Epic storm out west means better weather for Southeast

The massive storm that slammed into western Alaska today (Wed Nov 9, 2011) formed in the western Pacific, and was fuelled by tropical moisture near Japan. And while the storm is not headed to Southeast Alaska, its impact is being felt here – in slightly better weather than we might have otherwise.

KCAW’s Robert Woolsey spoke with NOAA meteorologist Joel Curtis about the effects of the big storm on Southeast weather, and some of the other weather phenomena the region has been experiencing in the past few weeks.

Curtis: This thing is headed into the Chukchi Sea. It’s going to die in the Arctic.
KCAW: It’s just tearing across the northwestern coast of the state?
Curtis: Of course, what’s critical to those folks is they have very little ice to protect their shores right now. So they’re getting the full fetch of the wind waves and the swell eroding the beach.
KCAW: Even though this thing is going to have no direct effect on us in Southeast Alaska, does it have an indirect effect?
Curtis: Of course! This storm is something that you would notice on a planetary scale. If you were on a satellite way out in space and you were looking at Earth in daylight hours, you’d see that thing. And because of it, there would be certain dynamics in the atmosphere that would bring better weather to Southeast. When I got up this morning, the sky was full of stars here. So, we’re on the downstream side of a ridge.
KCAW: Western Alaska’s pain is our gain, a little bit?
Curtis: That might be one way to think of it. When I looked at the satellite a few minutes ago, I could see a system off the west coast of the US. Trough, ridge, trough – I know that’s a little bit of meteorological terminology – what it’s saying is bad weather, good weather, bad weather.
KCAW: Let’s take this storm system in Western Alaska out of the picture and look at the weather in Southeast Alaska since about Halloween. That weekend prior to Halloween, in Sitka we had some tremendous thunderstorms, and they seemed to roll on all night long. And then just a couple of days ago same thing – another series of thunderstorms all night long. It always struck me that thunder and lightning were occasional phenomena here, but we seem to have had more intense storms lately. Has that been your observation as well?
Curtis: Honestly, this is our climatological time of year that we get them. October, November, maybe even early December. The reason that we get them here is because the ocean surface temperature is still quite warm. And lags behind the cooling of the air as we get further toward the solstice. What’s happening is we’re getting some pretty good cold air at upper levels – let’s say 18,000 feet or so – and this cold air moves over that warm water. Heating from below is a good ingredient for thunderstorms.
KCAW: Is it happening with any more frequency than you might expect?
Curtis: I would have to say that this has got a normal feeling to me. I remember going waterfowl hunting at Yakutat for about a week in October a couple of years ago, and having thunder and lightning every single day I was out hunting.
KCAW: And there’s often a bit of wind and some hail that come with these storms? That’s all part of the package, I guess?
Curtis: Sure. You get updrafts and downdrafts. Let’s say we’re getting one of these systems with ice pellets. Those ice pellets are helping to cool the air, and colder air will actually sink and add to wind gusts that you get around these cells. So, clearly you would expect gusty winds, especially in the later stages of one of these cells. Let’s say it’s reached its peak, and then the thunderstorm will actually collapse. During that collapse, all the air that’s cooled off that has been rising in that thunderstorm tends to sink, and you get a bit of a downdraft, and maybe a little bit of a downburst, but they’re nothing like the downbursts you get in the central US.
KCAW: Is all of this any comfort to you when you’re sitting out in your duck blind getting drenched?
Curtis: Well, as long as the ducks are flying, that’s all that matters, right?