A mid-level trough deepening along the US West Coast is forecast to evolve into a cutoff low over Southern California and a potential atmospheric river (AR) over the Pacific Northwest between November 19 and 24, 2025.
Tropical cyclone activity and heavy rainfall affected northern and central Vietnam from October through mid-November 2025, triggering flooding and landslides that killed at least 300 people and affected around 189 000. Vietnam activated the Union Civil Protection Mechanism on November 13 to request emergency assistance, while rainfall totals of up to 500 mm (20 inches) were forecast through November 20, maintaining high risks of renewed flooding and landslides.
An arctic blast could be in forecast for the U.S. during December 2025, with a sudden stratospheric warming (SSW) being forecast to disrupt the polar vortex. This will result in a spill of arctic air across mid-latitudes and below average temperatures across the U.S.
A major eruption at Mount Semeru, East Java, Indonesia, on November 19, 2025, produced large pyroclastic flows descending the southern slopes. One of them was captured on video, allowing both the sight and sound of the approaching flow to be recorded. The video shows a large pyroclastic density current moving downslope at high speed, generating…
Around 71 percent of wells in Myanmar’s Ayeyarwady Delta exceed World Health Organization (WHO) safe drinking water limits, placing up to 12 million people at risk of long-term arsenic exposure, a new study led by the University of Portsmouth finds. Travelers and residents relying on untreated well water may be exposed if they consume or use it for cooking.
Contrary to recent media coverage suggesting Mount Rainier had entered an unprecedented tremor phase, the U.S. Geological Survey (USGS) confirmed that no volcanic tremor is occurring at the volcano. The abnormal seismic signal detected over several days in mid-November 2025 originated from ice buildup and communication interference at the STAR station on Rainier’s west flank. Monitoring data from the Pacific Northwest Seismic Network (PNSN) show no signs of volcanic unrest, and the Alert Level remains at Normal.
Flash floods prompted multiple rescues in Wickenburg and Tonopah, Arizona, on November 18, 2025, following several days of heavy rainfall across western Maricopa and Yavapai counties.
Indonesia’s Geological Agency raised the alert level for Semeru volcano to the highest (Level IV) following a major eruption on November 19, 2025, that produced an ash column up to 17.9 km (59 000 feet) above sea level. Authorities ordered evacuations of at least 300 residents from nearby villages and expanded exclusion zones up to 8 km (5 miles) from the crater and along the Besuk Kobokan valley. No casualties have been reported so far.
The Weather Prediction Center (WPC) has issued a Moderate Risk of Excessive Rainfall for south-central Texas through Thursday, November 20, 2025, with 75–125 mm (3–5 inches) of rain possible and locally higher totals. The same frontal system is forecast to advance eastward into eastern Oklahoma and the Ozarks by Thursday night, bringing a Slight Risk of excessive rainfall to those regions.
Search and rescue operations are ongoing for a 70-year-old man who went missing after his vehicle got swept away by flooding in Cordes Lakes, Yavapai County, Arizona on November 18, 2025.
