Author: cw3e-web

CW3E Welcomes Mahdi Erfania

CW3E Welcomes Mahdi Erfani

January 16, 2024

Mahdi Erfani joined CW3E in January 2024 as a postdoctoral researcher. Mahdi earned his PhD in Water Resources Engineering from the University of South Carolina (2023). Mahdi’s doctoral dissertation focused on improving reservoir operation and water resource systems management. He investigated the application of hydro-economic modeling and machine learning in watershed and hydrological modeling and feasibility assessment of integrated watershed management approaches.

At CW3E he will work under supervision of Dr. Luca Delle Monache on development, evaluation, and application of forecast informed reservoir operations (FIRO) for reservoir sites throughout the Western United States.

CW3E AR Update: 10 January 2024 Outlook

CW3E AR Update: 10 January 2024 Outlook

January 10, 2024

Click here for a pdf of this information.

Atmospheric River Will Fuel Winter Weather in Pacific Northwest and Northern California This Weekend

  • An atmospheric river (AR) will help drive winter weather set to impact the PNW from Fri 12 Jan through the end of the weekend.
  • Model guidance is showing significant uncertainty in AR landfall location, as well as precipitation amounts and precipitation type, especially over the Willamette Basin.
  • The GEFS is forecasting the AR to make landfall in and primarily impact the PNW while the ECMWF EPS is forecasting the AR to make landfall in Central/Southern OR and propagate down the CA coast through the weekend.
  • The GEFS control run is forecasting AR1 conditions (based on Ralph et al. 2019 AR scale) from Central OR down through Central CA, with the greatest AR conditions (AR2/AR3) near the OR/CA border.
  • The ECMWF EPS is also forecasting at least AR1 conditions (based on Ralph et al. 2019 AR scale) from Cen. OR down through Central CA, but the greatest AR conditions (AR2/AR3) are forecast for Northern/Central CA.
  • Further uncertainty in how far south into OR an Arctic Air Mass progresses also presents uncertainty in precipitation type in the Willamette Valley.
  • Significant snowfall accumulations are expected throughout the Cascades.
  • The Weather Prediction Center’s (WPC) Winter Storm Severity Index (WSSI) indicates that major impacts are expected throughout the Cascades for the period ending 4 AM PT on Sat 13 Jan.

Click images to see loops of GFS IVT and IWV forecasts

Valid 1200 UTC 10 January 2024 – 1500 UTC 14 January 2024


 

 

 

 

 

 

 

 

 

 

 

 

 

 

Summary provided by M. Steen, C. Castellano, P. Iniguez and S. Bartlett; 10 January 2024

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*Outlook products are considered experimental

CW3E Subseasonal Outlook: 9 January 2024

CW3E Subseasonal Outlook: 9 January 2024

January 9, 2024

Click here for a pdf of this information.


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Summary provided by Z. Yang, C. Castellano, J. Wang, M. DeFlorio, and J. Kalansky; 9 January 2024

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*Outlook products are considered experimental

CW3E Welcomes Yazmina Rojas Beltran

CW3E Welcomes Yazmina Rojas Beltran

January 9, 2024

Yazmina Rojas Beltran joined CW3E in January 2024 as a postdoctoral scholar.

Yazmina earned her BSc in Geophysics from the Universidad de Concepcion, Chile (2016), and her PhD in atmospheric science from the University at Albany in New York (2023). Yazmina’s doctoral dissertation focused on improving the understanding of orographic precipitation over the mountains of Extratropical South America, and on analyzing the utility of different datasets and tools to investigate high elevation precipitation data in a region with limited long-term records. Using a combination of observations, modeling, and reanalysis, she investigated the processes and mechanisms modulating the rain shadow strength over the southern Andes including the role of stability, atmospheric rivers, barrier jets, moisture flux, and synoptic storm structures.

At CW3E, under the supervision of Dr. Jason Cordeira, Yazmina will contribute to improving the understanding of landfalling atmospheric rivers and their interaction with topography, including the influence of the Sierra Barrier Jet on the orographic precipitation distribution and predictability in Northern California.

CW3E AR Update: 8 January 2024 East Coast Outlook

CW3E AR Update: 8 January 2024 East Coast Outlook

January 8, 2024

Click here for a pdf of this information.

