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The American models throw a damper on the party this evening.

At this point, they may be the outliers… in contrast, to the Canadian that came in on point for the storm as advertised. As of this writing, I’m not inclined to change any of my general scenario… yet.

Several days ago, we talked about the possibility for Raleigh to miss this as the storm could skew to the east. Maybe that can happen with this? We’ll wait for any pivots until all of tonight’s runs come in; but, more importantly, tomorrow’s midday runs of the 12Z suite. Those will show us know if this is a blip vs. a trend.

For now, let’s reiterate the axis of heaviest snow, with a tweak to pull the west-most point of Albemarle to change to Pittsboro. This becomes the west-most point of the favored axis, continuing on to Norfolk.

Anyway you look at it, Scotland Neck to Norfolk will have the highest totals, 5-10″ there. Then from Scotland Neck back to Pittsboro, totals should range from 3-6″.

Updates tomorrow!

A quick update to confirm that we’re still on track for a moderate to possibly heavy winter storm, particularly in eastern NC.

As the arctic front enters NC on Thursday, rain will begin to changeover to sleet and snow as the cold air invades into Thursday evening and overnight. The front will serve as a focusing mechanism for waves of low pressure to ride from SW to NE along the Southeast Coast.

There are still plenty of details to be ironed out, but 3 days out, the models are converging on a consensus for an axis of heaviest snow lining up from Albemarle to Raleigh to Norfolk. Immediately, southeast of this line there looks to be the axis of heavy sleet.

Behind the storm it will be very cold. We’ll be dealing with whatever falls on the ground for a while after the storm is long gone.

I’ll have a more complete analysis late tonight.

As today’s storm winds down for us in NC, we can look back and say that it came and went pretty well according to plan.

Note: there is the possibility of a snow shower or two rotating thru Wake Co. near the upper level low in the 11pm to 1am timeframe this evening (Sun, 16 Jan). Nothing to worry about with respect to significant accumulation, just an opportunity to see more of the flakes that many wished they had gotten earlier in the day.

Looking ahead, we’ll have a relatively chilly week, but with moderating temps each day ahead of an Arctic front which arrives Thursday accompanied by rain showers. Then, the uncertainty begins as to the possibility of a coastal storm, which is now being alluded to in the long range models for next weekend.

The numeric guidance at this point depicts a different scenario than the setup for today’s storm. This setup would be more promising for a real snowstorm vs ice. It would be a coastal storm. If fact, one of the possibilities is that Raleigh could miss out by being on the western edge of the precip, while the coastal plain hits the sweet spot.

Again, waaaaaay too early for anything except dreaming. However, I will say that pattern thru the end of the month looks to be one of the most promising in a couple of years, if you are a winter weather lover. It will average well below normal for temps. We just have to get the timing right with the arrival of the moisture!

No real changes this evening to the aforementioned thinking as to evolution of the impending winter storm

Best estimation for Raleigh metro is that we begin close to 7am on Sunday morning with some light snow. The snow will quickly change to sleet, with snow/sleet accumulations of only a coating up to an inch. The snow/sleet should quickly change over to freezing rain. Look for the warm air intrusion from the coastal front to push Raleigh above freezing between 12-2pm. This will obviously end any additional accrual of freezing rain, however dangerous travel conditions will persist with the snow/sleet/ice that remain on the roads.

Estimates in Raleigh proper are for a coating to as much as an inch of snow/sleet. On top of that, expect .1 to .2″ of ice accrual. The farther west you are, the higher the totals of both snow/sleet and ice. And since Wake county will be the transition zone, impacts could range from significant (west) to ‘meh’ (east).

I’ll update with any new information on Saturday

We are now entering the “short term modeling window”. To this point, we’ve been using large-scale models for general macroscale storm guidance. There is now general consensus on the evolution of the storm such that, the track of the surface low (and coastal front with its warm push intrusion) probably won’t differ by more than 20 to 50 miles. Those 20-50 miles will be crucial for those on the eastern edge battle front, which will be near Wake County.

Let’s back up to clarify… barring any crazy last minute monkey-wrenches, the outline from last night holds. In Raleigh, we should see snow begin 4-6am Sunday morning. This will be short-lived. Expect the snow to change to sleet quickly. I expect the sleet to be short-lived as well.

The snow and sleet should lay down coverage from a light coating to an inch or so. Then, the freezing rain begins. The question becomes how long does the cold air damming remain in place against the intrusion of the warm air behind the coastal front moving from SE to NW. Here’s where the short term modeling comes into play…

Up to this point, we’ve been using large scale, coarse model grid points. Now, in the short term, the grid spacing gets much tighter, and more reliable for resolving local-scale problems like… “How far west will the surface freezing line make it?” This is key to Raleigh. The longer we stay below freezing, the more crippling accrual of ice we get.

