Author: cw3e-web

CW3E AR Update: 24 February 2022 Outlook

CW3E AR Update: 24 February 2022 Outlook

February 24, 2022

Click here for a pdf of this information.

Multiple Atmospheric Rivers to Impact the US West Coast

  • Multiple atmospheric rivers (AR) are forecasted to make landfall over the US West Coast this weekend into early next week
  • The first AR is forecasted to make landfall on 26 Feb and bring AR 1-2 conditions (based on the Ralph et al. 2019 AR Scale) to coastal Washington and Oregon
  • A second and stronger AR is forecasted to make landfall on 27 Feb, but there is substantial uncertainty in the timing, location, and duration of AR conditions
  • The 00Z ECMWF EPS is forecasting the second AR to make landfall earlier and bring stronger AR conditions to southern Oregon and far Northern California
  • The 00Z GEFS is forecasting the second AR to make landfall later and bring stronger AR conditions to northern Oregon and southern Washington
  • Heavy precipitation is possible in western Washington, western Oregon, and far northwestern California during the next 7 days, but models disagree on the location of the heaviest precipitation associated with the second AR
  • Compared to the 12Z GFS, the 12Z ECMWF is forecasting much higher precipitation in southwestern Oregon and northwestern California, and much lower precipitation in western Washington

Click images to see loops of GFS IVT & IWV forecasts

Valid 1200 UTC 24 February – 0000 UTC 4 March 2022


 

 

 

 

 

 

 

 

 

 

Summary provided by C. Castellano, S. Roj, B. Kawzenuk, and F. M. Ralph; 24 February 2022

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*Outlook products are considered experimental

IRI Weather Regime Subseasonal Forecast Product Added to CW3E S2S Webpage

IRI Weather Regime Subseasonal Forecast Product Added to CW3E S2S Webpage

February 23, 2022

The International Research Institute for Climate and Society (IRI) has recently collaborated with CW3E, the NASA Jet Propulsion Laboratory, and the University of Arizona on a project funded by the California Department of Water Resources to investigate sources of subseasonal-to-seasonal (S2S) predictability of precipitation over the western United States.

A main focus of this effort is to produce experimental S2S forecast products that are regularly updated throughout the water year. IRI’s subseasonal weather regime outlook, which shows the likelihood of particular large-scale circulation patterns influencing the western U.S. region out to 5-weeks lead time, has now been added to the suite of CW3E subseasonal forecast products on the CW3E S2S Webpage. The latest such forecast is shown below, along with a description of the forecast product.

The graphic shows forecasts of large scale meteorological patterns, issued every day during winter (along x-axis) by the NCEP CFSv2 model. The four large scale “weather regimes” are the West Coast Ridge (red), Pacific Ridge (blue), Pacific Trough (green), and Greenland High (yellow), each of which leads to distinct precipitation and temperature conditions over the West. Darker colors indicate more confident forecasts, which run diagonally up the chart from 0 to 45 days ahead. This product was developed with support from NOAA’s Next Generation Global Prediction System (NGGPS) program and the California Department of Water Resources. Please see https://wiki.iri.columbia.edu/index.php?n=Climate.S2S-WRs for the precipitation and temperature signatures of the regimes or Robertson, Vigaud, Yuan & Tippett (2020) for additional details.

CW3E’s collaboration with IRI on this DWR-funded effort has also involved the co-organization of the 2022 IRI S2S Water Workshop, which will take place virtually on March 15-17, 2022. NASA JPL and the University of Arizona have also served as co-organizing institutions for this event.

CW3E Publication Notice: First Airborne Measurements with a G-band Differential Absorption Radar

CW3E Publication Notice

First Airborne Measurements with a G-band Differential Absorption Radar

February 15, 2022

Richard J. Roy (Jet Propulsion Laboratory, California Institute of Technology (JPL)), along with JPL co-authors Ken B. Cooper, Matthew Lebsock, Jose V. Siles, Luis Millán, Robert Dengler, Raquel Rodriguez Monje, and Stephen Durden, and Forest Cannon and Anna Wilson (Center for Western Weather and Water Extremes, Scripps Institution of Oceanography), recently published a paper in the Institute of Electrical and Electronics Engineers (IEEE) Transactions on Geoscience and Remote Sensing. The article, titled “First Airborne Measurements with a G-band Differential Absorption Radar”, contributes to the goals of CW3E’s 2019-2024 Strategic Plan to support Atmospheric River (AR) Research and Applications and Emerging Technologies by providing a critical assessment that can be used to inform future G-band atmospheric radar applications, including potential methods for improved differential absorption radar (DAR) measurements and radar calibration stability.

