CW3E Hosts California DWR Winter Outlook Workshop

CW3E Hosts California DWR Winter Outlook Workshop

November 6, 2017

CW3E hosted the annual California Department of Water Resources Winter Outlook Workshop (WOW) from Nov. 1-3, at Scripps Institution of Oceanography. The purpose of the workshop is to highlight the latest science in seasonal to subseasonal (S2S), 1-month to 3-month, atmospheric forecasting. This timescale bridges the gap between weather and climate prediction. The meeting was organized by Jeanine Jones, ‎Interstate Resources Manager, and covered a variety of topics including paleoclimate, week three predictions, atmospheric rivers (ARs), summer North American monsoon, new forecasting tools, and drought.

During the first day, Dave Meko, from University of Arizona, discussed paleodrought in Southern California and how this compared to paleodrought in Northern California and in the Colorado River Basin. The second day of the workshop highlighted recent accomplishments in subseasonal to seasonal forecasting. Dr. David DeWitt, NCEP CPC Director, presented on the S2S activities on-going at the National Weather Service (NWS) Climate Prediction Center (CPC). Dr. Marty Ralph, Director of CW3E, gave an overview of the activities at CW3E related to observations, modeling and S2S prediction ARs. This was followed by a session chaired by Dr. Duane Waliser and Dr. Aneesh Subramanian on current S2S activities at CW3E and an experimental CW3E week-3 AR outlook product. The session had three talks presented by Dr. Alexander Gershunov, Dr. Michael DeFlorio, and Dr. Aneesh Subramanian on the experimental CW3E week-3 AR outlooks and the multi-pronged effort to design and evaluate the product. The day ended with presentation by Yolande Serra, from the University of Washington, on the dynamics and predictability of the summer monsoon. The third and final day began with a presentation on the influence of ARs in the Colorado River Basin as well an historical perspective on atmospheric river maps by Jon Rutz, National Weather Service. The last presentation of the day was by Dan Cayan on how various atmospheric patterns can lead to drought in the western U.S. WOW provided an opportunity for CW3E researchers and collaborators to share their latest advancements in subseasonal to seasonal forecasting and discuss future research collaboration and needs.

CW3E Director, Marty Ralph, discusses the research and activities at CW3E during the DWR WOW.

During the workshop Jeanine Jones also presented Department of Water Resources Climate Service Awards to Dr. Jason Cordeira, Plymouth State University, Dr. Duane Waliser, NASA JPL and Dr. Dave Meko, University of Arizona. The awards highlight the three individuals’ contribution to climate science as it applies to DWR operations. Jason Cordiera, a close collaborator of CW3E spoke of the honor, “My collaboration with CW3E has led to the synergistic development of many weather forecast tools that have benefited and informed water resource management and related impact-based decision support. Receipt of the CA DWR Climate Science Service Award reflects the dedication of many individuals at CW3E and Plymouth State who support and provide invaluable resources to maintain a productive research and application environment. Thank you to the CA DWR for the honor and I look forward to continued collaboration in pursuit of improving our ability to understand and forecast hydrological extremes”.

Recipients of the Department of Water Resources Climate Service Awards, presented at the WOW. From left, Dr. Duane Waliser, NASA JPL, Dr. Dave Meko, University of Arizona, and Dr. Jason Cordeira, Plymouth State University.

CW3E, UCAR, and NCAR Meet to Discuss West-WRF Regional Model Development

CW3E, UCAR, and NCAR Meet to Discuss West-WRF Regional Model Development

October 9, 2017

On 4-5 October 2017, CW3E had the privilege of hosting visitors from NCAR and UCAR to discuss the development and implementation of West-WRF, the regional forecast model that CW3E is developing focusing on extreme precipitation. The team from UCAR and NCAR included Bill Kuo, the director of UCAR Community Programs, who also helped lead the development of WRF. Chris Davis, NCAR associate director and leader of the Mesoscale and Microscale Meteorology (MMM) Laboratory also attended, along with, David Gill, Jake Liu, and Wei Wang, WRF experts in computation, data assimilation, and modeling, respectively.

