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.

Harvey near the coast of Texas

August 28th, 2017 |

GOES-16 ABI Band 8 (6.19 µm, “Upper Level Water Vapor”, lower left), ABI Band 10 (7.3 µm, “Lower Level Water Vapor”, upper left), ABI Band 13 (10.3 µm, “Clean Window Infrared”, upper right) and ABI Band 5 (1.61 µm, “Snow/Ice Channel”, lower right) from 1542-1857 UTC on 28 August (Click to animate)

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

Meandering Tropical Storm Harvey is near the Gulf Coast of Texas during the day on Monday 28 August as shown in the 4-panel Animation above. The Four panels include, clockwise from lower left, Upper Level Water Vapor (6.19 µm), Lower Level Water Vapor (7.3 µm), Clean Window (10.3 µm) and Snow/Ice Channel (1.61 µm) (ABI Bands 8, 10, 13 and 5, respectively). The deepest and strongest convection with Harvey has shifted eastward into Louisiana; dry mid-tropospheric air is apparent in both water vapor infrared images; Convection continues near the center of the storm; onshore low-level flow is apparent in the Snow/Ice channel. Total Precipitable Water computed from Microwave Imagery (at this site), below, shows that abundant moisture remains over southeast Texas and Louisiana.

Morphed Total Precipitable Water for the 24 hours ending 28 August 2017 (Click to enlarge)

GOES-16 Visible Imagery (0.64 µm), below, show the center of Harvey to be just offshore (Click here for the latest National Hurricane Center advisories on Harvey), with moist low-level flow from the Gulf into southeast Texas and southwest Louisiana. Geostationary Lightning Mapper (GLM) observations of Lightning Groups (Events are grouped into Groups, Groups are grouped into Flashes), show scant lightning associated with the center of Harvey. More lightning activity is apparent over southeastern Louisiana (including some apparently spurious signals near Baton Rouge). A similar animation over Infrared Imagery is here.

GOES-16 ABI Visible Imagery (0.64 µm) and GLM Observations of Lightning Groups from 1842-1927 UTC on 28 August (Click to enlarge)

For the latest on Harvey and its dangerous rainfall, consult the National Hurricane Center website, or the CIMSS Tropical Weather Website, or the Hydrologic Prediction Website.

Hurricane Harvey approaches the Texas Gulf Coast

August 25th, 2017 |
GOES-16

GOES-16 Low-Level Water Vapor Infrared (7.3 µm) images, 0217-1347 UTC on 25 August 2017 (click to play animation)

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

Low-Level Water Vapor Infrared imagery (7.34 µm) from GOES-16, above, shows Hurricane Harvey developing a distinct eye shortly after sunrise on 25 August 2017 after intermittent appearances of the eye during the night. Harvey is a strong Hurricane at 950 mb (as of 700 AM CDT according to the National Hurricane Center) and is approaching the central Gulf Coast of Texas. Strong upper-level outflow to the north and then east and south is apparent in the Water Vapor animation above, and an absence of dry air near the storm portends no significant weakening before the storm reaches the Coastline. Microwave estimates of Total Precipitable Water, below, from this site, continue to show extreme moisture amounts enveloping the storm.

MIMIC Total Precipitable Water estimates for the 24 hours ending 1300 UTC on 25 August 2017 (Click to enlarge)

Visible imagery, below, from after sunrise on 25 August 2017, show a symmetric storm with a visible eye. The “Cirrus Channel” near-infrared GOES-16 Channel (1.38), bottom, shows the extensive cirrus canopy from the storm covering much of the western Gulf of Mexico and adjacent states.

GOES-16

GOES-16 Visible Images (0.64 µm) images, 1242-1417 UTC on 25 August 2017 (click to play animation)

GOES-16 near-Infrared Images (1.38 µm) image, 1432 UTC on 25 August 2017 (Click to enlarge)

For the latest information on Harvey, consult the pages of the National Hurricane Center, or the CIMSS Tropical Weather Website. In addition to the flooding threat posed from Harveywith multiple days of rain, storm surge at the coast promises considerable inundation.

GOES-16 animation showing Clean Window IR (10.3 µm) and City Lights Background at night, True Color Imagery during the day, 1100-1900 UTC on 25 August 2017 (Click to enlarge)

A toggle between Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1853 UTC , below, provided a detailed view of the hurricane as it continued to near the Texas coast.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (Click to enlarge)

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (Click to enlarge)

Hurricane Harvey

August 24th, 2017 |

GOES-16

GOES-16 “Clean Window” Infrared (10.3 µm) images, 0432-1307 UTC on 24 August 2017 [click to play animation]

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

Overnight Satellite imagery from GOES-16, above, shows an increase in the size and convective activity with then-Tropical Storm Harvey. Harvey is forecast to make landfall on the Texas Gulf Coast (See the National Hurricane Center website for further details), and conditions favor strengthening. One of the favorable conditions is shown in the animation of Total Precipitable Water, below, from this site. There is abundant moisture surrounding the storm, extending into eastern and southeastern Texas. Flooding rains will likely precede and accompany this storm.

In addition to abundant moisture, Harvey’s projected path takes it over very deep very warm water (Link showing Oceanic Heat Content).

Note: Harvey achieved Hurricane Status at 1 PM CDT on 24 August 2017. Harvey continued to rapidly intensify during the day (ADT | SATCON).

GOES-16

MIMIC Total Precipitable Water, 24-hour animation ending at 1200 UTC 24 August 2017 [click to enlarge]

Harvey is a large storm. The GOES-16 “Cirrus Channel” 1.38 µm imagery, below, shows Harvey’s cirrus canopy covering much of the southwestern Gulf of Mexico. Cirrus from the storm should be visible from the south Texas Gulf Coast this morning.

GOES-16 “Cirrus Channel” (1.38 µm) Imagery, 1307 UTC on 24 August 2017 (Click to enlarge)

Suomi NPP overflew the southern Gulf after midnight on 24 August 2017, and the VIIRS  Day/Night Band Imagery, below, shows a few lightning streaks in the storm that is barely illuminated by airglow. Cloud-top heights computed from VIIRS data (Link) shows a large central dense overcast with heights exceeding 50000 feet. ATMS 88-GHz Imagery at the same time is shown here. Morphed Microwave imagery (from this site) hints at the development of a ragged eye shortly after sunrise on 24 August. (Animation). (A DMSP SSMI 85 GHz still image from near the end of the MIMIC animation is here).

Suomi NPP Day Night Band Visible (0.70 µm) Imagery over Tropical Storm Harvey, 0747 UTC on 24 August 2017 (Click to enlarge)

ATMS 88-GHz Imagery at the same time is shown here. Morphed Microwave imagery (from this site) hints at the development of a ragged eye shortly after sunrise on 24 August. (Animation). An 85 GHz still image from the end of the animation is shown below.

85 GHz Microwave imagery over Tropical Storm Harvey, 1300 UTC on 24 August 2017 (Click to enlarge)

Later in the day, a toggle between 1912 UTC Visible (0.64 µm) and Infrared Window (11.45 µm) Suomi NPP VIIRS images, below, provided a detailed view of the hurricane.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (Click to enlarge)

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (Click to enlarge)

For more information on Hurricane Harvey, a storm that people along the Texas Gulf Coast should be monitoring closely, consult the website of the National Hurricane Center, or the CIMSS Tropical Weather Website.