Application of the Method for Tracking Storms by Forerunners of Swell.

• Other Authors: SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CALIF
• Format: Text
• Language: English
• Published: 1948
• Subjects: Meteorology; Physical and Dynamic Oceanography; *OCEAN WAVES; *WEATHER FORECASTING; *STORMS; *MARINE METEOROLOGY; TIME INTERVALS; OCEAN SURFACE; GRAPHS; TRACKING; METEOROLOGICAL DATA; OCEANOGRAPHIC DATA; WIND DIRECTION; WIND VELOCITY; AIR WATER INTERACTIONS; PLOTTING; HARMONIC ANALYSIS; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/ADA052255; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA052255

The purpose of this study was to test the method of tracking storms by use of forerunners of swell. Copies of analyzed weather maps for the North Atlantic from 1 November 1945 through 30 November 1946 were made available by the Navy Weather Central, Washington, D. C. Wave spectrograms from Pendeen, England were provided by the Oceanographic Research Group, Admiralty Research Laboratory, Teddington, England. These records show amplitude factor versus period, as obtained by harmonic analysis of the original wave records. Analyses were made for twenty minute intervals every two hours. The records were inspected in order to find bands of forerunners that could be identified for a period of six hours or more. The identifying features of the band, such as the fore edge and the rear edge, were carefully marked. Next, the time of arrival, as shown on the analyzed wave records, and the period of these identifying features were tabulated and plotted on a 'Storm Tracking Graph'. This determined the foci which gave a time and position for the storm that generated the swell. Then, and then only, were the weather maps consulted to determine if a storm actually existed at the given time and place.