cw3e-web - Center for Western Weather and Water Extremes

CW3E Publication Notice: Advances in Precipitation Retrieval and Applications from Low Earth Orbiting Satellite Information

CW3E Publication Notice

Advances in Precipitation Retrieval and Applications from Low Earth Orbiting Satellite Information

September 27, 2023

CW3E postdoctoral researcher Vesta Afzali Gorooh, in collaboration with the UCI Center for Hydrometeorology and Remote Sensing, NOAA-NESDIS, NASA-JPL, and UMD System Science Interdisciplinary Center recently published a paper titled “Advances in Precipitation Retrieval and Applications from Low Earth Orbiting Satellite Information” in the Bulletin of the American Meteorological Society. This article summarizes a virtual NOAA workshop on “Precipitation Estimation from Low Earth Orbit Satellites: Retrieval and Applications,” organized with support from the Office of Low Earth Orbit Observations at NOAA-NESDIS.

The workshop brought together experts in satellite precipitation retrieval and operational data users for the two-day event (1-2 March 2023). It covered the state of the science and users’ needs for operational precipitation algorithms and products from current and future meteorological satellites (Fig.1). The work contributes to the goals of CW3E’s 2019-2024 Strategic Plan by sharing insights from the hydrologist, atmospheric scientists, and stakeholders, who provided essential insights for enhancing satellite-based precipitation sensing and addressing the associated requirements and considerations, resulting in the following overarching recommendations:

Observation system and data delivery requirements: NOAA should actively collaborate with national and international partners to enhance precipitation-sensing microwave sensors for frequent updates (hourly to sub-hourly). It is crucial to prioritize timely access (within one hour) to satellite data for nowcasting and short-term forecasting by expanding data acquisition capacities. Maintaining a joint satellite precipitation radar and passive microwave (PMW) radiometer reference systems is crucial for ensuring accurate intercalibration of constellation radiometers used in Level-3 global precipitation datasets.
Value/impact studies: NOAA should consistently invest in performing impact studies on precipitation products when new observation capabilities are introduced, involving domestic, international, and private sector partners, and these studies should also precede any decisions regarding decommissioning existing observation capabilities. NOAA should maintain its active involvement in International Precipitation Working Group activities, serving as a crucial platform for scientific collaboration in precipitation retrievals, facilitating the improvement of existing techniques, the development of innovative methodologies, and the resolution of pertinent challenges.
Measurement requirements: NOAA should use satellite/sensor impact study results to define and specify desired channel requirements, including resolution and polarization for PMW-based rainfall and snowfall retrieval, including window channels near 6, 10, 19, 37, and 89 GHz, together with temperature and water vapor sounding bands near 23, 50, 118, 166, and 183 GHz and higher.
Algorithm development and applications: The meeting showcased the enhancements of satellite precipitation estimation through diverse probabilistic and machine learning methods alongside global radar and ground observations for uncertainty assessment. Collaboration with the user community is essential for establishing a robust climate data record using precipitation radar reference, particularly given the long duration of operational PMW satellite missions dating back to 1987 with the Special Sensor Microwave Imager (SSMI) series. Moreover, incorporating spaceborne radars to calibrate passive sensors and integrating ground-based observations are vital for identifying errors and enhancing precipitation retrievals. Incorporating precipitation parameterizations and prior ground observation data can reduce uncertainties in spaceborne radar measurements, leading to more accurate and dependable multi-satellite precipitation retrievals. It is also recommended to develop location-specific error and uncertainty models for satellite products to optimize their use in hydrological modeling, water resource management, and climate studies, considering regional variations, timeframes, and specific applications.

Figure 1: Precipitation-related missions in Japan (Source: Misako Kachi and Takuji Kubota Presentations)

Afzali Gorooh, V., and Coauthors, 2023: Advances in Precipitation Retrieval and Applications from Low Earth Orbiting Satellite Information. Bull. Amer. Meteor. Soc., https://doi.org/10.1175/BAMS-D-23-0229.1, in press

CW3E AR Update: 22 September 2023 Outlook

September 22, 2023

Click here for a pdf of this information.

