487
FXUS06 KWBC 161902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Thu October 16 2025

6-10 DAY OUTLOOK FOR OCT 22 - 26 2025

There is good agreement among the 0z ECENS, GEFS, and CMCE models regarding an
amplified 500-hPa height pattern across North America during the 6-10 day
period. Compared to yesterday, the models are more amplified with initial
troughing across the Northeast reflective of the negative phase of the North
Atlantic Oscillation (-NAO). The troughing is forecast to weaken with time as
the mean ridge axis shifts eastward over the east-central CONUS. Deep troughing
is forecast across the Gulf of Alaska, extending into the Northeast Pacific and
western CONUS. Today`s 6-10 day manual 500-hPa height blend depicts
below-normal heights across much of the eastern third of the CONUS, with the
largest magnitude (-60 meters) over the Northeast. Above-normal heights are
indicated across the Interior West eastward through much of the Great Plains
into the Mississippi Valley. The high amplitude troughing over western North
America results in a broad region of below-normal heights extending from Alaska
to the West Coast of the CONUS. Above-normal heights are forecast across Hawaii.

The amplified troughing across the eastern U.S. supports an increase in the
probabilities for below-normal temperatures over the region. The uncalibrated
ECENS and GEFS, and to some degree, the reforecast tools are supportive of the
forecast trending cooler relative to yesterday. Elsewhere across the CONUS,
probabilities for above-normal temperatures are elevated, with the highest
chances (greater than 60 percent) over the Great Plains. Increasing Pacific
flow across the West favors an increase in cloud cover and precipitation later
in the period. Therefore, probabilities for above-normal temperatures are lower
than those to the east, with near-normal temperatures more likely over parts of
the Pacific Northwest and Southwest. Enhanced odds for near- to below-normal
temperatures are favored for much of Alaska underneath troughing. The exception
is across the northeastern Mainland, where above-normal temperature
probabilities are increased, supported by the reforecast and uncalibrated
forecast tools. Above-normal temperatures are strongly favored across Hawaii
tied to ridging and positive height anomalies predicted over the south-central
Pacific.

The major story for the precipitation outlook is the developing atmospheric
river event along the U.S. West Coast tied to troughing extending southward
from Alaska into the Northeast Pacific. While the outset of the period is
forecast to be relatively dry, precipitation signals increase greatly by days 7
and 8. The pattern supports high probabilities of above-normal precipitation
across much of the West. The largest probabilities (greater than 70 percent)
are focused across coastal Oregon and northwestern California, with decreasing
probabilities across the Southwest into the Southern Plains. Tied to increased
ridging and surface high pressure, odds for below-normal precipitation are
increased over much of the northern half of the Plains, Midwest, and into the
Southeast. The trough in the east and associated cyclonic flow favors a slight
tilt toward above-normal precipitation chances across New England. Near- to
above-normal precipitation chances are increased across Alaska, although the
strongest signals are predicted to shift to the south of the state by the end
of the period. Slightly elevated above-normal precipitation probabilities are
forecast across Hawaii, supported by the consolidation reforecast tool.

The official 6-10 day 500-hPa height blend consists of 30% of Today`s 0z 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
generally good model agreement, but offset by some uncertainty in the East
given the trend to more troughing compared to yesterday.

8-14 DAY OUTLOOK FOR OCT 24 - 30 2025

The high amplitude 500-hPa height pattern is forecast to continue across
western North America during the week-2 period, with anomalous troughing
persisting across the northeastern Pacific into the West Coast. Further
downstream, the pattern is predicted to be more transient, with initial ridging
over the east-central CONUS being replaced by shortwave troughing. The 0z ECENS
and CMCE are more robust with this feature compared to the 0z GEFS. The week-2
manual height blend depicts below-normal heights extending from Alaska into the
northwestern CONUS. Conversely, large above-normal height anomalies are
indicated over much of central and eastern Canada, extending into parts of the
north-central and northeastern CONUS. Near-normal heights are predicted over
much of the south-central and southeastern CONUS. Elongated ridging over the
central and eastern Pacific support above-normal heights extending from Hawaii
into the southwestern U.S.

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 largest
probabilities (greater than 70 percent) are highlighted across the Northern
Plains and Upper Mississippi Valley. Areas of near-normal temperatures are
forecast across the Mid-Atlantic tied to troughing and a weak -NAO persisting,
and 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 Lower Mississippi Valley. Slightly below-normal precipitation chances
remain elevated across the Great Lakes and Northeast further displaced from
this feature. Tropical cyclogenesis is possible across the Caribbean during
week-2, and any system that forms will need to be watched as climatology
generally favors a recurving track to the north. Currently most long-range
model solutions favor any system remaining over the western Atlantic, but
confidence is low given that a system has not yet formed. 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, northern
Mainland, 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 Hawaii.

The official 8-14 day 500-hPa height blend consists of: 25% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 50% of Today`s 0z European Ensemble Mean
centered on Day 11, and 25% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Above average, 4 out of 5, due to
good model agreement regarding an amplified trough near the West Coast of the
CONUS, offset by greater uncertainty further downstream.

FORECASTER: Thomas Collow

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






6-10 DAY OUTLOOK TABLE
Outlook for Oct 22 - 26 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Oct 24 - 30 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    N
UTAH        A    A     ARIZONA     A    N     COLORADO    A    A
NEW MEXICO  A    N     N DAKOTA    A    N     S DAKOTA    A    N
NEBRASKA    A    N     KANSAS      A    A     OKLAHOMA    A    N
N TEXAS     A    N     S TEXAS     A    N     W TEXAS     A    N
MINNESOTA   A    N     IOWA        A    N     MISSOURI    A    N
ARKANSAS    A    N     LOUISIANA   A    N     WISCONSIN   A    N
ILLINOIS    A    N     MISSISSIPPI A    N     MICHIGAN    A    B
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     A    N     NEW YORK    A    B
VERMONT     A    B     NEW HAMP    A    B     MAINE       A    N
MASS        A    B     CONN        A    N     RHODE IS    A    N
PENN        A    N     NEW JERSEY  N    N     W VIRGINIA  N    N
MARYLAND    N    N     DELAWARE    N    N     VIRGINIA    N    N
N CAROLINA  N    N     S CAROLINA  N    N     GEORGIA     A    N
FL PNHDL    A    N     FL PENIN    A    N     AK N SLOPE  N    A
AK ALEUTIAN B    A     AK WESTERN  B    N     AK INT BSN  N    N
AK S INT    N    N     AK SO COAST N    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.

$$