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

As 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 along the Texas coast around 03 UTC on 26 August 2017 (10 pm local time on 25 August). Overlapping 1-minute GOES-16 Mesoscale Sectors had been positioned over Harvey, providing images at 30-second intervals — “Red” Visible (0.64 µm) images prior to sunset (below) showed the approach of the eye. A comparison of GOES-16 vs GOES-13 (GOES-East) Visible images is available here.

Hurricane Harvey had a large-diameter eye in GOES-16 “Clean” Infrared Window (10.3 µm) images at landfall, which persisted — albeit becoming smaller with time — for several 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.

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

A recap of the torrential rainfall amounts and maximum wind gusts caused by Hurricane Harvey can be seen in the WPC Storm Summary. A map showing the final storm total rainfall from Harvey is available here. [January 2018 update: the NHC released its final report on Hurricane Harvey]

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

The Geostationary Lightning Mapper (GLM) on GOES-16 allows observations of lightning associated with Hurricane Harvey in the Gulf of Mexico. The animation above, from 1247 to 1332 UTC on 25 August 2017, shows lightning group observations every minute, color-coded by time (red is the oldest, yellow is the most recent, corresponding to the nominal time of the ABI Image), superimposed on GOES-16 ABI Channel 1 Visible Imagery (0.47 µm). Most of the Hurricane lightning is in the outer bands of the storm, with very little in the central core. This distribution is not unusual.

(A similar animation from 1812-1857 UTC on 24 August 2017, when lightning was observed near the storm core, is here.)

(Thanks to Dave Santek, SSEC, for this animation!)

Added: The animation below (for 1352-1437 UTC on 25 August) is over simulated True-Color Imagery, and for this GLM plot, the latest 1-minute Groups plots (that correspond to the ABI Image time) are red, and the earliest are Yellow.

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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.

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.

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.

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.

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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).

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.

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).

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.

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.

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.

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