Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 655 PM EDT Mon May 09 2022 Valid 12Z Fri May 13 2022 - 12Z Tue May 17 2022 ...Overview and Guidance/Predictability Assessment... The pattern across Alaska during the extended range period looks to remain rather amplified through at least next weekend with strong ridging over the Bering Sea and Aleutians and an elongated trough over the Mainland into the Gulf. A shortwave dropping south through western AK should result in an eventual closed low in the Gulf around next Sunday. After, another shortwave riding the top of the ridge and over the Alaska Peninsula should act to reinforce low pressure in the Gulf. Meanwhile, a system moving south of the Kamchatka Peninsula may finally try to push the ridge center eastward by early next week and de-amplify the flow a bit. The models show good agreement on the large scale pattern throughout the period, but offer some increasing uncertainties in the details of individual systems, especially late period. The UKMET continues to pull an upper low located well west of the Aleutians farther north than the rest of the guidance/ensembles which drags this low southward. For the first half of the period, a majority deterministic model blend (non-UKMET) was used as the basis for the WPC forecast. After this, amidst increasing detail differences, leaned more heavily on the ensemble means to help mitigate these uncertainties. Overall, the blend favored the ECMWF a little more through the period, and the GFS was not used past day 6 due to it being much farther south with a deeper upper low into the Arctic/northern Alaska. This maintains relatively good agreement with yesterdays forecast, as well as the forecast downstream across the CONUS. ...Weather and Hazard Highlights... Increased light to moderate precipitation chances are likely to organize across portions of Interior Alaska, slowly shifting southward, later this week and into next as upper disturbances and several surface fronts work across the area. Some increased precipitation may work its way into parts of the Panhandle early next week associated with less certain Gulf low pressure, but amounts don't look particularly heavy or posing any hazards. The Aleutians should be dry throughout the period as high pressure remains parked over the region and surface lows move well to the south of the area. Even though temperatures across much of the state are expected to be near to below seasonal Spring values, River flooding, significant in some places, is expected to be ongoing associated with snow melt and ice jams. 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