sentences:  Post-analysis revealed that this tendency was an indication of tropical cyclone development.After receiving the second report on the 29th, warnings were immediately put out on the cyclone, which was given the name "Nina" from the typhoon list.For 24 hours, the center of the storm was reported to be stationary as the weather on Palmyra was continuously abnormal, but the next day, an aircraft from the Air Force showed that the storm was 500 miles north of the island and that it had intensified to hurricane strength.