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; the eye then went on to approach 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.

Hurricane Irma

September 8th, 2017 |

GOES-16 “Clean Window” Imagery (10.3 µm) every six hours from 1500 UTC 31 August to 0900 UTC 8 September, centered on Irma (Click to animate)

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

The animation above shows Irma every 6 hours from 31 August through 8 September, using the GOES-16 “Clean Window” Imagery (10.3 µm). The animation below shows the GOES-16 Upper-Level Water Vapor Infrared Imagery (6.19 µm) (Click here for the Low-Level Water Vapor Infrared Imagery — 7.34 µm). All three animations show a gradual increase in the size of the storm. The structure of the storm at the very end suggests a slight weakening, most likely temporary, of Irma.

GOES-16 “Low-Level Water Vapor” Infrared Imagery (6.19 µm) every six hours from 1500 UTC 31 August to 0900 UTC 8 September, centered on Irma (Click to animate)

The recent slight weakening of Irma is mostly likely related to an Eyewall Replacement Cycle, shown in the Microwave Imagery below (from this site). In an Eyewall Replacement, an outer eyewall develops around the inner eyewall, after which time the inner eyewall will diminish and then dissipate, usually but not always weakening the storm. The outer eyewall will then contract, usually as the storm re-intensifies (if other environmental parameters that govern strengthening — Sea Surface Temperatures, Moisture, Shear — are favorable).

Morphed Microwave Imagery over Irma for the 48 hours ending 1200 UTC on 8 September 2017 (Click to enlarge)

The imagery below shows a recent 8-hour animation of Irma and Katia using the GOES-16 Clean Window (10.3 µm) Channel. The Inner Core of Irma looks a bit more ragged compared to previous days, although excellent outflow continues, and very little dry air is apparent. Katia in the southwest Gulf of Mexico is occasionally presenting an eye.

GOES-16 “Clean Window” Imagery (10.3 µm) 0717-1522 UTC on 8 September (Click to animate)

For more on this system, please consult the National Hurricane Center Website, or the SSEC/CIMSS Tropical Weather Website.

Hurricane Irma in the eastern Atlantic Ocean

September 1st, 2017 |
Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images (Click to enlarge)

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.

Hurricane Gert

August 15th, 2017 |

GOES-16 imagery (all 16 ABI Bands) from 1912-2132 UTC, 15 August 2017 [click to play animation]

GOES-16 imagery (all 16 ABI Bands) from 1912-2132 UTC, 15 August 2017 [click to play animation]

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

Hurricane Gert, a Category-1 storm on the Saffir-Simpson scale, is over the open Atlantic Ocean east of Cape Hatteras. It is close enough to the USA, however, that it is within GOES-16’s CONUS domain where 5-minute sampling is routine. The animation above shows all 16 channels from GOES-16 ABI, every five minutes from 1912-2132 UTC on 15 August 2017. A distinct eye is not apparent in the visible or infrared satellite imagery, but microwave data (from here) suggests an eye is present, at least at times. A comparison of 2035 UTC DMSP-16 SSMIS Microwave (85 GHz) and 2045 UTC GOES-13 Infrared Window (10.7 µm) images can be seen here.

The low-level Water Vapor imagery, below, shows that Gert is south and east of a front along the East Coast. This front should steer the storm to the north and east. Swells from the storm will affect the East Coast however.

GOES-16 imagery Low-Level Water Vapor (7.34 µm) Infrared Imagery from 1832-2137 UTC, 15 August 2017 [click to play animation]

GOES-16 Low-Level Water Vapor (7.34 µm) Infrared Imagery from 1832-2137 UTC, 15 August 2017 [click to play animation]

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

GOES-16 ABI Imagery from the morning of 16 August 2017, below, shows that an eye has appeared in visible and infrared imagery.

GOES-16 imagery (all 16 ABI Bands) from 1117-1337 UTC, 16 August 2017 [click to play animation]

GOES-16 imagery (all 16 ABI Bands) from 1117-1337 UTC, 16 August 2017 [click to play animation]

A closer view using 1-minute interval GOES-16 Mesoscale Sector “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images, below, showed that  the most vigorous areas of deep convection were generally confined to the northern semicircle of the eyewall region — cloud-top infrared brightness temperatures were as cold as -80º C (violet color enhancement) at times.

GOES-16 Visible (0,64 µm, top) and Infrared Window (10.3 µm, bottom) images [click to play MP4 animation]

GOES-16 Visible (0.64 µm, top) and Infrared Window (10.3 µm, bottom) images [click to play MP4 animation]