textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

- Flood Warnings and Advisories remain in effect across Susitna Valley. Most rivers have, or are currently cresting, and are expected to fall over the next several days.

- Labor Day Weekend: Mild with a chance of light rain Sunday and Monday afternoons for western portions of Southcentral. Localized breezy areas in the afternoon and evening.

Discussion:

This mornings water vapor imagery shows a broad ridge stationed over the Gulf with a shortwave trough moving through interior Alaska and another shortwave lifting towards Nunivak Island and the Southwest coast. Several more shortwaves can be picked out rotating around the large low spinning over the Bering Sea. A nice fetch of tropical moisture is being drawn up between the Gulf ridge and the Bering low...funneling towards the eastern Aleutians, AKPen, and Bristol Bay. A shortwave trough is starting to organize near Unalaska and will be the next system to lift north towards Nunivak Island through early afternoon. Widespread rain will move into Bristol Bay then along the southern Alaska Range, spilling over into the Susitna Valley by this evening. Models still have some disagreement with the exact position of the rain axis. The NAM moves the rain in slightly faster with rain moves in further east. The GFS is a bit slower and keeps the main precip axis along and just west of the Alaska Range due to having the trough digging deeper over the AKPen on Monday. Light rain will spread into the Susitna Valley Monday night into Tuesday as this next trough lifts north. Most of the rivers have crested as of this morning, but could tick back up with additional rainfall.

In addition to the light rain, there will be some areas that will experience breezy conditions as each of these shortwaves moves through the region. While the Copper Basin should remain generally dry the next few days, the northern part of the basin could see some scattered light rain showers work in from the west tonight and again Monday night. The southern half of the Basin should see some of the cloud cover scour out today. Bufkit model soundings do indicate more of a inverted-V sounding profile late this afternoon resulting in dryer low levels and breezy south winds.

- PP

AVIATION

PANC...VFR conditions will persist through the TAF period with high clouds preventing fog formation this morning. Winds will remain light and variable, with a southerly component at times, today and less then 10 kts. Winds turn southeasterly this evening but remain at 10 kts or less. The best chance for a few southeast gusts to work in over the terminal looks to be tonight into Monday morning. The core of strongest southeast winds and gusts will remain over Turnagain Arm.