Atmospheric River Forecast to Impact Pacific Northwest and Northern California

An atmospheric river (AR) is forecast to make landfall in the Pacific Northwest early Sun 24 Sep with the greatest IVT making landfall along the Oregon-California Border late Sun 24 Sep. IVT values above 250 kg m-1 s-1 are forecast to persist in the Pacific Northwest through Wed 27 Sep
AR 4 conditions (based on the Ralph et al. 2019 AR Scale) are forecast along the Oregon coast while AR3 conditions are forecast along the Washington and northern California coasts in both the GFS and ECMWF
The 00Z GFS is forecasting 5.28 inches of precipitation over the next 10 days in the Chetco Watershed, located in SW Oregon along the Oregon-California border, while the 00Z ECMWF is forecasting 2.97 inches over the same period. Some of the precipitation is forecast to fall after this AR
The NWS Weather Prediction Center (WPC) is forecasting 5-day precipitation totals >3 inches over the Olympic Peninsula and the Oregon-California border with >1.5 inches along the Oregon and Washington coasts. WPC excessive rainfall outlooks have a marginal risk for rainfall exceeding flash flooding guidance along the Oregon-California Border for 12Z Mon 25 Sep -12Z Tues 26 Sep
Despite higher amounts of precipitation along much of the Pacific Northwest Coast, both the CNRFC and NWRFC do not forecast any river stage locations to pass above action stage. This is largely tied to much of the Pacific Northwest currently experiencing Severe Drought conditions or worse

Click images to see loops of GFS IVT and IWV forecasts Valid 0000 UTC 24 September – 1800 UTC 27 September 2023

Summary provided by M. Steen, S. Roj, P. Iniguez and S. Bartlett; 22 September 2023

To sign up for email alerts when CW3E post new AR updates click here.

*Outlook products are considered experimental

CW3E Publication Notice: West-WRF 34-year reforecast: Description and Validation

CW3E Publication Notice

West-WRF 34-year reforecast: Description and Validation

September 19, 2023

A new paper titled “West-WRF 34-year reforecast: Description and Validation” by Alison Cobb, Daniel Steinhoff (CW3E), Rachel Weihs (CW3E), Luca Delle Monache (Deputy Director, CW3E), Laurel DeHaan (CW3E), David Reynolds (U Colorado), Forest Cannon (Tomorrow.IO), Brian Kawzenuk (CW3E), Caroline Papadopolous (CW3E), and Marty Ralph (Director, CW3E) was recently accepted to the Journal of Hydrometeorology. This paper describes the development and evaluation of a novel high-resolution long-term regional forecast product, based on CW3E’s near-real time forecast model, West-WRF. The West-WRF 34-year reforecast was generated by dynamically downscaling the control member of the GEFSv10 reforecast over the Western U.S. and northeastern Pacific Ocean during the cool season months (1 December through 31 March) between 1986-2019. The forecasts are available at a 9-km resolution over much of the Eastern Pacific and Western North America out to 7 days and at a 3-km resolution primarily over California. This valuable dataset is being used to further study extreme precipitation and atmospheric river activity through physical process studies, training for post-processing and machine learning techniques, and climatological analysis. It supports CW3E’s 2019-2024 Strategic Plan by providing an evaluation of West-WRF with the goal to identify benefits and added value of the forecasting system as well as and areas to further target model development.

This paper shows the added value of the dynamical downscaling of GEFS into the West-WRF reforecast on scales important for both basin/reservoir water management and for climatological understanding of extreme events across the West. Verification of near-surface temperature, wind, and humidity highlight the added value in the reforecast compared to GEFSv10. The West-WRF reforecast also shows clear improvement in atmospheric river characteristics (intensity and landfall) over GEFS. Figure 1 shows the intensity error, landfall position error, and distance from perfect MoE averaged across all categorized ARs for both the West-WRF 9-km reforecast and GEFS, as well as the differences between the two. For all three metrics, the reforecast has smaller errors across all forecast lead times than GEFS. The improvements are statistically significant at the 95% confidence level for three lead times for landfall position error, four lead times for AR intensity error, and all seven lead times for MoE (when the error bars for the difference are below 0). The largest improvement in intensity error occurs at the 48-hour forecast, improving the intensity forecast by almost 4 kg m^-1 s^-1, which is an average error reduction of over 5%, while the largest improvement in landfall position error occurs at the 144-hour forecast, with an improvement of over 30 km. The reduction in MoE error with the reforecast corresponds to an average improvement in location of the whole AR of 1% of the area of the AR. This 1% can range from an area of 20,000 km² for a small AR to over 500,000 km² for a large AR that is correctly forecasted as an AR. These results demonstrate a consistent, clear improvement in AR intensity, landfall, and location characteristics using the West-WRF reforecast compared to GEFS.

