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. 
 
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