CW3E Scripps

Assistant, Associate, or Full Research Meteorologist University of California, San Diego is hiring. Apply now!

The Scripps Institution of Oceanography is recruiting for an Assistant, Associate, or Full Researcher in Meteorology. This full-time academic appointment is similar to the tenure-track ranks of an academic professorship appointment. apol-recruit.ucsd.edu/JPF04327

Figure 2 from Yang et al. (2025). Grid LSTM‐RAPID daily discharge modeling framework. The basins, grids, and river networks depicted are simplified illustrations and do not represent their actual size, shape, or quantity.

CW3E Publication Notice: "Global Daily Discharge Estimation Based on Grid Long Short-Term Memory (LSTM) Model and River Routing" in @agu.org's Water Resources Research.

For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....

CW3E Publication Notice: "Impact of Airborne Radio Occultation Observations on Short Term Precipitation Forecasts of an Atmospheric River" in @agu.org Geophysical Research Letters. Read more about this research here: go.ucsd.edu/40oMk6O

CW3E in the Press: Recent Media Coverage From the New York Times, BBC, CNN and More: cw3e.ucsd.edu/cw3e-in-the-...

The operations-based validation framework forwarded in this work. From Figure 1 in Brodeur et al. (2025).

CW3E Publication Notice: "Synthetic ensemble forecasts: operations-based evaluation and inter-model comparison for reservoir systems across California" in @agu.org's Water Resources Research.

For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....

CW3E Publication Notice: "Analyzing Atmospheric River Reforecasts: Self-Organizing Error Patterns and Synoptic-Scale Settings" in @ametsoc.org 's Weather and Forecasting.

Read more here: cw3e.ucsd.edu/cw3e-publica...

Illustration of the combined role of changes in the climate system and impacts from emissions and land-use change stemming from various socioeconomic processes on overall risk (i.e., vulnerability, exposure, and hazard characteristics) to climate-related impacts. Source: Figure SPM.1 from IPCC (2014).

CW3E Publication Notice: "Kickoff of a Joint AMS/ASCE Effort to Assess the Potential Contribution of AI in Addressing Infrastructure Resilience in a Changing Climate" in @ametsoc.org's BAMS.

For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....

CW3E Publication Notice: "Wet Antecedent Soil Moisture Increases Atmospheric River Streamflow Magnitudes Non-Linearly" in the @ametsoc.org Journal of Hydrometeorology. Read more about this research here: cw3e.ucsd.edu/cw3e-publica...

Nice article covering why we use the Air Force and NOAA further upstream to improve atmospheric river forecasts for the US. @scrippsocean.bsky.social

Read more here: bbc.com/future/artic...

CW3E Publication Notice: "Characteristics of Precipitation Patterns in Moisture-dominated versus Wind-dominated Atmospheric Rivers over Western North America" in @agu.org's Journal of Geophysical Research: Atmospheres. Read more here: go.ucsd.edu/3SGsVd8

A comparison of the penetration depth of radio occultation (RO) data in terms of the proportion of profiles that extend down to a given geometric height. The figure also shows how RO observations are vertically distributed, expressed as the percentage of total profiles within each 200-meter layer of the atmosphere, for different integrated water vapor transport (IVT) levels. The IVT thresholds are indicated by different line dash patterns in the legend. Figure 10 from Murphy et al. (2025).

CW3E Publication Notice: "The Utility of a Two-dimensional Forward Model for Bending Angle Observations in Regions with Strong Horizontal Gradients" in @ametsoc.org's Monthly Weather Review.

For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....

CW3E Publication Notice: "Beyond Expectations: Investigating Anomalous 2022-2023 Winter Weather Conditions and Water Resources Impacts in California" in the Bulletin of the American Meteorological Society (BAMS). Read more about this research here: go.ucsd.edu/3GG2DVQ

CW3E Publication Notice: "An Analysis of Cloud Microphysical Features over United Arab Emirates using Multiple Data Sources" in @egu.eu's Atmospheric Measurement Techniques. Read a summary of this publication here: go.ucsd.edu/42H4mCO

One of the Weather World’s Biggest Buzzwords Expands Its Reach To many, atmospheric rivers are a West Coast phenomenon. But they’re also responsible for the devastating flooding that hit the Central United States in early April.

#AtmosphericRivers don't just impact the West Coast—these powerful weather phenomena are bringing floods to the central U.S. @cw3escripps.bsky.social director Marty Ralph spoke with @amyjeangraff.bsky.social of @nytimes.com on the need for expanding AR research across the country.

