Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 615 PM EDT Sun Jul 4 2021 Valid 12Z Thu Jul 8 2021 - 12Z Mon Jul 12 2021 ...Overview and Guidance/Predictability Evaluation... A rather amplified and slow moving pattern is expected to exist across the Alaska domain for the medium range forecast period. A deep upper level trough with embedded closed low should remain anchored in place across southern portions of the state for the end of the week, and then the core of the upper low should gradually settle south over the northern Gulf by next weekend while the polar vortex remains strong over the Arctic and this will support a frontal boundary near the Arctic Coast. A narrow upper ridge axis may try to build in between these two features across portions of the Interior for next weekend and into next Monday. The deterministic models and the ensemble means are in generally above average agreement on the synoptic scale pattern through most of the forecast period, with some timing differences on some of the individual shortwaves pivoting around the main upper level gyre over the Alaska Peninsula and northern Gulf. The extent of the upper level ridging over north-central Alaska is a bit less certain. In terms of model preferences, the WPC forecast was primarily derived from a deterministic model blend through Friday, and then more of the ensemble means for next weekend and Monday. Some previous WPC continuity was also maintained through day 7. ...Weather/Threats Highlights... Given the broad upper low/trough in place, increased cloud cover and widespread showers will tend to keep temperatures below average across most of the state through Saturday, with the greatest anomalies likely for south-central Alaska with highs running up to 20 degrees below normal. Readings should slowly return closer to average by the end of the forecast period. Another thing to monitor is the prospect for moderate to heavy rainfall from the Alaska Peninsula to western portions of the southeast Panhandle, where 1-3 inches of rain will be possible to close out the week across the favored windward terrain. Showers are also expected to be scattered during the afternoon hours across portions of the Interior as well. Gusty winds can also be expected for southern coastal regions with the unsettled weather pattern in place across the northern Gulf region. Hamrick Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html