906
FXUS06 KWBC 062002
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Sat December 06 2025

6-10 DAY OUTLOOK FOR DEC 12 - 16 2025

Today`s numerical models are in good agreement in depicting a very amplified
500-hPa flow pattern across North America and vicinity. An unusually strong
ridge (with positive height departures greater than 390 meters) is forecast
over the Bering Sea. Downstream troughing is forecast over southeastern Alaska
and a strong ridge is forecast over the western CONUS. Large scale anomalous
troughing is forecast over most of eastern North America. This overall pattern
is very similar to that forecast yesterday. Farther away from North America,
near to slightly below normal 500-hPa heights are forecast for Hawaii, on the
southeastern fringe of broadly cyclonic flow 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 Great Lakes
Region, Northeast, and northern Mid-Atlantic. 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 Southwest and adjacent areas of the Great
Basin. 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 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 as enhanced Pacific
flow is forecast ahead of a mean trough forecast near southeastern Alaska.
Predicted upslope low-level flow also increases chances of above normal
precipitation farther to the east, across parts of the Northern Plains. 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 Plains and the East. The
area of favored below normal precipitation extends northward along much of the
Eastern Seaboard as a surface low departs offshore of New England prior to the
start of the period. In the wake of this system, strong 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 near the
southeastern periphery of predicted broad cyclonic flow 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: Much above average, 5 out of 5,
due to good model agreement and consistency on a highly amplified 500-hPa flow
pattern across North America and vicinity.

8-14 DAY OUTLOOK FOR DEC 14 - 20 2025

The unusually high amplitude 500-hPa flow pattern is forecast to persist into
the first half of week-2 with uncertainty increasing significantly thereafter.
The period starts off with continued strong ridging across the Bering Sea and
the western CONUS. Anomalous troughing is forecast across the eastern CONUS and
southeastern Alaska. As we enter the second half of 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. 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 significant height falls across much of the higher
latitudes of North America as time progresses, suggestive of a potential
transition to a positive AO and NAO pattern later in week-2. Generally near
normal mean heights are forecast for Hawaii, as broad troughing to its
northwest slowly retrogrades westward and further away from the state.

Below normal temperatures are favored for the northeastern quadrant of the
CONUS as well as adjacent areas of the Southeast and Northern Plains.
Probabilities of below normal temperatures exceed 70 percent across much of the
Northeast and northern Mid-Atlantic due to abnormally strong troughing during
the first half of week-2. Conversely, above normal temperatures are favored for
most of the western CONUS due to predicted expansive ridging. Probabilities of
above normal temperatures exceed 80 percent across much of the Southwest and
adjacent areas of the Great Basin, where mean positive 500-hPa height
departures are forecast to be at a maximum. Below normal temperatures remain
favored for much of Alaska with the greatest confidence (more than 70 percent)
predicted across much of Southeast Alaska and adjacent areas of the
southeastern Mainland. 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 well
into 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 Rockies, and Northern Plains. Enhanced probabilities of below normal
precipitation are forecast across most 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 much of the Southwest and
adjacent areas of southeastern California as anomalous ridging is forecast to
persist well into week-2. Predicted surface high pressure, particularly during
the early and middle portions of week-2, favors below normal precipitation
across most of the Eastern Seaboard. Enhanced Lake Effect snow is still
possible, especially during the early week-2, leading to a tilt toward above
normal precipitation for most 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 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 predicted
broad cyclonic flow over the Pacific and 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 first half of week-2
offset by a potential 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:
20081206 - 20131211 - 19911203 - 20041220 - 20081211


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 - 19911202 - 20131212 - 20081211 - 20041219


6-10 DAY OUTLOOK TABLE
Outlook for Dec 12 - 16 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    N     NEVADA      A    B
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    A     S DAKOTA    B    N
NEBRASKA    N    B     KANSAS      N    B     OKLAHOMA    N    B
N TEXAS     N    B     S TEXAS     N    N     W TEXAS     A    B
MINNESOTA   B    N     IOWA        B    B     MISSOURI    B    B
ARKANSAS    B    B     LOUISIANA   B    B     WISCONSIN   B    N
ILLINOIS    B    B     MISSISSIPPI B    B     MICHIGAN    B    A
INDIANA     B    B     OHIO        B    B     KENTUCKY    B    B
TENNESSEE   B    B     ALABAMA     B    B     NEW YORK    B    B
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    B    A     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    A



8-14 DAY OUTLOOK TABLE
Outlook for Dec 14 - 20 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    B
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    A     S DAKOTA    N    A
NEBRASKA    N    B     KANSAS      N    B     OKLAHOMA    N    B
N TEXAS     N    B     S TEXAS     N    N     W TEXAS     A    B
MINNESOTA   B    A     IOWA        B    N     MISSOURI    B    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    B    B
TENNESSEE   B    B     ALABAMA     B    B     NEW YORK    B    N
VERMONT     B    N     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    B    A     AK N SLOPE  B    B
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

                           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.

$$