WeatherTrex.com

Good evening everyone.  I hope you’re all having success working through your depression over the pequeño fin de semana snow totals.  I’m a little bitter, but hey, with global warming and all i suppose i’ll need to move to Pocatello for better snow chances in the next couple of years. 

I’m posting tonight with a word of caution about tomorrow morning…it’s not a big chance, but if we get some precip in here early Tues morning then things could be slick.  As it most always is…the farther west the better the chances for problems.  Spotty freezing rain could break out over the area tomorrow morning.  Not that it would be a large amount of precip…but with the cold temps of the last couple days, sub-freezing surfaces abound.  So, it would be easy to get icy spots.  It’s most likely that the spotty precip is delay until later in the morning, and there will be no problem, but this is one of those low probability-high impact events…so, just so you know…

And finally, the cold shot coming late week looks to be the last in the near future. Sigh. Like I said…there’s always Pocatello!

peace, trex

Some of you apparently haven’t gotten as much as I have…opps.  Here’s a picture from my house.

As I crack open a “snow cap” beer (still clinging to hope!), I fear I must concede defeat.  Snow geese or no, we ain’t gonna make it to 4″.  Maybe my bird lady is right with her poo poo.  It seems that we spent a lot of our available moisture into cooling the atmosphere below 3000ft.  It seemed to take forever to get the column cooled…so many precious drops wasted!

So at this point, the light snow that will persist over the next several hours won’t be enough to overcome the wet, just-at-freezing surfaces to achieve the higher accumulations i was looking for.  At my house, I have a decent coating on the ground and my deck (insert joke here), so the real accumulating can begin, however much that will be.  My thinking now is that we will see steady light snow for another hour and then snow showers after that thru the middle of the night.  1-2″ is what it will be.  But the real danger is going to be the black ice.  The temps should really begin to drop in the next couple of hours and after midnight the roads will be a lot like ice rinks.  Be very careful tomorrow morning!  peace, trex

A wonderful lady, I have the privilege of knowing (and who poo-poos most everything meteorological that I have to say), always tells me to watch the birds just before it snows if you really want to know what the weather will be like.  Now I don’t know if this is what she had in mind, but…My wife and I are about to build a new house, and I went out to the homesite this morning to check things out…when much to my surprise a flock of geese descended from on high!  It was almost Biblical.  Now I know these weren’t really snow geese, but at least they were Canadian (i know this because they said “ay?” in their salutation).  I figure they have lots of snow in Canada, right?  So this is a foreshadowing of the snow to come. 

Just a quick post before a more comprehensive update in a little while.  I wanted to let you all know that the cold air is, in fact working its way in.  I was an eyewitness to a graupel siting at the Crossroads Starbucks in Cary at 10:45.  Some of you may be wondering what in the heck graupel is.  It’s a snow pellet that has been rimed by a coating of ice.  But that’s not really important.  The important part is that the we are just on the cusp of the cold air working its way down to the surface.  We’re in a relative lull in the precip shield now, but should see things pick up after lunch.  And some of you have expressed concern over some nameless on-air meteorologists poo-pooing the event.  While they are right to say that the most QPF will be south and east of Raleigh, that does not mean that we won’t see a decent shot ourselves.  more later…trex 

Some of you have previously heard me lament about the difficulty of weather forecasting.  I like to give the example of the surface of ocean with its gazillion little waves that ripple along the top.  The spectrum of wavelengths is almost literally infinite.  Now imagine trying to write an equation that could explicitly determine what the wave pattern looked like at any given instant on the water’s surface.  Pretty hard stuff, considering that the answer would, simplistically, be the superposition (sum) of all of those waves of varying size that we talked about before.  In this example, i have really only described one layer…in a sense, just a two-dimensional sheet.  But, of course we want to know more.  We need all three dimensions and so even if you had the answer to the first layer, you’d still need many, many more layers just like that one in the vertical.  AND…this is only predicting one quantity.  You still have to do the same thing for four or five other variables!  Do you get my point…or have i driven you into a nacroleptic seizure?  The point is that it’s amazing that we can predict much of anything given the scope and shear magnitude of the task at hand…which is to make deterministic forecasts for a gazillion individual points (using an incomplete set of equations, i might add). 

So, with that perspective in mind, determining where a low pressure system will track within 25-50 miles, 24hrs from now, and given the fact that it hasn’t really developed, would be a job well done.  Unfortunately, that 50 miles could make the difference between 1″ or 5″ of snow…or an even harder to resolve…dusting or 3″.  All this is to say that the game is about to start and the players are getting the normal pre-game gitters.

