SPECIFICATION OF LOW-CLOUD AMOUNT AND HEIGHT.
Technical rept. no. 2,
TRAVELERS RESEARCH CENTER INC HARTFORD CONN
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A study was made of the statistical diagnosis of lowcloud amount and cloud-base height from objective analyses of observed parameters and variables derived from them. Cloud data and other atmospheric data over the central and eastern United States were analyzed on a grid mesh of approximately 52 mi. Ability to specify cloud amount and cloud height was evaluated by using screening regression analysis and testing the diagnoses on independent data. This verification on 290 cases showed that it was possible to correctly specify low-cloud amount or cloud-base height in four categories, each about sixty percent of the time. In addition, a comparison was made of objective cloud analyses using only station cloud observations to form initial guess fields at gridpoints, and using diagnosed and station cloud data to obtain initial guesses. The analyses were improved slightly with the use of cloud diagnoses. Author