Weather Blog: Wintry weather possible next week

There is a lot of buzz on social media about the chance of an end-of-the-world, North Carolina blizzard on Tuesday, March 25th.  Blizzard?  Not likely, but here are some things that point our forecast in the direction of wintry weather on Tuesday.

model1Several medium-range models spin up a coastal low off FL/GA that travels up the Carolina coastlines by Tuesday afternoon.  It’s nice to see even a little agreement five days out, and that’s why we’re all a little breathless about the possibility of a late-March snow event.

Yes… snow, a rain-snow mixture, or cold rain, depending on what part of the state you’re checking out.  Here in the Piedmont, the likelihood of at least some snowflakes is looking pretty good.

Temperatures at critical levels of the atmosphere where ice crystals form is looking sufficiently cold enough to support snow all the way into South Carolina, but that isn’t the only element that determines precipitation type.

Surface temperatures may end up being favorable for snow, and that is where we have to consider how poorly our models have performed in the past few weeks.  The past couple of ice storms were not depicted by the models to be a) packing as much moisture, or b) bringing as much cold air as what ultimately occurred.

model2Considering these recent trends, it’s particularly interesting that with the last five model runs, Tuesday’s high temperature has followed a steady cooling trend:  58-53-50-47-43.  There is still a way to go before jumping onto the “snowmageddon” bandwagon, but we have a reasonable level of confidence that temperatures will struggle to get out of the 30’s on Tuesday.

The moisture that is available in these model runs is not favorable for large quantities of precipitation at this point.  There is still a lack of agreement on the ultimate position of the low as it curves along the NC coast.  A more inland track would bring more moisture to the Piedmont while a track to the east would limit moisture for our part of the state.

The official outlook for total liquid precipitation right now is on the order of 0.20″ to 0.25″, and using an average ratio of 10:1 (snow:liquid), that translates to 2″ to 2.5″.  This is a murky part of the forecast this far from the event, and pinning down total snowfall for a storm in North Carolina… five days out… in MARCH… is like nailing Jell-O to the wall.

The long and short of it is this…  March 2014 has been a month of unusually cold weather and misleading model guidance.  There is no reason to believe that the models will suddenly swing toward sunny skies and highs in the 70’s when they’ve been converging on a pretty consistent outlook.

For now, we can reasonably forecast a cold day with highs struggling to get to 40°, and at least a rain-snow mixture.  The probability that this forecast will change is high, but confidence should improve as we get into the weekend.

We’ll have an update on the models and the latest forecast on the FOX8 5:00 News.

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