Composite Map Day 8-14

Probabilistic Outlooks Temperature Hazards Precipitation Hazards Wind Hazards Snow Hazards

Valid Thursday October 15, 2026 to Wednesday October 21, 2026

US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT October 07 2026

Synopsis: Mid-level low pressure promotes chilly northeasterly flow supporting an increased risk of much below normal temperatures over the Northeast. Upstream, an eastward shifting area of mid-level low pressure favors possible surface low development and frontal activity in the lee of the Rockies. Although cooler temperatures behind the predicted front are not expected to reach hazardous thresholds, enhanced and potentially heavy precipitation is favored along the frontal boundary further south from the Southern High Plains northeastward to the Ohio and Tennessee Valleys. The added rainfall throughout this part of the country, as well as over the southeastern contiguous U.S. (CONUS) may trigger localized flooding following a very wet week-1. Favored low pressure at the surface and mid-levels over Alaska supports an increased risk of high winds and heavy precipitation, with this threat easing off towards the middle of week-2.

Hazards

• Moderate risk of periods of high winds across south-central and southeastern Alaska, Thu-Fri, Oct 15-16.
• Slight risk of high winds across the Aleutians, Alaska Peninsula, and coastal portions of southwestern, south-central, and southeastern Alaska, Thu-Sat, Oct 15-17.
• Slight risk of heavy precipitation for parts of south-central and southeastern Alaska, Thu-Sat, Oct 15-17.
• Slight risk of much below normal temperatures for much of the Northeast, Thu-Fri, Oct 15-16.
• Slight risk of heavy precipitation for parts of the Southern and Central Plains, and the Lower and Middle Mississippi, Ohio and Tennessee Valleys, Thu-Sat, Oct 15-17.
• Flooding possible for much of the eastern and central Gulf Coast region.

Detailed Summary

For Saturday October 10 - Wednesday October 14: WPC Days 3-7 U.S. Hazards

For Thursday October 15 - Wednesday October 21: By the outset of week-2, both ensemble mean solutions from the ECENS and GEFS have come into better agreement today in regards to a mean 500-hPa shortware trough ejecting eastward from the Rockies, but with added disagreement with troughing downstream over the Canadian Maritimes and the Northeast. As the upstream shortware trough propagates eastward into the Great Lakes and Ohio Valley later next week and into the following weekend, another troughing feature is indicated over the southwestern CONUS underneath an amplified ridge center to the north, which looks to aid in the advection of anomalous moisture into portions of the Interior West, lower Plains and Mississippi Valley early in the period. Meanwhile over Alaska, anomalous mid-level troughing remains favored over the Bering Strait early in week-2, where there is some model support for a faster deamplification of this mid-level feature, which would quell an active weather pattern over southern Alaska towards the middle of week-2.

Over the northeastern CONUS, a strong cold response is depicted in the ECENS tools associated with deep troughing favored in the model. The ECENS Probabilistic Extremes Tool (PET) now features 40-50% chances for nighttime minimum temperatures falling below the 15th percentile, with similar chances for temperatures falling below freezing from the northern Mid-Atlantic to the Northeast. This is an abrupt uptick since yesterday, and although there is modest support in the GEFS PET for temperatures falling below the 15th percentile, the uncalibrated GEFS shows non-negligible chances for subfreezing temperatures irrespective if the troughing is as amplified as the ECENS. Therefore, a slight risk of much below normal temperatures is posted for Oct 15-16. Climatologically, first fall freezes generally occur between late September through mid-October for this part of the country, though any temperatures dipping to near freezing levels may still trigger cold temperature advisories for areas that have not experienced their first frost and/or freezes early in the period.

Tied to the shortwave troughing over the Great Plains, surface low formation remains possible in the lee of the Rockies with accompanying frontal activity to bring a shot of anomalously cooler air into the Great Plains and Mississippi Valley. However, the strength of the cold air advection and negative temperature departures favored in the models are not particularly impressive at this time. Both the GEFS and ECMWF PETs are in good agreement depicting 10-20% chances for minimum temperatures falling below the 15th percentile, precluding any corresponding temperature hazards in the updated outlook.

Despite the lack of support for hazardous cold air, a frontal boundary is favored to extend southward into the Southern Plains and Lower Mississippi Valley. This looks to serve as a good forcing mechanism for enhanced, and possibly heavy precipitation across the south-central CONUS, where troughing established over the Four Corners supports the advection of added lower-level moisture into the region. There is growing support for a heavy precipitation risk in both the raw and calibrated precipitation tools, where both the GEFS and ECENS PET are in agreement depicting 30-40% chances for 3-day precipitation amounts exceeding the 85th percentile over the Southern High Plains, with a broader coverage of 20% chances and 3-day amounts exceeding an inch into the lower Missouri River basin and western portions of the Ohio and Tennessee Valleys. Therefore, a slight risk of heavy precipitation is posted from the Southern High Plains northeastward into the Ohio and Tennessee Valleys along the mean frontal boundary. Even if not considered heavy, additional precipitation in the highlighted slight risk area, as well as throughout much of the Gulf Coast, Southeast and Florida may support possible flooding during week-2 where an associated hazard remains posted. Locally heavy rain during week-1 is favored (ranging from 3-5+ inches near the coast) due to frontal activity and Tropical Storm Isaias that is forecast to track northward from the Gulf. Caution is highly advised with regard to flooded roads and waterways and if widespread flooding is occurring in your area.

Amplified 500-hPa troughing is favored to be established over the Bering Sea and western Alaskan Mainland heading into the week-2 period. While the ECENS deamplifies the trough later next week, the GEFS maintains a decent coverage of negative height departures, with some indications of the trough reloading over the Bering Strait. With the base of the trough axis established over the Gulf of Alaska supportive of surface low development, PETs continue to point to an increased risk of episodes of high winds and heavy precipitation. Therefore, corresponding slight risk areas remain posted along the southern Mainland and the Southeast in the updated outlook, valid for Oct 15-17. Although the ECENS PET features diminished signals in percentile space compared to yesterday due to the weakening trough, a moderate risk of high winds also remains issued where there are 30% chances for wind speeds exceeding the 85th percentile and 40mph along the coast. The moderate risk is now valid for Oct 15-16 to account for the potential for a less active weather pattern, with rising mid-level heights favored in the ECENS.

Forecaster: Nick Novella

$$ Please consult local NWS Forecast Offices for short range forecasts and region-specific information.

Resources

Week-2 Probabilistic Extremes Tool

GFS Ensemble Forecasts