 Operationally, the National Hurricane Center initiated advisories at 0300 UTC and erroneously indicated that it was a tropical depression and noted that conditions did not favor significant intensification.Later on November 22, a reconnaissance flight indicated Martha deepened to a compact hurricane, and the tropical cyclone attained a maximum sustained wind speed of 90 mph (150 km/h).Reconnaissance aircraft measured a minimum barometric pressure of , though it was later corrected to 979 mbar (28.92 inHg) in the post-season analysis.