Northeast US heavy rain and high wind event

October 30th, 2017 |

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly precipitation type symbols plotted in red [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly precipitation type symbols plotted in red [click to play MP4 animation]

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

GOES-16 Mid-level Water Vapor (6.9 µm) images with hourly surface weather symbols plotted in red (above) showed the large-scale evolution of a storm system that deepened rapidly as it moved across the Northeast US during the 29 October30 October 2017 period (surface analyses). This storm produced widespread high winds and heavy rain (WPC storm summary | NWS Boston PNS | NWS Caribou PNS). Record low sea level pressures for the month of October were set in New York at Albany (977.7 hPa) and Fort Drum (977.5 hPa), and in Massachusetts at Nantucket (982.6 hPa) — a map of the minimum sea level pressures from the New York State Mesonet can be seen here.

Closer views of the Northeast US using images from the GOES-16 Upper-level Water Vapor (6.2 µm), Mid-level Water Vapor (6.9 µm) and Low-level Water Vapor (7.3 µm) bands are shown below, with hourly surface wind gusts (knots) plotted in red. The high winds caused extensive damage to trees and power lines, leading to power outages in some areas — and also contributed to coastal storm surge.

GOES-16 Upper-level Water Vapor (6.2 µm) images, with hourly surface wind gusts (in knots) plotted in red [click to play MP4 animation]

GOES-16 Upper-level Water Vapor (6.2 µm) images, with hourly surface wind gusts (in knots) plotted in red [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly surface wind gusts (in knots) plotted in red [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly surface wind gusts (in knots) plotted in red [click to play MP4 animation]

GOES-16 Lower-level Water Vapor (7.3 µm) images, with hourly surface wind gusts (in knots) plotted in red [click to play MP4 animation]

GOES-16 Lower-level Water Vapor (7.3 µm) images, with hourly surface wind gusts (in knots) plotted in red [click to play MP4 animation]

One interesting aspect of this rapidly-deepening storm was the absorption/merging of the northward-moving remnants of Tropical Storm Philippe (storm track), which was shown by the CIMSS 850 hPa relative vorticity product (below).

850 hPa Relative Vorticity product [click to play animation]

850 hPa Relative Vorticity product [click to play animation]

Additional details of this event can be found on the Satellite Liaison Blog.

Hurricane Maria downgraded to a Tropical Storm off the East Coast

September 26th, 2017 |
GOES-13 Infrared Window (10.7 µm) image, with Deep-Layer Wind Shear product [click to enlarge]

GOES-13 Infrared Window (10.7 µm) image, with Deep-Layer Wind Shear product [click to enlarge]

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

After its final 2 days of northward motion as a Category 1 storm well southeast of the Outer Banks of North Carolina, Hurricane Maria was downgraded to a Tropical Storm at 2100 UTC on 26 September 2017. A comparison of the 2345 UTC September GOES-13 (GOES-East) Infrared Window (10.7 µm) image and an overlay of the 00 UTC 27 September Deep-Layer Wind Shear product (above) showed that Maria had been moving northward into an environment of increasing northeasterly shear, aiding the decrease of storm organization and intensity. However, due to the large size of the strong wind field associated with Maria, surface wind gusts as high as 59 mph were reported along the Outer Banks.

The effect of increasing wind shear was obvious in the satellite presentation of GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (below) — the low-level circulation center (LLCC) was becoming more exposed with time, while deep convection remained southeast of the LLCC.

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

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

The entrainment of dry air into the northern semicircle of Maria was evident as a warming/drying trend depicted on GOES-16 Lower-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below).

GOES-16 Lower-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play MP4 animation]

GOES-16 Lower-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play MP4 animation]

Tropical Storm Don

July 18th, 2017 |

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

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]

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

Hurricane Dora

June 26th, 2017 |

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

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.

DMSP-17 SSMIS Microwave (85 GHz) and GOES-15 Infrared Window (10.7 µm) images [click to enlarge]

DMSP-17 SSMIS Microwave (85 GHz) and GOES-15 Infrared Window (10.7 µm) images [click to enlarge]