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Wassila M. Thiaw and Vadlamani B. Kumar

decades, much attention has focused on advance risk planning in agriculture and water and, more recently, on health. These initiatives require updates of weather and climate outlooks. This paper describes the active role of NOAA’s African Desk in FEWS and in enhancing the capacity of African institutions to improve forecasts. The African Desk was established in 1994 to provide services to U.S. agencies and African institutions. Emphasis is on the operational products across all time scales from

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Rosalind Cornforth, Douglas J. Parker, Mariane Diop-Kane, Andreas H. Fink, Jean-Philippe Lafore, Arlene Laing, Ernest Afiesimama, Jim Caughey, Aida Diongue-Niang, Abdou Kassimou, Peter Lamb, Benjamin Lamptey, Zilore Mumba, Ifeanyi Nnodu, Jerome Omotosho, Steve Palmer, Patrick Parrish, Leon-Guy Razafindrakoto, Wassila Thiaw, Chris Thorncroft, and Adrian Tompkins

very intense convective events. Despite this, 24-h quantitative precipitation forecasts for West Africa often have no additional skill when compared to climatology in operational ensemble forecasts from global numerical weather predication models ( Vogel et al. 2018 ). Indeed, weather forecasting and “nowcasting” for the region has in recent years fallen behind relative to other parts of the world. To advance the scientific understanding of the weather and climate of West Africa and its human

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Robert A. Clark III, Zachary L. Flamig, Humberto Vergara, Yang Hong, Jonathan J. Gourley, Daniel J. Mandl, Stuart Frye, Matthew Handy, and Maria Patterson

—with the same input data—using multiple hydrological model cores (see Fig. 3 for more information on the organization of EF5 components). Most importantly, perhaps, ensemble forecasts provide an envelope of potential solutions applicable to a specific forecasting problem and can be used to get at the underlying uncertainty characteristic of a particular forecast scenario. In 2016, EF5 became operational across the U.S. National Weather Service (NWS) for flash flood forecasting by local Weather

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Zewdu T. Segele, Michael B. Richman, Lance M. Leslie, and Peter J. Lamb

decreasing frequency, 2) predictors that are decreasing in skill, 3) predictors that were not included in the selected sets that are starting to show additional skill, and 4) changes in the likelihood functions due to climate change. Updating the RV and LOOCV prediction models using the entire data with follow up real-time forecast evaluation realistically could lead to successful real-time operational use of the approaches. The simultaneous use of both approaches builds confidence in the value of the

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Lisa Hannak, Peter Knippertz, Andreas H. Fink, Anke Kniffka, and Gregor Pante

height between the actual ERA-I reanalysis and the short-term forecasts used here (not shown). Fig . 4. Surface downwelling shortwave irradiance in W m −2 : (a) CM SAF operational SEVIRI product, (b) CM SAF SARAH product, (c) ERA-I, and (d) mean over YoTC models. Climatologies from ground-based observations are depicted as circles. All data are temporally averaged over JAS but available periods differ: 2007–15 in (a), 1983–2008 in (b), and 1991–2010 in (c) and (d) with varying coverage for the

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Abdou L. Dieng, Saidou M. Sall, Laurence Eymard, Marion Leduc-Leballeur, and Alban Lazar

GATE . Mon. Wea. Rev. , 105 , 317 – 333 , doi: 10.1175/1520-0493(1977)105<0317:TSAPOA>2.0.CO;2 . 10.1175/1520-0493(1977)105<0317:TSAPOA>2.0.CO;2 Reed , R. J. , E. Klinker , and A. Hollingsworth , 1988 : The structure and characteristics of African easterly wave disturbances as determined from the ECMWF operational analysis/forecast system . Meteor. Atmos. Phys. , 38 , 22 – 33 , doi: 10.1007/BF01029944 . 10.1007/BF01029944 Thorncroft , C. D. , and M. Blackburn , 1999

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Susan Stillman, Xubin Zeng, and Michael G. Bosilovich

performed better in humid regions than in arid regions and overestimated light rainfall while underestimating moderate and heavy rainfall. Reanalyses combine model forecast with observations to provide globally continuous fields of the analyzed observations and other variables derived from the background model. While observationally driven, their ability to estimate physical processes, such as precipitation, depends on many factors, including observational coverage and model performance, and is

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Gang Zhang, Kerry H. Cook, and Edward K. Vizy

fields on 3-hourly intervals over West Africa. To reduce the uncertainty of using reanalysis data, other global reanalyses are also compared with MERRA, including the National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR; Saha et al. 2010 ), the ECMWF interim reanalysis (ERA-Interim; Dee et al. 2011 ), and the ECMWF reanalysis from their operational forecasts for the AMMA observational campaign with AMMA radiosonde data assimilated (ECMWF-OPERA; Agustí

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Elinor R. Martin and Chris Thorncroft

: An evaluation of the performance of the ECMWF operational system in analyzing and forecasting easterly wave disturbances over Africa and the tropical Atlantic . Mon. Wea. Rev. , 116 , 824 – 865 , doi: 10.1175/1520-0493(1988)116<0824:AEOTPO>2.0.CO;2 . Richter , I. , S.-P. Xie , S. K. Behera , T. Doi , and Y. Masumoto , 2014 : Equatorial Atlantic variability and its relation to mean state biases in CMIP5 . Climate Dyn. , 42 , 171 – 188 , doi: 10.1007/s00382-012-1624-5 . Roehrig

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Rahul S. Todmal

Tallaksen 2000 ). During the drought period, water scarcity affects all human activities in general and agricultural activities in particular, leading to reductions in agricultural production and productivity in the arid and semiarid regions ( Das et al. 2003 ; Pandey et al. 2008 ). To quantify various characteristics of drought, operational definitions are constructed in the form of drought indices ( Smakhtin and Hughes 2004 ). As drought is a relative phenomenon ( Van Loon 2015 ), various region

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