Two Low Pressure Systems to Bring Heavy Precipitation to East Coast

  • Two low pressure systems and associated atmospheric rivers (AR) are forecast bring heavy precipitation to much of the Eastern and Midwest US this week.
  • The first strong AR (IVT > 1200 kg m-1 s-1 in the core) is forecast to form early Mon 8 Jan, progressing up the US East Coast through Wed 10 Jan before moving out to the Atlantic.
  • The first system is forecast to bring heavy precipitation, a mix of rain and snow, to the Eastern US.
  • Given the recent AR that impacted the eastern US, there is an increased threat of flooding throughout this event, with the Weather Prediction Center (WPC) Excessive Rainfall Outlook (ERO) forecasting a Moderate Risk (level 3 of 4, or 40% chance) for flooding for select areas through Tuesday Night.
  • The second AR (IVT > 1200 kg m-1 s-1 in the core) forms in the Gulf Thu 11 Jan, propagating through the East Coast out over the Atlantic by Fri 12 Jan.
  • The NWS WPC is forecasting an additional 1+ inches of rainfall for the region as it progresses up the coast. This continues the threat for flooding throughout the region.

Click images to see loops of GFS IVT and IWV forecasts

Valid 0000 UTC 8 January 2024 – 0000 UTC 14 January 2024


 

 

 

 

 

 

Summary provided by M. Steen, S.Bartlett, C.Castellano, and P. Iniguez; 8 January 2024

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

*Outlook products are considered experimental

CW3E AR Update: 5 January 2024 Outlook

CW3E AR Update: 5 January 2024 Outlook

January 5, 2024

Click here for a pdf of this information.

Winter Weather Set to Impact US West Coast this Weekend into Early Next Week

  • A series of upper-level shortwave troughs and an atmospheric river (AR) will help drive winter weather set to impact the US West Coast from late Fri 5 Jan through the end of next week.
  • The first period of winter weather begins late Fri 5 Jan when the shortwave trough is forecast to form off the PNW coast, deepening and eventually progressing east throughout Sat 6 Jan.
  • The second period of winter weather is driven by an AR that is forecast to make landfall as an AR1 to AR2 (based on Ralph et al. 2019 AR scale) into the PNW early Mon 8 Jan.
  • A second and third shortwave are forecast to move into the region late Tue 9 Jan and late Thu 11 Jan respectively, continuing the unsettled weather in the region.
  • For the 7-day period encompassing both shortwaves and the AR, significant snowfall accumulations are expected in the Cascades and Sierra Nevada ranges.
  • The Weather Prediction Center’s (WPC) Winter Storm Severity Index (WSSI) indicates that Major Impacts are expected in portions of the Sierra Nevada during the first winter storm period (ending Mon 8 Jan).
  • The WPC’s probabilistic WSSI tools indicates greater than 60% chance of moderate impacts with the AR and shortwave trough for the Cascades.
  • Given low seasonal snow amounts thus far, these systems will be beneficial for water resources across the region.

Click images to see loops of GFS IVT and IWV forecasts

Valid 1800 UTC 5 January 2024 – 0000 UTC 13 January 2024


 

 

 

 

 

 

 

 

 

 

 

Summary provided by M. Steen, P. Iniguez and C.Castellano; 05 January 2024

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

*Outlook products are considered experimental

CW3E Subseasonal Outlook: 3 January 2024

CW3E Subseasonal Outlook: 3 January 2024

January 3, 2024

Click here for a pdf of this information.


 

 

 

 

 

 

 

 

 

 

 

 

 

 

Summary provided by Z. Yang, C. Castellano, J. Wang, M. DeFlorio, and J. Kalansky; 3 January 2024

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

*Outlook products are considered experimental

CW3E AR Update: 3 January 2024 East Coast Outlook

CW3E AR Update: 3 January 2024 East Coast Outlook

January 3, 2024

Click here for a pdf of this information.

Pair of Atmospheric Rivers Forecast to Bring Precipitation to East Coast

  • A pair of atmospheric rivers (AR) are forecast to develop over of the Gulf of Mexico, bringing heavy precipitation to much of the Eastern US.
  • The first AR is forecast to form early Fri 5 Jan, progressing up the US East Coast through Sun 7 Jan before moving out to the Atlantic.
  • The first system is forecast to bring heavy precipitation, a mix of rain and snow, to the Eastern US. The SE US and Mid-Atlantic are expected to receive rain and New England, NY and PA are expected to receive more mixed precipitation and snow.
  • The second, much stronger AR (IVT > 1200 kg m-1 s-1 in the core) forms in the Gulf last Mon 8 Jan into Tue 9 Jan, propagating through the region by Thu 11 Jan.
  • The NWS Weather Prediction Center is forecasting > 2 inches of rainfall near the core of the AR on Days 6 and 7 as it progresses up the coast.

Click images to see loops of GFS IVT and IWV forecasts

Valid 1200 UTC 5 January 2024 – 0000 UTC 11 January 2024


 

 

 

 

 

 

 

Summary provided by M. Steen, S.Bartlett, P. Iniguez and C.Castellano; 03 January 2024

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

*Outlook products are considered experimental