Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
033 FXAK68 PAFC 040031 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 431 PM AKDT Wed Jul 3 2024 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Tonight through Saturday)... An upper level ridge will continue to provide calmer weather for most of Southcentral through most of the day tomorrow. However, the nicer conditions over the 4th of July will quickly become unsettled as a frontal boundary sweeps over the region. Widespread rainfall is expected for most locations, however the rainfall is expected to be light due to the influence of dry westerly flow aloft. The front will pass over the Alaska Range by mid-afternoon tomorrow before exiting the region Friday afternoon. Models continue to slow down the main band of rainfall over Southcentral, with Anchorage and the Mat-Su likely not seeing any drops until the evening hours. In addition, a building pressure gradient over the Copper River Basin will likely result in gustier conditions for that portion of the forecast area starting tomorrow evening and continuing into Saturday. As the front exits off to the east on Friday, most lower elevation locations will see a break from the rain as weak ridging tries to build back over southern Alaska. Unfortunately, this break in rain won`t last long as a deep upper level trough in northwest Alaska begins to dig towards Southcentral. The placement of this trough, as well as the trough currently located in the Gulf, will result in a convergence boundary of southwesterly flow forming along the southern portion of the forecast area. This will produce a widespread and heavier rainfall event in comparison to the one expected to occur tomorrow and looks to persist through at least Saturday night. While the exact placement of this convergence band is still begin contested in current model guidance, all models are depicting a strong rainfall event to occur over the area. This pattern setup will also result in widespread cloud cover for most locations, as well as a brief cool down for the first half of the weekend. -BS && .SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3)... High pressure ridging extends over Southwest Alaska, promoting dry conditions for the rest of today. A front extending off a Kamchatka low stretches across the central Aleutians and Bering sea that will eventually feed into a shortwave dropping south into Southwest Alaska early Thursday morning. There is a decent moisture feed that will pull into Southwest, bringing widespread wetting rain showers on Thursday and Saturday. && .LONG TERM FORECAST (Days 4 through 7)... The long range models are in more agreement today with the pattern change mentioned in previous discussions. The areas of high pressure that have been persistent over the Bering Sea and the Gulf of Alaska in the early part of the period will start to break down allowing a North Pacific low to track northward into the Gulf. This combined with troughs of low pressure transiting across the Bering Sea and Kuskokwim Delta will track eastward across the region through the end of the period. As a result, expect scattered precipitation and cooler temperatures across the much of the forecast area. Additionally, gusty winds and possible small craft conditions are expected in Cook Inlet and coastal regions of the Kenai Peninsula Saturday afternoon and into Sunday. -DD .AVIATION... PANC...VFR conditions and light winds persist through tomorrow morning. Westerly winds begin shifting southerly this evening as Turnagain Arm winds strengthen ahead of an approaching front. Southerly to southeasterly winds then increase by late Thursday morning, with the potential for gusts 20-25 kt persisting through the afternoon. Light rain is expected late Thursday afternoon through Friday morning, with minor uncertainty in timing. Ceilings will drop with this rainfall, likely below 5000 ft, with some guidance even dropping ceilings to IFR. && $$