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R. E. Holmes, C. R. Stearns, G. A. Weidner, and L. M. Keller

1. Introduction The National Science Foundation’s Office of Polar Programs operates the United States Antarctic Program’s (USAP) year-round stations in the Antarctic at Anvers Island (Palmer Station), Ross Island (McMurdo Station), and at the South Pole (Amundsen–Scott Station). While Palmer Station is generally serviced via USAP research vessels from South America, McMurdo Station is partially supplied by aircraft from Christchurch, New Zealand, and Amundsen–Scott Station is supplied entirely

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Maziar Bani Shahabadi, Stéphane Bélair, Bernard Bilodeau, Marco L. Carrera, and Louis Garand

a model first-guess precipitation field with precipitation gauge observations, which are from land surface synoptic reports (SYNOP) network and aviation routine weather reports (METAR) surface observing network. The CaPA product has been validated extensively over the North America region ( Fortin et al. 2015 ). Therefore, precipitation forecast scores are only discussed over North America in this paper, even though the forecasts are global in nature. 3) Evaluation of soil moisture analyses The

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Lance F. Bosart

JUNE I989 LANCE F. BOSART 271 FORECASTER'S FORUiV~ Automation: Has Its Time Really Come? LANCE F. BOSARTDepartment of Atmospheric Science, State University of New York, Albany, New York(Manuscript received in final form 1 February 1989) Severe budgetary constraints are forcing NMCmanagement to cut back, and possibly curtail, the subjectively prepared North American

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Clive E. Dorman and Clinton D. Winant

the two events happened coincidentallyor were dynamically related. Other uncited west coast North American studieshave linked coastal trapping to the marine layer. Reason and Steyn (1988) used nonlinear Kelvin wave dynamics to explain why progressive stratus events alongthe central California coast stop at Cape Mendocino,a phenomenon that FW noted. Eddington and O'Brien(1992) modeled an upcoast, progressive event near Pt.Conception, California, using Kelvin wave dynamics.Reason and Dunkley

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Robert R. Gillies, Shih-Yu Wang, Jin-Ho Yoon, and Scott Weaver

.g., Weickmann et al. 1985 ; Mo 1999 ; Jones 2000 ) suggest that the ISO in North America is an atmospheric response to diabatic heating anomalies associated with the Madden–Julian oscillation (MJO; Madden and Julian 2005 ). Empirical and dynamical forecasts of the MJO exhibit skill at lead times beyond 2 weeks ( Waliser 2005 ), including the operational Climate Forecast System (CFS) of the National Centers for Environmental Prediction (NCEP), which has demonstrated credible skill in predicting the MJO as

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John E. Walsh and Boniface J. Mills

therather sudden intensification of the cyclonic circulationat the surface. The intersection of the frontal boundaries existed prior to 0300-0600 UTC 5 February, whenthe significant deepening of the cyclone began. Asshown in Doswell's Fig. 2a, the frontal intersection waspresent for 424 h prior to the time of maximum 500mb vorticity advection above the surface system. Aweak ( 1015 mb) surface low existed north of NorthDakota at 1200 UTC 4 February, but we are hardpressed to analyze any low center at

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Nicholas P. Klingaman, Matthew Young, Amulya Chevuturi, Bruno Guimaraes, Liang Guo, Steven J. Woolnough, Caio A. S. Coelho, Paulo Y. Kubota, and Christopher E. Holloway

ECMWF and NCEP mimics the strategy used for NCEP in the operational North American Multimodel Ensemble ( Kirtman et al. 2014 ). Similarly, the Subseasonal Experiment (SubX) project compared models by lagging ensembles over a 7-day window ( Pegion et al. 2019 ). Trenary et al. (2017) and Trenary et al. (2018) found that NCEP S2S ensembles lagged over a 5–10-day window showed optimium performance for MJO and ENSO, respectively. We test the sensitivity to our lagged-ensemble strategy by building

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Alan C. Chan, Stephen J. Colucci, and Arthur T. DeGaetano

surface low pressure systems ( Alberta et al. 1991 ). Lackmann et al. (1996) found an antecedent negative 500-mb height anomaly over the North Pacific Ocean, indicating strengthening and a southward shift of the Pacific jet stream, based on a 12-season sample of 42 explosive wintertime cyclones. Serreze et al. (1998) concluded that snowfall over the southeast, Midwest, and mid-Atlantic states increased under the positive phase of the Pacific–North America (PNA) pattern ( Wallace and Gutzler 1981

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Weiwei Li, Zhuo Wang, and Melinda S. Peng

1. Introduction Tropical cyclones (TCs) are among the most destructive weather-related natural disasters. In the past two centuries, TCs have caused approximately 1.9 million deaths worldwide and killed more than 300 000 people in North America and the Caribbean alone ( Tobin 1997 ; Shultz et al. 2005 ; Pielke et al. 2008 ). Meanwhile, property damage from TCs increases because of the growing coastal population and development. Skillful TC prediction is therefore of significant socioeconomic

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M. S. Alvarez, C. A. S. Coelho, M. Osman, M. Â. F. Firpo, and C. S. Vera

17–23 July in central South America. Between 24 and 30 July, warm anomalies were observed in central and north Argentina, Uruguay, Paraguay, Bolivia, and southeastern Brazil, while cold anomalies were observed in eastern Brazil ( Fig. 9e ). In this section we assess the performance of ECMWF model in forecasting the temperature anomalies for this anomalously warm week and compare it with the performance of the previous anomalously cold week presented in the preceding section. For this assessment

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