Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
766 FXAK02 KWNH 272137 PMDAK Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 537 PM EDT Thu Mar 27 2025 Valid 12Z Mon 31 Mar 2025 - 12Z Fri 04 Apr 2025 ...North Slope high wind and blowing snow threat Sunday into Tuesday, with snowy flow from western Alaska to the Interior... ...Guidance/Predictability Assessment... The 12 UTC cycle guidance solutions show reasonable agreement in and near Alaska. A GFS/ECMWF/UKMET/Canadian model blend again serves as a solid and detailed forecast basis early on, before some 12z NAEFS and 00z/12z ECWMF ensemble mean was used late in the forecast period. ...Weather/Hazards Highlights... An amplified upper trough with rotating surface lows will encompass portions of the Gulf of Alaska and northeast Pacific this weekend into mid next week as preceding ridging near the Arctic Circle becomes too long in wavelength, forcing a split mid- ridge not far from the International Dateline. Most rainfall will hold offshore, but light to terrain enhanced moderate activity will wrap into southern/southeastern Alaska. Expect enhanced gap flow on the backside of these lows from the eastern Aleutians and the Alaska Peninsula to the Gulf of Alaska, with the highest winds near the usual spots downwind of the AK Peninsula and close to Kodiak Island, where gusts above 50 kts/58 mph are expected on April 1-2. Meanwhile, a strong upper ridge over the Aleutians and Bering Sea will hold into the weekend. Modest upper troughing to the lee of the ridge in the Interior may support some local snow. Upstream, a dynamic upper trough set to exit eastern Asia and developing surface low/frontal system will lift robustly northeastward on the western periphery of the aforementioned upper ridge and then slam through the northern portion of ridge to impact western through northern and Interior Alaska into early next week. When combined with a surface high near the Aleutians which could approach record strength for April, a high wind and blowing snow threat is slated later Sunday into Monday/Tuesday across Northwest Alaska and the North Slope. Flow underneath the feature into western Alaska and the Interior is expected to support periods with organized moderate to locally terrain enhanced snows/winds, with gusts above 50 kts/58 mph expected on March 30-31. Roth/Schichtel 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 $$