Pacific typhoon set to trigger snow, flooding across western U.S. as multiple storms converge
By isabelle // 2025-10-10
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  • Typhoon Halong's remnants are set to disrupt weather patterns across the western United States after narrowly missing Japan.
  • Its energy will be absorbed by the jet stream, potentially generating hurricane-force winds in Alaska and pushing cold air into the West Coast.
  • This could trigger significant snow in the Sierra Nevada and heavy rainfall in the Bay Area by early next week.
  • The situation is complicated by former Hurricane Priscilla, which threatens the Southwest with flash flooding and heavy rain.
  • The coming days will test the West's readiness for these converging and extreme weather events.
A massive weather phenomenon unfolding across the Pacific Ocean is expected to significantly impact the western United States in the coming days. Typhoon Halong, which narrowly missed Japan this week as a powerful storm equivalent to a Category 4 hurricane, is now expected to send shockwaves across the ocean that will alter weather patterns from Alaska to California. Meteorologists warn these typhoon remnants could generate hurricane-force winds in Alaska's Bering Sea while pushing subarctic air into Washington, Oregon, and California by Monday, potentially triggering significant snow in the Sierra Nevada and heavy rainfall in the Bay Area. The complex weather scenario involves what scientists call "recurving typhoons," where the fast-moving jet stream absorbs a typhoon's energy and intensifies storms along its path. This phenomenon can send far-reaching effects across the ocean, disrupting normal weather patterns thousands of miles from where the original storm formed. The National Weather Service noted the situation bears resemblance to Typhoon Merbok in 2022, which caused millions of dollars in damage across western Alaska.

Amplified jet stream patterns

As Typhoon Halong moves into the North Pacific, its energy is forecast to perturb the jet stream and dislodge cold air from Canada toward California. Weather models predict an amplified jet stream pattern over the Pacific that could send modified subarctic air southward, resulting in potentially turbulent conditions across the western states. The American weather model predicts heavy rain and mountain snow in Northern California on Monday through Wednesday, although meteorologists caution that recurving typhoons tend to degrade the precision of weather models. If the storm tracks closer to the coast, the Bay Area could experience its heaviest rainfall since last winter. Alternatively, if the system stays to the east, Lake Tahoe could receive heavier snowfall. The Weather Prediction Center has already forecast heavy rain and mountain snow across Northern California for early next week. This represents a dramatic shift for the region, which has experienced varied weather conditions throughout 2025, with coastal areas experiencing unusually cool temperatures while inland valleys have seen periodic heat waves.

Multiple storm threats converge

Meanwhile, former Hurricane Priscilla adds another layer of complexity to the weather scenario. Now downgraded to a tropical depression, Priscilla is moving north in the Pacific and threatens southern California and Arizona with flash flooding. The National Hurricane Center has warned several southwestern states, including New Mexico, Colorado, Utah, and Nevada, to expect heavy rain and potential flooding from Priscilla's moisture through Sunday. The National Weather Service forecasts up to four inches of rain in the mountains of Arizona, with Phoenix potentially receiving up to two inches. The flood risk extends toward Palm Springs and Las Vegas, where strong thunderstorms are possible. AccuWeather lead hurricane expert Alex DaSilva noted that Priscilla's impact on Arizona could be particularly severe, with heavy rain and flooding forecasted throughout the state. The intense downpours could double the typical October rainfall in areas like Flagstaff. With Typhoon Halong's energy reaching Alaska this weekend and storm impacts spreading to California by Monday while Priscilla simultaneously drenches the Southwest, the next 72 hours will test the West's preparedness for rapidly shifting weather extremes. Sources for this article include: TheNationalPulse.com SFChronicle.com DailyMail.co.uk
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