496
FXUS06 KWBC 061959
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Mon October 06 2025

6-10 DAY OUTLOOK FOR OCT 12 - 16 2025

Today`s numerical models are in relatively good agreement in predicting an
amplified 500-hPa circulation pattern across much of North America and
vicinity. A moderately deep, anomalous trough is forecast to extend
southwestward from the Arctic Ocean across northern and western Alaska, the
Bering Sea and nearby northern Pacific Ocean. A strong anomalous ridge with
associated positive height anomalies is predicted over the eastern Pacific
(including the Gulf of Alaska), with the largest positive anomalies located in
the general vicinity of 45-50N/150W. As time progresses, this ridge is
generally forecast to weaken as the flow becomes more zonal. Downstream, a
mid-level trough is forecast from the Canadian Prairies southwestward across
the Northern Rockies, Intermountain region, and California. Farther east,
ridging and associated above normal heights are forecast, with the largest
positive departures over the Great Lakes and Northeast. A weak anomalous trough
is forecast just off the Southeast coast, especially in the early and middle
parts of this five day period.  Near normal heights are forecast for Hawaii by
today`s ensemble means.

Below normal temperatures are favored across most of the western third of the
CONUS due to a predicted trough near the West Coast. Probabilities exceed 70
percent over parts of Idaho. Downstream ridging elevates the chances of above
normal temperatures across most areas from the Great Plains and Southern
Rockies, eastward to the Atlantic coast. Maximum chances favoring above normal
temperatures exceed 80 percent over the vicinity of the Upper Great Lakes
region. Near normal temperatures are more likely for parts of the Southeast in
proximity to a weak mid-level trough near the coast. Above normal temperatures
are favored across most of Alaska due to predicted ridging across much of the
Mainland and broad west-southwest surface flow. Above normal temperatures are
likely for Hawaii (particularly the western and central islands), consistent
with above normal sea-surface temperatures (SSTs) in the adjacent Pacific
Ocean.

An active pattern is likely over most of the western and central CONUS, with a
tilt in the odds towards wetter-than-normal conditions from near the West
Coast, eastward across the Rockies, Northern and Central Plains, Southern High
Plains, most of the Upper and Middle Mississippi Valley, and Upper Great Lakes
region. This is warranted by the consolidation, automated, and reforecast
precipitation tools, and is associated with a deamplifying mid-level trough
moving across these areas of the country. Maximum probabilities exceed 60
percent over much of Arizona and southwestern New Mexico, associated with the
expected passage of Priscilla`s remnants.  A small area of favored below normal
precipitation is depicted over the north-central coast of California, as a
mid-level ridge approaches from the Pacific. A surface low pressure system is
forecast to develop off the East Coast, before gradually moving out to sea.
Wraparound moisture associated with this system justifies a slight risk of
above normal precipitation across the Northeast and Mid-Atlantic coasts, and
the southern tip of Florida. Below normal precipitation is indicated across
much of the southeast quadrant of the Lower 48 states, sufficiently removed
from storm tracks and/or downstream of the subtropical ridge axis over northern
Mexico and southern Texas. A small area of residual anomalous dryness is
favored over the vicinity of northern New England, associated with a mid-level
ridge over eastern Canada and greater positive height departures. An active
pattern is likely for most of Alaska due to forecast onshore flow associated
with the predicted ridge to the south of the state. Probabilities of above
normal precipitation exceed 60 percent for parts of southwestern Mainland
Alaska, where this enhanced onshore flow is likely to be the greatest. Above
normal precipitation is also favored for Hawaii, consistent with a
consolidation of calibrated precipitation amounts from the GEFS and ECMWF
ensembles.

The official 6-10 day 500-hPa height blend consists of

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above average, 4 out of 5, due to
fairly good agreement among today`s ensemble means in depicting an amplified
500-hPa pattern across much of the forecast domain.