Analysis of mean areal precipitation (MAP) shows that at the basin-scale, the reforecast can improve MAP compared to GEFSv10 and reveals a consistent low bias in the reforecast for a coastal watershed (Russian) and a high bias observed in a Northern Sierra watershed (Yuba). The reforecast has a dry bias in seasonal precipitation in the northern Central Valley and Coastal Mountain ranges, and a wet bias in the Northern Sierra Nevada, which is consistent with other operational high resolution (< 25 km) regional models.

Overall, the paper serves to introduce this reforecast dataset to the scientific community as a resource for quality, high resolution atmospheric forecasts of extreme precipitation events largely from ARs. It can be used to further quantify ARs, their characteristics, uncertainties and impacts, and the representation of those characteristics and impacts in the West-WRF reforecast beyond that presented in the paper. The positive verification results of the reforecast show that it can be leveraged for scientific studies of ARs and extreme precipitation, machine learning, and further model evaluation.

Figure 1: Figure 7 from Cobb et al. (2023) a) AR intensity error using a threshold of 500 kg m^-1 s^-1, where intensity is defined as the 90th percentile value within any AR object. Upper panel shows full values, and the lower panel shows the difference (Reforecast minus GEFS). b) AR landfall position error using a threshold of 500 kg m^-1 s^-1, where landfall position is defined as the latitude of maximum IVT at the coastline. c) distance from perfect MoE for a threshold of 500 kg m^-1 s^-1. In all cases, the error bars are the 95 % confidence interval computed with bootstrapping.

Cobb, A., Steinhoff, D., Weihs, R., Delle Monache, L., DeHaan, L., Reynolds, D., Cannon, F., Kawzenuk, B., Papadopolous, C., & Ralph, F.M. (2023). West-WRF 34-Year Reforecast: Description and Validation. Journal of Hydrometeorology (published online ahead of print 2023). https://doi.org/10.1175/JHM-D-22-0235.1

Heavy Rainfall in Arizona

CW3E Event Summary: Heavy Rainfall in Arizona

September 19, 2023

Click here for a pdf of this information.

A Fall “Transition” Monsoon Event Brings Heavy Rain to Parts of Arizona

On September 12-13, 2023, a deep southwesterly flow of moist air was directed into Arizona, ahead of an advancing upper level trough.
This setup was a classic “Transition” monsoon event, signified by the transition from the hot, humid active summer into quieter fall months. Synoptic conditions for transition events are distinctly different from typical monsoon events when high pressure is overhead. While precipitation trends down in September, the combination of summer moisture and fall dynamics can result in significant rainfall events. The pattern resulted in persistent convection near and just east of the Phoenix area.
The Southwest Monsoon runs from June 15 through September 30.
Heavy precipitation fell over the Salt River watershed in central Arizona, with some locations receiving more than 20% of the normal total water year precipitation in a 24-hour period.
In excess of 6” of rain fell near Roosevelt, AZ. The Return Interval (Annual Probability) of 5.5”/6 hr is over 1000 years (<0.1%). For a nearby COOP station (Roosevelt 1 S, 1905+), the all-time 1-day record is 4.14" (1978-03-02). For comparison the average annual precipitation total is 15.91”.
The heavy rain resulted in flooding and rock slides, causing at least one highway to close.
IVT tools (based on the GEFS) indicated the potential for this notable moisture flux days in advance.

Click Here for Satellite Loop

Click Here for Radar Loop

Click Here for IVT Forecast Loop

Summary provided by P. Iñiguez, C. Castellano, J. Cordeira, and M. Ralph; 19 September 2023

To sign up for email alerts when CW3E post new AR updates click here.

