« Archives in January, 2013


I’m sorry couldn’t post earlier on the severe weather threat…i had a major production this evening.

Obviously, it’s windy.  There is low-level jet with winds of up to 80mph just a couple thousand feet above the ground.  The entrainment of this energy down the ground, ahead of the cold front, is what is causing the high straight-line winds ahead of the storms in the squall line.  Winds outside of thunderstorms and the main squall line will continue to gust more than 40mph.  In the Triangle, we’ll expect the squall line to parade through in the next hour or so.  Higher wind gusts should be expected in this line…although the most recent history of this line has been to NOT realize its potential in mixing the high momentum air to the ground.  Still, we should be alert to the possibility of hurricane force gusts in the squall line as it passes.

Behind the front, it turns decidedly cold.  No more 70s!  Tomorrow in the 40s and Friday just 30s for highs.  Then, we can expect a couple of clipper systems to rotate thru.  Perhaps they could produce a snow flurry or two over the weekend.  Don’t run out to buy bread and milk for these!

There Once Was a Little Boy…

I’m just in from working offline and a little astonished to find WCPSS has a 3-hr delay tomorrow.  Indulge me here…

Once upon a time, let’s say back in 1977, a 4-year old boy lived in far away land…let’s say, Kalamazoo, Michigan.  He was an active, vibrant youngster who loved to run and play trucks, but would also give the biggest hugs.  One day at preschool, the children had just come in from an exhausting stint on the playground (with special fun on those dangerous monkey bars) to settle down at the tables for a tasty spring snack of grapes and cheese.  Our little friend loved cheese, and loved grapes even more.  So, he gobbled the snacks all down.  Except, wait.  Something was wrong.  One of the grapes was stuck in throat!  His teacher ran over, popped him on the back, and seconds later a half-chewed grape lay strewn on the table.  The little guy perked up, asked for seconds and was back on the playground hanging upside down from the monkey bars a half hour later.  But news of the horrible incident spread, and from that day forward, all grapes in preschool were to be cut in half…

Ok, so I’m being silly, and I’m not good with odds…but I would say the odds of this event causing accidents are really, really, really small.  So much so that I could write a similar fable as above about a little boy who traversed out into the scary elements only to find the one icy patch in the county.

All this to say that there could be an icy spot on a bridge or two….maybe…but to upheave 150,000 students plus teachers seems ultra cautious.  I’m expecting the precip to be spotty, short-lived and light…no more than a hundredth of an inch or two.  Most locations will not see more than a trace of precip.  Sigh.  But exciting for the kids to sleep in later tomorrow.

Final rant, it’s funny to me that they delayed schools 3 hrs when the NWS official advisory expires at 9am.  Whatever, I guess it’s easy to criticize when you’re not in charge.


All of the snow is over.  And a lot of the sleet is probably done (especially south of Raleigh), although it could mix in from time to time, especially at the onset of the next round of precip, set to arrive in Raleigh by 2:30.  Indicators now show the potential for the remainder of this event to take the form of a significant ice storm where glazing could accumulate to 1/4″.  Temps are solidly locked into the mid 20s and will remain there.  This will make for easy accrual of ice on most everything, including untreated roads.  If we start to  approach 1/4″, then we’ll begin to see problems with trees coming down and power outages.  If we see more sleet at the beginning and less freezing rain, we may only realize a little more than .1″ of ice, which is better for the power situation, but worse for the roads.  This is more likely from Raleigh and north.  But eventually, everyone goes to freezing rain and gets some glaze.  Watching…


Don’t Panic!

There is a forerunner band of snow and sleet that will be pushing thru the Triangle earlier than advertised.  In fact, this band wasn’t even picked up on by the latest runs of the NAM this AM…so consider it a bonus! It’s moving quickly from west to east.  It should arrive in Raleigh about 10:30 or so.  It will be mostly snow with maybe some sleet and should be enough to lay down a dusting.  But it will be short-lived lasting no more than 30 mins.  Then, the coverage will be rather spotty until the main batch of precip arrives later in the afternoon.  Just wanted you to have heads up on this so as not to panic, thinking snow-mageddon was imminent ;-).

Forecast Headaches

The 0Z runs are in and there’s no question that they are wetter.  Some up and down is expected, but we have two runs with a little more moisture depicted.  It will be quite cold at the surface thru this event, so the precip will all be frozen or freezing in Raleigh.  I’m thinking that the precip doesn’t begin until 2pm in Raleigh, probably as a brief period of snow then quickly mixing with and changing to sleet for the majority of the event.  Later in the afternoon to early evening, we’ll probably see a change over to freezing rain and drizzle for a light glaze overtop of the snow/sleet accumulation.  How much accumulation?  Since most of the accumulation looks to be sleet and since the nature of the precip will be showery, I’d be pleasantly surprised for more than 1/2″ in Raleigh.  Plus, you’ll get a little glaze overtop.  I think the media outlets have done a good job in emphasizing how little it will take on untreated roads for them to become very slick. The past several days have, obviously, been very cold and tonight we’ll dip to the lower 20s.  All this to say that, ice on untreated roads in your subdivision or cul de sac could make for fun sledding if we can get a thin layer down.

