523
FXUS06 KWBC 191902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Wed August 19 2026

6-10 DAY OUTLOOK FOR AUG 25 - 29 2026

The ECMWF, GEFS, and CMCE ensemble model forecasts agree in predicting a
relatively amplified 500-hPa height pattern for summer over the North American
region. Models predict an amplified ridge and positive 500-hPa height anomalies
across the Aleutian Islands into southwestern Mainland Alaska during the
period. A trough and negative 500-hPa height anomalies are predicted further
north over the Arctic and northwestern Mainland Alaska. Models agree in
predicting an amplified mid-level ridge that is centered over the Great Plains
during late August, persisting throughout the 6-10 day period. The manual
height blend is based on the 0Z ECMWF, GEFS, and Canadian model 500-hPa height
forecasts, weighting the ECMWF ensemble mean greater due to recent model skill.
The manual blend predicts an expansive area of height departures greater than
30 meters from the interior West to the Mississippi Valley. Relatively weak
troughs are predicted to the west over the North Pacific and to the east over
the northeastern contiguous United States (CONUS), with weaker negative
anomalies over the northeastern CONUS relative to yesterday`s forecast.

Above normal temperatures are favored across the Aleutian Islands under
predicted positive 500-hPa height anomalies. Below normal temperatures are
favored for northwestern and parts of interior Mainland Alaska, with enhanced
cyclonic flow and cloud cover. With a broad amplified ridge predicted to be
centered over the western central CONUS, above normal temperatures are likely
for most of the West, excluding the coasts of Northern California and the
Pacific Northwest. Under positive 500-hPa height anomalies, above normal
temperatures are likely for the central and southeastern CONUS, and parts of
New England, with probabilities exceeding 80 percent for parts of the Southwest
and the Southern Plains. Near normal temperatures are favored for much of the
northeastern CONUS, under a predicted weak trough. Supported by most
temperature tools, above normal temperatures are likely for Hawaii.

Above normal precipitation is favored for most of Mainland Alaska, excluding
the south coast, ahead of enhanced westerly flow and a predicted trough to the
northwest. Above normal precipitation is slightly favored for the Aleutian
Islands, consistent with the consolidation of calibrated model precipitation
forecasts. While most dynamical model forecasts favor above normal
precipitation for a large area of the western CONUS ahead of a weak trough,
precipitation amounts are predicted to be small. Above normal precipitation is
therefore only slightly favored for the Central Rockies and parts of the
northern and central Great Plains, where precipitation signals are greater.
Under the predicted ridge, below normal precipitation is favored for parts of
the Southern Plains. Predicted weak troughing over the northeastern CONUS
favors above normal precipitation for the Eastern Seaboard from the Carolinas
to the Northeast. Above normal precipitation is favored across Hawaii,
consistent with most dynamical model forecasts.

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: Average, 3 out of 5, due to good
agreement between model forecasts of the mean large-scale mid-level height and
temperature patterns, offset by weak signals in precipitation tools.

8-14 DAY OUTLOOK FOR AUG 27 - SEP 02, 2026

The overall predicted 500-hPa height pattern is relatively persistent into the
8-14 day period in ensemble model forecasts, while indicating increased
uncertainty and weaker anomalies than the 6-10 day period forecast. The ridge
over the CONUS begins to deamplify later in the week-2 period. The amplified
ridge over the Aleutians at the start of the period begins to deamplify and
progress eastward into the Gulf of Alaska during week 2, while the trough over
the North Pacific at the start of the period progresses eastward into the
Pacific Northwest. The manual blend of ECMWF, GEFS, and CMCE ensemble model
forecasts predicts positive 500-hPa height anomalies to continue but weaken
across the Aleutian Islands, southern Mainland Alaska, and Southeast Alaska. A
weak trough is forecast near and over the Pacific coast of the northwestern
CONUS in the week-2 manual blend. A ridge and positive 500-hPa height anomalies
are predicted to persist across the west-central CONUS through most of the
period by all models and the manual blend, progressing slightly eastward
relative to the 6-10 day period. Troughing persists over the northeastern CONUS
early the 8-14 day period, as negative 500-hPa height anomalies deamplify later
in week 2.

