Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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FXUS06 KWBC 301909
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Wed September 30 2026
6-10 DAY OUTLOOK FOR OCT 06 - 10 2026
The 0Z ECMWF, GEFS, and Canadian ensemble model forecasts predict an amplified
but variable 500-hPa height pattern over the North America region during the
6-10 day period. All ensemble means predict an amplified trough extending from
the Alaska Peninsula into the North Pacific to the north of Hawaii at the start
of the forecast period. The trough is predicted to amplify over the North
Pacific before retrogressing across the eastern Aleutians and Bering Sea later
in the period. A ridge and positive 500-hPa height anomalies are predicted over
the western and central contiguous United States (CONUS) throughout the 6-10
day period. This ridge is predicted to amplify during the middle of the 6-10
day period by all ensemble means. An amplified trough and associated negative
500-hPa height anomalies are predicted over the northeastern CONUS at the start
of the 6-10 day period, which quickly progresses eastward into the North
Atlantic, before another trough and associated negative 500-hPa height
anomalies extend southward into the northeastern CONUS from eastern Canada
later in 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.
Above normal temperatures are slightly favored for the far western Aleutian
Islands, under ridging early in the period. Below normal temperatures are
favored for far northwestern coastal 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 most of the western CONUS and 90
percent over parts of Southern California and Nevada, under the amplified
ridge. Above normal temperatures are favored for the central and eastern Gulf
Coast and Florida, to the south of a front. Below normal temperatures are
favored for much of the northeastern CONUS, under a predicted trough over the
region. 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 the Aleutian Islands, consistent with
the consolidation of calibrated ECMWF and GEFS precipitation forecasts. Above
normal precipitation is favored for southern and eastern Mainland Alaska and
Southeast Alaska, under southerly flow ahead of the predicted trough. Elevated
probabilities of below normal precipitation are forecast for the northwestern
CONUS, across the Northern and Central Plains, and for most of the Midwest,
under the predicted ridge. Above normal precipitation is likely for central and
southern Texas and the Southeast, consistent with the consolidation anomaly
forecast. Probabilities exceed 60 percent for above normal precipitation for
the eastern Gulf Coast and northern Florida Peninsula, 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 25% of Today`s 0z 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: About average, 3 out of 5, due to
good agreement between model forecasts of the large-scale mid-level height
pattern, offset by a variable pattern during the period and differences in
temperature and precipitation tools in some areas.
8-14 DAY OUTLOOK FOR OCT 08 - 14 2026
The 8-14 day 500-hPa height forecasts from the 0Z ECMWF, GEFS, and Canadian
models remain in relatively good agreement, despite a variable pattern. 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. A negatively tilted and high
amplitude trough is predicted over the Bering Sea extending southeastward into
the North Pacific. All models predict an amplified ridge and positive 500-hPa
height anomalies over the western and central CONUS in week 2, with the
greatest positive 500-hPa height anomaly over the northern High Plains. The
manual blend predicts negative 500-hPa height anomalies over parts of the
northeastern CONUS and weak anomalies over the Gulf and Atlantic Coasts in week
2, with some variations in the extent of negative 500-hPa height anomalies
throughout the period and some differences among model forecasts.
Below normal temperatures are slightly favored for the far western Aleutian
Islands, under negative 500-hPa height anomalies and consistent with most model
tools. Below normal temperatures are slightly favored for a small area of
northwestern Mainland Alaska, consistent with ECMWF model forecasts and the
consolidation. Above normal temperatures are favored for most of 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 and northern central CONUS in week 2, under a persistent ridge.
Below normal temperatures are slightly favored for most of the northeastern
CONUS, under a predicted trough through much of the period. Above normal
temperatures are favored for the Florida Peninsula, consistent with a consensus
of dynamical model forecast tools. Above normal temperatures are favored across
most of the Hawaiian Islands except for Kauai, consistent with an automated
blend of temperature tools 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 across Mainland
Alaska and Southeast Alaska. Under a persistent ridge, below normal
precipitation is favored over most of the northwestern CONUS, excluding far
northwestern Washington. Enhanced probabilities of below normal precipitation
extend eastward across most of the Great Plains, from the Red River Valley
north, and across the Central and Upper Mississippi Valley into the Midwest.
Above normal precipitation is favored across a band of the southern tier of the
CONUS in week 2, including parts of the Southwest border with Mexico, 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: 25% of Today`s 0z 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: 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 uncertainty
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
2026-09-30.
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:
20211011 - 20051010 - 20240915 - 20230929 - 20130927
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:
20051011 - 20230928 - 20211007 - 20240928 - 20211012
6-10 DAY OUTLOOK TABLE
Outlook for Oct 06 - 10 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 A B OKLAHOMA A B
N TEXAS N N S TEXAS N A W TEXAS A N
MINNESOTA A B IOWA A B MISSOURI A B
ARKANSAS N B LOUISIANA A A WISCONSIN A B
ILLINOIS N B MISSISSIPPI N A MICHIGAN N B
INDIANA N B OHIO N B KENTUCKY N B
TENNESSEE N N ALABAMA N A NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B N
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 N A S CAROLINA N A GEORGIA N A
FL PNHDL A A FL PENIN A A AK N SLOPE N N
AK ALEUTIAN N A AK WESTERN N N AK INT BSN N A
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
Outlook for Oct 08 - 14 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 N COLORADO A B
NEW MEXICO A N N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA A B
N TEXAS N N S TEXAS N A W TEXAS A N
MINNESOTA A B IOWA A B MISSOURI A B
ARKANSAS N B LOUISIANA N A WISCONSIN A B
ILLINOIS A B MISSISSIPPI N A MICHIGAN N B
INDIANA N B OHIO N B KENTUCKY N B
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 N N
MARYLAND B N DELAWARE B A VIRGINIA N A
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN A A AK N SLOPE N A
AK ALEUTIAN N A AK WESTERN N A 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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