The Atlantic hurricane reanalysis project analyzed the 1938 Atlantic hurricane season in 2012, and Weather Bureau forecaster Ivan Ray Tannehill noted that the knowledge of the storm's existence remained tenuous until September 17 when the cyclone had already increased to a hurricane.
Based on land and marine observations, the reanalysis project concluded that the 1938 hurricane began as a tropical depression just off the coast of West Africa at 12:00 UTC (8 a.m. Eastern Standard Time) on September 9, becoming the sixth tropical cyclone of the season.
The depression gradually strengthened, becoming a tropical storm less than a day after tropical cyclogenesis.
It was inferred to have reached hurricane intensity over the central Atlantic by September 15, though ship observations became increasingly sparse as the cyclone tracked farther away from land.
The first definitive indication of a tropical cyclone at sea was a report from the Brazilian ship SS Alegrete which documented a barometric pressure of 958 mbar (hPa; 28.29 inHg) within hurricane-force winds on September 17.
Based on this observation, the hurricane had maximum sustained winds of 125 mph (200 km/h), making it the equivalent of a high-end Category 3 hurricane on the Saffir–Simpson hurricane wind scale.

The hurricane continued to slowly strengthen and track westward at around 20 mph (32 km/h) about the southern periphery of a subtropical ridge centered over the Sargasso Sea.
On September 18, a strong extratropical cyclone developed just west of Chicago, generating a strong influx of cooler air from Canada into the eastern United States and thus forming a sharp cold front over the region; this frontal boundary resulted in a channel of moist, tropical air being steered northwards into New England.
At 18:00 UTC (2 p.m. EST) on September 19, the tropical cyclone strengthened further into a Category 5-equivalent hurricane with sustained winds of 160 mph (260 km/h) while north of the Turks and Caicos; this figure remained unchanged in reanalysis and serves as the storm's peak strength, although the reanalysis project noted that "considerable uncertainty" remains regarding the magnitude of the storm's maximum intensity at sea.
Concurrently, the hurricane began to interact with the cold front over the East Coast, causing the tropical cyclone to curve northward towards the northeastern United States; the presence of the subtropical ridge to the east and the stationary nature of the frontal boundary prevented the storm from continuing to curve out to sea.

As the hurricane accelerated northward, it gradually weakened.
On the morning of September 21, it passed roughly 75 mi (120 km) east of Cape Hatteras.
At 12:00 UTC (8 a.m. EST) that day, the storm was estimated to have a barometric pressure of 940 mbar (hPa; 27.76 inHg); this is the hurricane's lowest documented pressure.
At 19:45 UTC (3:45 p.m. EST), the hurricane made landfall on Long Island over Bellport, New York with maximum sustained winds of 120 mph (195 km/h) and a pressure of 941 mbar (hPa; 27.79 inHg), making it the strongest tropical cyclone to hit the New York City area.
It was moving rapidly northward at 47 mph (76 km/h), enhancing the intensity of the winds east of the center; in addition, its forward motion displaced its center of circulation 17 mi (28 km) away from the point of minimum barometric pressure.
Weather Bureau forecaster Charles Pierce argued that the hurricane became extratropical off of the Outer Banks, though Charles J. Neumann, Frances P. Ho, and the Atlantic hurricane reanalysis project suggested that it was tropical but in the process of extratropical transition at landfall.
Afterwards, it quickly tracked across Long Island and Long Island Sound before making a second and final landfall near New Haven, Connecticut as a slightly weaker hurricane with winds of 115 mph (185 km/h), making it one of only three recorded tropical cyclones to hit Connecticut as major hurricanes.
The storm steadily weakened, becoming fully extratropical over Vermont by 00:00 UTC on September 22 (September 21, 8 p.m
The Atlantic hurricane reanalysis project analyzed the 1938 Atlantic hurricane season in 2012, and Weather Bureau forecaster Ivan Ray Tannehill noted that the knowledge of the storm's existence remained tenuous until September 17 when the cyclone had already increased to a hurricane. Based on land and marine observations, the reanalysis project concluded that the 1938 hurricane began as a tropical depression just off the coast of West Africa at 12:00 UTC (8 a.m. Eastern Standard Time) on September 9, becoming the sixth tropical cyclone of the season. The depression gradually strengthened, becoming a tropical storm less than a day after tropical cyclogenesis. It was inferred to have reached hurricane intensity over the central Atlantic by September 15, though ship observations became increasingly sparse as the cyclone tracked farther away from land. The first definitive indication of a tropical cyclone at sea was a report from the Brazilian ship SS Alegrete which documented a barometric pressure of 958 mbar (hPa; 28.29 inHg) within hurricane-force winds on September 17. Based on this observation, the hurricane had maximum sustained winds of 125 mph (200 km/h), making it the equivalent of a high-end Category 3 hurricane on the Saffir–Simpson hurricane wind scale.
The hurricane continued to slowly strengthen and track westward at around 20 mph (32 km/h) about the southern periphery of a subtropical ridge centered over the Sargasso Sea. On September 18, a strong extratropical cyclone developed just west of Chicago, generating a strong influx of cooler air from Canada into the eastern United States and thus forming a sharp cold front over the region; this frontal boundary resulted in a channel of moist, tropical air being steered northwards into New England. At 18:00 UTC (2 p.m. EST) on September 19, the tropical cyclone strengthened further into a Category 5-equivalent hurricane with sustained winds of 160 mph (260 km/h) while north of the Turks and Caicos; this figure remained unchanged in reanalysis and serves as the storm's peak strength, although the reanalysis project noted that "considerable uncertainty" remains regarding the magnitude of the storm's maximum intensity at sea. Concurrently, the hurricane began to interact with the cold front over the East Coast, causing the tropical cyclone to curve northward towards the northeastern United States; the presence of the subtropical ridge to the east and the stationary nature of the frontal boundary prevented the storm from continuing to curve out to sea.
As the hurricane accelerated northward, it gradually weakened. On the morning of September 21, it passed roughly 75 mi (120 km) east of Cape Hatteras. At 12:00 UTC (8 a.m. EST) that day, the storm was estimated to have a barometric pressure of 940 mbar (hPa; 27.76 inHg); this is the hurricane's lowest documented pressure. At 19:45 UTC (3:45 p.m. EST), the hurricane made landfall on Long Island over Bellport, New York with maximum sustained winds of 120 mph (195 km/h) and a pressure of 941 mbar (hPa; 27.79 inHg), making it the strongest tropical cyclone to hit the New York City area. It was moving rapidly northward at 47 mph (76 km/h), enhancing the intensity of the winds east of the center; in addition, its forward motion displaced its center of circulation 17 mi (28 km) away from the point of minimum barometric pressure. Weather Bureau forecaster Charles Pierce argued that the hurricane became extratropical off of the Outer Banks, though Charles J. Neumann, Frances P. Ho, and the Atlantic hurricane reanalysis project suggested that it was tropical but in the process of extratropical transition at landfall. Afterwards, it quickly tracked across Long Island and Long Island Sound before making a second and final landfall near New Haven, Connecticut as a slightly weaker hurricane with winds of 115 mph (185 km/h), making it one of only three recorded tropical cyclones to hit Connecticut as major hurricanes. The storm steadily weakened, becoming fully extratropical over Vermont by 00:00 UTC on September 22 (September 21, 8 p.m
1938 New England hurricane