CW3E Publication Notice: Towards probabilistic post-fire debris flow hazard decision support

CW3E Publication Notice

Towards probabilistic post-fire debris flow hazard decision support

September 18, 2023

A paper titled “Towards probabilistic post-fire debris flow hazard decision support” was recently published in the journal Bulletin of the American Meteorological Society. This research was a collaboration among CW3E, the California Geological Survey, the U.S. Geological Survey, the University of Arizona, and the National Weather Service.

Post-fire debris flows (PFDFs) threaten life, property, and infrastructure in steep wildfire-prone terrain worldwide. PFDFs are mixtures of water and sediment, typically with a sediment concentration exceeding 50% by volume. In the first few years following a wildfire, PFDFs often initiate when short duration (typically <1 hour), high-intensity rainfall produces runoff that rapidly entrains sediment on steep slopes. Note that nearly all PFDFs that occur within two years after fires are distinct from shallow landslides; they are runoff-driven, not infiltration-driven, and do not require antecedent rainfall nor high storm-total or multi-hour rainfall. As PFDFs become a more frequent hazard affecting larger areas, there is an increasing need for decision-support tools to effectively convey uncertainty around rainfall intensities, PFDF likelihood, volume, and potential impacts. As PFDFs are rainfall-driven, there is a particular need for tools that merge rainfall forecasts from numerical weather prediction models with models designed to assess PFDF hazard.

This paper explores the challenges in operational forecasting and communicating information about PFDF hazards. Through two case study events on the 2017 Thomas Fire burn area (Santa Barbara/Ventura Counties, CA) using a high-resolution (1km), large ensemble (100-member) 24-hour lead time precipitation forecast. It proposes a framework for integrating ensemble forecasts from mesoscale models with PFDF likelihood and volume models to create decision-support tools. We find that the observed 15-minute rainfall intensities for the events evaluated are captured within the ensemble spread, although in the highest 10% of members (Fig. 1). Given this distribution, consideration of the full model ensemble spread in areas with values-at-risk is necessary. While this work demonstrates that it is feasible to integrate ensemble precipitation forecasts with PFDF likelihood and volume models (Fig. 2), additional work needs to be done to understand and potentially reduce the sources of uncertainty in forecasting short-duration, high-intensity rainfall. As demonstrated, the ensemble simulation is likely too computationally expensive to run operationally. Future research can optimize the forecast lead time, number and characteristics of ensemble members, domain size, and grid spacing.

This work addresses CW3E’s strategic plan goal of improving weather, hydrology, and coupled modeling capabilities for the western United States as it couples a numerical weather prediction model (using the West-WRF configuration) with debris flow likelihood and volume models. It provides insights to model successes and challenges associated with short-duration, high-intensity precipitation that can be further explored in future research. Additionally, it addresses the CW3E core value of collaboration. This work demonstrates the benefits of collaborations between the geomorphology and meteorology communities to improve decision support for PFDF hazards.

Figure 1: a) Histogram of 15-minute precipitation forecasts, in mm h^-1, from the 100 WRF ensemble members at the location of the Doulton Tunnel rain gauge, using a 1-km neighborhood and temporal window of +/- 1 h about the time of maximum observed rainfall. Vertical lines indicate ensemble mean and gauge observation. b) Time series of the observed (dots) and ensemble forecast 15-minute rainfall rates at the WRF grid cell closest to the location of the Doulton Tunnel rain gauge; no neighborhood method is used. The black star indicates the maximum 15-minute observed rainfall. The ensemble median, minimum, and maximum forecast values are denoted by the black, red, and blue lines, respectively, and the gray shading represents the ensemble interquartile range. c) As in a) for the KTYD gauge. d) As in b) for the KTYD gauge. See Fig. 4b for gauge locations. Gauge data acquired from County of Santa Barbara Department of Public Works via https://rain.cosbpw.net/.

