Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 717 PM EDT Wed Apr 9 2025 Valid 12Z Sun 13 Apr 2025 - 12Z Thu 17 Apr 2025 ...Gulf low pressure could lead to heavy precipitation and gusty winds for southern portions of Alaska this weekend/early next week... ...Overview... Guidance remains pretty consistent in showing a mean upper low moving from the Bering Sea into the Gulf this weekend. This supports surface low pressure in/around the Gulf region Sunday- Tuesday, eventually weakening as it lifts northward into the southern Mainland. Mean moist southerly flow near and east of the low will continue to bring locally heavy precipitation to southern portions of the state over the weekend into Monday. Northerly to northwesterly winds and gap winds on the backside of the low may be brisk behind this low over the weekend. Another shortwave will shift through the Aleutians around Tuesday next week, with a decently strong surface low lifting northward into the central Gulf by mid next week. ...Guidance/Predictability Assessment... Model guidance is in fairly good agreement on the overall upper pattern, but with plenty of uncertainty in the timing of systems and details. There is better agreement on the positioning of the upper low over the Bering into the Gulf this weekend, and the eventual weakening of this low/system early next week. Some uncertainty still in the details which would have implications on both precipitation amounts and winds. There is some timing uncertainty next week with the next shortwave crossing the eastern Aleutians on Tuesday and then exact placement of the surface low into the Gulf. Regardless, there is good agreement on this evolution and the presence of a fairly deep low in the Gulf next week. The WPC forecast for today used a blend of the deterministic guidance Days 4-6. For Days 7 and 8, incorporated some ensemble means to account for the increased late period uncertainty, but still maintained 60 percent deterministic guidance for increased detail where appropriate. ...Weather/Hazards Highlights... Precipitation should be ongoing by the weekend as surface low pressure consolidates in/near the Gulf. This provides support for more precipitation, with moderate to locally heavy amounts becoming more likely from the Kenai Peninsula into Southeast Alaska for the weekend into early next week. Some precipitation could reach into the Southwest part of the Mainland as well. Northerly to northwesterly winds on the backside of the low could be brisk to strong across much of this same region for the weekend and into early next week. The upper low moving from the Bering Sea to the Gulf should support below normal temperatures over the western part of the state, with warmer temperatures filtering in across eastern/central parts of the state underneath upper ridging. Forecast highs in the Interior should generally be in the 40s to low 50s by Sunday and beyond. Santorelli 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