Search Results

You are looking at 1 - 10 of 14 items for

  • Author or Editor: Lawrence A. Hughes x
  • Refine by Access: All Content x
Clear All Modify Search
Lawrence A. Hughes

Abstract

Full access

THE PREDICTION OF SURGES IN THE SOUTHERN BASIN OF LAKE MICHIGAN

Part III. The Operational Basis for Prediction

LAWRENCE A. HUGHES

Abstract

The development of operational surge prediction in southern Lake Michigan is reviewed through the 10-year span starting with the disastrous surge of June 26, 1954 which took several lives in the Chicago area. Particular emphasis is given to the application of the work of others, especially Platzman, to the surge-prediction problem. Considerable detail is given on the surge of August 3, 1960, for which a successful prediction was made. This example, with its messages to the public, could serve as a model for future surge predictions. Finally a set of steps is given by which a prediction is made, followed by comments on those items still needing research before we can evaluate all parameters for an operational surge prediction.

Full access
Lawrence A. Hughes

The methods for computing “instantaneous” upper-level pressure or height tendencies are revised to allow computation of the 500 mb height tendency using the observed surface (or sea-level) pressure tendency and an appropriate portion of the 1000–500 mb thickness advection. An evaluation is made as to what constitutes an appropriate portion of the thickness advection. Use of the method is discussed and an example is given.

Full access
Lawrence A. Hughes

Abstract

Data from a number of reconnaissance flights into large Pacific tropical cyclones are combined to obtain a generalized pattern of winds at low level (about 1000 feet) under both stationary and non-stationary conditions. With these winds, a number of dependent computations are made including relative trajectories, divergence, vertical motion, rainfall, energy, and relative vorticity.

Full access
Lawrence A. Hughes

Abstract

No Abstract Available

Full access
LAWRENCE A. HUGHES

Abstract

No Abstract Available.

Full access
LAWRENCE A. HUGHES

Abstract

No Abstract Available.

Full access
Lawrence A. Hughes

Abstract

A number of problems that arise in making probability of precipitation (PoP) forecasts are noted and discussed, and solutions are given where known. This effort is based on a long-standing extensive verification of PoP's issued by 66 offices of the National Weather Service's Central Region. Verification results were sent monthly to each office and each forecaster for the past 13 years. Some additional problems and solutions dealing in general with verification and evaluation of PoP'S are discussed. These include modifications of scores generally used, plus factors to consider when trying to compare scores of offices having different climatological conditions.

Full access
Lawrence A. Hughes and Wayne E. Sangster

Abstract

Using screening regression procedures, an attempt has been made to standardize probability of precipitation Brier scores for difficulty. Climatological factors affecting the difficulty of forecasting used are: precipitation frequency, time persistence and small amount frequency. Standardizing equations were derived for three-month seasons from seven years of data. Four-term regression equations were developed for each season and lead time. Local forecaster improvement over guidance scores varied inversely as the Model Output Statistics (MOS) scores, indicating that poor machine forecasts are easier to improve upon than good machine forecasts.

Full access
Lawrence A. Hughes and David W. Saxton

An incipient severe polar outbreak that eventually affected practically all of the United States is considerably delayed by retrogression of a major trough in the westerlies. An investigation of this retrogression shows how long-wave principles aid in the prediction of such outbreaks.

Full access