This study presents observations and analysis from the first airborne deployment of a G-band atmospheric radar, the Jet Propulsion Laboratory’s Vapor In-cloud Profiling Radar (VIPR). Analysis includes an assessment of radar calibration stability, the first observations of calibrated ocean surface backscatter above W-band and comparison with various scattering models, and investigations into partial column water vapor and in-cloud humidity profiling measurement capabilities from a nadir-viewing platform by comparing with collocated thermodynamic profiles from weather balloon soundings. Utilizing a combination of ground-based calibration measurements and airborne cloud observations that are validated by independent sensors, the study assesses transceiver cross-calibration stability between the two DAR frequency channels. By comparing calibrated, unattenuated ocean surface backscatter measurements with existing models, Roy et al.’s findings demonstrate the need for improvements in treating ocean surface scattering at G-band frequencies for future in-flight radar calibration applications. The study utilizes science-oriented flights off the coast of California to demonstrate partial column integrated water vapor (IWV) measurement capabilities with 0.3 mm precision in clear sky by performing a descent maneuver over an operational radiosonde launching site and comparing with the coincident in-situ profiles to find a root mean square error (RMSE) of 0.5 mm. Additionally, the study presents water vapor profiling and IWV measurements in the presence of clouds and precipitation when flying through a frontal weather system in the vicinity of Bodega Bay (Figure 1). By comparing with coincident radiosonde profiles, Roy et al. finds a RMSE for in-cloud humidity profile retrievals of 1.1 gm−3 and precision of 0.6 gm−3 while the IWV retrievals reveal a bias from differential hydrometeor extinction of 5 mm. The use of balloon soundings from CW3E were critical in the authors’ ability to assess bias and RMSE in the DAR retrievals.

Important implications of these investigations include the demonstration of long-term transceiver calibration stability, the need for further refinement of existing scattering models and ocean wave spectra to adequately capture the physics of ocean scattering at such high radar frequencies, and the need to account for bias in the DAR water vapor retrievals that come from frequency-dependent radar beam scattering from cloud particles. While there is still work to be done to optimize these techniques, this study presents important findings that can be applied to improve future G-band atmospheric radar applications.

Figure 1 (Fig. 10 in Roy et al., 2021): (a) Vertical temperature profiles from the CW3E radiosonde launches from BML. Also plotted is the temperature profile used for DAR retrievals (dashed line), which only assumes knowledge of the surface temperature. (b) Same as (a) for humidity profiles. Note that for the DAR IWV retrieval, only the shape of the humidity profile is assumed (here an exponential with scale height of 2.5 km), while the overall normalization is determined by the retrieval. (c) Time series of surface-to-aircraft column IWV retrieved from VIPR observations (blue circles) for flight leg in (d). Dashed line in (c) corresponds to radiosonde-derived IWV within the warm sector of the frontal system. (d) Aircraft track and overlaid IWV retrievals from flight leg near BML on Jan. 21, 2020 between 19:40 and 21:00 UTC, with dashed line denoting the qualitative frontal boundary.

Roy, R.J., Cooper, K.B., Lebsock, M., Siles, J.V., Millán, L., Dengler, R., Monje, R.R., Durden, S., Cannon, F., and A.M. Wilson, 2021: “First Airborne Measurements with a G-band Differential Absorption Radar,” in IEEE Transactions on Geoscience and Remote Sensing, doi: 10.1109/TGRS.2021.3134670.

CW3E Welcomes Xun (Jerry) Zou

CW3E Welcomes Xun (Jerry) Zou

February 15, 2022

Xun (Jerry) Zou joined CW3E on Feb 1, 2022, as a postdoctoral researcher. She earned a B.S. in Atmospheric Sciences from the Nanjing University (2015), and M.S. (2017) and Ph.D. (2020) degrees in Atmospheric Sciences from Ohio State University. Her dissertation research focused on the surface melting/warming over the Ross Ice Shelf, West Antarctica. She identified and quantified the contribution of foehn warming via Polar WRF simulation. She also found the impact of Atmospheric Rivers (ARs) on Antarctic ice shelf melting during the austral summer. After her Ph.D., Jerry continued as a postdoctoral scholar (2020-2021) at Ohio State University, where she is accessing the impact of extra radiosondes on Antarctic Weather forecast as part of the Year of Polar Prediction in the Southern Hemisphere (YOPP-SH) project. Jerry also got her collaborative research funded by NSF to investigate cloud radiative impact on the surface energy budget of the Antarctic Peninsula. This research will focus on the extreme surface melting events in the polar regions triggered by the ARs and foehn warming.

