Maria: Tropical Storm Watch for the Outer Banks of North Carolina

September 24th, 2017 |
Track of Hurricane Maria [click to enlarge]

Track of Hurricane Maria [click to enlarge]

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

Hurricane Maria was downgraded to a Category 2 storm at 12 UTC on 24 September 2017 (above), when it was located about halfway between Miami and Bermuda.

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (below) showed a close-up view of the eye region of Maria during the daylight hours.

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]

Due to the large size of the radius of Tropical Storm force winds, a Tropical Storm Watch was issued late in the day for the Outer Banks and adjacent inland areas of North Carolina (below).

NHC advisory

UPDATE: 12 hours later, much of the Tropical Storm Watch was upgraded to a Tropical Storm Warning.

The Eye of Maria north of Hispaniola

September 21st, 2017 |

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

Hurricane Maria presented a very interesting eye structure during the course of the day on 21 September 2017, as shown in the mp4 animation above (also available as a YouTube video).  The animation shows 10.3 µm imagery every 2 minutes from 0849 UTC through 2122 UTC on 21 September 2017.

Pete Pokrandt, at the University of Wisconsin Atmospheric and Oceanic Sciences Department, created a similar animation using the 0.64 µm Visible channel on GOES-16.

30-second interval (using overlapping 1-minute interval Mesoscale Sector) GOES-16 Visible (0.64 µm) and Infrared Window (10.3 µm) images covering the 6-hour period from 1031-1631 UTC are shown below. During this time, Maria re-intensified to a Category 3 hurricane, with the eye centered just off the northeastern coast of the Dominican Republic.

GOES-16 Visible (0.64 µm, left) and Infrared Window (10.3 µm, right) images at 30-second intervals (Click to animate)

GOES-16 Visible (0.64 µm, left) and Infrared Window (10.3 µm, right) images at 30-second intervals (Click to animate)

For more information on Maria, visit the National Hurricane Center website.  The CIMSS Tropical Weather Website has information as well.

Puerto Rico after Maria

September 21st, 2017 |

Suomi NPP Day Night Band Visible (0.7 µm) Imagery, ~0600 UTC, 21 September 2017 (Click to enlarge)

Suomi NPP Overflew Puerto Rico at ~0555 UTC on 21 September, and the Day Night Band Visible Imagery (0.7 µm), above (from Real Earth, direct link here), shows city lights from San Juan and Ponce on the northeast and southwest shores, respectively, shining through relatively thick clouds to the southeast of the eye of the storm.

Annotated Imagery from Suomi NPP (VIIRS Day Night Band Visible (0.7 µm) Imagery and Infrared (11.45 µm) courtesy of William Straka) are shown below.

Suomi NPP Day Night Band Visible (0.7 µm) Imagery, 0554 UTC on 21 September 2017 (Click to enlarge)

Suomi NPP VIIRS Infrared (11.45 µm) Imagery, 0554 UTC on 21 September 2017 (Click to enlarge)

Convective Development over the Upper Midwest

September 20th, 2017 |

GOES-16 Derived Convective Available Potential Energy (CAPE), 1702-2137 UTC on 20 September 2017 (Click to enlarge)

 

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

GOES-16 Data are used to create many Baseline Products that can be used to monitor and anticipate weather.  The animation above shows the GOES-16 Convective Available Potential Energy (CAPE).  Values increased by about 50-75% in a corridor from southern Wisconsin southwestward to Missouri over the course of four hours as shown in the loop.  CAPE varies over Illinois, with a minimum extending from Chicago southwestward, with larger values to the east and to the west.  The CAPE developed in a region where the Storm Prediction Center had a slight risk of severe weather. A Mesoscale Discussion for the region was also issued. Hail up to two inches in diameter was reported in central Wisconsin.

Baseline Stability Products are Clear-Sky only products. (They are also available online here, albeit delayed.) Because they are Clear-Sky products, they are most useful for monitoring the pre-convective environment.

GOES-16 Visible (0.64 µm) Imagery, 1702-2137 UTC on 20 September 2017 (Click to enlarge)

Visible Imagery (0.64 µm) for the same period as the CAPE animation, above, shows the development of convection along a front moving into Wisconsin. Note also the lack of cumulus development in the CAPE minimum over Illinois.  The large CAPE values over southwestern Missouri were not tapped, as convection did not trigger there.

(Added: Click here to see a Band 13 “Clean Window” Infrared (10.3 µm) animation from GOES-16, from 2302 UTC on 20 September to 0652 UTC on 21 September.)