953
FXUS06 KWBC 082043
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Mon December 08 2025

6-10 DAY OUTLOOK FOR DEC 14 - 18 2025

The 0Z ECMWF, GEFS, and Canadian ensemble means predict an amplified
circulation pattern over North America for the 6-10 day period. All models
predict an amplified ridge and a strong positive 500-hPa height anomaly
centered to the west of Mainland Alaska. Downstream, models predict a
positively tilted trough over Southeast Alaska and the Gulf of Alaska. Ensemble
means predict a ridge and positive 500-hPa height anomalies over the western
and central contiguous U.S. (CONUS) at the start of the 6-10 day period that
expand eastward over time. A trough and associated negative 500-hPa height
anomalies over the northeastern CONUS are predicted to progress to the
northeast with time, as mid-level heights rise. The ECMWF ensemble mean
indicates a more rapid expansion of positive 500-hPa height anomalies across
the East, while the GEFS ensemble mean predicts a more persistent trough over
the northeastern CONUS and associated negative 500-hPa height anomalies.

Above normal temperatures are favored for the western and central Aleutian
Islands under predicted positive 500-hPa height anomalies. Below normal
temperatures are likely for much of Mainland Alaska, excluding parts of the
northwestern Mainland, under anomalous northerly mid-level flow. Below normal
temperatures are likely for Southeast Alaska, under a predicted trough. Above
normal temperatures are very likely for the western and south-central CONUS,
under a persistent ridge. Probabilities exceed 80 percent over a large area of
the West, supported by the consolidation of calibrated GEFS and ECMWF
temperature probability forecasts. Below normal temperatures are likely over
the northeastern half of the CONUS stretching from the Northern Plains across
the Midwest to most of the Atlantic coast from Georgia to Maine, under
northerly flow and a predicted trough early in the period. There is greater
uncertainty over the Lower Mississippi Valley and Southeast, where the GEFS
forecast probabilities favor more extensive below normal temperatures, while
the ECMWF model favors above normal temperatures. Above normal temperatures are
favored for the southern Florida Peninsula, consistent with the temperature
consolidation. Above normal temperatures are very likely across Hawaii in the
6-10 day period, consistent with the temperature consolidation.

Below normal precipitation is likely for the eastern Aleutians and southwestern
Mainland Alaska, ahead of the positive 500-hPa anomaly center. Above normal
precipitation is slightly favored for a small area of northeastern Mainland
Alaska, consistent with all ensemble model precipitation forecasts. Above
normal precipitation is likely for the Pacific Northwest across the Northern
Rockies, and favored across the northern tier into parts of the Northern Plains
and most of the Great Lakes region, ahead of the trough over the North Pacific
and consistent with all ensemble model precipitation tools. Below normal
precipitation is favored over the southwestern quarter of the CONUS, under the
predicted ridge and positive 500-hPa height anomalies. Precipitation signals
are weak or model forecasts conflict over much of the eastern CONUS with
uncertainty in a changing pattern. Probabilities for above normal precipitation
precipitation are enhanced over southeastern areas of Texas and the southern
Florida Peninsula, where model forecasts are in agreement. Above normal
precipitation is favored for most of the Hawaiian Islands, excluding the Big
Island, consistent with model forecasts.

The official 6-10 day 500-hPa height blend consists of 30% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 40% of Today`s 0z European Ensemble Mean
centered on Day 8, and 30% of Today`s 0z Canadian Ensemble Mean centered on Day
8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above average, 4 out of 5, due to
overall agreement among ensemble means on the 500-hPa height pattern, offset by
differences among temperature and precipitation tools for the eastern CONUS
related to a changing pattern.

8-14 DAY OUTLOOK FOR DEC 16 - 22 2025

The 500-hPa height pattern persists somewhat into the 8-14 day period in 0Z
ECMWF, GEFS and Canadian ensemble mean forecasts. A very amplified ridge and
positive 500-hPa height anomaly persists to the west of Mainland Alaska, while
shifting slightly westward. The downstream trough and negative 500-hPa height
anomalies are predicted to shift westward over eastern Mainland Alaska and
Southeast Alaska in the 8-14 day period forecast. In the 8-14 day period, a
ridge and positive 500-hPa height anomalies expand across the entire CONUS in
the ECMWF forecast and the manual blend of models, while a trough persists over
the Northeast in the GEFS ensemble mean forecast.

Above normal temperatures continue to be favored for the western Aleutian
Islands in the 8-14 day period, under strong positive 500-hPa height anomalies.
Below normal temperatures are likely across the entire Alaska Mainland in the
week-2 period, as 500-hPa heights fall and northerly flow persists. Model tools
for the CONUS predict likely above normal temperatures across the West, under a
persistent ridge and positive 500-hPa height anomalies. Enhanced probabilities
for above normal temperatures expand across the Lower Mississippi Valley and
most of the Southeast in the 8-14 day period, as mid-level heights are
predicted to rise. However, continued disagreement in the GEFS and ECMWF
temperature forecast tools leads to only moderate forecast probabilities in
these areas. Below normal temperatures continue to be favored for the Great
Lakes and Northeast regions, under predicted anomalous northerly flow through
most of the 8-14 day period. The consolidation continues to support high
probabilities for above normal temperatures for Hawaii.

Below normal precipitation is favored for the eastern Aleutians and
southwestern Mainland Alaska in the week-2 period, as in the 6-10 day period,
under anomalous northerly flow ahead of the amplified ridge. Above normal
precipitation is slightly favored for a small area of the northeastern coast of
Mainland Alaska consistent with most model forecast tools. Ahead of the trough
over the North Pacific, above normal precipitation continues to be likely for
the Pacific Northwest, with probabilities exceeding 50 percent for most of the
region. Enhanced probabilities for above normal precipitation extend across
parts of the Northern Plains into the northwestern Great Lakes region, ahead of
a North Pacific trough. Below normal precipitation is favored for the
Southwest, the Central Plains, and the Central MIssissippi Valley, under the
predicted ridge. Uncertainty among precipitation forecast tools for the week-2
period leads to slightly enhanced probabilities of near normal precipitation
for much of the eastern CONUS. Above normal precipitation continues to be
favored for South Texas and the southern Florida Peninsula, consistent with
most tools. The precipitation consolidation supports slightly enhanced
probabilities of above normal precipitation for the northwestern Hawaiian
Islands, while below normal precipitation is favored for the Big Island.

The official 8-14 day 500-hPa height blend consists of: 30% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 40% of Today`s 0z European Ensemble Mean
centered on Day 11, and 30% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About average, 3 out of 5, due to
overall agreement on the evolving mid-level circulation pattern, with
increasing differences in forecasts for the eastern CONUS.

FORECASTER:

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 (gray, "N") normal.
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 (gray, "N")
normal. 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
December 18.


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:
20131212 - 20081207 - 19911204 - 19951129 - 20131218


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:
20131212 - 20081207 - 19911203 - 20131217 - 19951127


6-10 DAY OUTLOOK TABLE
Outlook for Dec 14 - 18 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Dec 16 - 22 2025

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

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