Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
601 FXAK68 PAFC 100106 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 506 PM AKDT Sun Jun 9 2024 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)... The broad longwave trough over the western Gulf of Alaska continues to linger and send waves of precipitation over the gulf coastline due to persistent southeasterly flow. A Flood Watch is still in effect for Kodiak Island through late tonight, with precipitation rates decreasing as the evening goes on. Gap winds for the Turnagain Arm and Knik River Valley are still ongoing, but should start to dwindle down by tomorrow morning. By late afternoon on Monday, the alignment of the longwave trough will result in the flow both out of the surface and aloft to shift to more of an easterly direction. In addition, weak ridging over the interior will help support the movement of multiple easterly waves of showers over Southcentral through the remainder of the forecast period. This pattern shift will also result in more widespread cloud cover, causing high temperatures for most locations to drop below 60 on Tuesday and Wednesday. The trough over the gulf will slowly move southward towards the North Pacific by Wednesday afternoon and slowly weaken as it does so. As a result, precipitation chances over the Gulf coast will slowly diminish over time, with higher chances occurring over mainland Southcentral and persisting into the latter portions of the week. -BS && SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA AND THE ALEUTIANS (Days 1 through 3)... Areas of persistent cloud cover and shower activity knocked high temperatures down several degrees across Southwest Alaska on Sunday. Expected highs well into the 60s only managed to warm into the mid/upper 50s for many areas. A broad but strong area of low pressure remains southeast of the Alaska Peninsula, and has maintained a tightened pressure gradient over the Greater Bristol Bay region. This has promoted elevated winds and showery conditions through much of the day across Southwest Alaska. Easterly winds gusting anywhere from 25 to as high as 45 mph have been observed from Iliamna to King Salmon to Dillingham. These winds will gradually diminish tonight, but are expected to briefly redevelop Monday afternoon to a lesser extent as the pressure gradient finally relaxes Monday night. Though mostly stationary, the low southeast of the Alaska Peninsula begins to weaken ever so slightly the next couple of days. Monday should see slightly warmer temperatures across Southwest Alaska, mainly due to less cloud cover and shower activity. Precipitation chances and slightly cooler temperatures return on Tuesday with the arrival of an easterly wave out of interior Alaska. While models are not in good agreement with placement of the wave nor placement of precipitation, rain looks most likely to occur at this time across the Lower Kuskokwim Valley and Greater Bristol Bay regions. Additional easterly waves will be possible into Wednesday along with subsequent shower activity as low pressure southeast of the Alaska Peninsula finally shifts eastward into the southern Gulf of Alaska. Lastly, weak northerly flow is forecast to prevail over the Bering Monday into Tuesday. High pressure begins to slide into the Bering from the west on Wednesday with drier conditions forecast. -BL && .LONG TERM FORECAST (Days 4 through 7) Thursday through Sunday... The Arctic upper level high continues to build over Mainland Alaska and ridges into the Bering through the forecast period. A portion of a North Pacific ridge extends towards the Alaska Peninsula, and looks to merge with the Mainland ridge through the period. In the Gulf of Alaska/North Pacific, the closed low weakens and slips into the Canadian coastal waters for Sunday. Out West, a Chukotsk upper low swings into the Russian Arctic, but a North Pacific low moves over the Aleutians to fill in. Several shortwave troughs rotate throughout the pattern through the weekend. The Interior ridge should warm and dry much of the Central portions of the state. Showers are expected along the North Gulf Coast for the last parts of the workweek. Most of the Aleutians and Bering should see periods of light rain through the weekend. The model ensemble means hold good confidence through the first half of the forecast, but become diffuse towards the ends as models move into different strengths and tracks. - Kutz && .AVIATION... PANC...Strong southeast winds out of the Turnagain Arm are likely to continue through the evening before abating overnight. Otherwise VFR conditions prevail. && $$