The first day of the two day visit began with CW3E director, Marty Ralph, briefing the NCAR/UCAR visitors on CW3E, and how West-WRF supports the mission and goals of the center. After this introduction, CW3E researchers and staff had the opportunity to learn about best practices with respect to WRF computation, modeling, and data assimilation, as well as the new MPAS modeling system. The entire CW3E group had lunch with the NCAR/UCAR visitors and had a chance to hear all the CW3E updates including on AR reconnaissance, publications, and instrument deployments.

After lunch, the CW3E West-WRF team shared the current applications and status of the West-WRF development with the UCAR/NCAR team. The afternoon ended with Bill Kuo giving the CASPO seminar on assessment of the impacts of assimilation of COSMIC radio occultation measurements in typhoon forecasts. The second day of the visit, allowed for detailed discussions on many of the technical aspects of West-WRF development and applications. The UCAR/NCAR team provided recommendations to the CW3E researches and staff on ways to improve the implantation of West-WRF as well as design experiments. In addition the groups discussed ways for the CW3E team to provide feedback in the WRF development at NCAR/UCAR through sharing new code for verification metrics and scientific and technical advancements made through recent experiments. The meeting was a very productive initial collaboration between CW3E and UCAR/NCAR and we are looking forward to many more. The engagement of UCAR and NCAR in supporting one of its member institutions technical development efforts is greatly appreciated.

Atmospheric Rivers: Recent Developments and Applications in California

Atmospheric Rivers: Recent Developments and Applications in California

May 19, 2017

In Sacramento on Tuesday, May 23rd, CW3E director, F. Martin Ralph will be presenting a seminar about atmospheric rivers and their impacts to California legislative and agency staff. The seminar, Atmospheric Rivers: Recent Developments and Applications in California, will provide updates on the impacts of ARs on the current water year and the ongoing research to better understand and better forecast ARs. Dr. Ralph is looking forward to sharing all of the exciting research being done at CW3E with the group.

May 31 – June 2 Big Data and The Earth Sciences: Grand Challenges Workshop

May 31 – June 2 Big Data and The Earth Sciences: Grand Challenges Workshop

April 17, 2017

Abstract deadline extended to April 21st

The Center for Western Weather and Water Extremes (CW3E) of UC San Diego’s Scripps Institution of Oceanography and the Pacific Research Platform (PRP) is excited to announce the organization of a workshop focused on earth sciences and information technology at the University of California San Diego. The workshop is a three-day Grand Challenges workshop May 31 to June 2 in La Jolla, Calif., on the topic of “Big Data and the Earth Sciences”.

CW3E is focused on advancing science and technology to support the unique information needs related to western U.S. extreme weather and water events, such as California’s recent flooding and multi-year drought and associated potential for subseasonal-to-seasonal forecasting. PRP is a consortium of universities in the western U.S. that is building a “science-driven, high-capacity data-centric freeway system on a large regional scale.” Funded by the National Science Foundation, PRP is based in the California Institute for Telecommunications and Information Technology (Calit2), a partnership of UC San Diego and UC Irvine. The workshop will take place in UC San Diego’s Atkinson Hall, headquarters of the Qualcomm Institute (the UCSD division of Calit2).

The goal of the The Big Data and Earth Sciences: Grand Challenges Workshop is to bring thought leaders in Big Data and Earth Sciences together for a three day, intensive workshop to discuss what is needed to advance our understanding and predictability of the Earth systems and to highlight key technological advances and methods that are readily available or in the final stages of development.

Sessions will include:

  • Big data collaborations;
  • Big data research platforms, networks, technologies and visualization;
  • Big data and predictability challenges in earth science data;
  • Pattern detection, segmentation and object recognition for earth sciences;
  • Structuring unstructured data in the earth sciences; as well as
  • Data mining and discovery, machine learning and predictive modeling.

For more information please visit:


Official workshop website:

Please send abstracts to

Abstracts are restricted to one page. Please include the abstract title, authors’ names and affiliations. A word document or .pdf is preferred.

