Post-Tropical Cyclone Lee makes landfall in Nova Scotia11 hours of 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed Post-Tropical Cyclone Lee as it approached Atlantic Canada and Maine on 16 September 2023. PTC Lee made landfall in far western Nova Scotia around 2000 UTC, and produced strong winds and heavy rainfall across much of Maine.
A longer animation of 5-minute CONUS Sector GOES-16 Air Mass RGB images (below) portrayed the large size of Lee, which transitioned from a Category 1 Hurricane to a Post-Tropical Cyclone by 0900 UTC. Shades of orange in the RGB imagery indicated that dry air had wrapped into the southern and eastern quadrants of Lee.Hourly MIMIC Total Precipitable Water (TPW) images (below) showed the moisture associated with Lee as it moved northward across parts of New England and the Canadian Maritimes. Darker shades of red represented TPW values of 2.5 to 3.0 inches. A plot of rawinsonde data (source) from Caribou, Maine KCAR at 0000 UTC on 17 September (below) indicated that the TPW value of that very moist sounding was 1.51 inches — which was not much less than the record value for all 17 September / 0000 UTC soundings (source) for Caribou, which was 1.63 inches (bottom).