Winter Forecast 2012-2013 (Part 1)
Yesterday we taped our Winter Forecast 2012-2013 and I thought I’d share some of the thoughts behind what we ended up forecasting. We’ll get more specific about the actual forecast in tomorrow’s blog and of course you can get the full report coming up TONIGHT on FOX 4 News @ 9PM
What we do during these roundtables is briefly look back through our previous forecast fro last year, go over some snow climatology, go through our reasoning about our forecasts for this coming winter and then issue our forecast individually. So I thought I’d present to you this AM the forecasting thoughts first with some explanations about them and links for what we’re talking about.
Let’s start with Michelle’s thoughts.
A couple of things here…first MT talks a bit about the warmer North Atlantic waters…this is connected to his thoughts concerning something called the AMO or the Atlantic Multidecadal Oscillation. There is interesting research that suggests that this feature plays an increasing large role in helping to change the weather across the USA. basically it’s connected to water temperature anomalies in the N Atlantic through Greenland. Right now we are in what’s called the “warm” phase of the AMO, basically meaning that the waters up there are warmer than average. You can see that using this graphic.
Notice that warm anomaly off the NE USA coast extending up through Greenland? That’s what we’re talking about. These changes affect the growth and reduction of Arctic ice…and there is some thought that this then affects the state of the Arctic Oscillation (AO).
You may remember that I blogged about the AO in my last blog over the weekend.
MT also talks about the Hudson Bay vortex, a feature that seemed to be largely absent from it’s “normal” location/strength last winter. It varies in location but typically sets up in Hudson’s Bay Canada and vacillates in intensity and location over the course of the winter…when it migrates up towards the pole, typically we warm up, when it descends through Southern Canada we get cold…it can drop into the States as well (we usually get very cold). We watch this like a hawk to try and figure out the temperatures over the next 5-15 days or so during the winter. When it locks in for a period of time, it will stay cold around here for awhile, when it’s migratory and moves around a lot, we just get brief interludes of chilly weather depending on where it goes.
Finally here are my thoughts.
Well as you know I’ve spent countless hours on the blog over the last month talking about all the things I look at for the Winter forecast so you already know my thoughts. Go through the blogs and you can see how much I’ve written in the past.
Basically, it seems we all agree on the drought continuing. Which is unfortunate news. During the winter season sometimes drought can be “hidden” in a sense. It doesn’t take much soil moisture to NOT have cracks in the yard etc. like during the spring/summer months. Evaporation rates are significantly lower and with lower sun angles, the moisture we get into the ground tends to last longer compared to the summer. From December 1st through the end of March we typically get about 6.5″ of precipitation. DEC-FEB are our driest 3 months of the year on average.
So IF the drought does rage on, tough to get a lot of snowfall when you’re not getting the opportunities to get precipitation in the first place…kind of like what we’ve been seeing for the past 7 months or so…since the rain shut down in April. I did, at the end of the discussion, mention that IF the drought eases somewhat, our chances of getting more than what we think for snowfall is better. I do think there will be colder air this winter compared to last winter because of the tendency to see increased blocking patterns in the atmosphere (I disagree with Michelle on that point and I laid out my reasoning in a previous blog concerning the NAO. ) allowing colder air to drain our way. Like the others though, this should be balanced and then some with milder flows of air So in a sense I’m expecting a more typical winter but with less snow and warmer than average temperatures.
Finally you already know what I feel about these exercises and our skill levels. You rarely see meteorologists go back and verify their forecasts after the winter or make mention about it (unless they were right). A few do though and as a reader of this blog, you know how I’ll hammer myself after the fact if it’s deserved (and it usually is).
OK that’ll do it for part 1.We put our numbers out there tomorrow on the blog and tonight on FOX 4 News @ 9PM