Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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FXUS06 KWBC 271909
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Mon July 27 2026
6-10 DAY OUTLOOK FOR AUG 02 - 06 2026
While the 0Z ECMWF, GEFS, and Canadian ensemble mean forecasts generally agree
on the average large-scale circulation pattern over North America for the 6-10
day period, models predict variations in the pattern during the period that
lead to greater uncertainty. The manual height blend is based on 0Z ECMWF,
GEFS, and Canadian model 500-hPa height forecasts, weighting the ECMWF ensemble
mean greater due to recent model skill. Models predict an amplified mid-level
ridge over Greenland, consistent with the negative phase of the North Atlantic
Oscillation (NAO). ECMWF and GEFS ensemble means predict a trough over the
southeastern contiguous United States (CONUS) at the start of the 6-10 day
period that quickly deamplifies, as positive 500-hPa height anomalies develop
over the region later in the period. A second high-latitude ridge and positive
500-hPa height anomalies are predicted over Mainland Alaska and northwestern
Canada. All models predict a ridge and positive 500-hPa height anomalies over
the North Pacific and the Aleutian Islands. Models predict a shortwave trough
over western Canada and northern areas of the Pacific Northwest that quickly
progresses eastward into central Canada and partially into the northern central
CONUS. All ensembles predict a second shortwave trough over the northeastern
Pacific to the south of Mainland Alaska at the start of the 6-10 day period,
which amplifies in the ECMWF ensemble mean solution before deamplifying in all
model solutions. A ridge and positive 500-hPa height anomalies that extend from
the southwestern CONUS to the northern central CONUS at the start of the period
retrogress westward, before amplifying near the coast of Northern California.
Positive 500-hPa height anomalies and ridging progress eastward from the Great
Lakes region into the northeastern CONUS during the period.
Above normal temperatures are favored over the central Aleutians, most of
Mainland Alaska excluding the southwest coast, and Southeast Alaska, under
positive 500-hPA height anomalies. Below to near normal temperatures are
favored for the eastern Aleutians and along the southwest coast of Mainland
Alaska, consistent with nearby negative sea surface temperature anomalies.
Expansive ridging over the western and northeastern CONUS supports likely above
normal temperatures for most of the CONUS. Near normal temperatures are favored
for parts of Washington, Oregon, the Northern Rockies, and the Northern Plains,
influenced by a predicted shortwave trough near the Canadian border. Near
normal temperatures are favored for parts of the eastern Gulf Coast northward
into the Tennessee Valley, under a predicted weak trough. Above normal
temperatures are likely for Hawaii, consistent with most model forecasts and
positive sea surface temperature anomalies in the vicinity.
Above normal precipitation is slightly favored across the Aleutians, consistent
with most model forecasts. Under a predicted ridge, below normal precipitation
is slightly favored for interior eastern Mainland Alaska. Above normal
precipitation is favored for western coast and northwestern Mainland Alaska,
consistent with the consolidation of calibrated ECMWF and GEFS precipitation
forecasts. Near normal precipitation is favored for parts of northwestern
Washington, influenced by shortwave troughing. Under the mean ridge over the
western CONUS, below normal precipitation is favored for most of the remaining
northwestern CONUS, southward into the northern Great Basin and eastward into
parts of the Northern and Central Plains. The location of the ridge over the
western CONUS supports enhanced probabilities of above normal precipitation for
parts of Southern California and the Desert Southwest. Anomaly forecasts from
the precipitation consolidation support above normal precipitation for much of
the Gulf Coast and eastern CONUS. Above normal precipitation is slightly
favored for all of the Hawaiian Islands, consistent with raw model
precipitation forecasts.
The official 6-10 day 500-hPa height blend consists of 30% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 50% of Today`s 0z European Ensemble Mean
centered on Day 8, and 20% 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 pattern,
offset by a variable pattern during the period and weak signals in
precipitation tools.
