


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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485 FXUS21 KWNC 141856 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT October 14 2025 SYNOPSIS: Strong low pressure at the surface and mid-levels is favored to shift from the Bering Sea into the Gulf of Alaska early in week-2, bringing with it potentially hazardous wind and precipitation initially to portions of Alaska, then into the Pacific Northwest by the middle of week-2. Widespread surface high pressure east of the Rockies throughout the forecast period precludes the potential for hazardous weather for most of the Contiguous U.S. (CONUS), although a strong pressure gradient near the margin with the surface low over the Pacific Northwest favors enhanced winds for portions of the Northern and Central Rockies and Northern Plains. HAZARDS Moderate risk of high winds for the Aleutians, Alaskan Peninsula and the western coast of Alaska south of Norton Sound, Wed, Oct 22. Slight risk of high winds for the Alaskan Peninsula as well as much of the western and southern coasts of Mainland Alaska, Wed-Fri, Oct 22-24. Slight risk of high winds from Cape Mendocino north to Puget Sound, Wed-Tue, Oct 22-28. Slight risk of high winds for portions of the Northern and Central Rockies and much of the Northern Plains, Wed-Tue, Oct 22-28. Slight risk of heavy precipitation for coastal southeastern Alaska east of Prince William Sound, Wed, Oct 22. Slight risk of heavy precipitation for much of coastal Oregon and Washington, Fri-Tue, Oct 24-28. Slight risk of heavy snow for the Northern Cascades, Fri-Tue, Oct 24-28. Slight risk of heavy for portions of the Northern Rockies, Fri-Tue, Oct 24-28. DETAILED SUMMARY FOR FRIDAY OCTOBER 17 - TUESDAY OCTOBER 21: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR WEDNESDAY OCTOBER 22 - TUESDAY OCTOBER 28: Today`s model solutions continue to depict a strong mid-level trough and associated surface low pressure over the Bering Sea at the outset of week-2. These features are favored to shift eastward quickly and become established over the Gulf of Alaska, shifting high winds and heavy precipitation from Alaska early in week-2 to the Pacific Northwest by the middle of week-2. Ensemble means for the surface low pressure center get as low as 982 hPa in the GEFS, and both the GEFS and ECENS are in very good agreement on the strength and evolution of this significant system. Uncalibrated probabilistic output from both models show chances exceeding 70% for more than 2 inches over a three-day period for much of Southeastern Alaska, with most of that total coming on day-8 (Oct 22), warranting a continuation of the slight risk of heavy precipitation for Southeastern Alaska east of Prince William Sound for Oct 22. High winds also continue to be a concern with this system for Alaska. Very tight pressure gradients are depicted over much of southern and western Alaska, especially at the outset of the forecast period. This is further supported by the ECMWF Probabilistic Extremes Tool (PET), which indicates widespread 20% or higher probabilities of 3-day maximum wind speed to exceed the 85th climatological percentile and at least 40mph early in week-2, with a diminishing signal as the week progresses. A moderate risk of high winds is maintained for much of the Alaskan west coast and Alaskan Peninsula for Oct 22, while a slight risk of high winds is posted for the above areas as well as the southern coast of Alaska as far as Yakutat for Oct 22-24. By the middle of week-2 this system is favored to shift into the Gulf of Alaska, where models depict an interaction with a long plume of enhanced atmospheric moisture, resulting in potentially hazardous precipitation for much of the Pacific Northwest in addition to high winds associated with continued tight pressure gradients along the coast. Uncalibrated probabilities from the GEFS and ECENS show chances of at least 30% for 3-day precipitation to exceed 2 inches by the middle of week-2, while both the GEFS and ECMWF PETs indicate at least a 20% chance of three-day precipitation to exceed the 85th percentile for much of the Pacific Northwest and Northern Rockies, with the GEFS PET for snow water equivalent (SWE) indicating the potential for heavy snow in higher elevations. A slight risk of heavy precipitation is posted for much of the Oregon and Washington coasts for Oct 24-28, as well as a slight risk of heavy snow for the Northern Cascades and Northern Rockies, also for Oct 24-28. A slight risk of high wind is posted for all of week-2 for western coast of the CONUS from Cape Mendocino north to Puget Sound, as well as for the Northern Rockies and much of the Northern Plains where the periphery of the incoming surface low pressure will form another zone of tight gradients with surface high pressure that dominates most of the rest of the CONUS throughout the forecast period. FORECASTER: Danny Barandiaran $$