Temperature rollercoaster goes up a couple of days, then down quite a bit
Monday certainly didn’t live up to its potential for rainfall, not that there was a lot expected, but most of the showers either went north or south of most of Southwest Virginia, and those that appeared to be headed our way from the west diminished crossing the mountains this evening. Roanoke ended up get 0.21 total for 2 days through 11 p.m. and Blacksburg right on a quarter of an inch, most of it on Sunday at both sites. There might be a few more showers overnight — even some snowflakes by morning, mainly higher elevations west of Roanoke — but for the most part this little episode of dampness is over. And the drought continues.
Get ready to ride the temperature rollercoaster the next few days. The 
cold front passing through overnight is hardly worthy of that title, as we’ll be right back in the 50s during the day Tuesday and possibly some 60s on Wednesday. It does look very likely that the next cold front will be fully worthy of the title, slamming through late Thursday, possibly kicking up some showers and maybe even a few rumbles of thunder ahead of it. Behind it, we’ll get a true shot of Arctic air from the core of a very cold air mass sitting over Canada. Even with sunshine it will struggle to make 40 in much of Southwest Virginia on Friday, with some 50+ mph wind gusts possible. Those northwest winds will trigger snow squalls in West Virginia’ s higher terrain, as is typical from the upslope flow squeezing out Great Lakes moisture in even colder air just above the surface, and a few inches may occur in the common upslope belts, even into the far western fringe of Virginia and the I-77 corridor. You know if your location typically gets upslope snow squalls on northwest winds — expect to see some white ground if you’re in one of those spots. At lower elevations and farther east, don’t be surprised to some snow showers scattering in the breeze in the New River Valley, along the Blue Ridge, and perhaps even briefly into the Roanoke Valley and western Piedmont or Southside by Friday morning.
The guidance has bounced around a little bit, but it now looks as if cold temperatures will hang on through Christmas, though it will be mostly dry. It is also becoming more evident that a large storm system will likely develop and affect some portion — potentially, a very large part — of the central and eastern U.S. a couple of days after Christmas or so. While the forecast models are bouncing around trying to locate where this storm will go, there is some reason to think a traffic jam of weather systems in eastern Canada may be able to cause a more southerly track than the storm systems we’ve seen so far. That would increase the chance of significant precipitation — wet or frozen — in Southwest Virginia. But it’s too far out for those details to be extremely clear. Something to keep on the backburner as we watch the approaching Arctic air mass this week — which will trigger an Upper Midwest snowstorm that will break record snowless streaks that date to early March in many of the bigger cities there.
December 17, 2012 - 11:33 PM
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49.5*
What a weather morning it has been! Fairly warm for this time of year when we got out of bed but then in minutes it changed. The sky to the north got really dark as the sun was coming up and we got to see a magnificent rainbow with a faint second rainbow. Then the rains started and then the wind turned on. Now it is very windy and dreary. I guess the front is going through.
Yep, another storm system that failed to deliver on the rainfall. Most forecasts I saw called for around a half inch to three-quarters. We barely got a quarter-inch, which is par for the course over the past 2 months…in which we’ve tallied about 34% of normal. It still wound up our biggest storm system total on over a month.
The second piece of the storm on Monday was a bust for needed rainfall. The overrunning moisture on Sunday slightly overperformed — as sad as it is that .15-.25 is overperforming — then the main storm system did its usual north/south split. GFS was closer than NAM on rain forecasts.
Some upslope-enhanced showers moving over from West Virginia on radar. Would typically be snow, but it’s just not cold enough behind this Pacific alleged “cold” front, except maybe in some of the higher elevations of West Virginia.
Euro now has its fifth different evolution of next week’s storm in as many runs, taking a north-south path about 500 miles west of us. Look at the extreme cold air flexing its muscle (note the pattern of purple) in the Tennessee and Mississippi river valleys.
http://raleighwx.americanwx.com/models/euro/00zeuro850mbTSLPUS240.gif
Not much point tracking the details on this yet. Lots of energy, deep Arctic air available, should be a large storm system somewhere in the central/eastern U.S. The western path might bring us some needed rain and milder weather just after Christmas. A more southerly/easterly path could be more wintry.
Euro now has its fifth different evolution of next week’s storm in as many runs, taking a north-south path about 500-800 miles west of us. Look at the extreme cold air flexing its muscle (note the pattern of purple) in the Tennessee and Mississippi river valleys.
http://raleighwx.americanwx.com/models/euro/00zeuro850mbTSLPUS240.gif
Not much point tracking the details on this yet. Lots of energy, deep Arctic air available, should be a large storm system somewhere in the central/eastern U.S. The western path might bring us some needed rain (though wouldn’t count out the way things have been going) and milder weather just after Christmas. A more southerly/easterly path could be more wintry.
Circled in the image below from the 0Z Euro for Christmas Eve is the “rex block” that you may have read Dave Tolleris mentioning, the “traffic jam” I refer to above. The patch of green is high pressure and the patch of blue underneath is low pressure.
http://blogs.roanoke.com/weatherjournal/files/2012/12/Euro500mbHeightsChristmasEve.png
His contention is that the models always try to take a storm system directly into the rex block for several runs, and weaken the rex block, rather than what typically happens, which is the rex block holds longer than models project, and storm systems are forced to detour around it. If that is the case, the post-Christmas storm would track farther south and east than many of the early model runs of both the Euro and GFS taking into the central U.S.
Interesting idea that makes sense — IF the rex block is correctly modeled. Eventually the Euro and later the GFS should pick up on this and alter the course if it is valid. We’ll see how it plays out.
I saw that DC, around 8 AM. Perfect shape and the most vivid colors I’ve ever seen. Then a partial one on the lower right corner. The reason it showed up so well was the dark clouds in the background.
