Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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FXUS06 KWBC 281918
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 28 2026
6-10 DAY OUTLOOK FOR OCT 04 - 08 2026
The 0Z ECMWF, GEFS, and Canadian ensemble model forecasts predict a variable
500-hPa height pattern over the North America region during the 6-10 day
period. Early in the forecast period, all ensemble means predict an amplified
trough over the Bering Sea and a second trough to the northeast of Hawaii and
west of the contiguous United States (CONUS) over the northeastern Pacific. As
the period progresses, the trough over the Bering Sea progresses southeastward
into the North Pacific, replacing the trough over this region at the start of
the 6-10 day period. A ridge and positive 500-hPa height anomalies are
predicted over western Canada and the western CONUS throughout the 6-10 day
period. However, this ridge amplifies during the period as the trough to the
west extends southward. Amplified positive 500-hPa height anomalies over the
southeastern CONUS deamplify during the period as a trough and associated
negative 500-hPa height anomalies over eastern Canada push southward into the
eastern CONUS, particularly in the ECMWF and GEFS ensembles. 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.
Above normal temperatures are favored for the western Aleutian Islands, under
ridging during the period. Below normal temperatures are favored for
northwestern Mainland Alaska, under a trough and consistent with most model
temperature tools. Above normal temperatures are favored for southeastern
Mainland Alaska and likely for Southeast Alaska, under southerly flow ahead of
the predicted trough. There are high probabilities favoring above normal
temperatures for the western CONUS, under the predicted ridge. Probabilities
exceed 80 percent over a large area, under the amplifying ridge. Above normal
temperatures are also favored for much of the Southeast, under positive 500-hPa
height anomalies early in the period. Below normal temperatures are slightly
favored for the Big Bend area and parts of central Texas, consistent with most
dynamical model temperature tools and the consolidation of calibrated ECMWF and
GEFS forecasts. Below normal temperatures are favored for parts of the
Northeast, as a trough pushed southward over the region in the 6-10 day period.
Below normal temperatures are slightly favored for the far northwestern
Hawaiian Islands, while above normal temperatures are favored for the
southeastern Hawaiian Islands, consistent with an automated blend of
temperature tools.
Above normal precipitation is favored for most of the Aleutian Islands,
consistent with the consolidation of calibrated ECMWF and GEFS precipitation
forecasts. Above normal precipitation is favored for southeastern Mainland
Alaska and Southeast Alaska, under southerly flow ahead of the predicted
trough. High probabilities of below normal precipitation are forecast for the
northwestern and northern central CONUS, under the predicted ridge. Near normal
precipitation is favored for the Southwest, consistent with the precipitation
anomaly forecast from the consolidation. Above normal precipitation is likely
for most of Texas, the southeastern CONUS, and the Eastern Seaboard, consistent
with most precipitation forecast tools. Probabilities exceed 60 percent for
above normal precipitation for much of the Gulf Coast and Southeast, where
predicted precipitation anomalies are greatest in the consolidation. Near
normal precipitation is favored for Hawaii, where precipitation tools are
inconsistent or indicate weak signals.
The official 6-10 day 500-hPa height blend consists of 30% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 45% 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: About average, 3 out of 5, due to
general agreement between model forecasts of the large-scale mid-level height
pattern, temperatures, and precipitation, offset by model differences related
to an evolving forecast pattern.
8-14 DAY OUTLOOK FOR OCT 06 - 12 2026
The 0Z ECMWF, GEFS, and Canadian ensemble model forecasts remain relatively
consistent through most of the 6-10 day period before diverging in week 2. The
manual height blend for week 2 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 predicted 500-hPa height pattern in the manual blend
for the 8-14 day period is similar to the predicted pattern for the 6-10 day
period with some evolution of the pattern. Compared to the Canadian ensemble
mean, the ECMWF and GEFS ensemble means predict a greater amplitude trough and
negative 500-hPa height anomalies extending from the Bering Sea southward into
the North Pacific, to the north of Hawaii. All models predict a ridge and
positive 500-hPa height anomalies over the western and central CONUS in week 2.