Above normal temperatures continue to be favored across the Aleutian Islands in
the week-2 period, under positive 500-hPa height anomalies. Below normal
temperatures are favored for parts of interior Mainland Alaska, with increased
precipitation and cloudiness under anomalous cyclonic flow. Above normal
temperatures are slightly favored for Southeast Alaska and adjacent areas of
the southeastern Mainland, due to predicted rising positive 500-hPa height
anomalies. Persistence of the ridge over the western central CONUS leads to
likely above normal temperatures for most of the CONUS, with probabilities
exceeding 80 percent in parts of Arizona and western Texas. Below normal
temperatures are slightly favored for western Oregon and Washington, under a
predicted weak trough. Above normal temperatures are slightly favored for the
northeastern CONUS in week 2, as a weak trough deamplifies. Dynamical model
forecasts agree on likely above normal temperatures for Hawaii.

Above normal precipitation is favored across most of Mainland Alaska, excluding
the south coast, in the week-2 period, consistent with most model forecasts and
the consolidation. Below normal precipitation is slightly favored for Southeast
Alaska, under rising mid-level heights. Above normal precipitation is slightly
favored for coastal areas of the Pacific Northwest, the Northern and Central
Rockies, and the Northern Plains, where dynamical model forecasts are most
consistent and the consolidation shows positive precipitation anomalies. Below
normal precipitation continues to be favored for parts of the Southern Plains,
under the center of a predicted ridge. Dynamical model forecasts continue to
support above normal precipitation for coastal areas of the Carolinas,
Mid-Atlantic, and Northeast, ahead of a predicted weak trough. Above normal
precipitation is likely for Hawaii in the 8-14 day period, consistent with most
dynamical model forecast tools.

The official 8-14 day 500-hPa height blend consists of: 30% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 40% of Today`s 0z European Ensemble Mean
centered on Day 11, and 30% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Average, 3 out of 5, due to good
agreement among dynamical models on the height and temperature forecasts,
offset by weak precipitation signals.

FORECASTER: D Collins

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
2026-08-19.


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:
20100801 - 20230825 - 20180730 - 20160825 - 20220730


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:
20100731 - 20050815 - 20230826 - 20090806 - 20180729


6-10 DAY OUTLOOK TABLE
Outlook for Aug 25 - 29 2026

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    N     OREGON      A    N     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       A    N     NEVADA      A    N
W MONTANA   A    N     E MONTANA   A    A     WYOMING     A    A
UTAH        A    N     ARIZONA     A    N     COLORADO    A    N
NEW MEXICO  A    N     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    B
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    N    N
INDIANA     N    N     OHIO        N    N     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     A    N     NEW YORK    N    A
VERMONT     N    A     NEW HAMP    N    A     MAINE       A    A
MASS        A    A     CONN        N    A     RHODE IS    A    A
PENN        N    A     NEW JERSEY  N    A     W VIRGINIA  N    A
MARYLAND    N    A     DELAWARE    N    A     VIRGINIA    N    A
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    N
FL PNHDL    A    N     FL PENIN    A    N     AK N SLOPE  N    A
AK ALEUTIAN N    N     AK WESTERN  B    A     AK INT BSN  B    A
AK S INT    N    A     AK SO COAST N    N     AK PNHDL    A    N



8-14 DAY OUTLOOK TABLE
Outlook for Aug 27 - Sep 02, 2026

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  N    A     OREGON      N    N     NRN CALIF   N    N
SRN CALIF   A    N     IDAHO       A    A     NEVADA      A    N
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    A
UTAH        A    N     ARIZONA     A    N     COLORADO    A    N
NEW MEXICO  A    N     N DAKOTA    A    A     S DAKOTA    A    A
NEBRASKA    A    N     KANSAS      A    N     OKLAHOMA    A    N
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B
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    N     NEW YORK    A    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    A
MASS        A    A     CONN        A    A     RHODE IS    A    A
PENN        A    A     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    N
FL PNHDL    A    N     FL PENIN    A    N     AK N SLOPE  N    A
AK ALEUTIAN A    N     AK WESTERN  N    A     AK INT BSN  B    A
AK S INT    N    N     AK SO COAST A    N     AK PNHDL    A    B

                           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.

$$