Just wanted to remind you all of Friday’s forecast (12/21)
http://www.laughnessmonster.com/wp-content/uploads/2012/12/Weather-for-12-211.png
No need to water the tree anymore.
Kevin, with all of the models showing different scenarios this far out – when should we start expecting them to start “nailing” it down and coming up with one scenario?
Trivia: Highest elevation on Poor Mt.[Rke. and Montgomery counties is 3,928′.
One more piece of trivia then I’ll call the dogs:
http://maps-n-stats.com/us_va_elevation.html
haha, pistol pete…I’ve seen that one floating around Twitter this week. Guess my golf game this weekend is out! I’m not sure there’s any SPF that’ll help that day though…
Forecast of mostly sunny with no precip? The clouds and showers I’ve been driving in (Salem -Roanoke) would beg to differ.
Pistol Pete, is that forecast just for the Roanoke Valley, or does it include Blacksburg area? I guess I will have to make sure to let the dog in.
Doppler Carol…
Quags says after the 12Z model runs on Sunday.
Pistol Pete, thanks for reminding me of Friday’s forecast. I sure am glad that I did not pack my shorts away yet.
Tuesday’s 12Z Euro just came out with the upteenth different solution in as many days. Here we go again. (face plant into palm of hand) A particular Met here in Virginia says that this afternoon’s Euro is trash and holds onto the after Christmas scenario. He said the same about the GFS too. tick…tock…tick…tock…
Henry M. is not even talking about blocking for next week storm and has it going into the great lakes. I am glad this is Henry because sorry to say he hugs the GFS model alot and most of the time is wrong. So hopefully Accuweather keeps its bad run of forecasting! DT says things are coming more in line with a coastal event next week as well as Quags! I guess one of the parties will be right. LOL
I did see where the Euro Weeklies have it cold into mid january!
See a winter storm watch has been issued for SE WV for Thursday nite into Sat. for Bluefield and the usual culprits. 5″ TO 10″, with higher amounts scattered around.
Dopplar Carol, JFR says about 10-14 days from now we should know without a doubt what to expect for next week’s potential storm.
Carol: The forecast models rarely have the exact same details even 12-24 hours out. I would think within 72 hours of an event they should be on basically the same page. More so with a large storm system than with a smaller weaker system.
Here’s the winter storm watch WD refers to:
http://www.erh.noaa.gov/rnk/emer/emer.php
Well, we’ve heard Quags, Henry M. and DT’s opinion on the models. What sayeth Mr. Myatt?
I kinda like John from Ruckersville’s idea of waiting 2 weeks and I’ll tell you what it does next week.
I would lean to a track a little west of us but not as far west as the current modeling. This could produce a wintry mix to rain scenario for us with some cold air damming. Maybe a Miller B type situation where 1 low goes into eastern Ohio Valley and fires a new low off the East Coast.
Best guess more than a week out, take with a shaker of salt.
I guess it is a “man thing” to say ask me in 2 weeks what it will do in a week.
That’s a typical response from the “Man of the House” whenever I ask.
Okay, I will keep an eye out for the 72 hour time frame and hope for the best. (snow)
The GFS says that all of West Virginia is going to turn white on Thursday night.
http://wxcaster.com/gis-gfs-snow-overlays.php3?STATIONID=FCX
Winter storm DRACO… The names keep getting worse and worse…
I am surprised that no one has mentioned the following: according to O.F.A., “The earliest winter since 1896 arrives with the solstice at 6:12 A.M. on (Friday) the 21st.” For once, I agree fully with the OFA and one of its predictions.
Blacksburg average high temperature for the first 17 days of this month: 54.6. For Roanoke, 58.4. Friday’s forecasted highs? Blacksburg 36 with a 30% chance of snow. Roanoke: 40*, and very windy. The first day of winter on Friday, both astronomically and actually. ……. Except for October 8th, and October 29th through November 7th.
Hey, John from Ruckersville, have you contacted the local Burger King to have them keep an eye out for Jared in case we actually DO get a snowstorm next week?? If a snowstorm does happen, or even if it only happens in Jared’s yard, there will be no need for him to post his feelings of elation here on the blog …… we will be able to hear him screaming like a banshee down here. :>)
Doug, I will be traveling to Giles the morning of the 26th. I figure my chances will be better for seeing snow there. If not I will use the Burger King there. LOL I will have to keep an eye on that supposed storm for travel purposes. I hope to see some snow there between the 26th and 31st!
Nice sunny and mild here today low this morning 40.High today 54.Now down to a chilly 36.Doug Griggs thats a great point about Jared I think he likes snow more than anyone on here.Well he might be tied with Scott Sanders!Anyway have a great night all i`m going to crash.
Draco here I come.
It’ll be a first for me. Flying thru a named winter storm.
We hit Boston Thursday PM go back out Friday to DC then the Sunshine State before coming back home Friday night. Should be fun.
FYI, between flights, I’ll be tweaking the website so it may be down some, but will have it up & running Friday night with a new Nowcast page.
Back this weekend.
Here is a message from the entire Roanoke Weather Blog to The Weather Channel: “Draco, get thee to a nunnery.”
Yes sir Mike….I <3 me some snow…ALWAYS have and I guess I always will. Nick from the Ellet Valley as he is known LOVES it too but haven't seen nary a peep out of him lately! Nurse Snow I assume loves it too and what ever happened to TWLS gals and Blossom? I agree, naming these winter storms is very silly but I'm sure we will not get any of Draco!!
Great news overnight by DT if your a fan of the coming storm! GFS moves way east and Euro keeps moving east. DT says good indications when both models starting to come together. He also said it was good news because just the other day everyone was saying this storm is dead!