CW3E Publication Notice: "Toward Calibrated Ensembles of Neural Weather Model Forecasts" in the @agu.org Journal of Advances in Modeling Earth Systems. For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica...

56 #AtmosphericRivers made landfall along the U.S. West Coast during the first six months of Water Year 2025. The main story this wet season: stark contrasts between regions - NorCal saw 8 strong-or-greater ARs, while SoCal had zero. #CAwx #CAwater Read our full summary here: go.ucsd.edu/4cGqwbz

(a) Profiles showing the difference between simulated 1D and 2D bending angles. Each grid box represents 10% bending angle difference. The labels A1, A2, A3, and A4 indicate in which part of the flight path the profiles are located in panel (c). Individual tangent points in the profile are color-coded by the integrated vapor transport beneath that point, and the size of each dot is scaled to corresponding IWV values. (b) Refractivity anomaly profiles (observation minus climatology) calculated from the dropsondes in transects A2 and A3. Dashed line indicates where the aircraft turned on the cold side of the AR core from transect A2 to A3. Blue shading indicates the levels in the profiles with large dew point depression (dry air), and red shading indicates levels with near saturation conditions. Profiles are offset by 10% for visibility. (c) Location of occultation profiles along transects A1 (outside the AR), A2 and A3 (inside the AR) and A4 (outside the AR).

CW3E Publication Notice: "Forward Modeling of Bending Angles With a Two-Dimensional Operator for GNSS Airborne Radio Occultations in Atmospheric Rivers" in @agu.org's Journal of Advances in Modeling Earth Systems.

For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....

Figure 2 from Wille et al. (2025). (a) Atmospheric river (AR) frequency (h per year, 1980–2020; teal shading) derived from the algorithm and MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications, version 2) reanalysis. Interannual variability is shown in white contours (h per year). Coastal (based on ice sheet and shelves) AR frequency is shown by longitude and grouped by season. (b) Relative change in AR frequency (%) by individual glacier basin from 1980 to 2020 is shown with shading, also based on the MERRA-2 reanalysis. Hatching indicates a linear fit of AR frequency (horizontal) or AR precipitation (vertical) per basin from 1980 to 2020 that has a P value <0.05. AR precipitation trend values are not shown. Despite being rare events, positive trends in AR frequency are responsible for increased snowfall in West Antarctica and Queen Maud Land during the 1980–2020 period.

CW3E Publication Notice: "Atmospheric Rivers in Antarctica" in Nature Reviews Earth & Environment.

For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....

CW3E Event Summary: 1-7 April 2025 East Coast ARs - Multiple ARs over the Southeastern US fuel prolific flooding over the Mississippi, Ohio, and Tennessee River Valleys. Read more in our latest Event Summary here: cw3e.ucsd.edu/cw3e-event-s...

Figure 1 from Sengupta et al. (2025). Schematic of the seasonal precipitation forecast methodology based on evolving SST modes of variability. Antecedent SST fields, 𝛹 (x, y), from multiple past seasons (t₀, t₀-1, t₀-2, …, t₀-n), illustrated in (a), are projected onto predictor variables, shown in (b), extracted from an extended-EOF analysis of observed SST anomalies. The derived modes of variability comprise natural variability ranging from interannual to decadal-multidecadal timescales as well as the secular trend. A statistical model is trained by leveraging the lagged relationships between these predictor modes and the predictand, which is precipitation anomaly, Pr (x, y), over the western U.S. in the following winter season (t₀+1), shown in (c).

CW3E Publication Notice: "Role of evolving sea surface temperature modes of variability in improving seasonal precipitation forecasts" in @nature.com's Communications Earth & Environment.

For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....

Page 1 of Quick Look. Summary of key forecast information.

Page 2 of Quick Look. (Top) GFS 500-hPa absolute vorticity (shading), geopotential height (contours), and wind (barbs) analysis valid at 5 AM PDT Mon 31 Mar (left) and forecast valid at 5 AM PDT Fri 4 Apr (right). (Bottom) CW3E's AR Landfall tool based on GEFS showing the probability of AR conditions [IVT ≥ 250 kg/(ms)] along the West Coast of North America during the next 16 days.

Page 3 of Quick Look. (Top left) Deterministic and ensemble 10-day mean areal precipitation forecasts for the New Bullards Bar reservoir catchment. (Top right) NWS Weather Prediction Center (WPC) quantitative precipitation forecasts (QPF) valid for the 48-hour period ending 5 AM PDT Wed 2 Apr. (Bottom) GEFS 7-day freezing level forecasts (lines and grey shading) with 6-hourly mean areal QPF from the WPC (bars) in the Upper Yuba watershed.

