cw3e-web - Center for Western Weather and Water Extremes

CW3E Attends BSMAR and SWEPSYM Virtual Events

October 10, 2020

On 6-8 October, CW3E participated in the 17th Biennial Symposium on Managed Aquifer Recharge (BSMAR-17) and Southwest Extreme Precipitation Symposium (SWEPSYM) crossover event. This year, BSMAR 17 teamed with the Floodplain Management Association and CW3E to hold the SWEPSYM. Unlike in previous years, these two events came together as a virtual event consisting of two presentation “tracks”, BSMAR topics and SWEPSYM topics, over the course of three days.

BSMAR is a collaborative effort between the Arizona Hydrological Society (AHS) and the Groundwater Resources Association (GRA) of California. The symposium continues a longstanding series of symposia originating in Arizona in 1978. The BSMAR 16 conference was held in March 2018 in San Diego. BSMAR 15 was combined with the Ninth International Symposium on Managed Aquifer Recharge (ISMAR 9) held in Mexico City in 2016.

SWEPSYM is an annual conference co-hosted by the Floodplain Management Association and CW3E that brings together the scientific community and water managers in the Southwest. The conference is at the interface of research and applications. In particular it has 4 main objectives:

Bring attention to precipitation extremes in the Southwest region of North America
Share technical and scientific information and knowledge about the various factors responsible for producing extreme precipitation and the hydrologic processes responsible for generating runoff in semi-arid and arid areas
Advance our understanding of the causes of extreme precipitation with the hope of increasing the warning time of precipitation extremes, ranging from droughts to floods
Exchange information on engineering, water management, flood control, agricultural, and other Southwest regional needs for information on extreme precipitation

CW3E’s director, Marty Ralph, Ph.D., started off the crossover event Tuesday with a keynote address titled “Bridging the Gap between Atmospheric Science and MAR!”. CW3E scientists Anna Wilson and Peter Gibson gave presentations in the SWEPSYM track on Wednesday and CW3E student Mike Sierks and CW3E researcher Forest Cannon helped moderate the event.

The next SWEPSYM and BSMAR events are scheduled for 2022. You can view the BSMAR Technical Program for the full 2020 schedule, and you can visit the SWEPSYM website to download slides and view presentations from the 2020 symposium.

Screenshots from the SWEPSYM track on Wednesday, 7 October. Top: Anna Wilson presents “Enhancing Hydrometeorological Observing Systems Throughout California”. Bottom: Peter Gibson presents “Forecasting Ridging Related to Precipitation Deficits Across the Colorado River Basin.”

CW3E AR Update: 9 October 2020 Outlook

October 9, 2020

Click here for a pdf of this information.

Update on Atmospheric Rivers Forecast to Impact the Northwestern US

Multiple landfalling ARs are forecast to bring significant precipitation to the northwestern US during the next 7 days
Current forecasts suggest that AR 3/AR 4 conditions (based on the Ralph et al. 2019 AR Scale) are possible over coastal Oregon and Washington in association with the first and third ARs
Inland penetration of these ARs may also produce AR 2/AR 3 conditions over portions of interior Oregon and Washington
7-day total precipitation is forecast to exceed 7 inches over the Olympic Mountains and North Cascades, with more than 3 inches of precipitation possible over the Northern Rockies

Click images to see loops of GFS IVT/IWV analyses and forecasts Valid 1200 UTC 9 October – 1200 UTC 17 October 2020

Summary provided by C. Castellano, J. Kalansky, B. Kawzenuk, and F. M. Ralph; 9 October 2020

*Outlook products are considered experimental

CW3E Welcomes Sarah Ogle

October 8, 2020

Sarah Ogle joined CW3E as a Climate Science Ph.D. student in September 2020. She received a B.S. in Geology from Carleton College in 2019. Native to San Diego, she’s excited to be back in her hometown for graduate school even though she enjoyed watching fabulous thunderstorms and walking to class when it felt like -50ºF in Minnesota.