CW3E Participates in Water in the West: A Science Policy Roundtable

CW3E Participates in Water in the West: A Science Policy Roundtable

December 10, 2016

CW3E was represented in a December 8, 2016 panel discussion hosted by UCSD’s School of Global Policy and Strategy (GPS)’s Science Policy Fellows Program and SIO’s Science Policy Discussion Group, titled “Water in the West: A Science Policy Roundtable”. The purpose of the event was to bring together our different communities and explore the sources of California’s water supply, how water supply can change, how it is used throughout the state and best practices for optimal regulation of its use.

CW3E director Dr. F. Martin Ralph acted as moderator. Other panel members were Dr. Jennifer Burney of GPS, Sandra Kerl of the San Diego County Water Authority, and Dr. Dan Cayan of SIO and a CW3E collaborator. Dr. Scott Sellars, the leader of the Science Policy Discussion Group, was involved in organizing the event. Other CW3E postdocs and graduate students assisted with logistics. The attendance was just over 100 people, with a very engaged audience. Questions were asked on topics ranging from specific projects run by the SD County Water Authority, to potential changes to academic funding sources with the incoming federal administration, to questions on groundwater and atmospheric rivers science. The event was recorded and can be viewed here.

More details are available in the GPS news story.

At podium: Marty Ralph (Scripps/CW3E); Left to right at table: Sandra Kerl (San Diego County Water Authority), Dan Cayan (Scripps/CW3E and USGS), Jennifer Burney (GPS)

CW3E Hosts Winter Outlook Workshop with California DWR

CW3E Hosts Winter Outlook Workshop with California DWR

November 18, 2016

The California Department of Water Resources (CDWR) and CW3E led a working meeting with researchers at the Scripps Institution of Oceanography in La Jolla, November 16-18, 2016. The workshop focused on efforts to improve sub-seasonal to seasonal prediction of precipitation, which could help agencies better manage water resources.

“We’d all like to know if 2017 will be wet or dry, but determining that is scientifically difficult. We’re trying to emphasize the need for prioritizing this research in the science community,” said Jeanine Jones, Interstate Resources Manager at CDWR.

Participants from the following agencies were in attendance: CW3E/Scripps, CDWR, Sonoma County Water Agency (SCWA), National Center for Atmospheric Research (NCAR), Natonal Weather Service (NWS), Western States Federal Agency Support Team (WestFAST), National Oceanic and Atmospheric Administration (NOAA), Plymouth State University (PSU), Oregon State University (OSU), University of California, Los Angeles (UCLA), Salt River Project (SRP), Climate Assessment for the Southwest (CLIMAS), Desert Research Institute (DRI), and Metropolitan Water District of Southern California (MWD).

Images courtesy DWR Photography – Florence Low

IARC 2016

The First International Conference on Atmospheric Rivers (IARC) is Being Hosted by the Center for Wester Weather and Water Extremes (CW3E) at the Scripps Seaside Forum from 8-11 August 2016

August 8, 2016

IARC is part of a multi-year effort led by CW3E’s Director F. Martin Ralph, Mike Dettinger of USGS and David Lavers of ECMWF to foster collaboration and exchange of ideas on atmospheric rivers (AR).

  • The first event was held in June 2015 and brought together about 30 key individuals in a workshop, with a special emphasis on identifying the relationships between ARs, warm conveyor belts, and tropical moisture exports, all phenomena involving horizontal water vapor transport. A brief workshop synopsis is available in EOS (Dettinger et al. 2015) and here. Two main directions emerged:
    • 1) agreement that it was time to develop a comprehensive monograph on ARs, and
    • 2) an atmospheric river focused conference should be organized.
  • The second event in this 3-year effort is the 2016 IARC conference held from 8-11 August (described below; agenda).
  • The third event is a summer colloquium intended for summer 2017 at Scripps. It is intended to bring together at Scripps authors of the AR Monograph Book Chapters and graduate students from around the world for roughly 3 weeks of lectures and mentored mini-research efforts.

Woven through this series of events over 3 years is the development of the AR Monograph, which has been funded by a grant, including publication by University of California Press. IARC brings together most of the Chapter authors, at a point in the writing where new ideas garnered during the conference can be incorporated into the Monograph. The goal is then to have the Monograph finalized and in print for the AR Summer Colloquium. A technical editor, Lauren Muscatine (and her experienced team from UC Davis), is supporting preparation of the Monograph.

