Foreshadow: Does Early Snow Equal More Snow More Often?

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The buzz in my neighborhood, now that the Halloween candy stockpiles have lost their sparkle, is the coming winter weather. Houston is full of people just like me who are northern transplants down here who miss the snow and the cold, but are happy that — for the most part — a winter on the Gulf Coast is tame and fairly mild. Still, the possibility of snow sets this town in an uproar almost as much as the possibility of the Texans going to the Super Bowl. Could it be possible, because of last weekend’s early and record-breaking snowfall, North America has been primed for an unusually cold and snowy winter?

No, not really. But perhaps it’s not a surprise that the New England Halloween Snow Spooktacular, as well as the early and so far seemingly regular snow around Denver has the whole country either hopeful or fearful that the coming winter season will be especially harsh and long-lasting. Certainly, there are many things to consider when examining the coming winter season’s potential.

The upper atmospheric flow (highlighted in purple) will direct storms along its path. Click to enlarge. Image: ImpactWeather StormWatch

First and most importantly, La Niña and El Niño. If you’re a fan of YourWeatherBlog or more than just a casual fan of the weather, you know the first thing we have to pin down is the presence and strength of one or the other of these two global climate forces. Each has its own personality and each can turn up or turn down the volume seemingly at will. It takes a seasoned meteorologist to be able to tap into the pulse and diagnose the coming few months. With a handle on global climate, we can then narrow the focus a bit and look at the nation as a whole and even speak some to regionality.

Most areas of the country will see near-normal precipitation. Unfortunately, "near-normal" does not apply to Texas and the Deep South where exceptional drought conditions continue with little relief in sight. Click to enlarge. Image: ImpactWeather StormWatch

By definition, a winter La Niña is identified when surface temperatures of the eastern tropical Pacific are cooler than normal, by 3-5 degrees Celsius. Consider these cooling waters to be a calming effect, without the drama of her excitable sibling, El Niño — identified by a similar, but opposite warming of the same waters. La Niña typically sets the stage for a warmer and drier southern half of the U.S., cooler and wetter in the Pacific Northwest and Midwest, while most other regions remain close to normal. El Niño, by contrast, will be the foundation of a wetter and cooler southern half of the U.S., with a warmer-than-normal Pacific Northwest, Northern Plains and New England. These climate features can often be in place for years at a time.

ImpactWeather’s long-range specialist Fred Schmude is preparing his seasonal outlooks to be released next week. Before he stepped out to lunch I cornered him for his opinions concerning the next few months:

The storm track acts as a divider between the cold air to the north and the warm air to the south. Click to enlarge. Image: ImpactWeather StormWatch

There’s little question that the upcoming weather pattern will be dominated by a moderate to perhaps strong La Niña which typically signals that most of the colder than normal and stormy weather will be centered over the northern tier of states, from the Pacific Northwest to the western Great Lakes.  I think there’s a good chance that above normal precipitation will be likely from the Pacific Northwest eastward across the central and northern Rockies will see above normal rain and mountain snow. Another area of above normal snowfall looks likely from the Upper Mississippi Valley eastward across the Great Lakes and most of the Northeast, generally north of the nation’s capital.  These areas will see a very active storm track this winter season with above to well above normal snowfall. However, I think most of the Deep South and Gulf Coast will be stuck in a standard La Niña pattern with a weaker than normal southern storm track resulting in below normal rainfall and near to above normal temperatures for most of the region.

Unfortunately this spells bad news for most of the drought stricken areas, including Texas where we are continuing to see one of the driest periods in decades. True, we will see some drought relief this winter over the Lone Star State as the storm track occasionally dips south at times bringing periods of rain. However, the overall trend will be below normal rainfall and we will likely see the drought intensify again next spring.  Even though we’re expecting above normal temperatures for most of the Deep South this winter season, don’t be surprised to see several strong Arctic fronts move by the region bringing short periods of very cold air with a risk of early morning hard freezes all the way to the Gulf Coast.

The typical La Niña scenario. Image: Wikipedia

Seasonal outlooks are just that — seasonal and fairly limited. They judge the season as a whole, unable to break down the forecast day by day or even week by week. In fact, even a “quiet” seasonal forecast cannot rule out the rogue snowstorm, Arctic blast and/or Nor’easter. Seasonal forecasts can’t see the peaks and lulls, only trends and tendencies. Invisible to the seasonal forecast are the specific ingredients of a record-breaking event that come together as critical components compound upon one another. The seasonal forecast is to the local storm what rainfall is to a specific bottle of wine — eliminate just one ingredient or mis-forecast the intensity by just a little bit and a would-be “generational” storm struggles to even create a dusting, or a would-be bottle of Chateau Mouton-Rothschild becomes just another $7.99 bottle of red with a fancy label.

Does an early and harsh snow storm foretell a harsh and extended winter season? Maybe. But as we’ve already seen over the past several weeks, there will be notable events (plural) over the coming months that will no doubt have my neighborhood — and yours, too — scratching their heads in wonderment while exclaiming, “I thought this was supposed to be a quiet winter!”

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