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]

Rain/hail swath in Nebraska and Kansas

June 26th, 2017 |

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

As indicated in the Tweet above from NWS Hastings, GOES-16 imagery highlighted the presence of a narrow swath of rainfall and hail in the wake of a small thunderstorm that moved south/southeastward across the Nebraska/Kansas state line area on 26 June 2017.

A 3-panel comparison of GOES-16 Visible (0.64 µm), Snow/Ice (1.61  µm) and Shortwave Infrared (3.9  µm) images (below) revealed a subtle signature of the hail swath on the Snow/Ice images (where ice features appear as darker shades of gray: southern NE  | northern KS), while the Shortwave Infrared images showed that the hail and rainfall swathaccumulations in southern Kansas included 0.58″ at Clay Center and 0.49″ at Hebron — remained slightly cooler (lighter gray) as the adjacent dry land surfaces continued to warm during the early to middle afternoon hours. SPC storm reports listed hail of 1.75 inches in diameter in southern Nebraska and 1.25 inches in northern Kansas.

GOES-16 Visible (0.64 µm, left), Snow/Ice (1.61 µm, center) and Shortwave Infrared (3.9 µm, right) images, with hourly surface reports plotted in yellow and SPC storm reports of hail size plotted in red [click to play MP4 animation]

GOES-16 Visible (0.64 µm, left), Snow/Ice (1.61 µm, center) and Shortwave Infrared (3.9 µm, right) images, with hourly surface reports plotted in yellow and SPC storm reports of hail size plotted in red [click to play MP4 animation]

Regarding the cooling seen associated with the rainfall/hail swath, a Land Surface Temperature (LST) product derived using Aqua MODIS data (below) indicated that LST values were generally in the upper 60s to upper 70s F within the narrow swath,  in contrast to LST values in the 90s to around 100º F adjacent to the swath.

Aqua MODIS Land Surface Temperature product, Visible (0.65 µm), Infrared Window (11.0 µm) and Shortwave Infrared (3.7 µm) images [click to enlarge]

Aqua MODIS Land Surface Temperature product, Visible (0.65 µm), Infrared Window (11.0 µm) and Shortwave Infrared (3.7 µm) images [click to enlarge]