Search Results

You are looking at 1 - 10 of 15 items for

  • Author or Editor: Samson Brand x
  • Refine by Access: All Content x
Clear All Modify Search
Samson Brand

Abstract

Fifteen years of typhoon data (1953–67) were evaluated to determine the general character of the “Fuji-whara effect” with respect to the separation distance between two interacting tropical cyclones. The results show that the rotation of the binary system is sharply dependent upon separation distance for distances <750 n mi. There appears also to be a slight attraction between the two vortex systems, which becomes well defined at separation distances <400 n mi. The results are compared with theoretical rotation rates for vortex systems with varying velocity profiles.

Full access
Samson Brand

Tropical cyclone research from the operational, applied viewpoint falls into two categories—forecasting research and decision-making research. One aspect of the latter is the typhoon haven evaluations being done by the Naval Environmental Prediction Research Facility in the western Pacific and Indian Ocean regions. Some 23 ports and harbors are being evaluated as to their suitability as tropical cyclone havens. The aim is to aid decision makers and commanding officers of ships in evaluating a typhoon threat situation and to assist them in making better decisions in regard to evasion, remaining in port, or the seeking of shelter within a harbor or specific section of a harbor. A number of aspects of the haven studies are discussed.

Full access
Samson Brand

The meteorologist in the navy is rarely the decision maker. The meteorological information that is produced by model output or remotely sensed data has to be presented in a more tactically relevant form before being applied by military decision makers. Because of the increasing sensitivity to atmospheric parameters of new, sophisticated navy platforms, sensors, and weapon systems, knowledge of the environments in which they operate is also growing in importance. This article briefly discusses how the present-day meteorologist assists the navy decision makers.

Full access
Samson Brand

Abstract

Typhoons of the western North Pacific Ocean are examined to determine the effects on tropical cyclones of cooler surface waters due to upwelling and mixing produced by a prior tropical cyclone. The results show that both the movement and the intensity of a tropical cyclone may be affected by the cooler water left in the wake of a prior storm.

Full access
Samson Brand

Abstract

Twenty-five years of tropical storm and typhoon data for the western North Pacific (1945–69) were evaluated to determine the geographic and seasonal variation of those tropical cyclones which rapidly intensified over the open ocean (≥50 kt increase in 24 hr), and those tropical cyclones that weakened at low latitudes over the open ocean (≥20 kt decrease In 24 hr, south of 25N). The results show distinct geographic and seasonal preferences for both rapid intensification and low-latitude weakening of tropical cyclones.

Full access
Samson Brand and Jack W. Blelloch

Tropical cyclone forecast improvements in the western North Pacific are examined in terms of Department of Defense decision making (evacuation, sortie, preparedness, etc.). The improved decisions are then related directly to Department of Defense potential cost saving.

Full access
Lawrence D. Burroughs and Samson Brand

Abstract

Twenty-five years of tropical cyclone data (1945–69) for the western North Pacific were evaluated to determine the, speed-of-movement characteristics of tropical storms and typhoons following recurvature. The results show that the acceleration of storms following recurvature is dependent on the meteorological characteristics of the storm, and the surrounding synoptic environment which is a function of the time of the year. Forecast equations derived by linear regression techniques are presented for the speed of movement of tropical cyclones 36 hr after recurvature.

Full access
Samson Brand and Jack W. Blelloch

Abstract

Thirty typhoons (1960–70) are examined to determine the effect of the Philippines an the intensity, speed of movement, and size characteristics of tropical cyclones crossing the Philippines. The results show an average intensity (maximum surface wind) decrease of 33%, a northward perturbation as the storms pass through the Islands, and a decrease of circulation size for weak typhoons. The study also showed an increase in speed of movement as storms approach the Philippines.

Full access
Samson Brand and Jack W. Blelloch

Abstract

Twenty-two typhoons (1960–72) are examined to determine the effect of Taiwan on the intensity and movement of tropical cyclones crossing the island. The results show an average intensity (maximum surface wind) decrease of over 40% and a distinct northward deflection as the storms approach the island with a southward deflection after passage. Forecast rules for typhoons approaching or crossing Taiwan are presented.

Full access
Robert W. Fett and Samson Brand

Abstract

A method to predict 24 h movement of tropical cyclones using consecutive daily satellite views is described. The method is based on the observation that changes in the location of major structural features of the storm are correlated with changes in the direction of movement of the storm centers. Major structural features appear to retain the same relative location with respect to the direction of movement of the storm center. The rotation of features noted in comparing satellite views over a 24 h period is frequently found to approximate in sense and value the further deflection the storm will take in its track during the following 24 h. A test evaluation of the method was conducted by seven individuals using 31 separate data sets of satellite data. For the purposes of the test only direction of movement forecasts were made and storm center displacement was neglected. The results on a post-analysis, non-real-time, basis compared favorably with official 24 h forecasts.

Full access