Tropical cyclones « CIMSS Satellite Blog

Tropical Storm Don

July 18th, 2017 | Scott Bachmeier

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

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

On 17 July Tropical Storm Don became the 4th named storm of the 2017 North Atlantic Basin season. The satellite presentation improved somewhat on 18 July, with GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) displaying a few brief convective bursts (some of which exhibited cloud-top infrared brightness temperatures of -80º C and colder).

A GOES-13 (GOES-East) Infrared Window (10.7 µm) image at 1845 UTC with overlays of the Tropical Overshooting Tops and Deep-Layer Winds products from the CIMSS Tropical Cyclones site is shown below.

GOES-13 Infrared Window (10.7 µm) images, with Tropical Overshooting Top and Deep-Layer Wind Shear products [click to enlarge]

Posted in GOES-13, GOES-16, Satellite winds, Tropical cyclones | No Comments »

Hurricane Fernanda

July 17th, 2017 | Scott Bachmeier

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

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

On 15 July Hurricane Fernanda became the first Category 4 tropical cyclone of the 2017 Northern Hemisphere season. GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) showed the development of a well-defined eye during the period of rapid intensification. As the National Hurricane Center mentioned, it was unusual to have a hurricane of this intensity at such a low latitude in the Eastern North Pacific Basin.

#Fernanda is among strongest hurricanes in the East Pacific at such a low latitude (<12°N). 100 kt at 10.9°N! @UMiamiRSMAS @capitalweather pic.twitter.com/nVJm622tE6

— Brian McNoldy (@BMcNoldy) July 14, 2017

Fernanda fluctuated between Category 3 and Category 4 intensity during the 15-17 July period (ADT | SATCON) as it passed over the warm waters of the East Pacific Ocean (Sea Surface Temperature and Ocean Heat Content) — and trochoidal oscillations in the northwestward motion of the eye could be seen in GOES-16 Infrared Window (10.3 µm) imagery (below).

GOES-16 Infrared Window (10.3 µm) images [click to play animation]

Posted in GOES-16, Tropical cyclones | No Comments »

GOES-16 and Tropical Depression #4 in the Atlantic Ocean

July 6th, 2017 | Scott Lindstrom

GOES-16 “Cirrus Channel” (1.38 µm) near-infrared imagery, 0900-2100 UTC on 6 July 2017 (Click to play animated gif)

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

Tropical Depression #4 formed in the tropical Atlantic on 5 July 2017 (Click here for National Hurricane Center advisories on the system). The Depression is not forecast to strengthen, and two GOES-16 products give evidence to its weakened state. The animation of GOES-16 Band 4 (1.38 µm “Cirrus Channel”), above, shows a general decrease in the high clouds associated with this system (located north of 10º North Latitude and between 40º and 50º West Longitude), meaning convection is not strong. A closer view reveals intricate cirrus transverse banding around the periphery of the system during the early part of the day. In addition, the 10.3 µm “Clean Window” image, below, overlain on top of the GOES-16 Baseline Total Precipitable Water (TPW) Product, shows dry air west of the circulation. A Saharan Air Layer (SAL) analysis from here that uses Meteosat data, shows dry air moving towards the system from the east as well (Link). A toggle between GOES-13 Infrared Window, Meteosat-10 SAL product, and MIMIC TPW imagery can be seen here.

Refer to the National Hurricane Center website, or the CIMSS Tropical Weather website, for more information on this sytem.

GOES-16 “Clean Window” Band (10.33 µm) and GOES-16 Total Precipitable Water, 2100 UTC on 6 July 2017 (Click to enlarge)

Posted in GOES-16, Meteosat, Tropical cyclones | No Comments »

Hurricane Dora

June 26th, 2017 | Scott Bachmeier

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

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

Dora became the first hurricane of the Eastern Pacific 2017 season on 26 June, and was also the first hurricane to be sampled by GOES-16. On Visible (0.64 µm) and Infrared Window (10.3 µm) images (above), Dora displayed an improving appearance as the day progressed — mesovortices were seen within the eye on Visible imagery, while the overall eye/eyewall structure improved as the eye diameter increased on Infrared Window imagery.

Early in the morning, a comparison between DMSP-17 SSMIS Microwave (85 GHz) and GOES-15 Infrared Window (10.7 µm) images from the CIMSS Tropical Cyclones site (below) showed that a well-defined eye was more apparent on microwave imagery. Dora was moving over fairly warm Sea Surface Temperatures, and was also in an environment characterized by low values of deep-layer wind shear.