8-14 DAY OUTLOOK FOR AUG 04 - 10 2026
High-latitude ridges and associated positive 500-hPa height anomalies persist
over Mainland Alaska and Greenland in the week-2 ensemble mean forecasts from
the 0Z ECMWF, GEFS, and Canadian models. Positive 500-hPa height anomalies
persist over the Aleutians in the 8-14 day period with decreased amplitude
relative to the 6-10 day period. A shortwave trough progresses over central
Canada, with negative 500-hPa height anomalies extending into the northern
central CONUS, before deamplifying later in week 2. Early in the week-2 period,
a second shortwave trough is predicted over the Gulf of Alaska, before being
replaced by positive 500-hPa height anomalies later in the period. A ridge and
positive 500-hPa height anomalies amplify near the Pacific coast of California
during the middle of week 2, with greater amplitude in ECMWF ensemble mean
forecasts compared to the GEFS and Canadian models. Positive 500-hPa height
anomalies and ridging over the northeastern CONUS early in the period extend
southward into most of the eastern CONUS before deamplifying later in the
period.
Below normal temperatures continue to be favored for the eastern Aleutians in
week 2, consistent with negative sea surface temperature anomalies in the
region. Above normal temperatures are favored for Southeast Alaska and most of
Mainland Alaska, excluding the southwest coast, under predicted positive
500-hPa height anomalies. Under expansive ridging and positive 500-hPa height
anomalies, above normal temperatures are likely for most of the CONUS. Near
normal temperatures are favored for parts of northeastern Montana, North
Dakota, and northern Minnesota, influenced by a shortwave trough progressing
eastward along the Canadian border. Above normal temperatures are likely for
Hawaii, with positive sea surface temperature anomalies in the vicinity.
Above normal precipitation is slightly favored for parts of the central and
eastern Aleutian Islands and parts of northwestern Mainland Alaska, consistent
with the consolidation. Precipitation signals are weak or inconsistent among
model forecasts for remaining areas of Alaska, favoring near normal
precipitation. Retrogression of a ridge over the western CONUS supports below
normal precipitation for the northwestern CONUS from the Pacific Northwest to
parts of the Northern Plains extending southeastward into the Central Plains.
The westward shift of the ridge over the West and a surge of moisture from the
eastern Pacific favor above normal precipitation for much of Southern
California and the Southwest with probabilities exceeding 50 percent for parts
of the Desert Southwest. Above normal precipitation is favored for much of
Texas, western Louisiana, and the northeastern CONUS, consistent with
precipitation anomaly forecasts from the consolidation. Above normal
precipitation is slightly favored across Hawaii consistent with the
consolidation.
The official 8-14 day 500-hPa height blend consists of: 30% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 50% of Today`s 0z European Ensemble Mean
centered on Day 11, and 20% 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 changing mid-level height pattern, and differences among precipitation and
temperature tools.
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
August 20.
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:
20160721 - 20030709 - 20010707 - 20250725 - 20050720
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:
20010706 - 20030709 - 20250726 - 20230715 - 20160721
6-10 DAY OUTLOOK TABLE
Outlook for Aug 02 - 06 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N B OREGON A B NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA N B E MONTANA A B WYOMING A B
UTAH A N ARIZONA A A COLORADO A B
NEW MEXICO A N N DAKOTA A N S DAKOTA A B
NEBRASKA A B KANSAS A B 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 A WISCONSIN A N
ILLINOIS A N MISSISSIPPI N A MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE N A ALABAMA N A 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 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 A A
AK ALEUTIAN B A AK WESTERN A N AK INT BSN A B
AK S INT A N AK SO COAST A N AK PNHDL A N
8-14 DAY OUTLOOK TABLE
Outlook for Aug 04 - 10 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A N
SRN CALIF A A IDAHO A B NEVADA A A
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A A ARIZONA A A COLORADO A N
NEW MEXICO A A N DAKOTA N B S DAKOTA A B
NEBRASKA A B KANSAS A N OKLAHOMA A N
N TEXAS A A S TEXAS A A W TEXAS A N
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A A WISCONSIN A N
ILLINOIS A N MISSISSIPPI A N MICHIGAN A A
INDIANA A N OHIO A A 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 N VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B N AK WESTERN A N AK INT BSN A N
AK S INT A N AK SO COAST A N AK PNHDL A 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.
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