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

$$