely, and preparing for its arrival. For more information, refer to the National Hurricane Center website, or the CIMSS Tropical Weather Website.

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Suomi NPP Overflew Hurricane Irma at around 0430 UTC on 4 September, and a nearly Full Moon supplied ample illumination for the Day Night Band on the VIIRS Instrument that is onboard Suomi NPP. The Slider above compares the Day Night Band Visible Imagery with the 11 Infrared Imagery (Drag the bar left and right to change imagery). A more zoomed-in set of images (all images courtesy Will Straka, SSEC/CIMSS) is below.

Irma is a category 3 Hurricane on the Saffir-Simpson Scale. The storm will threaten the Greater and Lesser Antilles this week, and the Mainland of the United States later this week into the weekend.

For more information on Irma, consult the National Hurricane Center website, or the CIMSS Tropical Weather Website.

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

A toggle between nighttime images of Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) data at 0347 UTC (courtesy of William Straka, SSEC/CIMSS) showed a high-resolution view of the eye of Category 3 Hurricane Irma.

Toggle of CIMSS True Color, GOES-16 Split Window Difference (10.3 µm – 12.3 µm) field, and GOES-16 Dust RGB Product, 1315 UTC on 1 September 2017 (Click to enlarge)

GOES-16 data (ABI and GLM) posted on this page are preliminary, non-operational and are undergoing testing

The animation above cycles through imagery from 1315 UTC on 1 September, showing CIMSS GOES-16 True Color Imagery, The GOES-16 Split Window Difference (10.3 µm – 12.3 µm), and the GOES-16 Dust RGB (Red-Green-Blue) Product. The Split Window Difference field highlights moist air (bright red in the enhancement) to the south of Irma, and also dryer air (blue in the color enhancement), to the north. The Saharan Air Analysis, below, from the CIMSS Tropical Weather Website, corroborates the placement of the dry air to the north of Irma, and Total Precipitable Water estimates (from here) also show dry air. This dry air could influence further strengthening of the storm in the short term.

Saharan Air Layer analysis on 01 September 2017 (Click to animate)

Irma is near the eastern edge of the GLM Domain for GOES-16 in the central Test position at 89.5 W Longitude; the animation below, with GLM Group information (every 10 minutes) over ABI Band 13 (10.3 µm, every 30 minutes from the Full Disk Domain), shows little lightning near the center of Irma on 30/31 August. Lightning was more active on 1 September.

GOES-16 ABI “Clean Window” 10.3 µm Infrared Imagery, every half hour, with GLM Group Data plotted in 10-minute increments from 0000 UTC on 30 September through 1200 UTC on 1 September 2017 (Click to animate)

Satellite trends with Irma show the development of an eye structure, as seen below in the screen capture from the GOES-13 Floater (source) at 1745 UTC, and DMSP-16 SSMIS Microwave (85 GHz) at 1829 UTC on 1 September.

GOES-13 10.7 µm Infrared Imagery, 1745 UTC, 1 September 2017 (Click to enlarge)

The evolution of the eye is also apparent in the GOES-16 Visible Imagery (0.64 µm), below, from 1315-1815 UTC on 1 September 2017.

GOES-16 Visible (0.64 µm) Imagery, 1315-1815 UTC, 1 September 2017 (Click to animate)

For more information on Irma, consult the webpages of the National Hurricane Center or the CIMSS Tropical Weather Website.

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Terra MODIS True-Color imagery off the Texas Gulf Coast on 23 and 30 August, 2017 (Click to enlarge)

MODIS Today imagery from 23 August (pre-Harvey) (cropped) and 30 August (post-Harvey) (cropped), above, show an enormous increase in turbidity in the nearshore waters off the coast of Texas. Further, many of the rivers change their appearance to brown and flooding in the post-Harvey image. (River gauges in flood stage; Source)

A similar toggle using Suomi NPP VIIRS Imagery, from this site, also from 23 August and 30 August, is shown below. The increase in turbidity was due to a combination of strong winds and runoff from very heavy rainfall associated with the hurricane.

Suomi NPP True-Color imagery off the Texas Gulf Coast on 23 and 30 August, 2017 (Click to enlarge)

Suomi NPP VIIRS Products include a River Flood estimate, developed by Sanmei Li and others at George Mason University. The toggle below from RealEarth shows Suomi NPP VIIRS True Color at 1904 UTC, and the River Flood Product for the same time.

Suomi NPP VIIRS True-Color imagery off the Texas Gulf Coast, 1904 UTC on 30 August, 2017, and the Suomi NPP River Flood Product at the same time (Click to enlarge)

(Thanks to Bill Taylor and John Stoppkotte, NWS in N. Platte NE, for noting this!)

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