8-14 DAY OUTLOOK FOR OCT 14 - 20 2025

During week-2, all of today`s ensemble means depict a transition to a more
zonal mid-level pattern across much of North America by the end of this seven
day period. The period begins with anomalous troughing over the Bering Sea and
northern Alaska, and anomalous ridging over much of the eastern Pacific/Gulf of
Alaska. A trough is forecast downstream from the north-central CONUS,
southwestward to California. The ridging predicted over the East during the
earlier 6-10 day pattern is forecast to split into two parts, with the greater
positive departures lifting northeastward across eastern Canada, leaving behind
a broad +30 meter height anomaly contour over the southern half of the CONUS on
the manual blend. As time progresses, the pattern over much of the CONUS
becomes dominated by zonal, Pacific flow. A weakness in subtropical ridging is
generally forecast to persist across the Southeast through the middle of the
period, with height anomalies slightly above normal. The center of the
predicted mean subtropical ridge is forecast farther to the west, across
northern Mexico and southern Texas. Today`s ensemble means continue to forecast
near-normal heights over the Hawaiian domain.

Above normal temperatures are favored for the Southern Rockies, and the Central
and Eastern CONUS, as above normal mid-level heights are forecast across most
of these regions. This is well supported by the consolidation, automated, and
reforecast temperature tools. Probabilities of above normal temperatures exceed
60 percent for parts of the southern Plains and vicinity of  northern New
England. Above normal temperatures are also favored over parts of the West
Coast, associated with the approach of a mid-level anomalous ridge over the
northeastern Pacific. Decreasing coverage of below normal temperatures
(compared to yesterday) is depicted over much of the Northwest, due to the
expected transition from anomalous northerly flow to a rapidly deamplifying
pattern. Southwesterly-to-westerly anomalous flow into Alaska tilts the odds
towards warmer-than-normal temperatures for most of the Mainland, Alaska
Peninsula, and Aleutians. Near to below normal temperatures are favored over
much of Southeast Alaska, in lingering northerly anomalous flow. Above normal
temperatures are likely for Hawaii (particularly the western and central
islands), consistent with above normal SSTs in the adjacent Pacific Ocean.

An active pattern remains likely for much of the western and north-central
CONUS associated with a weakening mid-level trough rapidly shearing out to the
east. Enhanced odds of above normal precipitation continue eastward across the
Northern and Central Plains, Upper and Middle Mississippi Valley, Great Lakes
region, much of the Ohio Valley, and northern New York and New England. This is
associated with a weakening but fast-moving trough embedded within rapidly
flattening flow. The southwestern portion of the trough which gets left behind
over the Southwest, coupled with the potential for tropical moisture influx
over this same region (associated with a tropical system after Priscilla`s
departure), leads to probabilities of above normal precipitation exceeding 40
percent over much of the region, and 50-60 percent over southern Arizona.
West-northwesterly flow downstream of a mean subtropical ridge over the
Southern Plains, in addition to weak positive height anomalies, leads to a
slight preference towards below normal precipitation from central Texas
eastward across the Gulf Coast states to northern Florida and Georgia. Above
normal precipitation is favored over far southern Florida associated with a
weak front. Below normal precipitation is slightly favored over parts of the
West Coast, as a mid-level ridge approaches the area from the northeastern
Pacific. An active pattern is favored to persist across most of Alaska ahead of
a trough over the Bering Sea.  Above normal precipitation is favored for
Hawaii, consistent with a consolidation of calibrated precipitation amounts
from the GEFS and ECMWF ensembles.

The official 8-14 day 500-hPa height blend consists of:

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Near average, 3 out of 5, due to
fairly good model agreement on the 500-hPa circulation pattern, offset by
uncertainties regarding a rapidly deamplifying flow pattern and associated
increase in uncertainty in the surface temperature and precipitation fields.