Sarah has been fascinated by weather ever since she was four years old and her mom taught her numbers by looking at the weather page in the newspaper. This developed Sarah’s interest in weather, climate and the natural world ultimately leading her to decide to start a PhD in climate science.

Sarah is no stranger to Scripps Institution of Oceanography (SIO) as she interned at SIO every summer in college. She worked with Dr. Lynne Talley for three summers and she researched air-sea fluxes in the Southern Ocean. In 2018, she worked at CW3E and researched her senior thesis on atmospheric rivers and their effects on landslides in Washington State.

After graduating from Carleton, Sarah worked at the United States Geological Survey (USGS) for a year on projects that seek to understand and model the geology and water resources of San Diego, Anza, Santa Monica, and Whittier. During this year, Sarah also coached football and spent time with her family. Throughout her PhD, Sarah hopes to continue working on California water resources research at CW3E as this combines her geology background with her climate science Ph.D. while allowing her to address pressing water resources issues in her home state.

CW3E AR Update: 7 October 2020 Outlook

October 7, 2020

Click here for a pdf of this information.

Update on Atmospheric Rivers Forecast to Impact the US West Coast

A unique large-scale flow regime is forecast to result in the landfall of two separate but concurrent ARs over the USWC
Current forecasts suggest the possibility of an AR 2/AR 3 between extreme Northern California and Washington in association with the first landfalling AR, but there is some uncertainty in the timing, duration, and magnitude of AR conditions
The GFS and ECMWF are forecasting at least 1–3 inches of precipitation across western Washington and Oregon during the next 5 days, with higher amounts possible over the Olympic Mountains and North Cascades
Unfortunately, little precipitation is expected in California, where many large fires are still active

Click images to see loops of GFS IVT/IWV analyses and forecasts Valid 1200 UTC 7 October – 1200 UTC 15 October 2020

Summary provided by C. Castellano, J. Kalansky, and F. M. Ralph; 7 October 2020

*Outlook products are considered experimental

CW3E AR Update: 5 October 2020 Outlook

October 5, 2020

Click here for a pdf of this information.

Update on Atmospheric Rivers Forecast to Bring Precipitation to the US West Coast

A unique large-scale flow regime is forecast to result in the landfall of two separate but concurrent ARs over the USWC
Current forecasts suggest that IVT magnitudes over southern Oregon may reach 500 kg m^–1 s^–1 while AR conditions are forecast to last ~27 hours, resulting in AR 2 conditions
There is currently a large amount of uncertainty in the forecast, which is resulting in a large spread of potential outcomes
The GFS, ECMWF, and NBM are forecasting different precipitation accumulations from Washington to Northern CA
Due to the numerous fires currently burning across California, this precipitation in the forecast may bring much needed relief to extremely dry conditions

Click images to see loops of GFS IVT/IWV analyses and forecasts Valid 0000 UTC 5 October – 1800 UTC 14 October 2020

Summary provided by C. Hecht, C. Castellano, J. Kalansky, and F. M. Ralph; 5 October 2020

*Outlook products are considered experimental

CW3E Event Summary: 23-27 September 2020

September 29, 2020

Click here for a pdf of this information.

Active weather pattern brings first major precipitation event of the season to the Pacific Northwest

A family of landfalling ARs produced heavy rainfall across western North America during 23–27 Sep
Some locations along the northwestern coast of Oregon experienced AR5 conditions [based on the Ralph et al. (2019) AR scale]
Total estimated 7-day precipitation ending 28 Sep exceeded 2 inches across most of western Washington and northwestern Oregon, with more than 5 inches (locally > 10 inches) in the Olympic Mountains and North Cascades

Click images to see loops of GFS IVT/IWV analyses Valid 0000 UTC 22 September – 0000 UTC 28 September 2020

Summary provided by C. Castellano, J. Kalansky, B. Kawzenuk, and F. M. Ralph; 29 September 2020

