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 north of Hispaniola

September 7th, 2017 |

GOES-16 Low-Level Water Vapor Infrared (7.34 µm) Imagery, 0737 – 1232 UTC on 7 September 2017 (Click to animate)

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

GOES-16 Captured very strong Hurricane Irma, north of Hispaniola, early on the day on 7 September. The 7.34 µm channel shown is sensitive to water vapor, that is, water vapor in the atmosphere absorbs energy at 7.34 µm. The animation shows the storm moving steadily to the west-northwest. A far less-organized Hurricane Katia is over the southwestern Gulf of Mexico, with a strong jet extending from Katia northeastward along the east coast. A short animation of Visible Imagery with Geostationary Lightning Mapper data, below, from 1015-1230 UTC, shows considerable lightning activity continuing in the eye of the storm and in some of the convective bands that surround it.

GOES-16 Visible (0.64 µm) Imagery at 15-minute intervals underneath plots of GLM Group Activity in 3-minute intervals, 1015-1230 UTC 7 September 2017 (Click to animate)

Suomi NPP overflew Irma at about 1800 UTC on 7 September. Visible (0.64 µm) and Infrared (11.45 µm) imagery from the VIIRS Instrument on Suomi NPP is below.

Suomi NPP VIIRS Visible (0.64 µm) imagery, 1808 UTC on 7 September 2017 (Click to enlarge)

Suomi NPP VIIRS Infrared (11.45 µm) imagery, 1808 UTC on 7 September 2017 (Click to enlarge)

Hurricane Irma over the British Virgin Islands

September 6th, 2017 |

Suomi NPP VIIRS Visible Imagery (0.64 µm) at 1646 UTC on 6 September 2017, with and without annotation (Click to enlarge)

 

Suomi NPP overflew Irma as the storm moved through the British Virgin Islands. The toggle above shows the 0.64 µm Visible Image of the storm at that time, with and without annotations.  An infrared view from VIIRS, at 11.45 µm is shown below.

Suomi NPP VIIRS Infrared Imagery (11.45 µm) at 1646 UTC on 6 September 2017, with and without annotation (Click to enlarge)

(Imagery courtesy Will Straka, CIMSS)

Category 5 Hurricane Irma over the Lesser Antilles

September 6th, 2017 |

Suomi NPP’s Day Night Band Image, below, from Real Earth, shows Hurricane Irma as it is over the island of Barbuda — note that the island is entirely within the eye! (Click here for an image with no underlying maps).

Suomi NPP Day Night Band Visible (0.7 µm) image, 0529 UTC on 6 September 2017, with underlying map (Click to enlarge)

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

GOES-16 Clean Window (10.3 µm) imagery at 30-second intervals, 0957 – 1202 UTC on 6 September 2017 (Click to animate)

GOES-16 Clean Window (10.3 µm) imagery, above, for two hours near sunrise on 6 September 2017 show a well-developed Irma moving through the islands to the east of Puerto Rico. The storm maintains its excellent satellite presentation with a distinct eye. Geostationary Lightning Mapper Data overlain on the 10.3 µm imagery (with a greyscale enhancement), below, shows that lightning continues to be active within the eyewall of this strong storm.

GOES-16 10.3 µm imagery at 15-minute intervals, with Geostationary Lightning Mapper (GLM) data overlain at 3-minute intervals, yellow oldest, red newest (Click to animate)

For the latest on this powerful storm, consult the National Hurricane Center website, or the CIMSS Tropical Weather Website.