Search Results

You are looking at 1 - 10 of 458 items for :

  • Bulletin of the American Meteorological Society x
  • All content x
Clear All
H. F. Dacre, P. A. Clark, O. Martinez-Alvarado, M. A. Stringer, and D. A. Lavers

Identifying the source of atmospheric rivers: Are they rivers of moisture exported from the subtropics or footprints left behind by poleward traveling storms? Studies of heavy precipitation occurring in the winter over land in the midlatitudes have found that these events are almost always associated with extratropical cyclones ( Lackmann and Gyakum 1999 ; Viale and Nunez 2011 ; Hawcroft et al. 2012 ). These heavy precipitation events often occur when warm moist air, located in the cyclone

Full access
Julie A. Vano, Bradley Udall, Daniel R. Cayan, Jonathan T. Overpeck, Levi D. Brekke, Tapash Das, Holly C. Hartmann, Hugo G. Hidalgo, Martin Hoerling, Gregory J. McCabe, Kiyomi Morino, Robert S. Webb, Kevin Werner, and Dennis P. Lettenmaier

A synthesis of studies on Colorado River streamflow projections that examines methodological and model differences and their implications for water management. The Colorado River is the primary water source for more than 30 million people in seven rapidly growing, mostly arid American states and Mexico. The Colorado River water supply system, which consists of two large reservoirs (Lakes Mead and Powell) and numerous smaller reservoirs, is already stressed because of growing water demand and an

Full access
Jason M. Cordeira, F. Martin Ralph, Andrew Martin, Natalie Gaggini, J. Ryan Spackman, Paul J. Neiman, Jonathan J. Rutz, and Roger Pierce

BACKGROUND. What is an atmospheric river? Atmospheric rivers (ARs) are broadly defined as long and narrow corridors of strong water vapor transport that are characterized by enhanced vertically integrated water vapor (IWV) and enhanced IWV transport (IVT) (e.g., Ralph et al. 2004 ; Neiman et al. 2008 ). The IWV and IVT corridors associated with ARs are typically >2,000 km long and 500–1,000 km wide, and they often represent areas of instantaneous poleward and lateral moisture transport in the

Full access
Amin Dezfuli

change. An atmospheric river (AR), originated from the tropical Atlantic Ocean, was found responsible for the heavy precipitation that initiated the floods. To easily distinguish it from similar large-magnitude events over the region, here this AR is named Dena, after the peak of the Zagros Mountains, which played a crucial role in precipitation formation. Moisture transport by AR Dena was equivalent to more than 150 times the aggregated flow of the four major rivers in the region, that is, Tigris

Free access
F. Martin Ralph, Forest Cannon, Vijay Tallapragada, Christopher A. Davis, James D. Doyle, Florian Pappenberger, Aneesh Subramanian, Anna M. Wilson, David A. Lavers, Carolyn A. Reynolds, Jennifer S. Haase, Luca Centurioni, Bruce Ingleby, Jonathan J. Rutz, Jason M. Cordeira, Minghua Zheng, Chad Hecht, Brian Kawzenuk, and Luca Delle Monache

Atmospheric rivers (AR) are long narrow corridors of water vapor transport that serve as the primary mechanism to advect moisture into midlatitude continental regions, including the U.S. West Coast ( Zhu and Newell 1998 ; Ralph et al. 2004 , 2006 ; Neiman et al. 2008 ). ARs yield beneficial impacts as their associated precipitation comprises a majority of western U.S. precipitation, including up to 50% of California’s annual water supply ( Dettinger 2013 ), but have also been responsible for

Full access
Frauke Hoss and Paul Fischbeck

described the relationship between river forecasts and decision making as weak (e.g., Hunemuller 2010 ; Rayner et al. 2005 ; Penning-Rowsell et al. 2000 ; Golden and Adams 2000 ; Parker and Handmer 1998 ). This paper describes emergency managers (EMs), a large and important group of NWS clients, and their use of hydrometeorological forecasts in decision making, with a special focus on the ways EMs cope with forecast uncertainty. This paper arrives at a number of recommendations for the NWS (printed

Full access
Laigang Wang and Kaicun Wang

Different digital elevation model datasets agree well in altitude but significantly differ in their derivative parameters, which introduces significant errors in the estimation of surface-received solar radiation and data from river networks. A digital elevation model (DEM) is a virtual representation of landforms, describing the surface elevation. As an important input parameter, DEM is widely used in hydrological ( Liou et al. 2013 ), meteorological ( Gu et al. 2012 ), and climatic modeling

Full access
Minghua Zheng, Luca Delle Monache, Xingren Wu, F. Martin Ralph, Bruce Cornuelle, Vijay Tallapragada, Jennifer S. Haase, Anna M. Wilson, Matthew Mazloff, Aneesh Subramanian, and Forest Cannon

The transport of water vapor in the atmosphere from tropical/subtropical regions to higher latitudes is critical to water supply in densely populated areas, the occurrence of devastating flooding events, droughts, and the understanding of climate and hydrological systems (Benton and Estoque1954; Koster et al. 1986 ; Zhu and Newell 1998 ; Ralph et al. 2006 ; Dettinger 2013 ; Lavers et al. 2015 ). Atmospheric rivers (ARs) are elongated corridors that transport water vapor from the subtropics

Full access
D. Durnford, V. Fortin, G. C. Smith, B. Archambault, D. Deacu, F. Dupont, S. Dyck, Y. Martinez, E. Klyszejko, M. MacKay, L. Liu, P. Pellerin, A. Pietroniro, F. Roy, V. Vu, B. Winter, W. Yu, C. Spence, J. Bruxer, and J. Dickhout

Environment and Climate Change Canada’s (ECCC) operational implementation of a numerical forecast system linking atmospheric, surface, river and lake/ocean models is described. The Water Cycle Prediction System (WCPS) was recently implemented over the Great Lakes and St. Lawrence River watershed (WCPS-GLS version 1.0) by Environment and Climate Change Canada’s (ECCC) Canadian Centre for Meteorological and Environmental Prediction (CCMEP, formerly CMC). WCPS simulates the complete water cycle

Open access
Edwin Sumargo, Anna M. Wilson, F. Martin Ralph, Rachel Weihs, Allen White, James Jasperse, Maryam Asgari-Lamjiri, Stephen Turnbull, Charles Downer, and Luca Delle Monache

The Russian River Hydrometeorological Observing Network (RHONET) has emerged over 20 years, driven by a series of developments in scientific programs and their application to meet operational challenges. The current network ( Fig. 1a ), as of 2019, represents a combination of influences originating from an overarching goal to advance scientific understanding of physical processes that create extreme precipitation in the region. The current network design is the result of interagency cooperation

Full access