354
FXUS06 KWBC 272002
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Thu November 27 2025

6-10 DAY OUTLOOK FOR DEC 03 - 07 2025

The GEFS, European ensemble (ECENS), and Canadian ensemble (CMCE) means are in
good agreement with the longwave 500-hPa pattern, which features a retrograding
amplified ridge over the northern Pacific and western Alaska, a downstream
trough extending from Hudson Bay to the southwestern contiguous U.S. (CONUS),
and a weak but persistent subtropical ridge from the central North Atlantic
into the Southeast. The amplified mid-level ridge over the northern Pacific and
Alaska is likely to promote Arctic surface high pressure shifting southward
into the lower 48 states beginning by the end of November, which becomes
centered across the Midwest prior to the start of this outlook period. Another
cold surface high pressure system will likely reinforce this around the middle
of the period. These surface highs, bringing cold air southward from higher
latitudes, favor below-normal temperatures across much of the northern and
eastern Great Plains, middle and upper Mississippi Valley, Midwest, Northeast,
and mid-Atlantic region. Farther south, the subtropical ridge is expected to
keep above-normal temperatures prevailing across part of the South Atlantic
States and along the immediate Gulf Coast. Farther west, near to above-normal
temperatures are likely from portions of the Rockies westward, closer to the
mid-level ridge; however, the mid-level trough extension into the Southwest is
expected to trigger one or more rounds of significant precipitation there,
lessening their odds for above-normal mean temperatures.

Between the cold high pressures over the central and northeastern CONUS and the
subtropical mid-level ridge nosing westward into Florida and adjacent areas, a
wavering quasi-stationary front should become established from approximately
the central Gulf Coast northeastward into the Atlantic Ocean. This favors a
widespread area with enhanced above-normal precipitation probabilities from the
Gulf Coast region northward along most of the Eastern Seaboard. Models are
forecasting a bit less precipitation in this broad region, so the odds for
surplus precipitation exceed 40 percent in the Southeast only rom the Bayou
through Georgia and the southern Appalachians, near where a surface low
pressure system may ride northward along the quasi-stationary front. The CMCE
drops over 1.5 inches of rain on parts of the Southeast where the odds for
surplus precipitation are highest, while the ECENS and GEFS means are slightly
less robust, showing 1.0 to 1.5 inches. Farther west, the longwave trough
draped from eastern Canada into the southwestern CONUS favors above-normal
precipitation throughout the Rockies. Consistent with raw and reforecast output
from the ensembles, the greatest odds for enhanced precipitation are centered
over the northern High Plains, and across portions of the Southwest near or
upstream from the base of the mid-level trough. Some guidance shows the
southwestern tail of the trough cutting off from the rest of the mid-level
circulation, forming a separate closed low over or near the Southwest. This
would further increase the odds for heavy precipitation there, but at this time
it is depicted by a minority of the model output, and is not currently the
favored solution . The amplified North Pacific mid-level ridge favors a region
of below-normal precipitation along the West Coast from central California
northward through southern Oregon for the period as a whole, but onshore flow
and retrogression of the mid-level ridge should increase precipitation near the
end of the period. This area is somewhat smaller than yesterday, consistent
with ensemble model guidance.

Enhanced southwesterly surface flow leads to an increased chance of
above-normal temperatures and above-normal precipitation throughout most of
Alaska. The odds for warmth exceed 70 percent in parts of southeastern Alaska
where mid-level height anomalies are expected to be largest. However, the
ensemble means remain in good agreement forecasting a retrogression of the
amplified ridge toward the Aleutians and Bering Strait by day 9 (December 6),
which would favor dramatic 500-hPa height declines over eastern parts of the
state and a pattern change for Alaska beyond this outlook period.

Based on the GEFS and ECENS, above-normal temperatures and above-normal
precipitation are favored for most of Hawaii, downstream from an anomalous
mid-level trough and upstream from a weak mid-level ridge. Above-normal sea
surface temperatures should re-inforce the persistent warmth.

The official 6-10 day 500-hPa height blend consists of 13% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 13% of Today`s 6z GFS Ensemble Mean centered
on Day 8, 41% of Today`s 0z European Ensemble Mean centered on Day 8, 12% of
Today`s operational 0z ECMWF centered on Day 8, and 21% 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
good agreement and consistency on the evolving longwave pattern among the
ensemble mean solutions, tempered slightly by differences in the southward and
westward extent of mean subnormal temperatures among the reforecast (warmest),
bias-corrected, and raw mean (coldest) ensemble output. There is also
uncertainty regarding the evolution of the pattern change across Alaska.

