Large extra-tropical storm affecting majority of state
Light rain and windy conditions have already been evident across a large portion of Southcentral and will only increase in the coming hours. Typically storms of this nature would at least bring some snow to Southcentral, but warmer than normal temperatures have led to all rain. The only areas seeing snow are higher elevations of the Chugach Mountains and areas north of Talkeetna. It's this area where a winter weather advisory remains in place through Sunday morning.
Rain has primarily come to an end for a large portion of the region outside of a few spot showers, with the parent low still swirling over the Aleutians. The reach of this storm is impressive, as it is impacting not only Southcentral, but 740 miles to the north in Utqiagvik. More than half of the state is under some form of a weather alert, with most of them coming in the form of a winter weather advisory or winter storm warning.
As the storm continues to devolve and fall apart it will do so by spreading an immense amount of energy across the state. Here in Southcentral we will see it through three different storm impacts. Those being strong winds, heavy rain and the potential for flooding.
Impact 1: Wind
Winds have already been on the breezy side today, but expect them to increase through the night and into Sunday. We'll really see an uptick in winds by Sunday afternoon as a warm front pushes through Southcentral. It's here where wind gusts will exceed 30 to 40 mph through most of the day. A high wind warning is in effect for Anchorage through 4a.m. Monday because of this. Maximum wind gusts in the Anchorage Bowl will top out near 40 mph, with lower Hillside seeing wind gusts up to 50 mph. The highest winds will be reserved for Upper Hillside and Turnagain Arm, where wind gusts will likely top out near hurricane force. Because of this there is a high potential for flying debris, power outages, and downed trees. These winds are a direct result of the large storm as it continues to weaken.
Impact 2: Heavy Rain
This storm has a significant supply of moisture to work with, as it continues to pull in plenty of moisture from the mid-latitudes. It's one reason why not only are we continuing to see warm temperatures, but why rain will be heavy at times. Because of the tropical nature of this system there will be plenty of moisture that will fall across the state as either rain or snow. The heaviest rain for Southcentral will come as a warm front pushes inland. It's here where the winds will increase as well. The heaviest rain looks to remain confined to coastal regions of Southcentral. This being Kodiak Island, the western side of Cook Inlet, Eastern side of the Kenai, and Western Prince William Sound. Many other areas will see rain, but not as heavy due to rain shadowing of the mountains. Typical storms of this nature would limit rainfall for us, but because of the amount of moisture available it will be hard not to see rain showers through the day. The good news for the Anchorage Bowl is that we'll see rain, but it will likely amount to less than half an inch through Monday.
Impact 3: Potential Flooding
With coastal areas seeing in excess of 5 inches of rain over a 24-36 hour period, flooding and mudslides will be a huge concern. This will likely only impact Seward and Kodiak Island. Be mindful that most of the flooding we'll see will come in the form of rising streams and rivers. On top of the potential flooding, the strong winds will help lead to toppled trees and mudslides in these areas. While it's hard to determine if it will happen, the ingredients are there and extra caution is needed.
Elsewhere across the state, southeast will remain dry and partly cloudy as high pressure remains in control. The interior, slope, and western Alaska will continue to see the impacts of this system in the form of wintry weather and rain showers.
If you have any photos send them to us on Facebook or through our KTVA Weather App!
-Meteorologist Aaron Morrison