Figure 2:: For the 9 January 2018 event, in the top row, ensemble 90^th percentile a) peak I₁₅, b) probability of debris flow occurrence, and c) predicted volume. In the middle row, ensemble median d) peak I₁₅, e) probability of debris flow occurrence, and f) predicted volume. In the bottom row, ensemble 10^th percentile g) peak I₁₅, h) probability of debris flow occurrence, and i) predicted volume. The coordinates of the top left and bottom right corners of each map are (34^o39’N, 119^o41’W) and (34^o15’N, 118^o56’W), respectively.

This research was supported by the California Department of Resources Atmospheric River Program and the NOAA Collaborative Science, Technology, and Applied Research (CSTAR) program.

Oakley, N. S., Liu, T., McGuire, L. A., Simpson, M., Hatchett, B. J., Tardy, A., Kean, J. W., Castellano, C., Laber, J. L., & Steinhoff, D. (2023). Toward Probabilistic Post-Fire Debris-Flow Hazard Decision Support. Bulletin of the American Meteorological Society, 104(9), E1587-E1605. https://doi.org/10.1175/BAMS-D-22-0188.1

CW3E Welcomes Ross Beaudette

September 15, 2023

Ross Beaudette joined CW3E on September 11^th, 2023 as a field research engineer. Ross spent the last 21 years as a lab manager for the Severinghaus Lab at Scripps Institution of Oceanography. In this role he helped his PI study paleoclimate though stable isotopes of air trapped in polar ice using mass spectrometry, as well as guide and train graduate students. Ross was awarded the Antarctic Service Medal in 2013 for his fieldwork in Antarctica on the West Antarctic Ice Sheet Divide replicate ice core. He holds a BS degree in Environmental Science from the University of Vermont, where he is originally from. Ross will be supporting the land based field team here at CW3E helping to better understand atmospheric rivers and is excited about this new endeavor.

CW3E Publication Notice: Influence of the freezing level on atmospheric rivers in High Mountain Asia: WRF case studies of orographic precipitation extremes.

CW3E Publication Notice

Influence of the freezing level on atmospheric rivers in High Mountain Asia: WRF case studies of orographic precipitation extremes

September 8, 2023

A new paper titled, “Influence of the Freezing Level on Atmospheric Rivers in High Mountain Asia: WRF Case Studies of Orographic Precipitation Extremes” by Deanna Nash (CW3E), Leila Carvalho (UC Santa Barbara), Jon Rutz (CW3E), and Charles Jones (UC Santa Barbara) was recently published in Climate Dynamics. This study evaluates changes in integrated water vapor transport (IVT) and the height of the 0°C isotherm (hereafter, freezing level) during wintertime atmospheric rivers (ARs) across High Mountain Asia (HMA) using Climate Forecast System Reanalysis (CFSR) dynamically downscaled to 20-km and 6.7 km horizontal resolution with the Advanced Weather Research and Forecasting (ARW-WRF) model. Results show that from 1979 to 2015, IVT during ARs that reach western HMA has increased 16% while the freezing level has increased up to 35 m. These changes have modified the fraction of frozen precipitation that falls during these storms. Figure 1 shows that ARs with an above-average freezing level produce 10-40% less frozen precipitation than ARs with a below-average freezing level. In light of a warming climate, this points to consequences such as increased frequency of precipitation-triggered landslides and floods in a region of complex topography, impacting water resources, infrastructure, and lives and livelihoods of those that live in that area.

Figure 1: Figure 4 from Nash et al. (2023) (a) WRF 6.7 km fraction of frozen precipitation (shaded; -) for Northwestern HMA ARs above-average freezing level conditions within the red box. (b) Same as (a) but for Western HMA ARs. (c) Same as (a) but for Eastern HMA ARs. (d) WRF 6.7 km fraction of frozen precipitation (shaded; -) for Northwestern HMA ARs below-average freezing level conditions within the red box. (e) Same as (d) but for Western HMA ARs. (f) Same as (d) but for Eastern HMA ARs. (g) Composite differences of WRF 6.7 km fraction of frozen precipitation (shaded; -) for Northwestern HMA ARs above-average freezing level conditions and below-average freezing level conditions within the red box. Only differences (above-average conditions minus below-average conditions) in the fraction of frozen precipitation that are considered at or above the 95% confidence level are shaded. (h) Same as (g) but for Western HMA ARs. (i) Same as (g) but for Eastern HMA ARs.

