Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
948 FXAK68 PAFC 151303 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 503 AM AKDT Sat Jun 15 2024 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Saturday through Monday)... The weather pattern is little changed from yesterday over Southcentral with an unstable airmass and northeasterly flow aloft. Some small differences revolve around temperatures and dewpoints being quite a bit higher than yesterday morning which may help initiate convection a little sooner today as well as help areas not just over mountains to see showers and thunderstorms as the day progresses. Aerial coverage of storms should be greater today with thunderstorms expected to develop over the Kenai Peninsula northward to the Susitna Valley as well as over the Matanuska Valley and Copper River Basin. Closer to Anchorage, there will probably be some thunderstorms over the Chugach Mountains this afternoon and evening with a chance for one to drift over the Anchorage bowl due to the northeasterly flow aloft. One additional caveat that may influence the thunderstorm development is that some models are showing a very weak wave at 500 mb moving westward across the central Chugach mountains this evening and over the Susitna Valley overnight. Normally such a weak wave would not be worth mentioning, but in an unstable atmosphere, there is a chance it helps to produce a more organized line of thunderstorms this evening which last past midnight as the propagate westward. This will be something to keep an eye on this evening. The northerly surface flow is also less than yesterday as the trough along the northern Gulf coast weakens. This will allow the seabreeze to develop again in Seward and Valdez and keep temperatures in those areas lower than yesterday. Sunday and Monday will both be rather similar to today, except that the are of most likely shower and thunderstorm development will shift farther west each day. Temperatures will also start to cool a little on Monday, but still remain near or above normal. && .SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3)... Mostly dry conditions with areas of fog likely along the Southwest coast. Upper level support increases potential for convective activity today and Sunday afternoon, expected to produce some wet thunderstorms along the Western Alaska Range. Potential for some isolated wet thunderstorms to develop further west into the lower Kuskokwim Valley and south over Bristol Bay by Sunday afternoon. The front sitting over the Central/Eastern Aleutians will continue to bring rounds of rain showers and small craft winds to the Western/Central Aleutians and will weaken through this weekend. && .LONG TERM FORECAST (Days 4 through 7) Monday through Thursday... A very active pattern on the Alaska Weather map as an upper level Arctic low spreads its influence across the North Slope into Interior Alaska through Thursday. A ridge remains across the Southern Interior, being squeezed between the Arctic low and a broad low stretching across the Aleutians and Gulf of Alaska through the period. This ridge is sufficient enough to support thermal surface troughs and raises the chances for convective activity. A number of weak perturbations are expected to slide through the pattern across the Southern portions of the state throughout the forecast. Most of the concentrated weather remains in the North Pacific to the South of the Aleutians and Alaska Peninsula. Showers and locally breezy conditions begin in the Central and Eastern Aleutians and the Bering up to the Pribilofs beginning Monday. Winds taper off late Monday. Showers will occur across the Southcentral Interior for late Monday. The Aleutians front continues its Eastward push over the Alaska Peninsula and Kodiak Island before spreading more rain over Southcentral, Prince William Sound and the Copper River Valley through midweek. Showers linger behind the front over the Aleutians and Bering. Temperatures range from the 40s across the Aleutians warming across the Mainland into the 70s and possible low 80s over the Eastern Interior through the period. Thunderstorms are possible over most of the Eastern inland areas. - Kutz && .AVIATION... PANC... VFR conditions are expected through tomorrow. Showers are likely to develop around the area by late afternoon though the evening with an isolated thunderstorm possible during the evening hours as well. && $$