IARC received 75 abstracts from people around the world studying ARs, their impacts and applications of AR information to decision making. Submissions represent work on 6 continents plus Greenland. It has been planned by an international steering committee of experts on the subject. 90 people have registered for the conference, which will include several invited presentations, oral sessions, a poster session, panels on “applications to decision making,” “converging on a definition of atmospheric rivers” and on “future directions.” Breakout sessions will be held on “AR Forecasting,” “AR Book Chapters” and on “ARs in future climates and subseasonal to seasonal prediction.”

Sessions are organized around the following themes, which represent sections in the AR Monograph:

  • AR Applications
  • Global and Regional Perspectives
  • Observing and detecting ARs
  • Impacts of ARs
  • Theory, Structure and Processes
  • Modeling methodologies

Contact: F. Martin Ralph (

Lake Mendocino Forecast-Informed Reservoir Operations (FIRO) Workshop Summary

Lake Mendocino Forecast-Informed Reservoir Operations (FIRO) Workshop Summary

July 5, 2016

Experts from multiple disciplines and organizations came together for the third annual FIRO workshop, which was held at UC San Diego/Scripps Institution of Oceanography (SIO) from 27-29 June 2016. This workshop was hosted jointly by the Sonoma County Water Agency (SCWA) and SIO’s Center for Western Weather and Water Extremes (CW3E). It was organized by the FIRO Steering Committee, co-chaired by CW3E’s Marty Ralph and SCWA’s Jay Jasperse. There were a total of 52 attendees from organizations including the US Army Corps of Engineers (USACE), California Department of Water Resources (CA DWR), National Oceanic and Atmospheric Administration (NOAA), US Geological Survey (USGS), US Bureau of Reclamation (USBR), SCWA and CW3E.

During the workshop, participants shared recent updates on FIRO activities, discussed reservoir conditions during water year 2016, summarized progress toward goals identified in the FIRO Workplan and identified issues to address regarding development of the Lake Mendocino FIRO “Preliminary Viability Assessment.” Progress was summarized on defining FIRO information requirements (e.g., forecast parameters and lead times), assessing current forecast skill, exploring the origins of forecast errors, advances in atmospheric river science, results of preliminary estimates of FIRO implications on Lake Mendocino water supply, and discussion of potential additional reservoirs for which FIRO may hold promise. Individual task groups (Preliminary Viability Assessment, Science, and Communications/Outreach) conducted break-out sessions in order to discuss progress and next steps towards meeting project goals (see photos below). In addition, the 11-member Lake Mendocino FIRO Steering Committee met afterward to review the workshop outcomes and plans. In short, the initial goals of year-1 of the 5-year FIRO Workplan are on track to be met, including development of the Preliminary Viability Assessment. Longer-term actions supporting the Full Viability Assessment are beginning and transferability is being discussed.

Lake Mendocino FIRO is summarized at

Contacts: F. Martin Ralph (CW3E Director; and J. Jasperse (SCWA Chief Engineer;

CW3E represented in recent policy and program meetings

CW3E Represented in Recent Policy and Program Meetings

June 8, 2017

During the last few weeks CW3E’s perspectives have been highlighted at three science policy-oriented meetings. The connection between CW3E’s scientific activities, practical applications and water policy implications is a common theme among them. The meetings and a brief synopsis are provided below:

1) AGU Congressional briefing on role of basic Geoscience in American Security May 2016

AGU invited three speakers to a Congressional briefing they organized to communicate to staff supporting a number of elected officials and policy committees. The goal was to make the connection between basic science advances (and the funding that has supported them), and benefits to American Security. CW3E’s Director, Dr. Ralph, represented the role of basic geoscience research in advancing water security in the Western U.S. His presentation emphasized the critical roles of key science funding strategies, from standard grants programs, to directed research efforts, cooperative agreements and federal labs. And in the end concluded that many breakthrough advances result not from a systems engineering approach to deciding what to do, but from ideas that are “outside the box.” He also highlighted that science, at its core, is fundamentally a creative endeavor that requires long-term support for people in their careers and for the organizations that host them. AGU has posted a video of the briefings here.