Nothing I’ve seen tonight in the new model runs really changes my thinking from earlier.  The stronger, outlier solution has come in more reasonable with it’s QPF this evening, which is a bit deflating for the glimmer of hope that you always hold onto for the forecast bust that could go explosive like the January 2000 blizzard.  So, to sum it up…a little rain in the morning before we change over to snow about 11-12noon.  I’m looking for 4″in Raleigh.  The storm will be much more established tomorrow and therefore a more predictable entity than it is tonight in it’s infantile-state.  More then.

I’m reminded of the old joke that talks about the “new” native american tribe chief who is inexperienced in “the ways of reading the sky.”  So when his people asked him about what the upcoming cold winter would be like, being put on the spot, he quickly said, “Cold…Go gather firewood!”  But being a practical man he decided to call the National Weather Service to see what they had to say.   They said, “Oh, it looks pretty cold.”  So, the chief went back to his people and told them that he expected the winter to be quite cold, indeed, and that they should work harder to gather more firewood.  A week later the chief called the NWS again to see if there was any change in the forecast.  They said, no…in fact, it’s even looking colder.  Hearing this, the chief told his people that they should get every scrap of wood they could find before the wintry weather arrived.  Then, just at the start of winter the chief called the NWS one last time for final update.  He asked, “are you certain it’s going to be very cold this winter?”  ”oh, absolutely”, the meteorologist answered, “very cold!”  The chief then asked him how he could be so sure.  The meteorologist said, “Well, I probably shouldn’t be telling you this, but the Indians have been gathering firewood like crazy!!”

hmm…I was reminded of this joke today as my son and I went to Whole Foods to pick up some lunch off the hot bar.  After circling the parking lot for, no joke, 15 minutes…we finally beat out two Priuses and Smartcar for a parking place on the other side of forever.  It was a madhouse inside!  The hysteria over snow potential in the south is amazing.  The funny thing is that in Whole Foods with everyone abuzz about the snow and snatching up the must haves…organic beer, soy milk, gluten-free baked goods, and kumquats …i found myself snatching right along with them even though i just wanted some lunch!

Now about that snow…The good news is that our chances are only increasing for a significant snow.  The bad news is that there are several complications that make predicting snow totals really tricky.  Basically, this is one of those storms where the highest snowfall amounts will be in the east, where the most moisture is in association with the low along the coast.  However, the coldest air will be racing in from the west.  This sets up the compromise between all snow in the west, but with less overall moisture, and rain to start with a changeover to snow in the east with lots more moisture.  Obviously, the hard part is predicting how long a given location is rain vs. snow and what the QPF (quantitative precip forecast) gradient looks like.  There are some models out there going crazy on the QPF, which I’d love to buy in to, but can’t.  While I believe that potential exists because of some strong upper-level dynamics in the subtropical jet, i don’t believe it’s likely to get the storm crankin’ that much.  So, the more reasonable solution is something like .4-.6 liquid equivalent for Raleigh.  So, now the question becomes…how much rain at the beginning before the changeover?  Well, it looks like the cold air is coming fairly quickly and i’d expect no more than a tenth to be lost to evaporative cooling and pre-freezing temps.  Some of the models suggest that it may be all snow for Raleigh.  I’m not sure I buy that, though.  With the tenth lost that gives us .3-.5 liquid equivalent or 3-5″ of the white stuff.  That’s it for now…i’ll update later tonight probably between 11 and 12 after i have a chance to digest the new model runs.

(this title is not the real title in my head, but i’m becoming wiser in my old age…email me for the real title if you like) Also thanks to Bob Jensen and Jimmy Rogers for pushing me into the 21st century and setting up this blog for me!

Now to the white stuff…I’m excited. Ok, you all know that I’m excited at the mention of snow, so that’s nothing extraordinary. What’s different here is that the expectation for this winter was hot, hot and more hot…which has really been the case so far. Now, in a sea of La Niña driven warmth, we’re actually going to have a little winter in Raleigh over the next week or so. It started with the cold shot on Tuesday and the not-much-of-anything event this morning. I got about a tenth of an inch of slushy snow here at the house. From conversations with others, apparently I was lucky.

So, about Saturday, a couple of days ago it looked like this storm would harmlessly scoot out to sea. Now, it looks like Raleigh will get a decent, honest to goodness snow. Friday should be warm and then the next shot of arctic air begins to arrive on Sat just as the moisture arrives from a Gulf storm racing along the SE coast. This will be the opposite case from the Friday storm in that this time, the cold air will be rushing into the moisture as opposed to the moisture filtering into retreating cold air. Now there’s a lot to go wrong in this setup and i’ll detail more of this tomorrow, but for now know this. I think there will be a band of 6+” somewhere in central to eastern NC. And since there’s arctic air infiltrating thru the event, Sunday should be a tough-go for the ole Jesus commute. Then, with clearing skies on Sunday night, and a fresh snow pack it’s not too much of a stretch to think we might make it to single digits on Monday morning!

We’ll see. In the meantime, i’ll crunch the numbers and update you tomorrow.

peace, trex