374
FXUS06 KWBC 041901
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Sat October 04 2025

6-10 DAY OUTLOOK FOR OCT 10 - 14 2025

Today`s numerical models are in fairly good agreement on the main features
across the higher latitudes of the Northern Hemisphere. While the most
amplified flow across the higher latitudes is generally forecast across the
Eastern Hemisphere, a strong anomalous ridge is predicted just south of the
Alaska Peninsula. As time progresses, this ridge is generally forecast to
weaken as the flow becomes more zonal. Downstream, a deep trough is forecast
off of the West Coast of the CONUS. This trough is forecast to linger in the
vicinity of the West Coast throughout the period. Farther to the east, ridging
and associated above normal heights are forecast across the Plains and
eventually spreading to the Great Lakes. Weak troughing is predicted along the
East Coast early in the period. Predicted height rises are noted in the
Northeast thereafter while a weakness in subtropical ridging persists across
the Southeast. Generally near normal heights are forecast for Hawaii. Above
normal heights are predicted to the east of the state while below normal
heights are predicted to the northwest of the island chain.

Above normal temperatures are likely across most of Alaska due to predicted
strong ridging centered near the Alaska Peninsula. Probabilities of above
normal temperatures exceed 70 percent across most of the southwestern Mainland,
Alaska Peninsula, and Aleutians. Below normal temperatures are favored across
much of California and the Pacific Northwest due to predicted troughing near
the West Coast. Above normal temperatures are more likely across most of the
central and eastern CONUS due to predicted downstream ridging. Confidence is
highest across the Plains, Upper Mississippi Valley, and western Great Lakes,
consistent with teleconnections from the predicted ridge location.
Probabilities of above normal temperatures are comparatively modest across the
Eastern Seaboard due to predicted weak troughing. 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 is likely across most of the western CONUS, consistent with
teleconnections from the predicted trough location near the West Coast.
Probabilities of above normal precipitation exceed 60 percent across much of
Northern California and parts of adjacent southwestern Oregon due to predicted
enhanced Pacific Flow associated with this trough. Chances of above normal
precipitation also exceed 60 percent across parts of the Southwest due to the
potential for tropical moisture advection into the region. Conversely, below
normal precipitation is more likely for much of the Great Lakes, Northeast,
Ohio and Tennessee Valleys, the Lower Mississippi Valley, and adjacent areas of
the Southern Plains due to predicted ridging and associated surface high
pressure. Near to above normal precipitation is favored for parts of the
Mid-Atlantic and Southeast, due to predicted enhanced onshore flow to the south
of forecasted mean surface high pressure over the Northeast. Above normal
precipitation is slightly favored for the southern tip of Texas near the tail
end of a predicted frontal boundary. An active pattern is likely for much 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 much of the western Mainland where this enhanced onshore flow is
likely to be the greatest. Conversely, below normal precipitation is more
likely across Southeast Alaska, downstream of the predicted ridge axis. Above
normal precipitation is modestly 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 20% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 45% of Today`s 0z European Ensemble Mean
centered on Day 8, and 35% of Today`s 0z Canadian Ensemble Mean centered on Day
8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: About average, 3 out of 5, due to
fair agreement among todays ensemble means.

8-14 DAY OUTLOOK FOR OCT 12 - 18 2025

During week-2, models begin to diverge, suggestive of a potential pattern
transition during this seven day period. The period begins with strong
anomalous ridging over the Gulf of Alaska and a deep trough downstream over the
west coast of the CONUS. As time progresses, this ridge-trough couplet is
forecast to deamplify, resulting in zonal Pacific flow across the western CONUS
later in the period. As this couplet de-amplifies, downstream ridging is
forecast to push east to the Great Lakes during the early to middle part of the
period. Thereafter the picture becomes more murky as the ECMWF mean maintains
above normal heights across the East while the Canadian mean develops a through
over the Great Lakes, with the GEFS landing somewhere in between. A weakness in
subtropical ridging is generally forecast to persist across the Southeast, with
slightly below normal mean heights noted for the Florida Peninsula. The center
of the predicted mean subtropical ridge is forecast farther to the west, across
northern Mexico. Near to slightly below normal heights are forecast for Hawaii
as today`s ensemble means are predicting a local mid-level height minimum near
the island chain.

Above normal temperatures are favored for the central and eastern CONUS due to
predicted mean above normal mid-level heights. Probabilities of above normal
temperatures exceed 70 percent for parts of the Southern and Central Plains,
the northern half of the Mississippi Valley, and parts of the Great Lakes
Region, where positive height anomalies are expected to be the most pronounced,
particularly in the early to middle part of this seven day period. Above normal
temperatures are also likely for much of Alaska, especially the western
Mainland,  well ahead of a trough forecast over the eastern Bering Sea. Below
normal temperatures are more likely across the western quarter of the CONUS,
consistent with teleconnections from the ridge predicted south of the Aleutians
and the trough forecast near the West Coast of the CONUS. 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 the western CONUS due to mean troughing
predicted near the West Coast. Teleconnections from the predicted mean trough
location supports enhanced odds of above normal precipitation across almost the
entire western third of the CONUS and extending eastward across the Northern
Plains. This trough, coupled with the potential for residual tropical moisture
over the Southwest, leads to probabilities of above normal precipitation
exceeding 50 percent across a broad area of the West. Downstream, predicted
ridging and multiple areas of mean surface high pressure favors below normal
precipitation across most of the Mississippi, Ohio, and Tennessee Valleys,
Great Lakes, inland areas of the Northeast, and eastern areas of the Southern
Plains. Above normal precipitation is favored for much of the Florida Peninsula
associated with predicted mean easterly low-level flow. An active pattern is
likely to persist across much of Alaska ahead of a trough over the eastern
Bering Sea. Probabilities of above normal precipitation exceed 50 percent
across much of the western Mainland, associated with enhanced onshore flow.
Near normal precipitation is more likely across Southeast Alaska and adjacent
areas of the southeastern Mainland, due to predicted ridging early in the
period, followed by a potential transition to a more active pattern later.
Above normal precipitation is modestly 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: 20% of Today`s 6z GFS
Ensemble Mean centered on Day 11, 45% of Today`s 0z European Ensemble Mean
centered on Day 11, and 35% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Below average, 2 out of 5, due to
uncertainties surrounding the evolution of the 500-hPa flow pattern across much
of the forecast domain later in the week-2 period.

FORECASTER: Scott H

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:
20040920 - 20080922 - 20071006 - 19850914 - 19621003


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:
20040921 - 19850916 - 20040926 - 20071003 - 20070921


6-10 DAY OUTLOOK TABLE
Outlook for Oct 10 - 14 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Oct 12 - 18 2025

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

                           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.

$$