050
FXUS21 KWNC 291913
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT September 29 2026

SYNOPSIS: Surface high pressure extending from southern Canada into the
northeastern contiguous U.S. (CONUS) from the end of week-1 into the start of
week-2 may bring lingering first frost to parts of the northeastern CONUS.
South of this surface high, cold fronts combined with potentially added
tropical moisture may bring episodic heavy precipitation to parts of the Gulf
Coast states and Southeast. A series of low pressure systems over the Alaska
Peninsula and Gulf of Alaska may result in heavy precipitation for parts of
southcentral and southeastern Alaska, as well as, high winds across coastal
portions of southwestern, south-central and southeastern Alaska, the Alaska
Peninsula, and Aleutians.

HAZARDS

Slight risk of much below normal temperatures across parts of the Northeast,
Lower Great Lakes region, Central Appalachians and northern Mid-Atlantic, Wed,
Oct 7.

Moderate risk of heavy precipitation for the Florida Peninsula and parts of the
Florida Panhandle, Wed-Sun, Oct 7-11.

Slight risk of heavy precipitation for parts of the Gulf Coast states and
Southeast, Wed-Sun, Oct 7-11.

Moderate risk of high winds for coastal portions of south-central and
southeastern Alaska, Thu-Sat, Oct 8-10.

Slight risk of high winds across coastal portions of southwestern,
south-central and southeastern Alaska, the Alaska Peninsula, and Aleutians,
Thu-Sat, Oct 8-10.

Slight risk of heavy precipitation for parts of southcentral and southeastern
Alaska, Wed-Sun, Oct 7-11.

DETAILED SUMMARY

FOR FRIDAY OCTOBER 02 - TUESDAY OCTOBER 06:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR WEDNESDAY OCTOBER 07 - TUESDAY OCTOBER 13: The GEFS and ECENS are in good
agreement today on an amplifying 500-hPa ridging (troughing) over western
(eastern) North America during early October. Surface high pressure is
anticipated to linger over southern Canada and parts of the northeastern CONUS
from the end of week-1 to the beginning of week-2, continuing the slight risk
of  much below normal temperatures posted across parts of the Northeast, Lower
Great Lakes region, Central Appalachians and northern Mid-Atlantic Oct 7. If
realized, this event would be the first frost for parts of the Northeast and
may impact susceptible vegetation in the eastern Corn Belt. Multiple
Probabilistic Extremes Tools (PETs) indicate at least a 20% chance of minimum
temperatures falling to the lowest 15th percentile climatologically and below
40 deg F across the highlighted hazard area (below 32 deg F across portions of
New England).



Cold fronts along the southern portion of the aforementioned surface high
pressure over the East to parts of the Gulf Coast states supports a slight risk
of periods of heavy precipitation for parts of the Gulf Coast states and
Southeast, Oct 7-11. Heaviest rainfall amounts are expected for coastal areas
in addition to parts of Florida. The GEFS and ECENS PETs are in good agreement
indicating 3-day precipitation totals exceeding the 85th percentile and one
inch across the designated hazard area. A moderate risk (40-60% chance) of
heavy precipitation is designated for parts of the Florida peninsula and
panhandle Oct 7-11 given a higher likelihood in the ECENS PET for exceeding
hazards criteria, and due to a persistence of enhanced daily amounts in the
uncalibrated guidance, suggestive of little relief. Increased chances of
tropical disturbances southwest of Baja California and the Bay of Campeche
could support further enhanced moisture to parts of the East. The corresponding
precipitation hazards are further supported by potentially added moisture from
the tropics, contributing to enhanced precipitation amounts. The southern
extent of the surface high pressure across the east serves as a contributing
factor of uncertainty in terms of how far north the heaviest rainfall occurs.



A highly amplified 500-hPa trough over the northeast Pacific is likely to
promote a series of low pressure systems that track from the Alaska Peninsula
eastward to the Gulf of Alaska. The greatest concern would be for high winds,
as depending on the track and evolution of the remnants of what is currently
Typhoon Surigae currently located south of Japan as this would increase the
risk of high winds especially to western portions of Alaska. A moderate risk
(40-60% chance) of high winds is designated for coastal portions of
south-central and southeastern Alaska, Oct 8-10, based on increasing
probabilities in the ECENS PET of wind speeds exceeding the 85th percentile and
40 mph, model guidance of increased probabilities of 10m wind gusts exceeding
50 knots (about 57 mph), and good day to day model consistency regarding the
pattern. A broader area of slight risk of high winds is posted for  coastal
portions of southwestern, south-central and southeastern Alaska, the Alaska
Peninsula, and Aleutians, Oct 8-10, where PETs indicate at least a 20% chance
of wind speeds exceeding the 85th percentile further supported by uncalibrated
guidance indicating elevated probabilities of wind gusts exceeding 50 knots.
Based on the enhanced onshore flow associated with these low pressure systems,
and support from the ECENS and GEFS PETs (20% chance of 3-day precipitation
amounts > 85th percentile and 2-3 inches), a slight risk of heavy precipitation
is maintained from the Kenai Peninsula to southeastern Alaska Oct 7-11. Recent
deterministic models indicate the potential for daily totals exceeding 2 inches.



Anticipated above-normal temperatures and dry conditions across the West may
enhance wildfire risk, especially across the Cascades eastward to the Northern
Rockies. Some of these areas are already experiencing active wildfires.



In the Central and Eastern Pacific, the tropics remain very active with two
hurricanes (Nolo and Polo), Tropical Storm Rachel, Tropical Depression 19E, and
a new watch area located to the south of Mexico where NHC designates 20%
chances for tropical cyclone development during the next week (as of 11am PDT)
Tropical Depression 19E is predicted to move generally eastward away from the
Hawaiian Islands. This is good news for the residents of Hawaii that have
already experienced a memorable hurricane season this year. It remains to be
seen whether or not the evolution of Tropical Storm Rachel results in
significant precipitation into the American Southwest in early October.

FORECASTER: Melissa Ou

$$