743 FXUS21 KWNC 031813 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT October 03 2026 SYNOPSIS: A stalled frontal boundary over the Gulf Coast, along with deep tropical moisture is favored to produce widespread heavy and potentially hazardous precipitation and elevated wind speeds across the region through the middle of week-2, particularly along the central and eastern Gulf Coast. Low pressure at the surface and mid-levels is favored to transit from the Bering Sea to the Gulf of Alaska, bringing the potential for high winds and heavy precipitation for much of the southern and southeastern coast of the state through the middle of the forecast period. HAZARDS Moderate risk of heavy precipitation for portions of the central and eastern Gulf Coast as well as northern and central Florida, and northward into South Carolina, Sun-Tue, Oct 11-13. Slight risk of episodic heavy precipitation for parts of the Upper Texas coast, much of the Lower Mississippi and Tennessee Valleys, Southeast, Mid-Atlantic, and approximately the southeastern half of New England, Sun-Wed, Oct 11-14. Slight risk of high winds for portions of the Gulf Coast, Sun-Thu, Oct 11-15. Moderate risk of high winds for the eastern Aleutians, Alaskan Peninsula, the southern coast of Mainland Alaska, and northern portions of coastal Southeast Alaska, Sun-Mon, Oct 11-12. Slight risk of high winds across the Aleutians, Alaska Peninsula, and coastal portions of southwestern, southcentral, and southeastern Alaska, Sun-Wed, Oct 11-14. Slight risk of heavy precipitation for parts of southcentral and southeastern Alaska, Sun-Wed, Oct 11-14. Flooding possible for much of the central and eastern Gulf Coast, and northern and central Florida. DETAILED SUMMARY FOR TUESDAY OCTOBER 06 - SATURDAY OCTOBER 10: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR SUNDAY OCTOBER 11 - SATURDAY OCTOBER 17: The GEFS and ECENS continue to be in good agreement on the large-scale height pattern, indicating amplifying 500-hPa ridging (troughing) over western (eastern) North America during mid-October. An area where the model ensembles disagree is the western contiguous U.S. (CONUS), where the ECENS and CMCE solutions favor mostly mid-level troughing, while the GEFS depicts mid-level ridging. South and east of the mid-level troughing over the eastern CONUS, a stationary front is forecast to extend from near the Gulf Coast to the Southeast Coast. This pattern supports a prolonged period of episodic heavy rainfall for much of the Gulf Coast, Florida, and along the East Coast through the middle of week-2 where a slight risk for heavy precipitation is posted, Oct 11-14. The GEFS and ECENS Probabilistic Extremes Tools (PETs) are in good agreement indicating at least a 20% chance of 3-day precipitation totals exceeding the 85th percentile and one inch across the designated hazard area. This is also well supported by the uncalibrated precipitation forecasts from these ensemble means. A moderate risk (40-60% chance) of heavy precipitation is designated for the central and eastern Gulf Coast, northern and central Florida and has been expanded northward into South Carolina, valid Oct 11-13. This is consistent with uncalibrated precipitation guidance from both ensemble means. Furthermore, multiple models are indicating the potential for surface low pressure originating in the Bay of Campeche that would enhance onshore flow, further enhancing heavy rain, and may also bring enhanced wind speeds to the region, supporting a slight risk of episodic high winds for the Gulf Coast, Oct 11-15. This is based on a subjective consensus of multiple wind PETS, and predicted GEFS/ECENS surface low pressure center distributions over the Bay of Campeche and Gulf of America. Anticipated heavy rainfall and strong onshore flow, combined with expected enhanced rainfall totals from week-1 (ranging from 2-7+ inches near the coast), could lead to widespread potential for urban and flash flooding across the central and eastern Gulf Coast. Therefore a flooding possible hazard remains valid for the affected region. Caution is highly advised with regard to flooded roads and waterways and if widespread flooding is occurring in your area unnecessary travel is strongly discouraged. An amplified 500-hPa trough over the Bering Sea and western Alaska is likely to promote a series of low pressure systems that track from the Bering Sea and Alaska Peninsula eastward to the Gulf of Alaska. This favors widespread onshore flow to most of coastal southern Alaska, and results in 2-3 inch precipitation amounts according to the GEFS and ECENS model ensembles. Uncalibrated and PET precipitation guidance supports this hazard at least into the middle portion of week-2, with precipitation totals possibly exceeding the 85th percentile. An even greater concern regarding impacts for the state would be for high winds, as this is the time of year when western Pacific typhoons often recurve into the temperate westerlies and have a significant impact on the circulation pattern downstream over Alaska. The specific details regarding timing and intensity of impacts are very uncertain, but for now a broad slight risk of high winds is depicted for the entire southern coast of Alaska, Oct 11-14, for wind speeds of at least 40 mph. A moderate (40%) risk of high winds (at least 40 mph) is posted for a significantly reduced area, from the Alaska Peninsula across the southcentral coast to perhaps as far east as Glacier Bay in Southeast Alaska. There has been a significant change among the model ensembles in the expected week-2 circulation pattern and associated surface temperature pattern over the western CONUS. Yesterday, more anomalous ridging was forecast over the West, while today more anomalous troughing is indicated. As is often the case during the shoulder seasons, there are fewer temperature hazards to note, due to the frequently changing and more variable circulation pattern. Therefore, no temperature hazards are indicated today over the U.S. FORECASTER: Anthony Artusa $$