415
FXUS06 KWBC 102001
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Wed December 10 2025

6-10 DAY OUTLOOK FOR DEC 16 - 20 2025

The 0Z ECMWF, GEFS, and Canadian ensemble means predict an amplified
circulation pattern over North America and surrounding regions during the 610
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 and negative 500-hPa height anomalies over
eastern and central Mainland Alaska, Southeast Alaska, the Gulf of Alaska, and
parts of the northwestern contiguous U.S. (CONUS). Ensemble means predict a
ridge and associated positive 500-hPa height anomalies over most of the CONUS
at the start of the 610 day period that expands eastward over time. A trough
and associated negative 500-hPa height anomalies over Maine at the start of the
period are predicted to rapidly progress northeastward as mid-level heights
rise. Near to below normal 500-hPa heights are predicted across Hawaii during
the 610 day period.

Above normal temperatures are favored for the western Aleutian Islands under
predicted positive 500-hPa height anomalies. Near to below normal temperatures
are likely for Mainland Alaska under anomalous northerly mid-level flow. Below
normal temperatures are likely for Southeast Alaska under a predicted trough.
Near to above normal temperatures are favored for most of the CONUS (except for
parts of Maine, where below normal temperatures are favored under below-normal
500-hPa heights) due to a persistent ridge and above normal 500-hPa heights.
Probabilities exceed 90 percent over parts of the Four Corners region,
supported by most of the dynamical temperature forecast tools. Above normal
temperatures are very likely across Hawaii in the 610 day period, consistent
with the temperature consolidation.

Below normal precipitation is likely for the Aleutian Islands and southern
Mainland Alaska under and ahead of the positive 500-hPa anomaly center. Near to
above normal precipitation is slightly favored for northern Mainland Alaska,
consistent with all ensemble model precipitation forecasts. Above normal
precipitation is very likely for the Pacific Northwest and across the Northern
Rockies, ahead of the trough over the North Pacific and consistent with all
ensemble model precipitation tools. Enhanced probabilities for above normal
precipitation extend as far south as central California, consistent with
teleconnections to the strong positive 500-hPa height anomaly center to the
west of Alaska. Above normal precipitation is favored across the northern tier
of the western CONUS into parts of the Northern Plains, much of the Great Lakes
region, and parts of the Northeast under strong westerly mid-level flow. Below
normal precipitation is favored over the southwestern CONUS and the Central
Plains under the predicted ridge and positive 500-hPa height anomalies. Below
normal precipitation is slightly favored over portions of the Middle Atlantic
and the Southeast, consistent with most model precipitation tools despite
uncertainty in a changing pattern. Probabilities for above normal precipitation
are enhanced over southeastern areas of Texas and the southern Florida
Peninsula, where model forecasts are in agreement. Near to above normal
precipitation is favored for most of the Hawaiian Islands, consistent with
model forecasts.

The official 6-10 day 500-hPa height blend consists of 30% of Today`s 6z 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
good agreement among ensemble model forecasts, offset by some differences among
temperature and precipitation forecast tools for certain areas.


8-14 DAY OUTLOOK FOR DEC 18 - 24 2025

The 0Z ECMWF, GEFS, and Canadian ensemble mean solutions for the 814 day period
predict a fairly consistent 500-hPa circulation pattern relative to the 610 day
period across North America and the surrounding regions. A very amplified ridge
and positive 500-hPa height anomaly persists to the west of Mainland Alaska. A
trough and associated negative 500-hPa height anomalies are predicted
downstream over eastern and central Mainland Alaska and Southeast Alaska.
Positive 500-hPa height anomalies expand across the entire CONUS in the manual
blend and the 0Z ECMWF, GEFS, and Canadian ensemble means. Near to below normal
500-hPa heights are predicted across Hawaii during the week-2 period.

Above normal temperatures continue to be favored for the western Aleutian
Islands in the 814 day period under strong positive 500-hPa height anomalies.
Below normal temperatures are likely across the Alaska Mainland in the week-2
period under anomalous northerly mid-level flow. Model tools for the CONUS
predict likely near to above normal temperatures across most of the CONUS in
the 814 day period under a persistent ridge and positive 500-hPa height
anomalies. Below normal temperatures are favored for parts of the Northern
Plains, the Upper Mississippi Valley, as well as portions of the Northeast
under predicted anomalous northerly flow through most of the 814 day period.
The consolidation continues to support high probabilities for above normal
temperatures for Hawaii.

Below normal precipitation is favored for southern and central Mainland Alaska
in the week-2 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 all ensemble model
precipitation forecasts. Ahead of the trough over the North Pacific, enhanced
probabilities for above normal precipitation continue to be likely for most of
the western CONUS, extending eastward across the Northern Plains, the Upper
Mississippi Valley, into the Great Lakes, and the Northeast regions, consistent
with the precipitation consolidation. Below normal precipitation is favored for
most of the southern CONUS under the predicted ridge. Above normal
precipitation continues to be favored for 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 6z 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
differences in temperature and precipitation forecast tools for some areas.


FORECASTER: Luke 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 (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:
20131213 - 19951129 - 19891122 - 20081208 - 19911204


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:
20131213 - 19951129 - 20081207 - 19911204 - 19891121


6-10 DAY OUTLOOK TABLE
Outlook for Dec 16 - 20 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    A     ARIZONA     A    B     COLORADO    A    B
NEW MEXICO  A    B     N DAKOTA    N    A     S DAKOTA    A    A
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    B
N TEXAS     A    N     S TEXAS     A    N     W TEXAS     A    B
MINNESOTA   N    A     IOWA        A    N     MISSOURI    A    B
ARKANSAS    A    N     LOUISIANA   A    N     WISCONSIN   N    A
ILLINOIS    A    N     MISSISSIPPI A    N     MICHIGAN    N    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     A    B     NEW YORK    N    A
VERMONT     N    A     NEW HAMP    N    N     MAINE       B    A
MASS        N    N     CONN        N    N     RHODE IS    N    N
PENN        N    N     NEW JERSEY  N    N     W VIRGINIA  N    N
MARYLAND    N    N     DELAWARE    N    B     VIRGINIA    N    B
N CAROLINA  N    B     S CAROLINA  A    B     GEORGIA     A    B
FL PNHDL    A    N     FL PENIN    A    N     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    B



8-14 DAY OUTLOOK TABLE
Outlook for Dec 18 - 24 2025

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

                           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.

$$