
A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Timothy Greten
Director, Office of Observations (Acting)
Mr. Timothy Greten is currently the Director of the National Weather Service’s (NWS) Office of Observations. In this position, he oversees the collection of space, atmosphere, water, and climate observational data either owned or leveraged by the NWS. The Office of Observations serves as the primary office responsible for the development, acquisition, and management of systems and programs to meet NWS requirements. These platforms and sensors include radars, wind profilers, buoys, surface- based systems, and upper air systems.
Mr. Greten has served in several leadership roles during his time at NWS. Before taking the helm as the Director of the Office of Observations, he led the team responsible for maintaining and improving AWIPS - the NWS nationwide communication, forecasting, and data transmission system linking 170+ Weather Forecast Offices, National Centers, River Forecast Centers, the U.S. Navy, and NASA. He led the “AWIPS in the Cloud” program, building NWS’s next-gen AWIPS. He was also responsible for sustaining the NWS Weather and Climate Operational Supercomputer (WCOSS2) and securing the next-gen WCOSS3. Previously, Mr. Greten served as the Acting Chief Financial Officer in 2022-23, during which he oversaw the NWS FY23 budget enactment, FY24 Congressional passback negotiations, and the first phases of the FY25 Presidential Budget submission. Mr. Greten also previously served as the Director of the Office of Facilities; in this role, he was responsible for nationwide NWS facilities strategic planning, budgeting, policy development, and comprehensive life-cycle activities.
Before joining NOAA, Mr. Greten was the Senior Policy Advisor to the Federal Mine Safety and Health Review Commission. FMSHRC annually resolves thousands of trial and appellate- level disputes arising under the Federal Mine Safety Act of 1977 between miners, industry, and MSHA. Mr. Greten also previously served as the Deputy Director of the FEMA’s Technological Hazards Division, ensuring community safety around commercial nuclear power plants and U.S. Army chemical weapons destruction facilities.
Mr. Greten received a B.S. in Management from the U.S. Coast Guard Academy, an MPA from The American University, and a JD from Antonin Scalia Law School at George Mason University. In his free time, Mr. Greten enjoys competing in triathlons, rooting for the Buffalo Bills, and mixing great golf shots in with his bad ones.