Alaska Extended Forecast Discussion National Weather Service College Park MD 800 PM EDT Mon Oct 27 2025 Valid 12Z Fri 31 Oct 2025 - 12Z Tue 04 Nov 2025 ...Heavy Mountain Snow and Lower-Elevation Rain Expected Late Week Along Much of the Gulf Coast... ...Synoptic Overview... A series of upper lows will impact parts of the state beginning late this week. An upper low over Bristol Bay will merge with another low south of the Alaska Peninsula on Thursday into Friday. This low will produce an occluded surface reflection that will move into the central Gulf Coast and panhandle this weekend. A shortwave trough will dive down into the Northeast Pacific late this weekend and reinforce the main low in the Gulf and expand over the mainland. ...Guidance Evaluation and Preferences... There's good agreement between the Euro, GFS and Canadian suites on the 500mb pattern through day 5. Model variance picks up considerably on day 6, with most of the uncertainty centering around the weakening upper low over the central Gulf Coast on Sunday. Models are in reasonably good agreement on a third vort max diving southeast through the western Aleutians and North Pacific on Sunday/Monday The Euro suite diverges from the GFS and Canadian suites on day 8 as it depicts a weaker, nearly zonal, trough driving south through the Aleutians, while the other models have a much deeper and less progressive cyclone propagating through the same region. A general model blend consisting of the ECMWF, GFS and CMC were used for days 4 and 5, before the Euro and Canadian ensembles were introduced for days 6-8. ...Weather/Hazards Highlights... A very deep occluded surface low (sub 955mb) will bring heavy mountain snow and strong surface winds to much of the Gulf Coast Friday through Sunday. Fortunately, the strongest winds will remain offshore, which is why a high wind hazard wasn't issued on today's final hazard's product. The precipitation, however will be significant enough to warrant a heavy precip hazard on our final issuance. QPF amounts totaling between 4-8 inches are forecast from the Alaska Peninsula down through the panhandle on Friday. Precip and winds gradually weaken through the rest of the weaken while remaining impactful until conditions finally improve early next week. Temperatures will be mostly around average except for the Alaska Peninsula where troughing aloft will keep conditions at the surface cooler than average. && Kebede 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