Tropicfreak's Central Virginia Weather Blog

Annual Winter Weather Outlook....Bang or Bust?

By: tropicfreak, 7:46 PM GMT on November 25, 2012

It feels so great to be blogging again! After an exciting hurricane season I am ready to get winter cranking! Without further ado, here is my annual winter weather outlook for 2012-2013.

Anyone remember the dreadful winter we had last year? Yeah... that is one that I would love to forget about, unless you were a fan of warm weather. So what went wrong? Why didn't we see much in the way of snow?

First off, the pattern we had all winter was rather zonal... with mainly a west to east flow, bringing little to no snow. As a result we had no blocking up in Canada, so the NAO (north atlantic oscillation) was positive. This is what a positive NAO looks like. Note that there is no high pressure in Greenland to amplify the jet stream in the eastern US, and an area of high pressure was in place in the NE, keeping us warm around here.



The cold air was locked up in Canada as well, which kept things quite toasty around here. As a result we had a +AO (positive Arctic Oscillation)



We also had a -PNA (Pacific-North American pattern), with low pressures moving through the Pacific Northwest, one of many components that keep the jet stream locked in Canada in the east and dipping in the Pacific northwest.



Now that was a nightmare setup (for snow lovers) for winter. Now here are some good news I can give you. I am not expecting that type of pattern this year. So it will be a boomer... right?

Not exactly. We have all the components falling into place, a -NAO



A -AO



BUT we don't have a +PNA setting up favorably quite yet. Yes the NAO we are setting up with favors coastal storms, and the -AO would provide below average temperatures, but in order to have these big snows, you need the jet stream amplified, and it all starts with the PNA. A positive PNA means we have a dominant area of high pressure sitting over the Pacific Northwest, keeping the jet stream confined in NW Canada.



Now... there are signs in late December into early January that the PNA could kick into positive and afterwards we are home free. But since we are in a La Nada (between El Nino and La Nina) aka neutral, the -NAO, -AO, and +PNA would be a big wild card in this case. So with that said, I am looking at varying storm tracks, though I think most of the winter weather we will see will be moving out of the west and move east offshore, but if everything sets up just right, we may see a few east coast riders that might provide some snows. It's a bit premature, but it is worth watching.

To sum it all up.

I am forecasting a wetter/a bit snowier than normal winter.
Temperatures will be slightly colder than normal.
A winter not quite like 09-10, but much better than the previous winter. I do believe we will see a typical winter around here, with a decent snow or two this season, with other minor winter weather events mixed in there as well.

Happy Winter!

Now onto the forecast. We saw our coldest air of the season. Richmond International recorded a low of 26 this morning. Here in a western suburb of Richmond I recorded a low of 24. It has been quite the frigid morning, but we have warmed up some, into the upper 40s/low 50s. I am expecting more of the same as we head into Monday as well.

Now if you have been watching, there has been some talk about a storm moving in from the west that would be in our area Tuesday. From what I can see on the models, it just doesn't appear to be materializing. The low seems to be rather disorganized and any totals we see will be very light. 850 mb temperatures (temperatures aloft) would be cold enough, but surface temperatures will hover around the upper 30s/ low 40s. Since the above freezing layer at the surface is thin, we could see a few ice pellets mix in from time to time throughout the day Tuesday, and as the temperatures nudge down slightly into the upper 30s and the layer thins up even more, we may see a few flakes mixing in at the end of it. Any pure snow should be confined to I-81 and points northward into Maryland and PA. Afterwards we should stay around normal with highs in the low 50s through the end of this week, with a potential warmup into next week. December just doesn't look to pan out well for winter and it is already beginning to show.

Have a great week!

TF

Winter Weather Snow Cold Snap Nor'Easter

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About tropicfreak

Live in Richmond VA. I'm a recent high school graduate who is looking to pursue a career in meteorology. Winter storms and the tropics fascinate me.

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