398
FXUS06 KWBC 051901
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Sun October 05 2025

6-10 DAY OUTLOOK FOR OCT 11 - 15 2025

Today`s numerical models have come into better agreement in depicting a more
amplified 500-hPa pattern across much of North America and vicinity. A strong
anomalous ridge is predicted just south of the Alaska Peninsula. As time
progresses, this ridge is generally forecast to weaken as the flow becomes more
zonal. Downstream, a deep trough is forecast over the West Coast of the CONUS.
This trough is forecast to slowly progress eastward and deamplify across the
Interior West. Farther to the east, ridging and associated above normal heights
are initially forecast across the Plains and then predicted to strengthen as it
progresses eastward across the Great Lakes and interior Northeast. A more
amplified trough is forecast across the Southeast relative to yesterday,
especially in the early and middle parts of this five day period.  Near to
slightly below normal heights are forecast for Hawaii as today`s ensemble means
are predicting a local mid-level height minimum near the island chain.

Below normal temperatures are favored across most of the western quarter of the
CONUS due to a predicted deep trough near the West Coast. This trough has
trended stronger and farther to the east relative to yesterday, resulting in an
increase in chances of below normal temperatures. Probabilities of below normal
temperatures now exceed 50 percent across most of Northern California, Oregon,
and northwestern Nevada. With this trough stronger in today`s model solutions,
downstream ridging is also more amplified across the central and northeastern
CONUS, resulting in an increase in above normal temperature chances across
these regions. Chances of above normal temperatures exceed 80 percent for parts
of the Great Lakes region, Upper Mississippi Valley, and Central and Southern
Plains. Near normal temperatures are more likely for parts of the Southeast and
southern Mid-Atlantic, replacing the slight tilt toward above depicted
yesterday, as troughing across the region has trended stronger. Above normal
temperatures are favored across most of Alaska due to predicted ridging across
the Mainland. This ridge has trended weaker relative to yesterday so enhanced
probabilities of above normal temperatures have been reduced accordingly. Below
normal temperatures are slightly favored for southern portions of Southeast
Alaska underneath predicted anomalous northerly mid-level flow. Above normal
temperatures are likely for Hawaii (particularly the western and central
islands), consistent with above normal SSTs in the adjacent Pacific Ocean.

An active pattern is likely across the western CONUS eastward to the Northern
Plains, consistent with teleconnections from the deep trough predicted near the
West Coast. Probabilities of above normal precipitation exceed 60 percent
across much of the Northern Great Basin and vicinity due to predicted enhanced
Pacific flow associated with this trough. Chances of above normal precipitation
also exceed 60 percent across much of the Southwest due to the potential for
tropical moisture advection into the region. Conversely, below normal
precipitation is more likely for much of the interior Northeast, eastern Great
Lakes, Ohio and Tennessee Valleys, the Lower Mississippi Valley, and adjacent
areas of the Southern Plains and Southeast due to predicted ridging and
associated surface high pressure. Above normal precipitation is favored for
parts of the Mid-Atlantic and coastal Southeast, due to predicted enhanced
onshore flow to the south of forecasted mean surface high pressure over the
Northeast. Potential surface low pressure development increases above normal
precipitation chances to above 40 percent for parts of the southern
Mid-Atlantic coast. An active pattern is likely for much of Alaska due to
forecast onshore flow associated with the predicted ridge to the south of the
state. Probabilities of above normal precipitation exceed 60 percent for parts
of the western Mainland where this enhanced onshore flow is likely to be the
greatest. Above normal precipitation is modestly favored for Hawaii, consistent
with a consolidation of calibrated precipitation amounts from the GEFS and
ECMWF ensembles and with a predicted mid-level low near the island chain.

The official 6-10 day 500-hPa height blend consists of 20% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 45% of Today`s 0z European Ensemble Mean
centered on Day 8, and 35% 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 among todays ensemble means in depicting a more amplified
500-hPa pattern across much of the forecast domain.

