It's about to get blustery and wintryPosted Dec31, 2007 at 05:04 PMSeveral counties in the higher elevations to our west are under winter storm watches, snow advisories and heavy snow warnings (click here for the National Weather Service's map of current advisories) as a strong cold front and some upper-level disturbance brings windy, much colder weather and rounds of snow showers the next couple of days. The Roanoke Valley is on the edge, again, of the snow threat. We will see much colder, windy weather and quite likely off and on snow showers, but accumulation depends on whether one of these disturbances the next 36 hours can trigger enough widespread snow above and beyond the upslope snow shower stuff that will be hammering the mountains. It certainly would not be out of line for us to get an inch or two out of this, and the New River Valley is very likely to see that much. This cold blast will only last a few days. Things will be getting milder again by the weekend. Old year warmth out, new year chill inPosted Dec31, 2007 at 12:04 AMAppropriately for the last day of a year that will finish as our warmest on record in Roanoke, we will see mild temperatures today, certainly in the mid to upper 50s and possibly even topping 60. But the first day of 2008 will bring a rude awakening that winter is still alive and well. A strong Arctic cold front will usher in a few days of breezy, cold, snow-showery weather. The snow will likely pile up nicely in the western upslope regions of West Virginia and far western Virginia during that time. A couple of stronger disturbances moving through the atmosphere may even push some accumulating snow eastward into our region by Wednesday. It won't be a lot of snow but a white ground is certainly possibly by Thursday morning. Snow or not, it will be cold, with lows in the teens to lower 20s and highs probably not getting above freezing at least one or two days in the middle to latter part of the week. The cold air will arrive after the rainPosted Dec29, 2007 at 10:08 PMThe cold air appears to be arriving too late for much more than just another cold rain on Sunday. While we can't rule out some freezing rain in some of the colder areas just to the north like the Greenbrier Valley of West Virginia and maybe even Virginia's Alleghany Highlands, a little mixed-in sleet here and there, and perhaps some brief wet snow on the back side of the rain as colder air wraps into the system Sunday night, this looks like a potential winter storm with a few pieces missing. Later in the week, a sharp shot of true Arctic air is expected to arrive on New Year's Day. This won't last terribly long, maybe 3-5 days, but we could have a day or two where the temperature struggles to make the freezing mark. We'll probably get our typical snow showers on stiff northwest winds, accumulating in favored upslope ares to the west, and there are some signs that a vigorous Alberta clipper could make a move at us Wednesday. If there is enough moisture, that could deliver a quick shot of snow. Beyond this coming cold snap, early-mid January is looking quite warm. Cold air may be too stale for winter storm on SundayPosted Dec28, 2007 at 06:08 PM
What it will deliver is needed rain. Here are projected rainfall maps from tonight's system and the one that follows on Sunday. Some needed rain, then much colderPosted Dec27, 2007 at 05:25 PM
Long term, this map from the Climate Prediction Center shows lots of red over much of the country, indicating the expectation of above-normal temperatures. For all the snow lovers, it looks like it will be difficult in the coming few weeks to match the fast-moving storm systems with the quick shots of cold air. Precipitation mostly stays to our eastPosted Dec26, 2007 at 12:52 PMSome light snow accumulation occurred in the northwest North Carolina mountains and there were a few reports of brief rain mixed with sleet closer to us, but for the most part, today's storm system slipped just east of us, and it wasn't quite cold enough for wintry precipitation, anyway. Looks like additional shots of rain -- and maybe some still-needed abundant rain -- will affect the area Friday and Sunday. Only the second of those two has any potential at all for wintry precipitation, and from this distance, that chance looks small in the Roanoke and New River valleys. Colder weather is likely to settle for a few days as 2008 begins, but it probably will not stick around long. Coastal low could make things interestingPosted Dec25, 2007 at 01:14 PMThe disturbance passing south of us is expected to trigger a surface low pressure system along the coast near the Outer Banks this evening and Wednesday. The low may be just strong enough to throw some moisture back into our region for some precipitation overnight into Wednesday morning. The question is whether there is enough cold air for the precipitation to be of a wintry variety, or whether it will be just warm enough to stay rain. It's something to keep an eye on, and in this December of on-the-borderline, surprise, light winter weather events, my eyes will be open a little