As I said earlier this afternoon, we’ll see how the precip shield breaks out to the west of NC overnight.  And we have one more full model cycle to look at late tomorrow morning.  For now, it looks like areas just east of Raleigh, north and east to Elizabeth City and the Tidewater of VA stand the best chance of significant ice issues.

More tomorrow AM.

Too Pessimistic?

Not that one should waffle back and forth with each model run, but as you get closer to an event, presumably model guidance should improve.  After several cycles of trending drier, the 18Z models have come back around wetter, owing to more precip from the low deepening as it exits the coast.  Under the the latest runs, it would be snow at the onset, to sleet, to a freezing rain glaze on top.  Could be, but I’m not ready to fall for this tease yet.  For now, we’ll just wait for more data to come in and watch the system as it begins to organize tonight over the TN Valley.  Tonight’s model runs should be more reliable with fresh data included in their initializations.  We’ll see if we have reversed the trend back a little wetter or not.  Any way you slice this, it will not be a heavy event.  The question is…will this be just a nuisance or create minor travel headaches.  More tonight.


Trim It Back

Moisture really looks starved for tomorrow.  So, for the second dance in a row, it looks like the guest of honor won’t show.  For a good portion of central NC, I think this will play out as a couple of snow and sleet showers that will in some places accumulate enough for a dusting to a half inch, and other places not even that.  Actually the locations that will stand the best chance of getting and inch or so look to be from Rocky Mount northeastward.  It’s ashamed to waste all this perfectly great cold air…alas, it is NC.

Next week we thaw out with the possibility of highs flirting with 70, before the cold returns.  And it could be another significant cold spell thru the first half of Feb.  Perhaps more chances for the elusive snow then.

Bang for the Buck

As I, and everyone else it seems, have said, the limiting factor with this next round of winter is moisture.  The range of possibilities for the Triangle are from a couple of spotty snow or sleet showers that dust the surface, to a band or two of heavier precip that lay down a couple of inches.  Right now, at best I could wishcast 2-3 inches in Raleigh.  For those who love to see white stuff on the ground, the good news is that antecedent conditions are so cold that pretty much whatever falls should stay there, making for easy accumulation.  The question will be…how much moisture is available to overcome the very dry air in place.  I can see the potential for how this could swing for enhanced QPF, but really that’s just wishful thinking at this point.  My first call for Raleigh is 1″ of frozen ‘stuff’…snow and sleet…maybe some frozen drizzle on the back end.  Remember though that this event will begin after lunch on Friday and continue thru the evening to impact rush hour, so it may cause disproportionate headache to the depth of accumulation.

More tomorrow.

The Dance

Last dance, I asked ‘Cold’ if she’d come, because I knew I was bringing the wet.  This go round, I’m asking ‘Wet’ to the dance, because I’m bringing the cold.

Last week, we had a lot of moisture with only marginal cold.  This time it looks like we’ll have plenty of cold air (at the surface, at least), but an abundance of moisture is the question with Friday’s system.  In fact, the extent to which the air mass in place will be cold and quite dry makes me fear this will be one of those events that we agonize over available moisture…how much it takes to saturate the dry in situ air vs. what’s left over for ice accumulation.   You know the drill…we see radar echoes roll in from the west, patiently waiting for them to reach the ground, only to end up with a spotty sleet shower or two.

There’s lots of time to figure this out, so we’ll patiently follow the trends.  To clarify timeframe…probably beginning Friday, early afternoon.

So, here’s me hoping that ‘Wet’ shows up this time.  But I’m a little dejected lately, with ‘Cold’ just flirting last time and what about that preseason-advertised Wolfpack?  Yes, they’ll dance, but will they be special?





Well, I Said There Might Be a Mess…

…and it looks like we’ll have one on Friday.  Whether or not the wintry materializes, the meteorologists will be sweating this one, no doubt.

It’s funny that we rely on models so much for our forecasts, but in this case the meteorologists have really been observing patterns that may turn out to have outwitted the long-range numerical gibberish.  Friday looks to be a classic cold air damming (CAD) event for NC.  The US models, in particular, have not respected this solution, but the European is trending toward a low track farther south, around the base of the cold pool.  This solution would create an icy mess across the NC Piedmont with more snow farther west in the foothills and mountains.  It’s way too early to say any more than, we have the potential for an winter weather event.  So, I’ll leave it at that, and go see if I can find a date for this dance!