Page 4 of Quick Look. WPC Days 1-3 Winter Storm Severity Index and official NWS snowfall forecasts valid for the 72-hour period ending 5 AM PDT Thu 3 Apr.

A storm will bring additional rain and mountain snow to Northern and Central California through tomorrow. Warmer and drier conditions are expected over much of the western US this weekend into early next week.

See our latest quick look for more information: cw3e.ucsd.edu/wp-content/u....

(Left and center) GFS integrated water vapor transport (IVT; shading and vectors) and sea-level pressure (SLP; contours) forecasts initialized at 00 UTC 28 Mar and 12 UTC 28 Mar. (Right) Difference in forecast IVT (orange/red = earlier run higher; green/blue = current run higher). Forecasts valid at 5 PM PDT Wed 2 Apr.

CW3E has posted an update on the potential for an impactful #AtmosphericRiver in California next week. #CAwx

See our latest outlook for an overview of how the forecast has changed: cw3e.ucsd.edu/cw3e-ar-upda....

A first #AtmosphericRiver has made landfall along the Pacific Northwest today and a second, potentially stronger storm may impact CA next week. #CAwx #ORwx #WAwx

Read our latest forecast outlook for more information on what's to come: cw3e.ucsd.edu/cw3e-ar-upda...

CW3E Publication Notice: "Are AI weather models learning atmospheric physics? A sensitivity analysis of cyclone Xynthia" - Read more here: go.ucsd.edu/4iXYCKc

CW3E's AR Landfall Tool based on GEFS showing the probability of AR conditions [IVT ≥250 kg/(ms)] along the West Coast of North America over the next 16 days.

An unsettled weather pattern is forecast to continue into next week with the potential for multiple #AtmosphericRiver landfalls and heavy precipitation over the US West Coast.

See our latest quick look for more information: cw3e.ucsd.edu/wp-content/u....

New Report Shows Implementation of Forecast-Informed Reservoir Operations at Lake Oroville and New Bullards Bar Can Increase Region’s Resilience to Floods A new report released today shows that changes to reservoir operations at Lake Oroville and New Bullards Bar Reservoir can further reduce flood risk for communities along the Yuba and Feather rivers d...

Exciting news! Last week, the Final Viability Assessment detailing the potential benefits of forecast-informed reservoir operations (FIRO) at Lake Oroville and New Bullards Bar was published. #FIRO

Read more about the report here: water.ca.gov/News/News-Re....

Page one of the quick look showing forecast highlights.

Page two of the quick look. On top are select timesteps of GFS IVT showing each AR forecast to impact the USWC. On bottom are AR Scale (based on the Ralph et al. 2019 AR Scale) forecasts from the West-WRF Ensemble for select locations in the PNW.

Page three of the quick look. On top are WPC precipitation forecasts for each AR period and the next 7-days. In the middle are model and ensemble mean forecasts (left) and GEFS, EPS and West-WRF members 10-day forecasts (right) for the Howard Hanson Dam. On bottom are select stream level forecasts for gauges in Oregon.

Page four of the quick look. On top are freezing level forecasts from the GEFS for the Upper Skagit watershed showing the rise in freezing levels with the second AR. On bottom are snowfall forecasts from the NWS and WSSI for the Cascades over the next 3 days.

CW3E's most recent quick look covers the #AtmosphericRiver activity across the USWC over the next week. These systems are likely to bring precipitation across the Pacific Northwest and Northern California.

Check out the latest forecast here: cw3e.ucsd.edu/wp-content/u...

(Left) GEFS maximum observed AR Scale along the coast for the 7-day period ending 5 AM PT Mon 17 Mar. (Center) NWS Stage IV quantitative precipitation estimates (QPE) for the 6-day period ending 5 AM PT Tue 18 Mar. (Right) NWS snowfall estimates for the 6-day period ending 5 AM PT Tue 18 Mar.

CW3E has posted an event summary for the two #AtmosphericRivers that produced heavy rain, heavy snow, and flooding in California and Oregon during March 12-17.

Read more about these storms and their impacts here: cw3e.ucsd.edu/cw3e-event-s.... #CAwx #ORwx

CW3E has posted a Quick Look at the upcoming #AtmosphericRiver activity over the US West Coast, with discussion of a potential long-duration AR over the Pacific Northwest forecast to begin this weekend. Read the full Quick Look here: cw3e.ucsd.edu/wp-content/u...

CW3E Publication Notice: "Changes to Atmospheric River Related Extremes Over the United States West Coast Under Anthropogenic Warming" - Read more here: go.ucsd.edu/4ixUalg