528
FXUS06 KWBC 072002
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Sun December 07 2025

6-10 DAY OUTLOOK FOR DEC 13 - 17 2025

Today`s numerical models are in good agreement in depicting an amplified
500-hPa flow pattern across North America and vicinity. An unusually strong
ridge (with positive height departures greater than 420 meters) is forecast
over the Bering Sea. Downstream troughing is forecast over southeastern Alaska
and an expansive ridge is forecast over the western and central CONUS. Large
scale anomalous troughing is forecast over most of eastern North America. This
overall pattern is slightly less amplified over the CONUS relative to the
forecast yesterday, reflecting a potential transition to a more zonal pattern
toward the end of the period. Farther away from North America, near normal
500-hPa heights are forecast for Hawaii, ahead of a  broad trough forecast over
the central Pacific.

Below normal temperatures are likely across much of the eastern and
north-central CONUS due to strong and persistent troughing. Probabilities of
below normal temperatures exceed 80 percent across much of the Northeast,
northern Mid-Atlantic, and the eastern Great Lakes. Conversely, expansive
ridging across the West favors above normal temperatures. With this forecast
ridge showing good run-to-run consistency, chances of warmer than normal
temperatures exceed 90 percent for parts of the Great Basin and adjacent areas
of the Southwest. Conversely, a cold pattern is likely for much of Alaska due
to anomalous northerly flow ahead of the predicted unusually strong Bering Sea
ridge. Chances of below normal temperatures are greater than 80 percent for
most of Southeast Alaska and adjacent areas of the southeastern Mainland. Above
normal temperatures are favored for Hawaii, consistent with dynamical model
output and with above normal SSTs in the adjacent Pacific.

An active pattern is favored for the northwestern CONUS and parts of the
Northern Plains as enhanced Pacific flow is forecast, consistent with
teleconnections from the positive height anomaly center associated with the
predicted strong ridge over the Bering Sea. Below normal precipitation is
likely across most of the southern two-thirds of the CONUS due to a combination
of anomalous mid-level ridging across much of the West and mean surface high
pressure across much of the East. The area of favored below normal
precipitation extends northward along much of the Eastern Seaboard as surface
high pressure builds into the region. Mean northerly or northwesterly low-level
flow is forecast over the Great Lakes, setting up the potential for enhanced
Lake Effect snow. A tilt toward above normal precipitation is indicated for
much of the Great Lakes region due to this potential. Farther to the south, a
slight tilt toward above normal precipitation is indicated for southern Florida
and southern Texas, near the southern periphery of the predicted trough over
eastern North America. Conversely, below normal precipitation is likely for
much of Alaska consistent with predicted northerly offshore flow ahead of the
very strong ridge over the Bering Sea. Above normal precipitation is favored
for Hawaii ahead of a predicted broad trough over the central Pacific and
consistent with dynamical model guidance.

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 model agreement and consistency on a highly amplified 500-hPa flow pattern
across North America and vicinity in the mean offset slightly by the potential
transition to lower amplitude pattern across the CONUS near the end of the
period.

8-14 DAY OUTLOOK FOR DEC 15 - 21 2025

The week-2 period features the continuation of a highly amplified 500-hP
pattern across Alaska and a transition to a lower amplitude pattern across the
CONUS. The period starts off with continued anomalous ridging across the Bering
Sea and the west-central CONUS. Anomalous troughing is forecast across the East
Coast of the CONUS and southeastern Alaska. During week-2, the very strong
ridge forecast over the Bering Sea is generally forecast to become increasingly
cut off from the large-scale 500-hPa flow and slowly deamplify. Should this
ridge become cut-off, this would open the door for a pattern change across the
CONUS as lower-amplitude Pacific flow undercuts this ridge. Additionally,
models are in good agreement in predicting below normal heights across much of
the higher latitudes of North America as time progresses, suggestive of a
potential transition to a positive AO pattern. However, spread in the predicted
AO index values is very high among the GEFS ensemble members, indicating large
uncertainties on how this transition may play out. Generally near normal mean
heights are forecast for Hawaii, ahead of a broad trough forecast to the
northwest of the state.

Below normal temperatures are favored for the northeastern quadrant of the
CONUS as well as adjacent areas of the Northern Plains. Probabilities of below
normal temperatures exceed 60 percent across parts of northern New England due
to abnormally strong troughing during the first half of week-2. Conversely,
above normal temperatures are favored for most of the western CONUS and
Southern Plains due to predicted expansive ridging. Probabilities of above
normal temperatures exceed 80 percent across much of the Southwest and Great
Basin, where mean positive 500-hPa height departures are forecast to be at a
maximum. A moderating trend is forecast across the southeastern CONUS as the
anomalous trough over eastern North America weakens and lifts to the north and
east. Near normal temperatures are now favored for most of the Southeast due to
this expected moderation. Below normal temperatures remain favored for much of
Alaska with the greatest confidence (more than 80 percent) predicted across
parts of Southeast Alaska. Enhanced northerly flow and below normal 500-hPa
heights are expected to continue well into week-2 across this region. Above
normal temperatures are favored for Hawaii, consistent with dynamical model
output and with above normal SSTs in the adjacent Pacific.

