Hurricane Harvey makes landfall

August 26th, 2017 |

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

As Hurricane 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 (which occurred around 03 UTC on 26 August 2017, or 10 pm local time on 25 August). A GOES-16 Mesoscale Sector had been positioned over Harvey, providing images at 30-second intervals; some of these are shown with “Red” Visible (0.64 µm) images prior to sunset (below). A GOES-16 vs GOES-13 (GOES-East) Visible image comparison is available here.

GOES-16 Visible (0.64 µm) images, with hourly surface ports plotted in yellow (Click to play MP4 animation)

GOES-16 “Red” Visible (0.64 µm) images, with hourly surface ports plotted in yellow [click to play MP4 animation]

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

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly surface reports plotted in yellow [click to play MP4 animation]

A sequence of 4 Infrared Window images, from Suomi NPP VIIRS and Terra/Aqua MODIS, covering the period 0419-0851 UTC (below) showed the shrinking eye and the erratic path of Harvey once it moved inland.

Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) Infrared Window images [click to enlarge]

Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) Infrared Window images [click to enlarge]

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.

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]

Severe thunderstorms, as viewed by 4 GOES

August 2nd, 2017 |
GOES-15, GOES-14, GOES-16 and G0ES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]

GOES-15, GOES-14, GOES-16 and G0ES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]

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

With a Severe Thunderstorm Watch in place, storms developed over far northeastern Colorado late in the day on 02 August 2017 which produced hail as large as 2.0 inches in diameter (SPC storm reports). Since GOES-14 (which had been placed into on-orbit storage as a spare satellite) was briefly activated for testing and evaluation, it afforded the unusual opportunity to view these storms from 4 different GOES perspectives (above). The Visible images (0.63 µm for the 3 legacy GOES, and 0.64 µm for GOES-16) are displayed in the native projections for each satellite.

A closer look using a higher image zoom factor (below) helps to demonstrate the advantage of higher spatial resolution with the GOES-16 0.64 µm “Red” Visible band (0.5 km at satellite sub-point, vs 1.0 km for the 3 legacy GOES) — especially for clearly identifying features such as thunderstorm overshooting tops. Also note that the 3 legacy GOES visible images do not appear as bright as those from GOES-16; visible imagery from GOES degrades with time, and older GOES Imager instruments do not have on-board calibration to account for this. However, the GOES-16 ABI instrument does have on-board visible detector calibration, so dimming of visible imagery over time should not be as noticeable.

GOES-15, GOES-14, GOES-16 and GOES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]

GOES-15, GOES-14, GOES-16 and GOES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]

Tornado in Maryland

July 24th, 2017 |

GOES-16 Infrared Window (10.3 µm) images, with surface station identifiers plotted in yellow [click to play MP4 animation]

GOES-16 Infrared Window (10.3 µm) images, with surface station identifiers plotted in yellow [click to play MP4 animation]

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

An isolated thunderstorm that was moving eastward across Maryland just after Midnight on 24 July 2017 intensified as it crossed Chesapeake Bay, eventually producing a waterspout which moved onshore near Bay City (just southwest of Stevensville/Bay Bridge Airport, station identifier KW29) — this tornado was responsible for 1 injury and EF2-rated damage (NWS Mount Holly PNS  | SPC storm reports). GOES-16 “Clean” Infrared Window (10.3 µm) images (above; also available as a 23-Mbyte animated GIF) showed that there were 3 distinct “pulses” when cloud-top infrared brightness temperatures cooled to the -71 to -75º C range (lighter gray pixels embedded within dark black regions) before the storm produced the tornado at 0529 UTC. Since one of the default GOES-16 Mesoscale Sectors was providing coverage over the eastern US, imagery was available at 1-minute intervals.

A comparison of 1-minute GOES-16 vs 15-minute GOES-13 (GOES-East) Infrared Window images (below; also available as a 17-Mbyte animated GIF) provided a convincing demonstration of the value of more frequent image scan intervals for monitoring severe convection. The improved spatial resolution of GOES-16 Infrared imagery — 2 km at satellite sub-point, vs 4 km for GOES-13 — also allowed for a more accurate depiction of cloud-top IR brightness temperature patterns and values.

1-minute GOES-16 (10.3 µm, left) vs 15-minute GOES-13 (10.7 µm, right) Infrared Window images [click to play MP4 animation]

1-minute GOES-16 (10.3 µm, left) vs 15-minute GOES-13 (10.7 µm, right) Infrared Window images [click to play MP4 animation]