Social media was abuzz over the weekend with “talk” of significant snowfall in north Georgia this month and, to a lesser degree, discussions about a coming Polar Vortex which will cover the area in bitterly, abnormally cold weather.
And now, the National Weather Service (NWS) has now weighed-in and says such predictions, which are coming from other agencies and even some individuals, should be taken lightly.
“With storms behind us, we’re sure you’ve now seen posts showing fantastical amounts of snowfall from cherry-picked model runs valid triple-digit hours in the future for Atlanta,” the NWS Peachtree City office says on its Facebook page. “We urge you to ignore any numbers you’ve seen and focus on TRENDS! What do trends tell us?
“Otherwise, the main takeaway at this point is:
1) We cannot, with any meaningful confidence, forecast snowfall values 10+ days (or even a week!) out. Nailing down just the temperature forecast is difficult this far out, and snow in the south is delicate — requiring precision within a degree or two.
2) It does look like we’re trending toward a very cold start to the New Year and the month of January. If these patterns hold *and* we see a pattern conducive to increased moisture in the Southeast, we *could* see conditions favorable for the development of wintry precipitation.
All this to say: focusing on deterministic (exact value) forecasts at this range will lead to disappointment every time. They have no skill and provide no value. Keep your eyes on the forecast as we move into January, and we’ll keep you updated as details become clear.”
The area most likely to be impacted by a Polar Vortex in the near future is the Eastern Seaboard with the most significant deviations from normal temperatures occurring in the Southeast. (See accompanying map.) States west of the Mississippi are less likely to see unusually cold temperatures.
The NWS does expect overnight lows to dip into the mid-20s this weekend but beyond that is not yet ready the pin things down for the following week.
And just what is a Polar Vortex? According to the NWS “the polar vortex is a large area of low pressure and cold air surrounding both of the Earth’s poles. It ALWAYS exists near the poles, but …many times during winter in the northern hemisphere, the polar vortex will expand, sending cold air southward with the jet stream”