Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 758 PM EDT Fri Apr 01 2022 Valid 12Z Tue Apr 05 2022 - 12Z Sat Apr 09 2022 ...Overview... A general pattern of upper troughing is forecast to persist through much of next week across western Alaska and the Bering Sea, with periodic reorienting and reloading. By late week, current forecasts show the southern part of the trough/energy separating and moving eastward through the Gulf of Alaska. At the surface, lows could pivot across the southern mainland while additional lows track south of the state. Likely the strongest low should track northeastward toward the Panhandle Wednesday-Thursday. This will promote a wet pattern for southern Alaska, particularly over the Panhandle, though amounts do not look to be terribly heavy. ...Guidance/Predictability Assessment... The latest model guidance continues to show fairly good clustering with the overall pattern of elongated upper troughing with its axis initially across the western mainland Tuesday and drifting slowly westward through around Thursday. Low pressure/frontal systems are forecast to pass through the Aleutians and linger over the mainland near the base of the trough. Recent models are more agreeable regarding a wave of low pressure potentially forming along the cold front crossing the Aleutians around Wednesday and tracking across the Gulf Thursday-Saturday, with the ECMWF and UKMET joining the GFS runs that have been persistent in showing the low forming by midweek. Additionally, there has been a multi-day signal for a reasonably strong low to track toward the Panhandle on Wednesday-Thursday, with only minor differences among guidance. Thus deterministic guidance seems agreeable enough for a blend of the operational models (led by the ECMWF/GFS) early in the medium range period. By late week, some model spread arises as energy from the southern part of the trough could detach and track eastward while the northern side persists over northwestern Alaska. The GFS and ECMWF runs happen to be fairly similar, but the CMC appears to be a slow outlier as the southern upper low may separate earlier/more significantly. This affects the surface low positions as well. At this point, favored the GFS and ECMWF operational runs along with the ECWMF and GEFS ensemble means for the late week forecast blend, since they were reasonably well clustered for a days 7-8 forecast. ...Weather/Hazard Highlights... Precipitation is possible over southern parts of Alaska from the Aleutians and Alaska Peninsula east into Southcentral Alaska and the Panhandle through much of next week near low pressure systems. Some rain/snow amounts could be enhanced at times especially for the Southcentral/Panhandle regions, but the heaviest totals through the period will be dependent on exact low tracks and timing. One period of precipitation enhancement could be around midweek as moist inflow increases ahead of a low headed for the Panhandle. In fact, the forecast continues to indicate southern portions of the Panhandle may receive the most precipitation overall, but as it falls over a several day period, it should not be too hazardous. Interior Alaska should see generally dry conditions as the storm track stays to the south, though scattered snow showers cannot be ruled out. Periods of gusty winds are also possible over the Gulf and Panhandle with the midweek low pressure system, and breezy northwest winds may impact the Aleutians late in the week. Near to below average high temperatures forecast for Tuesday across much of the state may ease a bit as the week progresses. The Brooks Range and the North Slope in particular could flip to above normal later in the week for highs. Meanwhile, low temperatures will generally be above normal across the mainland, with the exception of the eastern Interior earlier in the week. The Panhandle can expect to see below normal highs and around average lows through the period owing to mostly cloudy skies and wet conditions. Tate 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