VIIRS imagery from Suomi NPP and NOAA-20, above, show the structure of Hurricane Ernesto as it pulls away from Puerto Rico. Dry air is entrained within the storm, as evidenced by the regions near the center where convection is absent. Sea-surface temperatures in the region are quite warm, however, and shear is small, as shown below: strengthening is forecast.

Ernesto is tucked within the southeast corner of the GOES-16 CONUS sector field of view. Five-minute GOES-16 Low-Level Water Vapor infrared imagery (Band 10, 7.34 µm) and GLM observations of Flash-Extent Density, below, show very warm brightness temperatures over the Greater Antilles. MIMIC Total Precipitable water fields (at bottom) show dry air there as well. The future intensity of Ernesto will be directly affected by how much of the dry air continues to infiltrate into the storm circulation. Lightning observations at this time were mostly confined to Ernesto’s outer bands.

For the latest information on Ernesto, refer to the National Hurricane Center: https://www.nhc.noaa.gov .

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Tropical Cyclone’s Debby slow progress up the east coast of the US (Blog Post) resulted in a prolonged rain event. The slider above compares the Susquehanna River on 1 August (a clear day before Debby) and on 13 August, after the inundation. The turbidity of the river, and its discharge into Chesapeake Bay increased enough to be obvious to satellite detection.

Data from the USGS Gauge at Harrisburg, below, shows the heavy rain (especially on 9 August), the increase in river height, and the large increase in river flow for the week ending 13 August 2024.

Thanks to Dave Zaff, NWS Eastern Region HSD, for alerting us to this imagery. Imagery for this post was created with Geo2grid.

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Aurora Borealis made a return appearance to the northern United States early in the morning on 12 August. Imagery above from the VIIRS Imagery Viewer, which viewer repackages Direct Broadcast imagery processed at CIMSS with CSPP software, shows the aurora over the eastern USA at 0704 UTC o 12 August as captured by NOAA-21. The image below shows the Aurora at 0843 UTC on 12 August — on NOAA-21’s next pass over the USA. The character of the Aurora has certainly changed in the 90+ minutes!

The Aurora was also present on 13 August, but it did not extend quite so far to the south, being more restricted to northern Canada, as shown below.

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GOES-16 Clean Window infrared (Band 13, 10.3 µm) images from 2-9 August 2024 show the development of Debby over the greater Antilles and then northward from Cuba, landfall in Florida and subsequent slow progress north along the eastern United States coastline, finally exiting the region on 9 August. The above animation was created using geo2grid software.

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