Prognostic Meteorological Discussion
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FXUS06 KWBC 252006
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Tue November 25 2025

6-10 DAY OUTLOOK FOR DEC 01 - 05 2025

The GEFS, ECENS, and CMCE are in good agreement with the longwave 500-hPa
pattern which features a retrograding amplified ridge over the northern Pacific
and Alaska, a downstream trough extending from Hudson Bay to the southwestern
contiguous U.S. (CONUS), and a weakening subtropical ridge across the
Southeast. The amplified mid-level ridge over the northern Pacific and Alaska
is likely to promote a series of Arctic surface highs to shift southward into
the lower 48 states, beginning by the end of November. The ensemble mean
solutions remain consistent that a pair of strong surface highs become centered
across the Midwest just prior to the start of this outlook period and then
again by day 9, December 4. These surface highs, accompanied by anomalous cold,
favor below-normal temperatures across much of the Great Plains, Mississippi
Valley, Midwest, and Northeast. The subtropical ridge is expected to favor
above-normal temperatures for the Southeast, but anomalous cold may overspread
the Southern Appalachians and Carolinas by the end of this period. The
southwest extension of anomalous troughing along with the likelihood of one or
two rounds of precipitation result in the outlook leaning on the colder side
for southern California and the Southwest. Near to above-normal temperatures
are more likely across northern California and the Pacific Northwest.

A couple of low pressure systems and trailing cold fronts are forecast to cross
the central and eastern CONUS which favors a widespread area with enhanced
above-normal precipitation probabilities. A front may become stationary across
the Tennessee Valley and based on the ensemble means having more than 1.5
inches of precipitation during this 5-day period, probabilities exceed 50
percent. A longwave trough favors above-normal precipitation throughout the
Rockies. Due to a shortwave trough digging into the southwestern CONUS, an
increased chance of above-normal precipitation is forecast for southern
California and the Southwest. The drier climatology results in above-normal
precipitation probabilities being maximized from the Desert Southwest east to
the Rio Grande Valley. Although the nearby amplified ridge early in the period
favors below-normal precipitation from the Bay area of California north to
western Oregon, onshore flow with increasing precipitation chances may return
by day 10, December 5.

Enhanced southwesterly surface flow leads to an increased chance of
above-normal temperatures and above-normal precipitation throughout most of
Alaska. However, the ensemble means remain in good agreement and consistent
with an amplified ridge shifting west to the Aleutians by day 10 which would
favor 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.

The official 6-10 day 500-hPa height blend consists of 35% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 35% 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 and consistency on the evolving longwave pattern among the
ensemble mean solutions.

8-14 DAY OUTLOOK FOR DEC 03 - 09 2025

The GEFS, ECENS, and CMCE continue to favor the amplified 500-hPa ridge
retrograding west to the Aleutians early in week-2 with a broad anomalous
trough over the higher latitudes of central and eastern North America. In
response to the retrograding ridge upstream, a mid-level trough is forecast to
develop along or offshore of the West Coast. The deep trough, centered over
eastern Canada, along with cold air advection favors below-normal temperatures
throughout the Northeast, Midwest, and Northern Great Plains. The largest
below-normal temperature probabilities (more than 60 percent) are forecast for
northern New York and New England where model solutions depict the strongest
cold air advection and the ECENS has 7-day temperature anomalies of near -10
degrees F. Following a cold start to December for the Southern Great Plains, a
warming trend is expected later in week-2 as 500-hPa heights rise and the
anomalous cold shifts well northeast of this region. Therefore, an increased
chance of above-normal temperatures are forecast across the Southern Great
Plains. Since strong cold air advection is unlikely to overspread the Southeast
during week-2 and slightly positive 500-hPa height anomalies are predicted by
the model suite, above-normal temperatures are favored for this region. The
week-2 temperature outlook remains somewhat uncertain again today for the
western CONUS, but enhanced cloudiness and precipitation would tend to favor
near to below-normal temperatures for the Desert Southwest and southern
California. Elsewhere across northern California along with portions of the
Pacific Northwest and Great Basin, a return of onshore flow supports an
increased chance of above-normal temperatures.

The week-2 outlook leans on the wet side for a majority of the lower 48 states
due to the amplified 500-hPa trough extending southwestward from Hudson Bay to
the west-central CONUS. Relative to yesterday, the outlook is drier for parts
of the Great Plains and Midwest as surface high pressure is forecast to become
more prevalent for these areas. The Tennessee Valley only has slightly elevated
above-normal precipitation probabilities with the heaviest precipitation with a
low pressure system likely timing off by day 8. A combination of a digging
shortwave trough towards southern California and/or the southwestern CONUS at
the beginning of week-2 along with the return of onshore flow later in the
period favors above-normal precipitation from the West Coast to the Continental
Divide.

A rapid transition from above to below-normal temperatures is expected for
Alaska due to the westward shifting mid-level ridge and an increasing chance
for Arctic high pressure to affect the state later in week-2. Since this
transition is likely to occur around day 10, near normal temperatures are
favored for western and northern Mainland Alaska. Based on the analog tool
derived from the manual 500-hPa height blend and the uncalibrated model output,
below-normal temperatures are most likely across southeastern Alaska. The rapid
transition warrants a two-category change from above (6-10 day) to below-normal
(8-14 day) temperatures. A wet start to the period leads to slightly elevated
chances of above-normal precipitation for much of the state.

Based on the GEFS and ECENS, an increased chance of above-normal temperatures
and above-normal precipitation are forecast for Hawaii. Positive sea surface
temperature anomalies also support above-normal temperatures, especially across
the northwestern islands.

The official 8-14 day 500-hPa height blend consists of: 35% of Today`s 6z GFS
Ensemble Mean centered on Day 11, 35% 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
agreement among the ensemble means on the longwave pattern offset by
conflicting temperature tools for the western CONUS and a predicted
retrogression in the high amplitude 500-hPa ridge over the North Pacific.

FORECASTER: Brad Pugh

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:
19961125 - 19801115 - 19851207 - 19831125 - 19871123


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:
19961125 - 19851206 - 19801208 - 19801115 - 19581208


6-10 DAY OUTLOOK TABLE
Outlook for Dec 01 - 05 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  N    N     OREGON      N    N     NRN CALIF   N    B
SRN CALIF   B    A     IDAHO       N    A     NEVADA      N    A
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    A
UTAH        B    A     ARIZONA     B    A     COLORADO    B    A
NEW MEXICO  B    A     N DAKOTA    B    A     S DAKOTA    B    A
NEBRASKA    B    A     KANSAS      B    A     OKLAHOMA    B    A
N TEXAS     B    A     S TEXAS     B    A     W TEXAS     B    A
MINNESOTA   B    A     IOWA        B    A     MISSOURI    B    A
ARKANSAS    B    A     LOUISIANA   B    A     WISCONSIN   B    N
ILLINOIS    B    A     MISSISSIPPI B    A     MICHIGAN    B    A
INDIANA     B    A     OHIO        B    A     KENTUCKY    B    A
TENNESSEE   B    A     ALABAMA     A    A     NEW YORK    B    A
VERMONT     B    N     NEW HAMP    B    A     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    N    A
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    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 03 - 09 2025

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

$$