Windy low-pressure fronts hightailing it out of here

By Jenny Neyman

Redoubt Reporter

Anyone wishing for a reprieve from recent windstorms and a return to more normal winter weather on the Kenai Peninsula may just get that wish for Christmas.

According to Dave Stricklan, a hydro-meteorological technician with the National Weather Service’s Anchorage Forecast Office, Southcentral is in line for one more low-pressure system to blow through early this week — though nowhere near as severe as recent storms to hit the area in November and December — before the pattern is expected to change.

“By Thursday we’re going to start seeing the highs in 20s and lows in the teens, more normal temps compared to the 30s we’ve been seeing. It’s going to be kind of a gradual change. It’s not going to be a big, all-of-a-sudden huge cold air in behind it, like we see a lot of times,” Stricklan said. “You guys should be done with the winds for a little while.”

Southcentral has been pummeled by winter storms with high winds recently, resulting in widespread power outages and dangerous driving conditions. Anchorage has clocked extreme gusts of up to 105 mph. On the peninsula, winds have been less intense, though record keeping isn’t as thorough here as in Anchorage, so it’s possible winds have been stronger than official records let on.

Still, Stricklan said that the Kenai Municipal Airport recorded a gust of 51 mph Dec. 18. Also on Dec. 18, a gust of 51 mph was recorded in Seldovia, and 47 mph in Nikiski. On Dec. 10 and 11, Homer recoded wind speeds of 41 mph, and winds were whipping at 38 mph in Nikiski and 44 mph in Seldovia. On Dec. 4, winds were recorded at 41 mph in Nikiski and in the 30s at other stations on the peninsula.

The windy weather has been caused by an interaction between low-pressure systems swirling in from the North Pacific meeting a high-pressure ridge centered over western Canada.

“The long wave pattern just hasn’t changed a whole lot, so we keep getting these storms that track right in, all the way down from the north Pacific, and they intensify as they move north. It seems like most of them track straight up from the Bristol Bay area and head north, and that creates those east, southeast winds that we get here,” Stricklan said.

The low-pressure systems have been fairly deep, from the 950 to 970 millibars, Stricklan said. But it isn’t the depth of the air pressure that really causes the wind so much as it is the interaction between the low-pressure front and the high-pressure front to the east.

“Normally, lows in the 980s or 990s usually don’t cause a whole lot of extreme winds. A lot of it kind of depends on the high-pressure ridge that you’ve got sitting somewhere else. If you’ve got a really strong high, even a weak low can be a little more windy. Basically, it’s the pressure gradient that you’re worried about, it’s really not the strength of the low,” he said.

This cycle of lows blowing in from the west and meeting the high to the east over western Canada has been holding for about a month now, and finally is looking like it’s about to change.

“That’s normal,” Stricklan said. “We see that a lot — a couple weeks then we slide into the next pattern for a couple weeks.”

In this case, the change will mean sliding into cooler temperatures. The low-pressure fronts coming in from the North Pacific were bringing warm, Chinook winds up from the West Coast, bumping temperatures in Southcentral above freezing at times and causing precipitation in the form of rain, rather than snow.

The chance of precipitation is expected to decrease along with temperatures through the weekend. That means Southcentral may not get fresh snow on Christmas, but the white stuff already on the ground is likely to stay there.

Advertisements

Leave a comment

Filed under weather

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s