2) NOAA Water Information “Listening Session” in Sacramento May 2016

NOAA invited water management stakeholders from across the West to hear about the National Water Center they are creating in Alabama and to listen to stakeholders interests and needs for weather and water information to support water supply, flood mitigation and endangered species restoration in the West. CW3E was represented by Dr. Ralph, who brought Scripps science into the discussion, and supported major points presented by water managers concerning the vital role of atmospheric rivers in western water decisions. NOAA held one other regional “listening session” – in Alabama, and is holding one more “National” session in July. They will be considering input from these meeting as they develop their agency’s strategies in the coming years to support water information needs for the nation.

3) WSWC S2S Workshop San Diego June 2016

The National Academies of Science recently released a report on the subject of science needed to enable subseasonal-to-seasonal predictions to support decisions. The Western States Water Council (a group supporting the Governors of 17 Western States) organized a regional Workshop in San Diego in early June to discuss both the user requirements for better forecasts and the science opportunities to achieve them. CW3E was represented well, including participation by Sasha Gerhunov, Tamara Shulgina and Marty Ralph, including a presentation by Marty on observing system needs to support the goals.

Atmospheric Rivers Workshop: June 15-17, 2015

Atmospheric Rivers Workshop: June 15-17, 2015

June 19, 2015

An atmospheric rivers (AR) workshop was held 15-17 June at the Seaside Forum at UC San Diego/Scripps Institution of Oceanography (SIO). This workshop was sponsored by the Center for Western Weather and Water Extremes (CW3E) at SIO. Mike Dettinger, David Lavers and Marty Ralph were co-chairs of this workshop. The photo below shows the workshop participants.

Left to right: Jay Jasperse (Sonoma County Water Agency), Jennifer Haase (Scripps), Lauren Muscatine (UC Davis), Brian Kawzenuk (Scripps/CW3E), Tamara Shulgina (Fulbright Scholar at Scripps/CW3E), Sasha Gershunov (Scripps/CW3E), Joel Norris (Scripps and CW3E), Roger Pierce (NOAA/NWS), Harald Sodemann (Univ. of Bergen), Marty Ralph (Scripps/CW3E; Workshop Co-Chair), Nina Oakley (Univ. of Nevada Reno), Mike Dettinger (USGS & Scripps/CW3E; Workshop Co-Chair), Dale Cox (USGS), David Lavers (Scripps/CW3E; Workshop Co-Chair), Jon Rutz (NWS), Jason Cordeira (Plymouth State Univ.), Andrew Martin (Scripps/CW3E), Allen White (NOAA/ESRL), Bin Guan (UCLA), Heini Wernli (ETH Zurich), Larry Schick (US Army Corps of Engineers), Dan Cayan (Scripps/CW3E and USGS), Julie Kalansky (Scripps/CW3E), Ryan Spackman (Science and Technology Corp. and NOAA/ESRL), Maximiliano Viale (Univ. of Chile). Attendees not in picture: Mike Anderson (California Dept. of Water Resources), Bruce Cornuelle (Scripps & CW3E), Duane Waliser (NASA/JPL)

This workshop brought together experts from around the world to survey the current state of atmospheric-river (AR) science and plan the First International Atmospheric Rivers Conference to be held in summer 2016 at Scripps’ Seaside Forum. The group also planned the development of a Monograph on atmospheric rivers that is intended to become the standard reference on the roughly 20 years of AR research. The meeting addressed an outstanding debate in the science community about the physical relationship between ARs, the warm conveyor belt (WCB) in extratropical cyclones and tropical moisture exports (TME) to the extratropics.
The workshop concluded with a plan for the conference in 2016, a strategy for the book, and development of a schematic summary of the relationships between ARs, WCBs and TMEs, each of which plays a critical and complementary role in transporting water vapor through the atmosphere, in terms of horizontal transport and sloped ascent in extratropical cyclones.
The term “atmospheric river” was first coined in 1994 to describe atmospheric water vapor transport across the mid-latitudes. Subsequent research has shown them to be responsible for the majority of extreme hydrologic events in the western United States, Europe, and South America, as well as being critical to water resources in these regions.

For real-time observations and forecasts of atmospheric rivers, please visit the “AR Portal”