Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
363 FXAK68 PAFC 111255 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 455 AM AKDT Tue Jun 11 2024 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)... The low that has been lingering in the western Gulf is continuing to gradually weaken and slowly nudging its way east over the next couple days. High pressure over the northern interior of Alaska is helping to flatten the flow and allowing for most of the flow east to west. Widespread cloudiness and increasing chances for showers over the next couple days will keep the temperatures more cool and mild. Surface winds are predominately from the south to southeast and gap flows are expected to return to Turnagain Arm, Knik River, and Copper River Valley, but is not expected to be a strong as the previous few afternoons. The nature of the easterly waves and pop up showers makes this forecast more challenging to determine exactly where and how much rainfall will occur. Generally though, showers along the coast are expected to gradually lift today and spread across the Copper River Basin early. A few small, quick moving showers have developed off the foothills of the western Chugach through Sutton into the Matanuska Valley and also Anchorage and the western Kenai Peninsula. Chances will increase throughout the day and move from east to west under the prevailing flow. Models are not capturing the progression and precipitation amounts very well, but the general pattern points westward, spreading rainfall into the Susitna Valley later this afternoon. A similar set up is expected for Wednesday as well. Thursday, precipitation chances decrease and the weather will begin to trend towards a warmer and drier (and perhaps more convective) weather will continue through the later half of the week and through the weekend. rux && .SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3)... Winds have diminished overnight across Bristol Bay as the pressure gradient across Southwest Alaska weakens. Broad low pressures sits in south of the Alaska Peninsula, cycling weak shortwaves over Southwest and south towards the Eastern Aleutians. Conditions will be mostly dry, however, there will be periods of light rain showers today and tonight as well as a chance for some wet thunderstorms in western Bristol Bay and along the Western Alaska Range. High pressure builds in the over the western Bering Sea and will progress eastward over the next several days. A low developing west of the Western Aleutians will push south of the Aleutian Chain mid-to-late week, eventually stalling in the North Pacific south of Adak. This will bring rounds of rain showers and small craft winds to the Western/Central Aleutians Wednesday through the end of the week. && .LONG TERM FORECAST (Days 4 through 7) Friday through Monday... High pressure looks to continue for the interior of the state while much of the Bering Sea, North Pacific, and Gulf of Alaska will remain under the influence of low pressure. This pattern will continue to promote dry and warm weather inland with cool and showery conditions for the Gulf coast, Aleutian Chain, and Alaska Peninsula. There are still some questions in how each of these pressure cells orients themselves throughout the long-term. No one period looks to be a washout, rather there can be transient periods of drier weather between shortwaves moving through the flow along the Gulf and Aleutian Chain. While there is very general agreement with the synoptic pattern, there are plenty of disagreements with placement and track of mesoscale shortwaves embedded within the synoptic flow. && .AVIATION... PANC...Light rain is possible through the early afternoon with a passing easterly shortwave. With any rain, there is a moderate chance of ceilings below 5000 ft and a low chance for MVFR ceilings. This afternoon, gusty southeasterly Turnagain Arm winds return to the terminal, peaking in the 20 to 30 knot range as ceilings lift above 5000 ft. Winds weaken and shift out of the south with up-inlet flow in the late evening to near midnight timeframe. Rain returns on Wednesday, bringing greater chances for MVFR ceilings. Quesada && $$