8-14 DAY OUTLOOK FOR DEC 05 - 11 2025

The GEFS, ECENS, and CMCE favor the amplified 500-hPa ridge retrograding west
to the Aleutians and Bering Strait over the course of week-2 with a broad
anomalous trough over the higher latitudes of most of North America. The ECENS
mean still maintains more amplitude with the Pacific ridge than other ensemble
means, but there is a bit less model spread than yesterday. In any case, all
guidance is in agreement showing 500-hPa heights dropping to near or below
normal across most of the state by the end of week 2. The ensemble means are
not in good agreement regarding the details of this evolution, especially late
in the period. Toward the end of week 2, The ECENS mean keeps significantly
below-normal heights in Southeast Alaska, with a stripe of above-normal 500-hPa
heights along the western coastline from an eastward extension of the
developing mid-level ridge in Siberia. In contrast, the GEFS mean covers the
entire state with below-normal heights by the end of week 2, keeping the
Siberian ridge confined farther west. The CMCE mean is a compromise of the
other two, leaning toward the GEFS mean. The manual blend features a compromise
of these three solutions, there being no obvious reason to favor one over the
other. Farther east, the ensemble means are in better agreement showing a
stripe of subnormal heights along the northern tier of the CONUS, with negative
height anomalies extending southward a bit farther in the eastern CONUS.
Farther south, the CMCE maintains more of a subtropical ridge across the
Southeast than the other ensemble means, although all maintain at least
slightly above-normal heights in the South Atlantic region. Teleconnections on
the prominent mid-level features tend to favor a more stubborn subtropical
ridge across the South Atlantic region, so the forecast is shaded in this
direction. Between the subnormal heights in the northern CONUS and slightly
above-normal heights across the southern tier, a broad zonal jet is
established, with relatively weak shortwaves moving through the flow over the
course of week 2 while the wavering quasi-stationary front persists over the
Southeast.

This pattern should keep below normal temperatures and surface high pressure
entrenched across the northeastern quarter of the CONUS. To the south, the
less-meridional mid-level flow and weak but stubborn subtropical ridge should
allow temperatures to rebound above normal from the southern Great Plains
through the Gulf Coast region and into much of the Southeast. The largest
below-normal temperature probabilities (more than 60 percent) are forecast from
the Great Lakes into the Northeast, closest to the broad area of well
below-normal 500-hPa heights. Farther west, return flow on the backside of the
cold high pressure should favor above-normal temperatures in most areas from
the High Plains and Rockies westward to the Pacific Ocean..

The week 2 outlook leans on the wet side for a majority of the lower 48 states
due to the potential for shortwaves to periodically trigger precipitation
across varying parts of the CONUS. In addition, the quasi-stationary boundary
over the Southeast should persist in some form between the cold surface high
pressure over the Northeast and lower surface pressures closer to the
subtropical ridge, and this front could serve as a focus for increased
precipitation. Guidance continues to show the best odds for surplus
precipitation along the northern Front Range, where likelihoods exceed 50
percent. This solution is highly consistent in the raw means and the
reforecasts from all 3 ensembles. Chances for wetness exceed 40 percent in
several fairly broad areas, specifically across parts of the Southwest, close
to the quasi-stationary boundary in the Southeast, and along most of the
northern tier of the CONUS. The outlook is somewhat drier from the southern
Plains northward through the central Great Plains, Middle Mississippi Valley,
and lower Ohio Valley. There is even a slight tilt of the odds toward
below-normal precipitation in part of the central and south-central Great
Plains. These areas are northwest and west of the frontal boundary where
precipitation is more likely to be generated.

Although specifics are uncertain, guidance agrees that 500-hPa heights should
drop quickly across Alaska, especially in eastern sections. How far west
subnormal heights reach is uncertain, but the general set-up should abet some
incursion of Arctic high pressure into the state. However, lower surface
pressures offshore of Southeast Alaska should keep Arctic air from sliding too
far toward that region, so above-normal temperatures are slightly favored
there. The low surface pressure also favors wet weather across Southeast
Alaska, potentially extending northward into south-central and eastern parts of
the Alaskan Mainland. Farther west, closer to the mid-level ridge, odds for
heavy precipitation decline, with subnormal precipitation expected over
northwestern parts of the state.

Based on the GEFS and ECENS, an increased chance of above-normal temperatures
and above-normal precipitation persists across Hawaii, with warmth especially
likely over the western islands. Positive sea surface temperature anomalies
should also continue to support above-normal temperatures.

The official 8-14 day 500-hPa height blend consists of: 22% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 28% of Today`s 0z European Ensemble Mean
centered on Day 11, and 50% 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
general agreement on the broadscale pattern among the ensemble means,
especially over central and eastern North America, tempered by significant
uncertainties regarding the placement and timing of individual features. The
marked disagreement on the evolution of 500-hPa heights across Alaska further
increases uncertainty.

FORECASTER: Rich Tinker

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:
19581209 - 19961124 - 20021122 - 19911107 - 19551126


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:
19911106 - 20021122 - 19581209 - 19961124 - 20081114


6-10 DAY OUTLOOK TABLE
Outlook for Dec 03 - 07 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Dec 05 - 11 2025

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

                           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.

$$