To differentiate the synoptic and mesoscale characteristics of ARs with above-average freezing level from ARs with below-average freezing level, this study compares two ARs with broadly similar characteristics (e.g., high IVT, low-level southwesterly flow, and dynamic support by an upper-level trough) that both resulted in extreme precipitation, but strikingly different impacts. The key difference between these two events is that one featured an above-average freezing level (January 1989), while the other featured a below-average freezing level and 12-h longer duration (February 2010). The longer duration is likely why the February 2010 AR case resulted in higher amounts of precipitation overall. Perhaps more notably, between 1-3 km (i.e., where changes in the freezing level are more likely to influence the fraction of frozen precipitation), the February 2010 AR had more rain and less snow than the January 1989 AR (Figure 2i, j). Although freezing levels were only 50-600 m higher during the 2010 AR, this event resulted in 10-70% less frozen precipitation than the 1989 AR (Figure 2k, l).

Overall, the examples of below- and above-average freezing level ARs presented here demonstrate the importance of mesoscale processes in orographic precipitation and highlight the varying outcomes that can result across HMA from relatively small differences in freezing level height. This study intersects with extensive CW3E research focused on a better understanding of precipitation extremes, precipitation type (the fraction of which is liquid vs. frozen within a watershed being sometimes greatly modified by relatively small changes in freezing level), and implications for water resources in an area of complex topography: California. Even as these efforts expand to other U.S. states, this study highlights the increasingly global reach of CW3E research and applications. This work is associated with two of five major priorities outlined in CW3E’s Strategic Plan: “Atmospheric Rivers Research and Applications” and “Monitoring and Projections of Climate Variability and Change.” This work addresses those priorities by furthering the understanding of AR dynamics and providing insights on historical extreme AR events.

Figure 2: Figure 6 from Nash et al. (2023) (a) Total event WRF 6.7 km rain (shaded; mm event⁻¹) for the January 1989 AR. The black contours are the location of 1- and 3-km elevation. (b) Total event WRF 6.7 km snow (shaded; mm event⁻¹) for the January 1989 AR. (c) Average event WRF 6.7 km fraction of frozen precipitation (shaded; -) for the January 1989 AR. (d) Average WRF 20 km freezing level (shaded; m ASL) for the January 1989 AR. (e–h) Same as (a–d) but for the February 2010 AR. The yellow diamonds and black triangles indicate the location of a precipitation-triggered landslides during the 2010 AR event, the triangles are the same points in Figs. 1b and 9e,f. (i) The difference in rain (shaded; mm event⁻¹) for the February 2010 AR minus the January 1989 AR. (j) Same as (i) but for snow (shaded; mm event−1). (k) Same as (i) but for the fraction of frozen precipitation (shaded; -). (l) Same as (i) but for the freezing level (shaded; m ASL). The black triangles indicate the points of two of the six landslides triggered during this event and are also shown in Figs. 1b and 6e–h.

Nash, D., Carvalho, L.M.V., Rutz, J.J., and Jones, C. Influence of the freezing level on atmospheric rivers in High Mountain Asia: WRF case studies of orographic precipitation extremes. Climate Dynamics (2023) https://doi.org/10.1007/s00382-023-06929-x

Jackson Ludtke Recognized as a 2023 Triton Student Employee of the Year For His Role in the 2023 AR Recon Season

June 06, 2023

Jackson Ludtke came to CW3E in the fall of 2021 as a UCSD undergraduate student interested in the center’s Atmospheric River (AR) Reconnaissance program. Flight tracks for these missions are developed in Google Earth and require close coordination between CW3E staff and collaborators around the world. Jackson’s position requires him to start as early as 6 am, update a variety of background fields in Google Earth, create draft flight tracks, present them during weather briefings, revise them on-the-fly as needed with feedback from senior scientists and aircraft personnel, and then produce and provide coordinate and spacing information on a tight and inflexible timeline. He quickly learned how to use the Google Earth flight planning tool during the water year 2022 season and enjoyed the work so much that he decided to join us again for the water year 2023 season. During his first season, he provided key support but did not use the tool in real-time on his own. However, he fully embraced the opportunity this season and excelled in the high-pressure work. He was always able to complete his tasks on deadline which required close collaboration with the team and excellent communication skills. Jackson was able to exceed our expectations in communication and teamwork as well as in the precision of his work. He has great initiative, shares well thought out ideas, and makes sure everyone is included. He routinely asks questions to make sure his tasks are completed correctly and by the middle of the season did not need much supervision.

