NOAA 6-10 Day and 8-14 Day Outlooks: Below-Average Temperatures and Above-Average Precipitation Expected for Parts of Western US

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6-10 Day Outlook:

Below-average temperatures are expected for the Western United States with above-average precipitation for the Western and Central US. Snowfall is expected to impact much of the Pacific Northwest and parts of the Rocky Mountains by the end of the weekend into next week.

8-14 Day Outlook:

Below-average temperatures are expected to persist in the Western United States with above-average precipitation for the next 8-14 days. The Central and Eastern US are expecting near-normal to above-average temperatures and generally normal levels of precipitation. Parts of Alaska are expecting below-average temperatures and above-average precipitation during this period.

Full discussions from NOAA below: 

6-10 DAY OUTLOOK FOR OCT 24 - 28 2022 
There is good agreement in the predicted mean 500-hPa heights among the  
dynamical models during the 6-10 day period. Dynamic ensemble models agree on  
an amplified pattern across the forecast domain with strong positive 500-hPa  
height anomalies over eastern North America and the North Pacific south of the  
Aleutian Islands and anomalous troughing over western North America, eastern  
Siberia, and south of Greenland. Relative to yesterday, the negative 500-hPa  
height anomalies are weaker across the west. However, these changes do not  
substantially alter the forecast. 
The amplified mean mid-level ridge over eastern North America leads to  
increased chances for above-normal temperatures across most of the eastern  
Continental United States (CONUS). The highest probabilities are in the  
Northeast where positive 500-hPa height anomalies are the greatest. A strong  
cold front is favored to develop across the center of the country. This is  
likely to be a focus for precipitation and reduces confidence in the  
above-normal temperature chances. Thus, probabilities for above-normal  
temperatures are reduced across parts of the Great Plains and Midwest. Across  
the West, negative 500-hPa height anomalies lead to good agreement for  
below-normal temperatures across the region. With slightly weaker negative  
500-hPa height anomalies across the West, cold chances are slightly reduced  
relative to yesterday. Likewise, the eastward extent of enhanced below-normal  
odds is also reduced but is maintained through the Front Range of the Rocky  
Mountains and much of the High Plains. In Alaska, there is fair agreement among  
the temperature tools for below-normal temperature chances across much of the  
state. However, the Aleatians and Alaska Peninsula are favored to have  
above-normal temperatures closer to the mid-level ridge in the North Pacific. 
The amplified mid-level trough across the west ushers in enhanced probabilities  
for above-normal precipitation across the western CONUS. Reforecast tools are  
in good agreement for enhanced probabilities for above-normal precipitation  
across the Pacific Northwest. There is disagreement on how far south the  
enhanced chances for above-normal precipitation should extend along the Pacific  
coast. The ECMWF reforecast tools bring high probabilities down towards the Bay  
Area of California while the GEFS-based tools keep these elevated chances  
closer to the California-Oregon border. Likewise, analog tools favor dryer  
conditions in California. Therefore, strongest chances for above-normal  
precipitation are confined to Washington and Oregon with relatively lower  
chances for above-normal precipitation in Northern California. Across the  
center of the country, near the boundary between positive and negative 500-hPa  
height anomalies, chances for above-normal precipitation remain enhanced.  
Deterministic and ensemble model runs indicate chances for lee side  
cyclogenesis off the Rocky Mountains. Along with cyclogenesis, return flow from  
the Gulf of Mexico is also expected near and along the Mississippi Valley  
bringing higher chances for above-normal precipitation to these regions. Along  
the Atlantic Coast, tools are mixed for above or below-normal precipitation  
among models and between model runs. Therefore, much of the East Coast is  
favored for near-normal precipitation. In Alaska, ensemble and deterministic  
models bring a series of strong low-pressure systems to western parts of the  
state. These storm systems are likely to follow the onshore 500-hPa height  
pattern. Therefore, much of western Alaska is expected to experience  
above-normal precipitation. Relative to yesterday, eastern parts of Alaska are  
dryer and many tools lean towards below-normal precipitation. However, raw  
probabilities still lean above-normal, therefore, much of eastern Alaska is  
favored to have near-normal precipitation. 
The official 6-10 day 500-hPa height blend consists of 10% of Today's 0z GFS  
Ensemble Mean centered on Day 8, 30% of Today's 6z GFS Ensemble Mean centered  
on Day 8, 40% 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 5, due to good  
agreement on a highly amplified mean 500-hPa pattern offset by only fair  
agreement among surface forecast tools. 
8-14 DAY OUTLOOK FOR OCT 26 - NOV 01, 2022  
Dynamic tools show fair agreement for the 500-hPa height pattern during week-2.  
All tools indicate positive height anomalies centered over the Canadian  
Maritimes and south of the Aleutian Islands. There is also good agreement for  
negative 500-hPa height anomalies stretching from Siberia through Alaska and  
into the Pacific Northwest. There remains some disagreement on the southward  
extent of the negative 500-hPa height anomalies in the Pacific Northwest.  
Across the center of the country, neutral height anomalies are indicated in the  
dynamic tools. This belies a very transient pattern in this portion of the  
country during the week-2 period.  
Relative to yesterday, temperature probabilities are more muted across much of  
the CONUS. The west is slightly favored for below-normal temperatures as  
mid-level troughing is favored to bring below-normal temperatures to the  
region. However, there is significant disagreement among the dynamical tools as  
some tools are now indicating increased chances for above-normal temperatures  
in the region. This is likely due to the transient nature of the 500-hPa height  
pattern as there is more potential for weak positive 500-hPa height anomalies  
to develop. Meanwhile, above-normal temperatures are slightly favored for much  
of the eastern two thirds of the CONUS as many tools continue to support this  
solution. However, there is much less confidence relative to yesterday. In  
Alaska, below-normal temperatures are favored across much of the state as  
northerly flow from the Arctic and Siberia is expected during week-2.  
Above-normal precipitation remains favored across the Pacific Northwest as  
tools continue to promote strong onshore flow and chances for atmospheric river  
events. There remains some disagreement between reforecast tools on the  
southern extent of the precipitation but with better agreement for  
precipitation reaching parts of central and even southern California. There are  
significant differences relative to yesterday across the Plains as tools have  
trended dryer. Much of this area is now favored for below-normal precipitation  
in the reforecast tools. This is likely related to a more transient 500-hPa  
height pattern and more surface high pressure being developed in the ensemble  
tools during the period. However, due to rapid transition from yesterday much  
of the Plains is favored to have near-normal precipitation. Along the East  
Coast, tools are generally mixed on precipitation chances. There is some  
agreement between the dynamical tools and statistical guidance for an area of  
above-normal precipitation to be favored along the Southeast and Mid-Atlantic  
coast. In western Alaska, dynamical tools are dryer relative to yesterday as  
the flow pattern has turned more northerly. Therefore, precipitation  
probabilities are reduced relative to yesterday but above-normal precipitation  
is still favored for western and central parts of the state.  
The official 8-14 day 500-hPa height blend consists of: 10% of Today's 0z GFS  
Ensemble Mean centered on Day 11, 15% of Today's 6z 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: Below-Average, 2 out of 5, due to  
poor agreement between models and tools for the forecast 500-hPa height pattern  
offset slightly by relatively better agreement among the temperature and  
precipitation tools. 

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