FORECASTER: Anthony A

Notes:


The notation for the categorical forecast indicated on the maps is the same as
that in the tables: A-above   N-near normal   B-below


The temperature map shows regions with > 33% chance of being warmer (orange,
"A"), colder (blue, "B"), or close to (unshaded, "N"). Historical average
values for the calendar period of the forecast (dashes, "f").  Labels on the
shaded lines give the probability (> 33%) of the more likely category (B or A).
 Probability of N is always < 40%.


The precipitation map shows regions with > 33% chance of being wetter (green,
"A"), drier (tan, "B"), or close to (unshaded, "n"). Historical median values
for the calendar period of the forecast (dashes, "inches").  Labels on the
shaded lines give the probability (> 33%) of the more likely category (B or A).
 Probability of N is always < 40%.


In the southwest and other climatologically dry regions - there will be a
greater than 33.3% chance of no precipitation and occasionally even a normal
(i.e. Median) value of zero - especially during the dry seasons.  In such cases
a forecast of near normal is effectively a forecast of little or no
precipitation.


The climate prediction center uses 1991-2020 base period means as reference in
the climate outlooks.

The next set of long-lead monthly and seasonal outlooks will be released on
October 16.


Analogs to the 5 day mean observed pattern centered 3 days ago (D-3)
for the region from 20N to 70N latitude and 175E to 60W longitude
include the 5 day periods centered on the following dates:
19830930 - 20070923 - 20081012 - 19850916 - 19701008


Analogs to the 7 day mean observed pattern centered 4 days ago (D-4)
for the region from 20N to 70N latitude and 175E to 60W longitude
include the 7 day periods centered on the following dates:
19830930 - 20070922 - 19850917 - 20081011 - 19701009


6-10 DAY OUTLOOK TABLE
Outlook for Oct 12 - 16 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    N
SRN CALIF   B    A     IDAHO       B    A     NEVADA      B    A
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    A
UTAH        B    A     ARIZONA     B    A     COLORADO    A    A
NEW MEXICO  A    A     N DAKOTA    A    A     S DAKOTA    A    A
NEBRASKA    A    A     KANSAS      A    A     OKLAHOMA    A    A
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    A
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    B     LOUISIANA   A    B     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI A    B     MICHIGAN    A    A
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    B
TENNESSEE   A    B     ALABAMA     A    B     NEW YORK    A    N
VERMONT     A    N     NEW HAMP    A    A     MAINE       A    N
MASS        A    A     CONN        A    A     RHODE IS    A    A
PENN        A    N     NEW JERSEY  A    A     W VIRGINIA  A    N
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    N     GEORGIA     A    B
FL PNHDL    A    B     FL PENIN    N    N     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A



8-14 DAY OUTLOOK TABLE
Outlook for Oct 14 - 20 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    N     OREGON      A    N     NRN CALIF   A    B
SRN CALIF   N    A     IDAHO       B    A     NEVADA      N    A
W MONTANA   B    A     E MONTANA   N    A     WYOMING     N    A
UTAH        N    A     ARIZONA     A    A     COLORADO    A    A
NEW MEXICO  A    A     N DAKOTA    A    A     S DAKOTA    A    A
NEBRASKA    A    A     KANSAS      A    A     OKLAHOMA    A    N
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    N
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    N     LOUISIANA   A    B     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI A    B     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    N     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     A    B     NEW YORK    A    N
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    A
MASS        A    N     CONN        A    N     RHODE IS    A    N
PENN        A    N     NEW JERSEY  A    N     W VIRGINIA  A    N
MARYLAND    A    N     DELAWARE    A    N     VIRGINIA    A    N
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    B
FL PNHDL    A    B     FL PENIN    A    N     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    N    A

                           LEGEND
TEMPS WITH RESPECT TO NORMAL     PCPN WITH RESPECT TO MEDIAN
A - ABOVE   N  - NEAR NORMAL     A - ABOVE   N - NEAR MEDIAN
B - BELOW                        B - BELOW

THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.

FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.

$$