Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 652 PM EST Fri Feb 10 2023 Valid 12Z Tue Feb 14 2023 - 12Z Sat Feb 18 2023 ...High winds may affect the Alaska Peninsula/Kodiak Island/Kenai Peninsula into Monday and the Aleutians Monday-Tuesday... ...Much below normal temperatures expected through Tuesday for the western Mainland... ...Overview... Gulf of Alaska energy and a surface low could cause lingering precipitation across the Panhandle as well as possibly high winds around the Alaska Peninsula/Kodiak Island/Cook Inlet with northwesterly flow. Meanwhile a persistent closed low is forecast to be near the Bering Strait around Monday-Wednesday while another notable closed low tracks across the northern Pacific. These features will likely merge into a single trough by Wednesday and create much below average temperatures for western Alaska, and could produce potentially strong low pressure at the surface, which could affect parts of Alaska with high winds and precipitation. This appears most likely for the Aleutians but it is becoming more likely for the southern coast as well, dependent on the eventual storm track. Yet another surface/upper low over the Bering Sea later next week could also produce a round of winds and precipitation for the Aleutians and perhaps beyond. ...Model Guidance/Predictability Assessment... The large scale pattern is handled fairly well initially amongst the global models with an upper low centered near the Bering Strait and another bout of energy and low pressure weakening across the Gulf of Alaska. There is good clustering in the lower and mid-level lows with the south of the western Aleutians in the northern Pacific on Monday. There has been divergence with this feature by midweek of late and that has persisted with the latest guidance. The consensus keeps the low tracking south across the Aleutians and into the Gulf. Farther upstream, an upper low looks to develop near the Kamchatka Peninsula along with a potentially large and strong surface low. The guidance continues to differ on how far east it will track thus increasing forecast uncertainty for the mid-to-late periods. Regardless energies rounding the low on the southern/eastern side, as well as frontal systems, could affect Alaska, especially the Aleutians. But the details will have to be ironed out in future forecasts. The WPC preferred blend was a compromise of the 12Z ECMWF/CMC/GFS and 00Z EC ensemble mean, with increasing weighting of the means during the mid and later periods. ...Weather/Hazard Highlights... Most of the active weather will focus over the Aleutians, the southern coast and the Southeast along the expected storm track. Pacific moisture will be directed onshore across the southern Mainland and into the Panhandle as a surface low enters and remains over the Gulf of Alaska.The low is expected to gradually weaken across the northern Gulf beyond Monday and the precipitation associated with it will lessen as well and the possibility for strong northwesterly gap winds over portions of the Alaska Peninsula/Kodiak Island/Kenai Peninsula across the Cook Inlet on the backside of the low are forecast to die down too. Light snow chances across the central mainland are forecast to decrease as well. The weather will become more active by midweek for the south-central and southeast portion of the state as an upper troughing and surface low pressure tracking eastward likely through the northern Pacific. The specifics with this system remains a bit uncertain given the model difference and the amounts and location will be dependent on where it tracks. This system will usher in another round of precipitation for southern Alaska with snow possible for inland locations along with enhanced winds in the Aleutians. Additionally, another round of precipitation and winds are likely to affect the Aleutians as a frontal system stemming from a Bering Sea low comes in, which could spread farther east by the latter half of the week. The upper trough developing over the western/southern mainland will lead to below normal temperatures for the first half of the week. The greatest anomalies look to stay in the southwestern mainland, where temperatures are forecast to be below normal by 20-30F and perhaps locally lower, while eastern parts of the mainland have a mix of above and below average temperatures. Temperatures should moderate closer to normal across western Alaska by Thursday-Friday. Campbell/Tate Hazards: - High winds across portions of mainland Alaska, Mon, Feb 13. - High winds across portions of the Aleutians, Mon-Tue, Feb 13-Feb 14. - Much below normal temperatures across portions of mainland Alaska, Mon-Tue, Feb 13-Feb 14. Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook 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