After winning the award he was presented with a plaque and various gift certificates at the 2023 CW3E Annual Meeting. The AR Recon team is very thankful for his contribution and endorsed him for 2023 Triton Student Employee of the Year. Congratulations Jackson, and job well done! Hope to see you during the upcoming water year 2024 season.

CW3E Welcomes Taylor Dixon

August 28, 2023

Taylor Dixon joined CW3E as a Senior Hydrologist in August 2023. Taylor and his wife and children recently relocated to the San Diego area from Camas, WA. Although they enjoyed living, working, and playing in the Pacific Northwest for many years, they welcome the sun, outdoor living, and culture across San Diego County.

In his new role, Taylor will serve as a liaison between the Center and the National Weather Service (NWS) River Forecast Centers, support the growing Forecast Informed Reservoir Operations (FIRO) program, and help advance the Center’s hydrologic forecasting capabilities. In addition to leading and contributing to technical developments and project/program management activities, he will be focusing on helping maintain and develop partnerships between CW3E and the academic community, water managers across the West, and operational forecasting entities.

Prior to his new position, Taylor was the Development and Operations Hydrologist (DOH) at the NWS Northwest River Forecast Center (NWRFC) in Portland, Oregon. As part of the management team, he helped oversee the daily and event-driven streamflow forecasting operations and led the RFC’s multifaceted and collaborative research-to-operations (R2O) portfolio. He was also responsible for training and developing forecasting staff, and with building and nurturing productive, relevant relationships across the agency and beyond. Before moving into the DOH position, Taylor was an operational forecaster for the NWRFC for several years. His professional hydrology experience also includes time with the U.S. Bureau of Reclamation (USBR), where he conducted basin-scale climate change and water management studies and supported USBR water managers, and with the Idaho Department of Water Resources (IDWR), where he led field-, laboratory-, and modeling-based studies focused on groundwater-surface water exchanges (and drivers) in cultivated, mountainous watersheds. His education includes a B.S. in Chemistry (Boise State University) and an M.S. in Hydrology (Colorado School of Mines), as well as professional certification in Data Science (HarvardX).

Altogether, Taylor has nearly 20 years of professional hydrology experience, and is well-versed in the complex challenges associated with modeling, forecasting, and managing water across the West. He is thrilled to be working with the highly capable, forward-leaning teams of scientists, engineers, and project managers at CW3E and throughout its partnering entities to help advance the state of hydrologic forecasting operations and water management capabilities in Western North America.

CW3E Event Summary: Hurricane Hilary 20-21 August 2023

August 24, 2023

Click here for a pdf of this information.

Hurricane Hilary Brings Heavy Rain, Flooding and High Winds to Southern California

Hilary made landfall as a Category 1 hurricane in Baja California and weakened into a tropical storm before crossing into California
The cyclone produced heavy rain and high winds across Southern and Central California on 20 and 21 August
Much of Southern California and Southwestern Nevada received > 2 inches of precipitation with stations in the Transverse Range measuring > 10 inches
Several stations set new daily precipitation records for the month of August while Death Valley set its all-time single day precipitation total at 2.20 inches
Precipitable water observed during this event in San Diego was 2.38 inches, tying for the second highest recorded value per Storm Prediction Center records
Many streamflow stations throughout Central and Southern California saw streamflows > 90th percentile of climatology because of the record-breaking rainfalls
Heavy rainfall resulted in widespread flash flooding and debris flows that damaged roadways
High winds caused trees to fall and resulted in power outages for more than 50,000 people across Central and Southern California
Per the National Oceanic and Atmospheric Administration Hilary was the first tropical storm to pass over California since Nora in 1997

National Hurricane Center

Valid 9 AM PDT 16 August to
2 AM PDT 21 August 2023