8-14 DAY OUTLOOK FOR OCT 13 - 19 2025

During week-2, all of todays ensemble means depict a transition to a more
zonal mid-level pattern across much of North America by the end of this seven
day period. The period begins with strong anomalous troughing over the Bering
Sea and anomalous ridging to its south over the northeastern Pacific.
Downstream, a deep trough is forecast downstream over or just inland of the
West Coast of the CONUS. Strong anomalous ridging is forecast over eastern
Canada southwestward to the Southern Plains. As time progresses, the pattern
becomes markedly less amplified as zonal, Pacific flow dominates much of the
CONUS by the middle of the period. A weakness in subtropical ridging is
generally forecast to persist across the Southeast through the middle of the
period, with slightly below normal mean heights noted for the southern Florida
Peninsula. The center of the predicted mean subtropical ridge is forecast
farther to the west, across northern Mexico and southern Texas. Near to
slightly below normal heights are forecast for Hawaii as today`s ensemble means
are continuing to predict a local mid-level height minimum near the island
chain.

Above normal temperatures are favored for the central and eastern CONUS as
above normal mid-level heights are forecast across most of these regions.
Probabilities of above normal temperatures exceed 70 percent for parts of the
Southern and Central Plains, the northern half of the Mississippi Valley, and
most of the Great Lakes Region, where positive height anomalies are expected to
be the most pronounced, particularly in the early to middle part of this seven
day period. Above normal temperatures are favored for much of Alaska, but with
reduced confidence relative to yesterday as a trough approaches the state from
the Bering Sea. Below normal temperatures are more likely across southern
portions of Southeast Alaska underneath modestly anomalous northerly flow.
Below normal temperatures are also favored for the western quarter of the
CONUS, particularly early in the period, consistent with anomalous troughing
just inland of the West Coast of the CONUS. Above normal temperatures are
likely for Hawaii (particularly the western and central islands), consistent
with above normal SSTs in the adjacent Pacific Ocean.

An active pattern remains likely for the most of the western CONUS associated
with mean troughing predicted near the West Coast. Teleconnections from the
predicted mean trough location supports enhanced odds of above normal
precipitation across almost the entire western third of the CONUS and extending
eastward across the Northern Plains. This trough, coupled with the potential
for tropical moisture over the Southwest, leads to probabilities of above
normal precipitation exceeding 50 percent across much of the Great Basin and
Southwest. Downstream, predicted ridging and multiple areas of mean surface
high pressure favors below normal precipitation across most of the lower half
of the Mississippi Valley and adjacent areas of the Southern Plains, much of
the Ohio and Tennessee Valleys, the eastern Great Lakes, and much of the
Northeast. Above normal precipitation is favored for much of the Florida
Peninsula associated with predicted mean easterly low-level flow. Above normal
precipitation is also favored for much of the Mid-Atlantic coast and adjacent
areas of the coastal Southeast due to predicted enhanced onshore flow and
potential surface low development. An active pattern is favored to persist
across much of Alaska ahead of a trough over the Bering Sea. Above normal
precipitation is modestly favored for Hawaii, consistent with a consolidation
of calibrated precipitation amounts from the GEFS and ECMWF ensembles.

The official 8-14 day 500-hPa height blend consists of: 20% of Today`s 6z GFS
Ensemble Mean centered on Day 11, 45% of Today`s 0z European Ensemble Mean
centered on Day 11, and 35% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Near average, 3 out of 5, due to
fairly good model agreement on the 500-hPa pattern offset by uncertainties
regarding a potential pattern change during the middle and later portions of
this seven day period.

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 (unshaded, "N"). Historical average
values for the calendar period of the forecast (dashes, "f").  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 (unshaded, "n"). Historical median values
for the calendar period of the forecast (dashes, "inches").  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
October 16.


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:
19830929 - 20040920 - 19850915 - 20070923 - 20081011


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:
19850916 - 20070921 - 19830930 - 20061004 - 20081011


6-10 DAY OUTLOOK TABLE
Outlook for Oct 11 - 15 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Oct 13 - 19 2025

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

$$