At CW3E, Jerry will continue her research on ARs in the polar regions and expand her study to the West Coast under the supervision of Dr. Luca Delle Monache. She will work with other CW3E scientists on improving the understanding of ARs events and contribute to the development of the West-WRF.

Dr. Michael Dettinger Elected to National Academy of Engineering

Dr. Michael Dettinger Elected to National Academy of Engineering

February 14, 2022

Dr. Michael Dettinger, visiting researcher at CW3E/Scripps Institution of Oceanography, research professor at the Desert Research Institute, and founder of Climate Science, LLC, was recently elected to the National Academy of Engineering (NAE). Dr. Dettinger, elected for his hydroclimate research that significantly enhances the understanding and management of water resources in the western United States, is among the NAE’s 111 new members and 22 international members announced by NAE President John L. Anderson on February 09, 2022.

Election to the NAE is among the most notable of distinctions awarded to an engineer, honoring those who have made contributions to “engineering research, practice, or education, including, where appropriate, significant contributions to the engineering literature” and to “the pioneering of new and developing fields of technology, making major advancements in traditional fields of engineering, or developing/implementing innovative approaches to engineering education.”

CW3E offers our deepest congratulations and celebrates Dr. Dettinger’s impressive accomplishments that have culminated in this well-deserved honor. We are grateful for the opportunity to work with Dr. Dettinger and for his insightful research and critical contributions to hydroclimate research and water resources management in the western United States. Visit the NAE Press Release to learn more about this year’s elected members.

CW3E Welcomes Hillary Beckmeyer

CW3E Welcomes Hillary Beckmeyer

February 9, 2022

Hillary Beckmeyer joined CW3E as a Field Researcher in November 2021. She has previously worked in a wide range of fields, including graphic design, marketing, logistics, and politics. She earned a degree in Atmospheric and Oceanic Science from the University of Colorado – Boulder in 2021, and one in International Relations/Comparative Cultures and Politics from Michigan State University’s James Madison College in 2015. In the spring of 2021, Hillary joined Dr. Kris Karnauskas’ Oceans and Climate Lab, at CU Boulder, for a two-month independent study examining the representation of oceanic barrier layers in the IPCC’s CMIP6 models, and how such models predict barrier layers will respond to global climate change.

In the summer of 2021, Hillary participated in CW3E’s internship program. Her research, under the mentorship of Alison Cobb, Tom Corringham, and Forest Cannon, focused on analyzing potential correlations between atmospheric rivers and commercial shipping vessel damage in the North Pacific.

As a Field Researcher at CW3E, Hillary will continue to assist with field research campaigns, site maintenance, and other facets related to improving and expanding observational efforts. She is elated to be a part of CW3E’s important research endeavors and to work with such knowledgeable colleagues, affiliates, and partner organizations.

CW3E Welcomes Dr. Mohammadvaghef Ghazvinian

CW3E Welcomes Dr. Mohammadvaghef Ghazvinian

February 8, 2022

Mohammadvaghef Ghazvinian joined CW3E as postdoctoral researcher in January 2022. He received his PhD in Civil Engineering-Water Resources from the University of Texas at Arlington under the supervision of Dr. Yu Zhang.

His research interests include hydrometeorological forecast postprocessing, probabilistic forecasting and mathematical methods for forecast verification.

During his PhD, he focused primarily on developing statistical postprocessing models to improve medium-range precipitation/flood forecasts from state-of-the-art operational/research-based schemes. His proposed methods adequately address practical limitations in current mechanisms and improve their robustness and efficacy, in particular forecasts accuracy for heavy-to-extreme, high impact events. He is among a few researchers in the field that successfully improved the performance of probabilistic quantitative precipitation forecasting using end-to-end, computationally efficient deep learning frameworks. These frameworks allow for simultaneous generations of reliable and highly skillful postprocessed precipitation forecasts over multiple forecast horizons and seasons in a unified manner.

At CW3E, Mohammadvaghef will focus on development of machine learning prediction tools for extreme weather and water events under supervision of Dr. Luca Delle Monache. His research outcome will support CW3E’s objectives in improving flash flood decision support systems and forecast informed reservoir operations.