682
FXUS06 KWBC 151902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Tue September 15 2026

6-10 DAY OUTLOOK FOR SEP 21 - 25 2026

Today`s dynamical models depict an omega-like pattern with a ridge over
south-central Canada bracketed by troughs over the Canadian Maritime provinces
and near the West Coast. The anchoring ridge becomes established early in the
period and gains strength through the period. Farther to the south, a trough or
closed low is forecast near the central Gulf Coast region with remnant weakness
in the subtropical ridge potentially persisting into week-2. In Alaska, an
early strong trough is forecast to weaken through the period. This could be an
indication of ensemble guidance struggling with the eventual track of any
recurving tropical cyclones from the West Pacific and the effect on the
longwave mid-level height pattern. This complex forecast evolution in Alaska
and downstream along the West Coast results in increased model spread and
uncertainty across the region. The tropical eastern and central Pacific remains
active and may influence the sensible weather across Hawaii.

Above normal temperatures are favored across most of the CONUS, tied to
predicted widespread above normal mean mid-level heights. A greater than 60
percent chance for above normal temperatures is forecast 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. Meanwhile, a
second area of chances greater than 60 percent chances forecast for the
northern High Plains, associated with the ridge over south-central Canada.
Weaker chances for above normal temperatures are forecast across much of the
West due to uncertainty surrounding the potential evolution of a cut-off low
near the coast. Near 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 anomalous troughing. 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 shortwave trough 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. 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 30% of Today`s 6z 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: 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 23 - 29 2026

By the beginning of week-2, an omega-like pattern is forecast with anomalous
ridging predicted over south-central Canada. However, there are differences
between the evolution of the mid-level height pattern among the dynamical model
guidance. The ECENS and CMCE maintain a stronger ridge center over central and
eastern Canada with more troughing along the West Coast of North America.
Meanwhile, the GEFS has a weaker and more transient ridge across Canada and
brings an additional quick moving positive height anomaly into the western US.
In light of the stronger agreement between the ECENS and CMCE, this is the
favored solution in the manual 500-hPa height blend. In Alaska, the pattern is
quite uncertain with mid-level heights rising to be near-normal with time.
Hawaii will continue to be susceptible to influxes of tropical activity as the
tropical eastern and central Pacific remain active.

With the ECENS and CMCE forecasting a stable expansive ridge forecast over
south-central Canada, above normal temperatures are favored across most of the
CONUS. The strongest chances are forecast over the Upper Mississippi Valley,
Upper Great Lakes, and Northern Plains and separately over the western Gulf
Coast where probabilities exceed 60%. Confidence is lower over the western
CONUS where differences among the dynamical models and statistical guidance
lead to a slight tilt towards above normal temperatures. Weaker chances for
above normal temperatures is also found over the Northeast and Mid-Atlantic,
closer to mid-level troughing and chances for onshore flow around the southern
periphery of the mid-level ridging. In Alaska, a slight tilt towards below
normal temperatures is favored with the mid-level height pattern breaking down
over the state. Above normal temperatures remain likely across Hawaii.

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 interior portions 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. In Alaska, above normal precipitation is slightly favored
consistent with the reforecast guidance. Probabilities of above normal
precipitation also exceed 50 percent across the eastern islands 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: Ryan Bolt

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:
20180921 - 20190928 - 20050922 - 20200912 - 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:
20180923 - 20200912 - 20190928 - 20180830 - 19900826


6-10 DAY OUTLOOK TABLE
Outlook for Sep 21 - 25 2026

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    N     OREGON      A    N     NRN CALIF   A    A
SRN CALIF   A    A     IDAHO       A    N     NEVADA      A    A
W MONTANA   A    N     E MONTANA   A    N     WYOMING     A    A
UTAH        A    A     ARIZONA     A    A     COLORADO    A    A
NEW MEXICO  A    A     N DAKOTA    A    B     S DAKOTA    A    N
NEBRASKA    A    A     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    B
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    N
VERMONT     A    N     NEW HAMP    A    A     MAINE       N    N
MASS        A    A     CONN        A    A     RHODE IS    A    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    A     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 23 - 29 2026

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    N     OREGON      N    A     NRN CALIF   A    A
SRN CALIF   A    A     IDAHO       A    A     NEVADA      A    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    A
NEBRASKA    A    A     KANSAS      A    A     OKLAHOMA    A    N
N TEXAS     A    N     S TEXAS     A    A     W TEXAS     A    A
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    N
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     A    A     NEW YORK    A    N
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N
MASS        A    N     CONN        A    A     RHODE IS    A    A
PENN        A    N     NEW JERSEY  A    A     W VIRGINIA  A    N
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  N    N
AK ALEUTIAN A    N     AK WESTERN  B    N     AK INT BSN  N    N
AK S INT    N    N     AK SO COAST N    N     AK PNHDL    N    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.

$$