812
FXUS06 KWBC 141909
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Mon September 14 2026

6-10 DAY OUTLOOK FOR SEP 20 - 24 2026

Today`s dynamical models depict a transition to an omega-like pattern with a
developing ridge over south-central Canada bracketed by troughs over the
Northeast and near the West Coast. The anchoring ridge is forecast to be
disorganized and relatively weak early in the period before establishing itself
and gaining strength during days 8 through 10. Farther to the south, a trough
or closed low is forecast early in the period near the central Gulf Coast
region with remnant weakness in the subtropical ridge potentially persisting
thereafter. A much stronger trough is forecast over western Mainland Alaska and
a second, weaker trough is forecast early in the period near Southeast Alaska.
Shortwave energy may break off from the main cyclonic flow over the
northeastern Pacific and affect the West Coast of the CONUS as a cut-off low.
This complex forecast evolution along the West Coast results in increased model
spread and uncertainty across the region. The tropical eastern and central
Pacific remains active with the National Hurricane Center tracking one named
storm (Norbert) and a tropical depression to its east. The evolution of the
tropics will determine the sensible weather across Hawaii but an active pattern
is favored given the elevated tropical activity.

Above normal temperatures are favored across a wide swath of the CONUS, tied to
predicted widespread above normal mean mid-level heights. Confidence is high
(greater than 60 percent chance) for above normal temperatures across the
Tennessee Valley southward to the Gulf Coast, in the warm sector ahead of a
developing surface low over the central Plains and middle Mississippi Valley.
Confidence is also high (greater than 60 percent chance) for above normal
temperatures across the northern High Plains, associated with the developing
ridge over south-central Canada. Confidence is low across much of the West
Coast due to uncertainty surrounding the potential evolution of a cut-off low
near the coast. Near or above normal temperatures are modestly favored in these
areas of higher uncertainty. Below normal temperatures are modestly favored
over parts of northern New England, associated with a trough centered near
Atlantic Canada. Below normal temperatures are likely across western and
central mainland Alaska as well as the Alaska Peninsula due to persistent
anomalous troughing. Confidence is high (greater than 60 percent chance) for
below normal temperatures across parts of the western Mainland. Above normal
temperatures are favored for parts of the Aleutians, associated with above
normal sea surface temperatures in adjacent waters. Above normal temperatures
are likely across Hawaii due to widespread above normal SSTs in the tropical
eastern and central Pacific associated with the current El Nino.

Increased tropical moisture advection and cyclonic flow continue to result in
elevated probabilities for above-normal precipitation across southern and
central sections of the western CONUS. The highest probabilities (greater than
50 percent) are focused across the Southwest and adjacent areas. A tilt toward
below normal precipitation is indicated for the Upper Mississippi Valley and
western Great Lakes, due to predicted surface high pressure. Enhanced
northeasterly maritime flow on the southern and eastern fringe of this surface
high favors above normal precipitation along much of the Eastern Seaboard.
Additionally, the potential for a closed low or weakness in subtropical ridging
leads to elevated chances of above normal precipitation across the southeastern
quadrant of the CONUS. Persistent cyclonic flow and associated surface low
pressure favors above normal precipitation across most of eastern and central
Alaska.  Confidence is high (greater than 50 percent chance) of above normal
precipitation for much of Southeast Alaska and parts of the southeastern
Mainland, ahead of a persistent surface low near the South Coast of the
Mainland. An active eastern and central tropical Pacific favors above normal
precipitation across Hawaii. Please stay tuned to the National Hurricane Center
for the latest developments in the tropics.

The official 6-10 day 500-hPa height blend consists of 25% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 50% of Today`s 0z European Ensemble Mean
centered on Day 8, and 25% of Today`s 0z Canadian Ensemble Mean centered on Day
8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Average, 3 out of 5, due to good
model agreement regarding an evolution toward an omega-like pattern offset by
large model uncertainty regarding the evolution of individual features,
especially along the West Coast.

8-14 DAY OUTLOOK FOR SEP 22 - 28 2026

By the beginning of week-2, an omega-like pattern is firmly established with
anomalous ridging predicted over south-central Canada. This anomalous ridge
looks to persist at least through the middle of the period and is especially
strong in the European ensemble mean. With this ridge firmly in place, upstream
troughing is favored across the West Coast of the CONUS, with the potential for
one or more cut-off lows to develop within this cyclonic flow. On the other
side of the ridge, cyclonic flow is forecast to persist across parts of the
Northeast, before eventually giving way to rising heights later in the period.
Strong troughing and associated below normal heights are forecast to continue
across western Mainland Alaska well into week 2. A shortwave trough is forecast
to rotate within the larger cyclonic flow over the Gulf of Alaska early in the
period, maintaining an active period across much of the state. Hawaii will
continue to be susceptible to influxes of tropical activity as the tropical
eastern and central Pacific remain active.

With a stable expansive ridge forecast over south-central Canada, above normal
temperatures are favored across the central CONUS. Teleconnections derived from
this ridge supports a high likelihood (greater than 60 percent chance) for
above normal temperature across the Red River Valley of the North and
surrounding areas. Confidence is lower along the West Coast of the CONUS, where
near or above normal temperatures are modestly favored, tied to uncertainty
regarding the evolution of individual shortwave trough(s) along or near the
coast. Near normal temperatures are favored for eastern New England, behind a
departing trough over Atlantic Canada. Below normal temperatures are favored
for western Mainland Alaska associated with persistent cyclonic flow. A slight
tilt toward above normal temperatures is indicated for the Aleutians associated
with nearby above normal SSTs. Hawaii is likely to continue to be warmer than
normal associated with the deep reservoir of above normal SSTs in the eastern
and central tropical Pacific.

A continued active pattern is favored across the West, due to the combination
of cyclonic flow along the coast and potential advection of moisture from an
active eastern tropical Pacific. Below normal precipitation is favored farther
to the east, across the Great Lakes, the northern half of the Mississippi
Valley and northern areas of the Northeast, associated with predicted surface
high pressure. Above normal precipitation is favored to the south and east of
this surface high, associated with enhanced northeasterly or easterly maritime
flow.  An active pattern is likely to continue across eastern and much of
central Alaska as persistent troughing is forecast to be slow to dissipate.
Multiple areas of surface low pressure are forecast within this cyclonic flow
near the southern coast of the Mainland, elevating chances of above normal
precipitation to above 50 percent for parts of Southeast Alaska. Probabilities
of above normal precipitation also exceed 50 percent across much of Hawaii, as
the tropical Pacific is favored to remain active.

The official 8-14 day 500-hPa height blend consists of: 25% of Today`s 6z 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: Below Average, 2 out of 5, due to
a predicted complex pattern over the western CONUS and elevated uncertainty
regarding the evolution of the tropics.

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 (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
September 17.


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:
20200912 - 20180920 - 20050922 - 20190928 - 20180829


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:
20200911 - 20050911 - 19900826 - 20180923 - 20180830


6-10 DAY OUTLOOK TABLE
Outlook for Sep 20 - 24 2026

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



8-14 DAY OUTLOOK TABLE
Outlook for Sep 22 - 28 2026

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

$$