No need to guess tonight, I’ll provide more precise ideas on what that looks like in a post tomorrow. Tonight, the key takeaway is that Sunday looks to be a treacherous travel situation. Make alternate plans.

Bonus… some of the short term models suggest that we may see a period of snow Sat afternoon. Should be inconsequential, but pretty!

Lots of time before this event… Tonight, the best guess for Raleigh is for a little bit of snow — to significant sleet — to significant ice — and then rain at the end of the event.

Happy New Year!

I could/should wax poetic over the couple of different scenarios on the table as to our impending winter weather event. However, the main message to convey is that a significant winter storm is likely to impact Raleigh west thru the mountains, beginning early Sunday morning (earlier from the west to east).

As disappointing as it might be for clarity, there’s no need to hypothesize as to scenarios until we get closer in the Fri PM/Sat AM timeframe. Honestly, all solutions are on the table at this point, and we’ll probably waffle back and forth over the next couple days.

Tonight’s read indicates an impactful snow to sleet to freezing rain to rain event in Raleigh. Then, along a gradient as you go west to Greensboro you’ll see an all frozen… more snow, more sleet and freezing rain.

Happy snow-dreaming!

Raleigh has escaped the storm with the best possible outcome…a beautiful 4-7″ snow and temps hovering just above freezing to avoid any damaging ice build up.

But wait, there’s more…

It looks like there will be another round of snow and sleet early tomorrow AM as another shortwave rounds the trough.  The latest trends in the modeling indicate there could be another burst of heavy precip for at least a couple hours.  Surface temps will again be hovering close to freezing, but the precipitation rates should be high enough to achieve more accumulation.  This doesn’t look to be the case for everyone in NC, but under this band should be a thumping of 1-2″ …possibly isolated cases of 3 or 4″.   Right now the Triangle looks to be included in this next round.  And this would be just in time for tomorrow’s morning commute.  More winter fun!

Tomorrow evening clearing will following and temps will drop to the mid 20’s for lows.  Refreezing will be a major issue on Tuesday morning.

As much as everyone wants to hear the latest… the latest is that what I outlined yesterday still looks good to me tonight.

I can see concerns for bust potential above and below my current forecast.  My thoughts on Wake Co. follow, but really they are applicable to the wider region…

• bust big?… there will be a period of heavy snow after the initial onset of precip which quickly cycles thru rain to sleet to snow.  some models say there could be as much as 6-8″ in that initial hit.  so, you’d have that and then sleet and then frz rain.
• bust small?… fears of the warm tongue penetrating earlier and more pronounced would limit the initial accumulation of snow and changeover precip to sleet and freezing rain much more quickly.

I’m going in the middle on this and holding firm to my forecast from yesterday.  The action starts overnight with snow beginning in earnest between 2 and 3am.  I’ll nowcast early morning with an update for how that tricky transition zone looks.

It’s been many, many years since NC has experienced a winter snow of this magnitude this early in December.  This storm promises to make it a December to remember.

As has been widely advertised, there are going to be heavy snows to the west, rain to the south and east and a battle zone that should line up fairly close to a line from Raleigh to Charlotte where the forecast is super complicated and the weather super messy. I can hear the bemoaning of the infamous “line” as I type.  There are some interesting numerical modeling disagreements ongoing behind the scenes that hopefully will be resolved soon, but in the larger picture here are a couple of key points:

• There will be a lot of moisture available for this system.  Liquid equivalents will run about 2″ for most along and south of the Triangle and Triad with amounts tapering to an inch along the Virginia border.
• Heavy snows of 12 to 20″ will be common in places like Greensboro, Hickory, Boone, Asheville where most of the moisture comes in the form of snow with little mixing.
• The zone to the south and east, in places like Burlington, Chapel Hill, Salisbury and Concord, should probably expected half snow, half sleet and a little freezing rain.
• The next zone to the south and east has Durham and Raleigh and Charlotte.  I expect a mixed bag of it all…something like 3-6″, 1-2″ of sleet and 1/4 of freezing rain.  Remember that west and north in these zones you are more likely to skew to snow.  For instance, Durham may get 6″, Raleigh may only get 3 or 4″.
• Remember that whatever snow you get will be compacted by any sleet falling on top of it.  So, you could measure 6″ pre-sleet and shrivel down to only 3″ afterwards.
• IMPORTANT: The impacts of this event will be high and widespread no matter what form the frozen stuff on the ground is.  And after you get a couple inches, it’s really all the same in terms of impacts.  It just takes longer to go away with more of it there when it’s over.
• Something to watch will be the extent of the freezing rain.  If the warm nose penetrates farther north and west and deeper than is currently thought, significant ice accrual could become a real problem.
• Timing:  this looks to arrive from south to north overnight tomorrow.  For Raleigh, perhaps in the 1-3am timeframe.

As always, stay tuned as we monitor the latest trends and I will update as necessary.