067
FXUS06 KWBC 171902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Fri October 17 2025

6-10 DAY OUTLOOK FOR OCT 23 - 27 2025

An amplified mid-level height pattern is forecast for the 6-10 day period with
a deep trough across the northeastern Pacific progressing into the northwestern
contiguous U.S.(CONUS) A mid-level ridge is forecast ahead of this trough with
above-normal 500-hPa heights increasing across the Plains. A mid-level trough
and negative 500-hPa height anomalies are forecast along and just offshore the
Eastern Seaboard. Near-normal heights are favored across the southern tier of
the CONUS. Negative 500-hPa height anomalies are forecast for Alaska with a
negatively tilted trough centered over the Gulf of Alaska. Heights are favored
to rise across the Bering Sea during the period, limiting the potential for
additional strong low pressure systems to develop during the 6-10 day period.
In Hawaii, positive 500-hPa height anomalies are forecast to be centered north
of the state.

Above normal temperatures are forecast across much of the CONUS today with the
strongest chances in the Plains with decreasing confidence towards both coasts.
This is the result of relatively strong ridging across the central CONUS during
the forecast period. As this ridge shifts east with time, chances for
above-normal temperatures will increase over the eastern CONUS. A slight tilt
towards below-normal temperatures are favored for the Mid-Atlantic where tools
are in good agreement for a brief period of cooler conditions. Along the West
Coast, near-normal temperatures are forecast with strong onshore flow into the
region. This onshore flow will likely limit diurnal temperature swings and
near- to below-normal temperatures are favored in most of the tools. In Alaska,
below-normal temperatures are favored across the western third of Mainland
Alaska, the Aleutians, and Southeast Alaska closer to the mid-level negative
500-hPa height anomalies. Above-normal temperatures are favored for the
northeast Mainland. Above-normal temperatures remain strongly favored across
Hawaii.

The main story during the 6-10 day period are the very strong chances of
above-normal precipitation across the western CONUS. Chances for 70% or higher
are forecast for much of the West Coast north of the Bay Area. The highest
chances exceed 80% straddling the California-Oregon border. Above-precipitation
chances are elevated through the Central and Northern Rockies. Relative to
yesterday, there is increased confidence for above-normal precipitation in the
Plains and into the Mississippi Valley. This is a fairly substantial change
relative to yesterday. However, a shortwave trough ejecting out of the Rockies
is the favored solution amongst most of the forecast guidance at this time.
Below-normal precipitation remains favored across much of the eastern CONUS
with surface high pressure forecast across the region. In Alaska, near to
below-normal precipitation is favored for southwest Mainland Alaska with
above-normal favored for the northern and eastern Mainland and into Southeast
Alaska. In Hawaii, a slight tilt towards above-normal is favored for the
eastern islands while near-normal is favored further west.

The official 6-10 day 500-hPa height blend consists of 10% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 35% of Today`s 6z GFS Ensemble Mean centered
on Day 8, 40% of Today`s 0z European Ensemble Mean centered on Day 8, and 15%
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. Very
good agreement among the temperature and precipitation dynamical and
statistical tools is offset by diverging model solutions late in the period.

8-14 DAY OUTLOOK FOR OCT 25 - 31 2025

At the start of week-2 a deep 500-hPa trough is forecast to be just offshore of
the Pacific Northwest. Conversely, a strong 500-hPa height ridge is forecast
over the Plains and Mississippi Valley. A weak 500-hPa height trough is
forecast along the East Coast. The strong trough and ridge dipole over the
western two-thirds of North America will drive strong southerly flow into much
of the West during the first half of week-2. Heights then slowly rise across
the southwestern CONUS shifting the strongest onshore flow further north by the
second half of the week. A shortwave trough pinched off from the 500-hPa height
trough over the eastern Pacific will progress across parts of the northern tier
by the middle of the week. Ahead of this trough the mid-level ridge will
progress into the Great Lakes and Northeast before stronger mid-level troughing
develops over the eastern CONUS at the end of the period. Overall, the pattern
across the CONUS is amplified and progressive during week-2. In Alaska,
mid-level heights remain below-normal with strong troughing over the
northeastern Pacific. By the end of the period, tools suggest falling heights
across the Bering Sea. For Hawaii, positive 500-hPa heights remain forecast
north of the state with associated surface high pressure.

Increased probabilities for above-normal temperatures are forecast across the
interior CONUS underneath transient ridging early in the period and good
support from the ECENS and GEFS reforecast and uncalibrated tools. The highest
probabilities (greater than 70 percent) are highlighted across the Northern
Plains and Upper Mississippi Valley. Reduced chances for above-normal
temperatures are forecast across the Mid-Atlantic tied to troughing and a weak
-NAO persisting. Below-normal temperatures slightly favored over the West due
to enhanced cloud cover and precipitation. The temperature forecast for Alaska
and Hawaii is very similar to that of the 6-10 day period. Near- to
below-normal temperature probabilities are increased for much of Alaska
underneath troughing, with higher odds for above-normal temperatures remaining
across the northeastern Mainland. Above-normal temperatures continue to be
strongly favored across Hawaii.

The ongoing atmospheric river event across the West Coast continues to favor
high probabilities for above-normal precipitation across much of the West. The
highest chances (greater than 70 percent) are focused across portions of
western Oregon and northwestern California where several inches of rain may
fall during the week-2 period based on the 0z ECENS and GEFS. Additional
shortwave troughing as depicted in the 0z ECENS and CMCE favors an increase in
the odds for above-normal precipitation across portions of the Great Plains
into the Mississippi Valley and Southeast. Slightly below-normal precipitation
chances remain preferred for parts of Northeast further displaced from this
feature. A drying trend remains forecast across Alaska, with near-normal
precipitation favored across most of the state, with the exception of portions
of the Aleutians and Southeast Alaska where weak probabilities for above-normal
precipitation are favored. A slight tilt toward enhanced probabilities for
above-normal precipitation is forecast for western Hawaii with near-normal
favored further east.

The official 8-14 day 500-hPa height blend consists of: 10% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 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 20%
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. Good
agreement among the temperature and precipitation dynamical and statistical
tools is offset by diverging model solutions as the period progresses.

FORECASTER: Ryan Bolt

The next set of long-lead monthly and seasonal outlooks will be released on
November 20.






6-10 DAY OUTLOOK TABLE
Outlook for Oct 23 - 27 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Oct 25 - 31 2025

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

$$