185
FXUS21 KWNC 041754
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT October 04 2024

SYNOPSIS: Mid-level high pressure is forecast over the western two-thirds of
the contiguous U.S. (CONUS) during week-2, favoring above-normal temperatures
for much of the region. A lingering stationary front from the end of week-1
into week-2 may support enhanced rainfall and exacerbated flood conditions
across parts of the Florida Peninsula. At the beginning of the period a storm
is predicted to form over the Gulf of Alaska, increasing the likelihood for
heavy precipitation and high winds for coastal portions of Prince William Sound
eastward through Southeast Alaska at the beginning of the period. The risk of
Rapid Onset Drought (ROD) has been expanded to parts of the Great Plains and
Mississippi Valley.

HAZARDS

Slight risk of heavy precipitation for coastal portions of Prince William Sound
eastward through Southeast Alaska, Sat-Sun, Oct 12-13.

Slight risk of high winds for coastal portions of Prince William Sound eastward
through Southeast Alaska, Sat-Sun, Oct 12-13.

Possible flooding for parts of the Florida Peninsula.

Risk of Rapid Onset Drought (ROD) across portions of the Great Plains and
Mississippi Valley.

DETAILED SUMMARY

FOR MONDAY OCTOBER 07 - FRIDAY OCTOBER 11:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR SATURDAY OCTOBER 12 - FRIDAY OCTOBER 18: Multiple model ensembles indicate
mid-level troughing over the eastern CONUS during week-1 exiting the Northeast
by week-2 translating to decreasing anomalous cold signals across the region by
this period. There is some indication in the models of a trough rebuilding
across parts of the East by the middle of week-2, although with high
uncertainty regarding the orientation and amplitude, precluding an associated
cold hazard from being designated.



The rapid onset drought (ROD) area is expanded to cover parts of the Great
Plains and western Mississippi Valley, based on anticipated anomalously warm
temperatures during week-2, 30-day precipitation deficits, low soil moisture,
and little predicted rainfall during the next two weeks.



A stationary front may linger across southern Florida from the end of week-1
into the onset of week-2 which may support continued rainfall. The
Probabilistic Extreme Tools (PETs) indicate enhanced chances for 3-day rainfall
totals exceeding the 85th percentile and one inch to a fairly limited area,
across southern and eastern Coastal Florida. Thus a highlighted heavy
precipitation area is not specified in todays outlook. Any enhanced rainfall,
however, could exacerbate flood conditions, thus an area of possible flooding
is posted over parts of the Florida Peninsula where the National Water Center
(NWC) designates an area of Limited Flood Impacts during the 4-7 day period.



Amplified mid-level troughing is predicted over the Gulf of Alaska at the
beginning of week-2, supporting surface low pressure centered near the Kenai
Peninsula. A slight risk of heavy precipitation is maintained for parts of the
Prince William Sound eastward through Southeast Alaska, Oct 12-13. The ECENS
PET shows at least a 20% chance of 3-day rainfall totals exceeding the 85th
percentile climatologically, and 3 inches for parts of the highlighted risk
area (the GEFS indicates localized areas reaching these thresholds). Recent
deterministic guidance suggests the potential of precipitation totals exceeding
at least 4 inches in a 24-hour period in this region. A slight risk of high
winds is highlighted for the same region and period, where PETs indicate at
least a 20% chance of wind speeds exceeding the 85th percentile and 40 mph.

FORECASTER: Melissa Ou

$$