Weekend Forecast: Retrograde

Posted at 8:36 AM on September 9, 2009 by Paul Huttner (2 Comments)

European model shows upper low has moved back west into Montana late Saturday.

Here's a geeky weather term to throw out at cocktail parties this weekend. Retrograde.

That's what happens when weather systems move backwards in the atmosphere. In this case the system in question is a cut-off low that will move toward Minnesota Friday. The latest model runs then retrograde the system back to the west into Montana on Saturday.

Retrograding systems can be a forecaster's worst nightmare. Forecast models have a tough time accurately resolving the movement of these erratic systems. The computer models want to make nice and just keep things moving along in the flow. Retrograding systems throw a monkey wrench into that notion.

The resulting forecast differences can be striking. Will it be 65 and showery this weekend, or mostly sunny hazy humid and 75 to 80? You'll see a lot of local forecasters "splitting the difference" the next two days.

Here's the bottom line for you weekend forecast. If this system retrogrades all the way back into Montana Saturday we'll see a nice weekend here. I'm leaning toward that solution right now. We may get a shot of showers Friday evening as the cut-off approaches, and then look for more sun and warmer temperatures Saturday into Sunday. Showers may return Monday into Tuesday as the system wobbles back our way.

So here's my weather limb for this weekend.

Wednesday: A few scattered showers. High 77.
Thursday: Mostly dry and warmer. High 81.
Friday: Chance of showers late, especially west of the metro. High 80.
Saturday: Partly cloudy. High near 75 to 80.
Sunday: Mixed sun and clouds. High 75 to 80.

Stay tuned. This forecast may change yet again!

PH

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Comments (2)

Oh I do hope your predictions are right! I had accepted the fact that I would have a rainy wedding on Saturday, but the potential for a sunny day would be icing on a really tasty cake! Thanks Paul! you made my day.

p.s. love the blog

Posted by Jeanette | September 9, 2009 10:18 AM

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Thanks Jeanette:

And, congratulations! Remember, even a little rain on your wedding day is good luck.

It still looks pretty good though for that "icing on the cake." There is even a shot at 80 degrees this weekend.

PH

Posted by Paul Huttner | September 9, 2009 1:58 PM

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