The origin of Hugo was detected on satellite imagery on the 9th of September when a cluster of thunderstorms moved
off the coast of Africa. It developed into a tropical depression to the southeast of the Cape Verde Islands the following
day, then moved westward near 20 mph across the tropical Atlantic Ocean, becoming a tropical storm on the 11th and
a hurricane on the 13th, while located 1100 nm east of the Leeward Islands.  The storm turned west-northwest and
slowed its forward motion in response to low pressure to the north of Puerto Rico which weakened the subtropical
ridge to its north.

Hugo struck Guadeloupe just past midnight on the 17th.  Continuing to decelerate, the eye moved over St. Croix very
early on the morning of the 18th.  It then accelerated, moving over Vieques, Puerto Rico mid-morning and then over the
extreme northeast tip of mainland Puerto Rico an hour later.   Below are maps showing the rainfall distribution across
Puerto Rico and the U.S. Virgin Islands, using data provided by the National Climatic Data Center in Asheville, North
Carolina.

It slowly turned to the north-northwest in response to an  upper cyclone offshore Georgia.  The track slowly bent to
the left as it circumnavigated the upper low as it moved southwest away from the storm. The cyclone then accelerated
northwest in the confluent zone between the upper low and the subtropical ridge to its northeast.

Landfall in South Carolina occurred at midnight on the night of the 21st as the system sped northwest at 26 mph.
It moved inland, passing between Columbia and Shaw Air Force Base early on the morning of the 22nd.  Hugo
weakened to a tropical storm by mid-morning as it passed to the west of Charlotte, North Carolina.  Thereafter,
it responded to a major extratropical cyclone moving across the central United States by moving more to the north.
It passed quickly through western Virginia, West Virginia, and eastern Ohio to Erie, Pennsylvania by the evening
of the 22nd as it become an extratropical storm. It then fled northeastward across eastern Canada into the far
North Atlantic Ocean.  Below is the track of Hugo, supplied by the National Hurricane Center.

The graphics below show the storm total rainfall for Hugo.  Note the maxima near the point of landfall in South Carolina, and
where the best upslope into the Appalachians occurred to the right of its track.