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depression are made for periods up t o 36 hours using observed700-mb. charts and initial and 12-hr. forecast vertical motion charts from the JNWP Unit's thermotropic model.Results show that moisture can be successfully forecast by this technique. Through establishment of a relationshipbetween 700-mb. dewpoint depression, instantaneous vertical velocity, and large-scale weather, a forecast scheme isdevised using forecast 700-mb. dewpoint depression and forecast vertical motion from the thermotropic model

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September 1968E. Lee Geraldson649A COMPARISON OF THE ACCURACY OF OBJECTIVE TECHNIQUES FOR FORECASTING TYPHOON MOVEMENT DURING 1967E. LEE GERALDSONJoint Typhoon Warning Center, GuamABSTRACTIn the past, many objective techniques have been evaluated for severe tropical cyclones in the Atlantic, butlittle has been done along this line in the Pacific. A computer program was developed at the Joint Typhoon WarningCenter, to verify 10 separate 24-hr. forecast techniques. During the course of the 1967

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Luying Ji, Xiefei Zhi, Clemens Simmer, Shoupeng Zhu, and Yan Ji

et al. (2006) is adopted for calculating verification scores in this study. MODE is a typical feature-based displacement approach and an example for a spatial diagnostic technique. MODE attempts to mimic the way a human would subjectively evaluate a forecast via setting a precipitation threshold and spatially convoluting (scale-dependent averaging) the precipitation field. The median of maximum interest (MMI; Davis et al. 2009 ) and the object-based threat score (OTS; Johnson et al. 2011a

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Lin Dong and Fuqing Zhang

models per se, but are instead combinations of forecasts from multiple models ( Cangialosi and Franklin 2014 ). Therefore, the performance of a consensus model is determined by two factors: the consensus technique and the consensus components. Consensus technique refers to how the weight of each component is assigned, and can be divided into two categories: equal weights and unequal weights. Equal weights are calculated by a simple arithmetic average, whereas unequal weights are determined using more

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Sheng-Lun Tai, Yu-Chieng Liou, Juanzhen Sun, Shao-Fan Chang, and Min-Chao Kuo

, a cloud-scale model formulated using the Cartesian coordinate system and a warm rain microphysical process, is adopted as a forward forecast model ( Sun and Crook 1997 ). Using this prognostic model as a constraint and applying the 4DVAR technique, VDRAS is able to find an optimal initial state that minimizes a cost function ( J ), which measures the distances between the model predictions and the observations, and can be written as In (1) , the summation is conducted over space ( σ ) and time

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Theodore W. Funk

548 WEATHER AND FORECASTING VOLUME6FORECASTING TECHNIQUESForecasting Techniques Utilized by the Forecast Branch of the National Meteorological Center During a Major Convective Rainfall Event THEODORE W. FUNK*NWS/NMC /Meteorological Operations Division/Forecast Branch, Washington, D. C.28 February 1991 and 10 July 1991 Meteorologists within the Forecast Branch (FB) of the

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Wansuo Duan and Zhenhua Huo

mean of the forecasting members is often regarded as the result of a deterministic forecast. The ensemble mean may filter the unpredictable parts and leave the common parts of the forecasting members, ultimately decreasing the uncertainties of single forecast results ( Leith 1974 ; Leutbecher and Palmer 2008 ). With its benefit of producing probabilistic distribution information of forecast results, ensemble forecasting has become a major technique in numerical weather and climate forecasting

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Anu Simon, Andrew B. Penny, Mark DeMaria, James L. Franklin, Richard J. Pasch, Edward N. Rappaport, and David A. Zelinsky

during HFIP ( Cangialosi and Franklin 2016 ). To extend these improvements in NWP skill, multimodel consensus postprocessing techniques can also be applied. Multimodel consensus forecast guidance is widely used in many operational weather forecasting centers. The National Hurricane Center (NHC) relies on various consensus aids to help improve TC track and intensity forecasts. Goerss (2000) found that a simple, equally weighted average of several models consistently outperforms each of the

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Andrew J. Condon, Y. Peter Sheng, and Vladimir A. Paramygin

which can be important. As pointed out by Rego and Li (2009) and Jelesnianski (1972) , neglecting the forward speed and angle of approach may not be appropriate as there is a “critical motion relative to a coast that gives the highest possible surge.” Additionally the technique does not account for tides and wave setup, which can contribute significantly to the surge and inundation. This paper addresses the rapid generation of high-resolution probabilistic inundation forecasts. The optimal storm

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Lynette van Schalkwyk and Liesl L. Dyson

Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis data ( Kalnay et al. 1996 ) to investigate the synoptic circulation patterns that lead to fog over the northeastern part of the United States, focusing specifically on patterns resulting in fog in the New York region. After using clustering techniques to obtain more information about the nature of fog at three different airports in Finland, 40-yr European Centre for Medium-Range Weather Forecasts

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