Enhanced Pacific flow is forecast to persist across the northwestern CONUS and
expand into the Northern Plains during week-2. Additionally, teleconnections
from the mean positive height anomaly center associated with the strong cut-off
ridge over the Bering Sea is supportive of Pacific flow across much of the
northern tier of the CONUS. As a result, above normal precipitation is favored
for the Pacific Northwest, northern California, Northern Rockies, and Northern
Plains. Enhanced probabilities of below normal precipitation are forecast
across much of the southern two-thirds of the CONUS, farther removed from the
predicted mean storm track. Probabilities of below normal precipitation exceed
50 percent across parts of the Southwest as anomalous ridging is forecast to
persist well into week-2. Predicted surface high pressure, particularly during
the early and latter portions of week-2, favors below normal precipitation
across most of the Eastern Seaboard. Probabilities of drier than normal
conditions exceed 40 percent along much of the Mid-Atlantic Coast northward to
southeastern New England. Chances of below normal precipitation are more modest
across much of the Mississippi, Tennessee and Ohio Valleys due to the potential
for transient northward moisture advection from the Gulf during the early to
middle parts of the period. Enhanced Lake Effect snow is still possible,
especially during early week-2, leading to a tilt toward above normal
precipitation for many areas adjacent to the Great Lakes. A tilt toward above
normal precipitation persists for southern Florida and southern Texas near the
southern periphery of the broad mean trough forecast over eastern North
America. Conversely, a dry pattern is favored for most of Alaska, underneath
mean offshore flow ahead of the predicted Bering Sea ridge. Above normal
precipitation is favored for Hawaii near the southeastern fringe of a predicted
broad trough over the Pacific, consistent with dynamical model guidance.

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: Average, 3 out of 5, due to good
model agreement on an amplified 500-hPa pattern during the start of week-2
offset by a likely shift to a lower amplitude pattern across the CONUS
thereafter.

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 (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 - 19911203 - 19951128 - 20131219


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:
20081206 - 20131212 - 19911203 - 20081211 - 20131219


6-10 DAY OUTLOOK TABLE
Outlook for Dec 13 - 17 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    N
UTAH        A    B     ARIZONA     A    B     COLORADO    A    B
NEW MEXICO  A    B     N DAKOTA    B    N     S DAKOTA    B    N
NEBRASKA    B    B     KANSAS      N    B     OKLAHOMA    N    B
N TEXAS     N    N     S TEXAS     N    N     W TEXAS     A    B
MINNESOTA   B    N     IOWA        B    N     MISSOURI    B    B
ARKANSAS    B    B     LOUISIANA   B    B     WISCONSIN   B    A
ILLINOIS    B    N     MISSISSIPPI B    B     MICHIGAN    B    A
INDIANA     B    B     OHIO        B    N     KENTUCKY    B    B
TENNESSEE   B    B     ALABAMA     B    B     NEW YORK    B    N
VERMONT     B    B     NEW HAMP    B    B     MAINE       B    B
MASS        B    B     CONN        B    B     RHODE IS    B    B
PENN        B    N     NEW JERSEY  B    B     W VIRGINIA  B    B
MARYLAND    B    B     DELAWARE    B    B     VIRGINIA    B    B
N CAROLINA  B    B     S CAROLINA  B    B     GEORGIA     B    B
FL PNHDL    B    B     FL PENIN    N    N     AK N SLOPE  N    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    B



8-14 DAY OUTLOOK TABLE
Outlook for Dec 15 - 21 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    N
W MONTANA   A    A     E MONTANA   N    A     WYOMING     A    A
UTAH        A    N     ARIZONA     A    B     COLORADO    A    B
NEW MEXICO  A    B     N DAKOTA    B    A     S DAKOTA    N    N
NEBRASKA    N    B     KANSAS      A    B     OKLAHOMA    A    B
N TEXAS     A    B     S TEXAS     A    N     W TEXAS     A    B
MINNESOTA   B    A     IOWA        B    B     MISSOURI    N    B
ARKANSAS    N    B     LOUISIANA   N    B     WISCONSIN   B    N
ILLINOIS    B    N     MISSISSIPPI N    B     MICHIGAN    B    A
INDIANA     B    N     OHIO        B    N     KENTUCKY    N    B
TENNESSEE   N    B     ALABAMA     N    B     NEW YORK    B    A
VERMONT     B    N     NEW HAMP    B    N     MAINE       B    N
MASS        B    B     CONN        B    B     RHODE IS    B    B
PENN        B    N     NEW JERSEY  B    B     W VIRGINIA  B    B
MARYLAND    B    B     DELAWARE    B    B     VIRGINIA    B    B
N CAROLINA  B    B     S CAROLINA  N    B     GEORGIA     N    B
FL PNHDL    N    B     FL PENIN    N    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.

$$