Autumn 2019 looks warm across Canada according to the latest 90-day outlook from the Canadian Meteorological Center. The catalyst to the warm forecast is the exceptionally warm ocean surface surrounding North America.

The forecast keeps Dorian just offshore South Carolina today but may take the storm inland the southeast coast of North Carolina around dawn tomorrow. The closer proximity to land coupled with southwesterly upper shear should cause some weakening of Dorian but not much as models indicate surface pressure near 957 MB now rises only slightly to 963-965 MB for the encounter with North Carolina.

Dorian may be a candidate for a similar extreme rainfall to Harvey (2017) and Florence (2018) as blocking high pressure systems either side of Dorian cause a slow turn over Florida that could take up to 3 days to execute. The NOAA/WPC 7-day rainfall forecast already indicates a large swath of 15-20 in. of rain for much of eastern Florida.

Dorian may slow on approach to Puerto Rico today, lose some intensity tonight crossing the island then re-emerge north of Puerto Rico reaching hurricane strength in 2 days. Dorian turns more west-northwest due to steering guidance of a strengthening Bermuda High on the weekend. Tropical cyclone models indicate Dorian could become a major hurricane in the day 4 to 5 period while east of Florida.