584
FXUS21 KWNC 051856
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT October 05 2025

SYNOPSIS: After the formation of Tropical Storm Priscilla in the East Pacific,
a second tropical cyclone (TC) is likely to develop offshore of southwestern
Mexico with a potential track near the Baja Peninsula. Due to this potential TC
in the East Pacific, there is a continued chance of heavy rainfall across the
Four Corners region and Desert Southwest through the middle of the forecast
period. Enhanced convection near a frontal boundary may bring a chance of heavy
precipitation to the Florida Peninsula and portions of the Mid-Atlantic. A
Rapid Onset Drought risk remains for parts of the Southern Plains and Lower
Mississippi Valley where above-normal temperatures and limited precipitation is
forecast over the next 2 weeks. Over Alaska, a strong low pressure system may
bring high winds to portions of the Bering Sea and Chukchi Sea coasts.

HAZARDS

Moderate risk of heavy precipitation for portions of the Desert Southwest and
southern Great Basin, Mon-Tue, Oct 13-14.

Slight risk of heavy precipitation for much of the Desert Southwest as well as
portions of the Southern and Central Rockies and southern Great Basin, Mon-Thu,
Oct 13-16.

Slight risk of heavy precipitation for southern portions of the Florida
Peninsula, Mon-Wed, Oct 13-15.

Slight risk of heavy precipitation for portions of the Mid-Atlantic region,
Mon-Tue, Oct 13-14.

Slight risk of heavy precipitation for the southern coast of Alaska from Prince
William Sound to Yakutat as well as the Alaskan Panhandle, Mon-Wed, Oct, 13-15.

Slight risk of heavy precipitation for portions of the Pacific Northwest,
Wed-Fri, Oct 15-17.

Slight risk of high winds for coastal portions of the Mid-Atlantic region,
Mon-Tue, Oct 13-14.

Slight risk of high winds for the Alaska Peninsula as well as the southern and
southeastern coast of Alaska, Mon-Wed, Oct 13-15.

Slight risk of high winds for coastal portions of the Pacific Northwest,
Wed-Fri, Oct 15-17.

Flooding possible across portions of the Southwest and Four Corners Region.

Rapid Onset Drought (ROD) possible for parts of Texas and Louisiana, and
Mississippi.

DETAILED SUMMARY

FOR WEDNESDAY OCTOBER 08 - SUNDAY OCTOBER 12:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR MONDAY OCTOBER 13 - SUNDAY OCTOBER 19: Following the formation of Tropical
Storm Priscilla in the East Pacific, the National Hurricane Center (NHC) is
continuing to monitor a second disturbance south of the Gulf of Tehuantepec,
which currently has a moderate chance of forming into a TC (60% in the next 7
days) while moving northwestward parallel to the Mexican coast. Todays model
solutions from the 0z ECMWF and GEFS differ quite a bit with respect to TC
formation associated with the second disturbance in week-2, but both favor
Priscilla to move northwesterly and eventually away from land, while steering
the second disturbance generally toward the Gulf of California, regardless of
intensity. Along with mid-level troughing favored over the eastern Pacific and
West Coast, this scenario would transport copious amounts of tropical moisture
into the Desert Southwest and generate potentially hazardous heavy
precipitation. This is well-supported by the ECMWF and GEFS Probabilistic
Extremes Tools (PETs) which both indicate at least 40% chances of 3-day total
precipitation to exceed the 85th climatological percentile, with the ECMWF PET
indicating similar chances for at least 1 inch early in week-2. This signal
drops off as the forecast period progresses but still indicates at least a 20%
chance of 3-day precipitation exceeding hazardous thresholds through the middle
of the week extending further north into the Great Basin and Rocky Mountains. A
moderate risk of heavy precipitation is posted for much of Arizona as well as
adjacent areas of Utah, Colorado, and New Mexico for Oct. 13-14, as well as a
slight risk of heavy precipitation extending further inland to cover the
western slope of the Southern and Central Rockies as well as much of the
Wasatch and Uinta Mountains, for Oct 13-16. A flooding possible hazard is also
posted for portions of the Southwest and Four Corners Region associated with
the moderate risk of heavy precipitation and the potential for localized
flooding and flash flooding, particularly in canyons and creeks where
topography can focus runoff resulting in quickly rising water levels.



Model ensembles depict a stalled frontal boundary over the Southeast U.S early
in week-2 which combines with plentiful tropical moisture, resulting in
potentially heavy precipitation which is favored to remain mostly offshore but
may affect portions of the East Coast. Todays model solutions favor a surface
low pressure center to form off the Outer Banks with potential tropical
characteristics, bringing the potential for hazardous weather to portions of
the Mid-Atlantic. For both the Mid-Atlantic and the Florida Peninsula,
uncalibrated probabilities from the ECMWF and GEFS indicate at least a 20%
chance of daily precipitation totals to exceed half an inch early the period
while the PETs indicate at least a 20% of 3-day precipitation to exceed the
85th percentile and at least 0.75 inch through the middle of the period. Going
with the highest consensus among various guidance, a slight risk of heavy
precipitation is posted over southern portions of the Florida Peninsula for Oct
13-15 as well as a slight risk of heavy precipitation for  eastern portions of
the Mid-Atlantic region for Oct 13-14. A slight risk of high winds is also
posted for coastal portions of the Mid-Atlantic for Oct 13-14. Models indicate
a large pressure gradient and associated strong winds with the surface low
favored to develop; the ECMWF and GEFS PETs both show at least a 20% chance of
3-day maximum wind speed to exceed the 85th percentile and at least 25mph.
Localized flooding and flash flooding is a possibility given the often very
high rainfall rates encountered in tropical squalls, although no associated
flooding hazard is posted at this time.



An amplified 500-hPa trough over the Bering Sea is forecast to shift east to
the Gulf of Alaska and spread southward towards the Pacific Northwest through
the middle of week-2. Model ensembles depict sharp pressure gradients initially
over the southern Alaskan coast and shifting southward towards Washington and
Oregon. This is well indicated by the EMCWF and GEFS PETs, which show at least
a 20% chance of maximum wind speed to exceed 40mph along the Alaska coast early
in week-2, then exceeding at least 25mph along the Pacific Northwest coast in
the middle of week-2. Therefore, a slight risk of episodic high winds is posted
from the Alaska Peninsula eastward along the southern coast and down the
southeastern coast for Oct 13-15, and for the Washington and Oregon coasts for
Oct 15-17. Heavy precipitation is also anticipated with this system. Both ECMWF
and GEFS PETs indicate at least a 20% chance of 3-day total precipitation to
exceed 3 inches near Yakutat and 2 inches for most of the southern Alaskan
coast early in the period, and at least 1.5 inches over coastal portions of
Oregon and Washington in the middle of week-2, warranting a slight risk of
heavy precipitation for the southern coast of Alaska from Prince William Sound
east as well as the Alaskan Panhandle for Oct 13-15, and for the Washington and
Oregon coasts for Oct 15-17.



Across portions of Texas, Louisiana, and central Mississippi, 30-day
precipitation deficits range from 2 to 5 inches. This antecedent dryness along
with little to no precipitation anticipated during the next week to ten days
and increased likelihood of above-normal temperatures (highs in the mid 80s to
low 90s) results in a rapid onset drought risk for portions of southeastern
Texas, much of Louisiana, and central Mississippi.

FORECASTER: Danny Barandiaran

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