CW3E Welcomes Linghan Li

September 29, 2020

Linghan Li joined CW3E as a Research Data Analyst in September 2020. Linghan received her PhD in Oceanography from Scripps Institution of Oceanography, University of California, San Diego, under the guidance of Art Miller. She also holds a MS in Space Physics from Chinese Academy of Sciences and a BE in Electrical Engineering from Wuhan University. Linghan’s PhD dissertation focused on sea ice variability in the Bering Sea, including its atmospheric and oceanic dynamic and thermodynamic controls, using global and regional ocean/ice models and satellite observations. After completing her dissertation, she worked on several coastal ocean modeling projects as a Research Associate at University of Washington.

In her new position at CW3E, Linghan will study ocean-atmosphere interactions, particularly relating to the understudied field of local and remote ocean influences on atmospheric river (AR) evolution and predictability. In this regard, her research will also explore the current ability of coupled models to represent AR evolution over the global oceans via satellite remote sensing and field campaign data. Collectively, these efforts target the improved understanding and forecasting of ARs and their impacts in the western US and globally. Beyond her primary research on ocean-atmosphere interactions, Linghan will also support an ongoing assessment of California climate variability and change in collaboration with scientists in California-Nevada Climate Applications Program.

CW3E AR Update: 24 September 2020 Outlook

September 24, 2020

Click here for a pdf of this information.

Update on Active Period of Atmospheric Rivers over the Pacific Northwest

As an AR is currently impacting the Pacific Northwest, two additional ARs are forecast to bring precipitation to the region and British Columbia
Current forecasts suggest that IVT magnitudes over northern Oregon may not drop below 250 kg m^–1 s^–1, which would result in total AR condition duration of ~75 hours
The combination of strong IVT magnitudes and long durations results in an AR 5 on the AR Scale (Ralph et al. 2019)
Since this is an early season AR and soil moisture across the PNW is dry, impacts associated with these ARs may not be as hazardous as an AR of similar strength that makes landfall in the middle of winter
As much as 7 inches of precipitation has already fallen over the Cascade Mountains of northern Washington and an additional 4–5 inches is forecast to fall during the next period of AR activity

GOES-17 PACUS Domain GeoColor

Valid 0000 UTC 22 September – 1200 UTC 24 September 2020

Click images to see loops of GFS IVT/IWV analyses and forecasts Valid 1200 UTC 24 September – 1200 UTC 04 October 2020 Forecasting an active week of ARs in the PNW

Summary provided by C. Hecht, B. Kawzenuk, J. Kalansky, and F. M. Ralph; 21 September 2020

*Outlook products are considered experimental

Virtual Happy Hour: CW3E Post-Doc Appreciation

CW3E Launches Public Subseasonal-to-Seasonal (S2S) Experimental Forecast Webpage for Winter 2020-2021

September 24, 2020

In honor of National Post Doc Appreciation Week, CW3E got together to appreciate and celebrate all of our post-docs during a virtual happy hour. We are extremely fortunate to have a group of such smart, motivated, and collaborative post-docs. Thank you all for your many valuable contributions to CW3E!

Our current CW3E post-docs are:

William (Ty) Brandt, PhD

Allison Michaelis, PhD

Alison Cobb, PhD

CW3E Event Summary: 14-18 September 2020

September 22, 2020

Click here for a pdf of this information.

Landfalling AR and Cutoff Low bring much-needed rainfall and improved air quality to the Pacific Northwest

A landfalling AR and cutoff low produced light-to-moderate precipitation (0.50–2 inches) over portions of western Washington and Oregon
Weak-to-moderate AR conditions persisted for more than 48 consecutive hours along the Oregon coast [AR3 based on the Ralph et al. (2019) AR Scale]
Precipitation and changes in wind direction and humidity significantly improved the air quality and alleviated the wildfire threat in western Washington and Oregon