The GEFS and ECMWF ensemble means and the manual blend predict negative 500-hPa
height anomalies over the northeastern CONUS and weak anomalies over the
southeastern CONUS, while the Canadian ensemble forecast positive 500-hPa
height anomalies over the southeastern CONUS in week 2.
Above normal temperatures are favored for the far western Aleutian Islands,
under predicted positive 500-hPa height anomalies. Below normal temperatures
are slightly favored for a small area of the far northwestern Mainland Alaska
coast, consistent with ECMWF model forecasts and the consolidation. Above
normal temperatures are favored for southern and eastern Mainland Alaska and
Southeast Alaska, under southerly flow ahead of the predicted trough. The
likelihood of above normal temperatures remains high for the western CONUS in
week 2, under a persistent ridge. Below normal temperatures are slightly
favored for much of southeastern Texas, consistent with an automated blend of
temperature tools. Below normal temperatures are slightly favored across a
large area of the northeastern CONUS, under a predicted trough through much of
the period. Above normal temperatures are favored for the Florida Peninsula,
consistent with nearly all dynamical model precipitation tools. Above normal
temperatures are favored across most of the Hawaiian Islands except for Kauai,
consistent with ECMWF model temperature forecasts and supported by positive sea
surface temperature anomalies in the vicinity.
Above normal precipitation is slightly favored across the Aleutians in week 2,
consistent with the precipitation consolidation. Under southerly flow ahead of
the predicted trough, above normal precipitation is favored for southern
Mainland Alaska, eastern interior Alaska, and Southeast Alaska. As the ridge
persists over the western CONUS, below normal precipitation is favored across
the northwestern and northern central CONUS extending eastward across most of
the Midwest into far western New York and Pennsylvania. Above normal
precipitation is favored across much of the southern tier of the CONUS in week
2, including parts of the Southwest, the Rio Grande Valley, the Gulf Coast, and
the Southeast, consistent with the precipitation consolidation anomaly
forecast. Probabilities exceed 50 percent for parts of the Southeast, where
precipitation signals are greatest. Near normal precipitation is favored for
Hawaii, consistent with a consensus of calibrated precipitation forecasts.
The official 8-14 day 500-hPa height blend consists of: 30% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 45% 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: About average, 3 out of 5, due to
general agreement between model forecasts of the large-scale mid-level height
pattern, temperatures, and precipitation, offset by increasing model
differences related to an evolving forecast pattern.
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
October 15.
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:
20230927 - 20211008 - 20051012 - 20240915 - 20240927
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:
20230926 - 20051011 - 20111006 - 20211003 - 20240927
6-10 DAY OUTLOOK TABLE
Outlook for Oct 04 - 08 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A B ARIZONA A N COLORADO A B
NEW MEXICO A N N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS N B OKLAHOMA N N
N TEXAS N A S TEXAS N A W TEXAS N A
MINNESOTA N B IOWA N B MISSOURI N B
ARKANSAS N A LOUISIANA A A WISCONSIN N B
ILLINOIS N B MISSISSIPPI A A MICHIGAN N B
INDIANA N N OHIO N N KENTUCKY N A
TENNESSEE N A ALABAMA A A NEW YORK B A
VERMONT B A NEW HAMP B A MAINE B A
MASS B A CONN B A RHODE IS B 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 A
FL PNHDL A A FL PENIN A A AK N SLOPE B N
AK ALEUTIAN N N AK WESTERN N N AK INT BSN N N
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
Outlook for Oct 06 - 12 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A B ARIZONA A A COLORADO A B
NEW MEXICO A N N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA N B
N TEXAS B N S TEXAS B A W TEXAS N N
MINNESOTA A B IOWA N B MISSOURI N B
ARKANSAS N N LOUISIANA N A WISCONSIN N B
ILLINOIS N B MISSISSIPPI N A MICHIGAN B B
INDIANA B B OHIO B B KENTUCKY B N
TENNESSEE N N ALABAMA N A NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B A
MASS B N CONN B N RHODE IS B N
PENN B N NEW JERSEY B N W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN A A AK N SLOPE N N
AK ALEUTIAN N A AK WESTERN N N AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A 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.
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