Winter Outlook 2010

>> Thursday, October 21, 2010

**Issued October 27, 2010**

Above is the video to accompany the winter forecast. Please see it for all of the graphical information. I picture is worth a thousand words.

For those of you that are new to my winter outlooks, my goal each year is to put out my forecast prior to Halloween. The temperature and precip forecasts relative to average are based on December, January, and February, and any snowfall ideas are first flake to last flake, whatever month they occur in.

Last year's winter forecast worked out very, very nicely. I still have all of those maps saved, and the video is still on my youtube channel for those interested. Overall, it went about as well as a seasonal forecast can go.

This time around, my confidence is somewhat lower. One of the dominant weather players for this winter is a strong La Nina. The La Nina is a strong one, and that means there is a relatively small sample size of analog years with similar La Nina values. Due to the low number of analog years, this can sometimes lead you down the wrong path.

Another key factor is how the Atlantic behaves. For much of the year, the NAO and the AO have been on the negative side of things, or at most neutral. One recent exception is a positive spike in those values in early October. How these values unfold will play a major role this winter.

At this point, I am going with the idea that a neutral to negative NAO/AO combination will be with us, at least through the first half of winter.

So, with all of that said, here we go...

The analog years I have gone with are the winters of 55/56, 73/74, 75/76, 88/89, 98/99, 99/00. I have placed more weight in the analogs from the 50s and 70s....reason being a much closer match with the current solar cycle than the other years mentioned as well as a better overall match with the cycle of the PDO, or the Pacific Decadal Oscillation.

So, my overall forecast for the winter.


Please see the maps at the bottom for the individual month breakdowns of the analog years for temps and precip.

For the Carolinas
:
Temperatures: Above average Precipitation: Average to a bit below

That is very vague, so let's get a little more specific. I anticipate, relative to averages, December to be our coldest winter month. For the Southeast, I will go with average December temps. From there, January and February are look above average for the Southeast's temps.

For precip, each of the months look to be fairly close to average. The closer you get to the Gulf coast, the drier it looks overall.

Snowfall forecasts are always tricky. It only takes one quite healthy snow event to reach averages around much of our non-mountain areas. I do think we will have our chances this winter, however, unlike last winter where we had one potential event right after another, they will be fewer in number. If we can cash in on one or two of these potential events, then the region will do OK for snow. If not, then not so much.

I think December could be our best opportunity for winter events, with the potential dwindling a bit as the winter unfolds. However, even in a sea of above average temperatures, it only takes one well-placed upper level low to dump snow. So, back away from the ledge, snow fans. There is always hope.

So again, to recap, the coldest winter temperatures overall look to be during the first half of winter with above average temps taking over as we get deeper into winter. However, the mid-Atlantic to the Tennessee Valley could wind up being a battle ground for airmasses, so there will be some temps swings. And with colder air sitting fairly close by, that could lend itself to some ice or wintry mix events.

Again, please see the video...I get into lots of graphics with more detailed information in there.


December
Temps:

Precip:


January
Temps:

Precip:


February
Temps:

Precip:

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