Now that the ‘official' winter outlook has been released, it probably raises more questions than answers. On the right you can see what the expectations are for precipitation and temperature during the Dec-Feb time frame which is considered to be the winter months. Keep in mind this is an outlook, not a forecast. In other words, there will be some individual, short term forecast events that will be the opposite of what the longer term outlook would suggest. For example, a cursory examination of the maps on the right strongly suggests a relatively mild, relatively dry winter for Oklahoma. That does not mean that we will not have any cold, wintry weather at all. It just means that when everything is averaged out at the end of the winter, if this outlook verifies, then on average conditions will have been milder and drier.
A couple of points need to be made. I am sure everyone remembers how severe last winter was both with respect to some individual, extreme events and the winter as a whole. And, no the outlook for last winter did not foresee those events at all. Same thing with this past summer. It was not expected to be as extreme as it turned out to be. These outlooks are general guidelines based on quite a number of factors and if you want to read more about them, you can go to http://www.cpc.ncep.noaa.gov/.
With that in mind, you may be wondering if they have any utility at all. Turns out that over the long run, they will be better than persistence or just climatology, so there is some value in these long range outlooks. It is just that some shorter range cycles that cannot be foreseen more than a week or two in advance will at times overwhelm the larger scale cycles that these outlooks largely rely on. For example, the Arctic Oscillation is a relatively short term cycle that can only be reliably predicted a week or two in advance. Last winter, it maintained a strong negative phase which is favorable for cold air to penetrate well into the U.S. That was very unusual and it cannot be determined at this time if a similar situation will develop this winter. But, given the extremes which occurred last winter, that would seem to be very unlikely.
Another point is what about the early freeze that we had this morning. We are two weeks ahead of our normal first freeze date and you may be wondering if that has any bearing on the coming winter. Well, perhaps the easiest answer to that is to consider what happened this time last year. We did not have our first freeze till several days later than the normal first freeze date. Turns out there is little if any correlation between when we get our first freeze and how the following winter will be.
Notice I have made no mention of wooly worms, persimmon seeds, or any of the other ‘Old Wives Tales' that are often referred to at this time of year. We will be evaluating those in the coming weeks.
Have neither the time nor the space to provide an analysis for the forecast through the weekend and into next week. Alan will have his usual excellent discussion first thing Friday morning.
In the meantime, stay tuned and check back for updates.