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Eswar R. Iyer, Adam J. Clark, Ming Xue, and Fanyou Kong

utilizing ensembles to depict the high degree of forecast uncertainty often associated with convection. However, due to computational limitations, it has only been very recently that operational models with sufficient resolution to explicitly depict convection [hereafter referred to as convection-allowing models (CAMs) 1 ] have become available, and assessing and improving their capabilities is a rich area of research. Recent work has shown that CAMs provide advantages relative to models that

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Jaymes S. Kenyon, Daniel Keyser, Lance F. Bosart, and Michael S. Evans

provides a metric of lateral motion, between that of the laterally quasi-stationary and laterally translating categories (refer to Fig. 1b ). We hypothesize that a much larger sample of hybrid snowband events than the sample of seven events considered in this study might facilitate the identification of coherent subcategories of hybrid snowbands, from which composites could be constructed. Investigation of this hypothesis is suggested for future work. b. Applications to operational forecasting The

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Jaymes S. Kenyon, Daniel Keyser, Lance F. Bosart, and Michael S. Evans

provides a metric of lateral motion, between that of the laterally quasi-stationary and laterally translating categories (refer to Fig. 1b ). We hypothesize that a much larger sample of hybrid snowband events than the sample of seven events considered in this study might facilitate the identification of coherent subcategories of hybrid snowbands, from which composites could be constructed. Investigation of this hypothesis is suggested for future work. b. Applications to operational forecasting The

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Sim D. Aberson and J. Kaplan

) in 24 h ( Kaplan and DeMaria 2003 )] has been by Klotzbach (2012) . They found that, in the Atlantic basin, RI is 4 times more likely during the active MJO phase than during the inactive phase, but did not explore whether the MJO can be useful in predictive schemes for RI. The current study is an effort to extend Klotzbach (2012) to the central and east Pacific, and to test whether the MJO may have predictive capability in current forecast schemes. Section 2 describes the data used, followed

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Morten Køltzow, Barbara Casati, Eric Bazile, Thomas Haiden, and Teresa Valkonen

forecast accuracy by the use of optimized physics for the targeted area and finer horizontal and vertical resolution ( Jung et al. 2016 ). However, operational convection permitting resolution models have just recently started to appear for the Arctic domain. Müller et al. (2017) and Yang et al. (2018) describe added value from operational high-resolution HIRLAM–ALADIN Research on Mesoscale Operational NWP in Euromed (HARMONIE)–Applications of Research to Operations at Mesoscale (AROME) runs in the

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S. Vannitsem

1. Introduction Model output statistics (MOS) techniques are used worldwide to improve meteorological operational forecasts. The MOS method consists of correcting the model outputs based on the information gathered from past forecasts ( Wilks 2006 ). The most popular and approach is the use of a linear regression between the predictors coming from the forecasts and the observations (or predictands). This approach has been proven to be very successful for global ( Glahn and Lowry 1972 ; Klein

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Ryan D. Torn and Gregory J. Hakim

) for reviews of the EnKF. Progress on EnKF systems has reached the point where several groups have applied it to global NWP models in operational settings. Houtekamer et al. (2005) used an EnKF to assimilate all available observations with the Canadian Meteorological Center (CMC) Global Environmental Multiscale (GEM) model. Their results show that the error in EnKF-initialized forecasts is similar to those in the CMC operational three-dimensional variations data assimilation (3DVAR) scheme. This

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Raymond F. Toll Jr. and William M. Clune

to identify systematic pressure, displacement, and directional errorsin the 48-hour surface pressure forecast of extmtropical cyclones by the Navy Operational Global AtmosphericPrediction System (NOGAPS) has been completed for the 1983 Northern Hemisphere winter season (5 January31 March). All available NOGAPS 0000 and 1200 GMT forecast cycles are verified for the Western Pacific,Eastern Pacific, and Atlantic Oceans north of the equator. NOGAPS generally underforecasts the intensity of

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Tan Phan-Van, Thanh Nguyen-Xuan, Hiep Van Nguyen, Patrick Laux, Ha Pham-Thanh, and Thanh Ngo-Duc

National Centers for Environmental Prediction (NCEP) Climate Forecast System (CFS), which became operational in 2004 ( Saha et al. 2006 , 2014 ). Several studies have been carried out to evaluate the skill of CFS products in subseasonal-to-seasonal predictions of rainfall and monsoon indices worldwide (e.g., Siegmund et al. 2015 ; Yuan et al. 2011 , 2012 ; Liu et al. 2013 ; Pattanaik and Kumar 2010 ). According to Yuan et al. (2012) , the CFS has a high degree of skill in forecasting monsoon

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C. Lemcke and S. Kruizinga

MAY 1988 C. LEMCKE AND S. KRUIZINGA 1077Model Output Statistics Forecasts: Three Years of Operational Experience in the Netherlands C. LEMCKE AND S. KRUIZINGARoyal Netherlands Meteorological Institute (KNMI), de Bilt, The Netherlands(Manuscript received 20 July 1987, in final form 5 November 1987)ABSTRACT In the Netherlands, one to five day Model Output Statistics

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