wider. The dark side of a white ChristmasPosted Dec24, 2007 at 01:15 PMIt's going to be a very white Christmas in parts of the upper Midwest after a massive snowstorm the last couple of days, but all that snow and wind has snarled holiday travel and killed nearly 20 people. Click here for the Associated Press story. Our Christmas looks dry and seasonably cold, with lows in the 20s and highs in the 40s. A weak disturbance passing to the south will likely be too far south and too dry to squeeze out any Christmas snowflakes. Weather or not, have a Merry Christmas!!! Something fun for ChristmasPosted Dec22, 2007 at 04:52 PMWith gloomy, rainy weather settling in the next couple of days, and while we're still waiting to see how things line up for the system in the days after Christmas, here is something a little fun. Click here to check out Roanoke.com's most recent "E-cast." At about the 2:30 mark of the Webcast, there's a certain heavily bearded weather geek talking about our chances of a white Christmas ... and at the end, his lovely wife singing a line or two of "White Christmas." This was shot more than a week ago, so my vague reference to "mild and dry weather" around Christmas is definitely not accurate now, with Christmas Day looking quite cold. But it does look like we will not have a white Christmas ... unless, a disturbance passing south of us that day swings north and gives us another "surprise snow." A few photos of our surprise snowPosted Dec21, 2007 at 06:00 PM
Melting snow clings to a pine branch on, appropriately enough, Southern Pines Road in south Roanoke County Snow on pines and pine cones along Southern Pines Road The wet snow clung to every branch of many trees A little leftover slush along South Mountain Road. Some streets became slushy early this morning. Seth Gitner's video of the Broderick Family of southwest Roanoke County. The family recently moved to Roanoke from Alabama, and the children have only experienced snow once before. Taking advantage of a day off from school, they spent their day playing in the snow. What you may have missed early this morningPosted Dec21, 2007 at 02:11 AMYou may be waking up to some white this morning that you weren't expecting (nor was I, nor just about anybody else). I just finished walking my dog at 2 a.m. in a steady snow here in south Roanoke County. Some slushy accumulation on grass and car tops, but it appears to be slightly above freezing. (UPDATE 4:30 a.m.: Now about 3/4 inch of snow, sticking on pavement as well). From my deck, I watched the rain -- splotchy on my windshield headed home, signaling that it was melting snow not far above the surface -- gradually mix with and change to snow early this morning. It doesn't appear that all of the Roanoke Valley is experiencing this snow, as the airport was still reporting rain at last check, but some sleet and snow may be mixing with the rain. (UPDATE 3:20 a.m. -- Roanoke Regional Airport now reporting light snow and 34 degrees). I would be interested to know how much snow you folks in the higher elevations have gotten out of this. (I've gotten one report of over an inch near Christiansburg). Why did this happen? A low pressure system high in the atmosphere was stronger and earlier than expected. More moisture than expected arrived faster than expected, catching up to a cold atmosphere. (UPDATE 9:30 A.M. -- To keep this entry going as the place to post any snow reports you may have in the comments section, I have added the National Weather Service's latest public information statement on snow accumulations in the extended entry below. Sounds like snow accumulation may have varied a lot across the Roanoke Valley, from a dusting to about an inch, which is what I got where I live just south of the city. It's really the fifth "spotty" winter weather event we've had this month -- it all depends on exactly where you were. Here, it was pretty impressive for a few hours early this a.m. as very large conglomerated flakes up to half-dollar size plummeted down. Now, it's all melting rapidly, and walking under trees is like being in a rainstorm. I plan to post some pictures later today) Continue reading "What you may have missed early this morning" » Mixed bag of precipitation moving into the areaPosted Dec20, 2007 at 11:55 PMAs I write this very late Thursday night, 5 minutes to midnight, rain is falling in Roanoke with temperatures in the lower 40s. Most temperatures in the area are above freezing, but there are a few reports of snow and sleet here and there. Could be some freezing rain in local pockets of cold air. Again, doesn't look like a huge winter storm, just another brush with some wintry precipitation. Backing up on my word a littlePosted Dec20, 2007 at 03:45 PMOK, we now have two potential brushes with wintry weather to watch out for, neither of which look extremely serious at this point, but since I said there would be no significant ice or snow for the rest of 2007 just a couple of days ago, I need to retreat slightly. * A weak low moving south of the area on Friday might be able to kick enough moisture into just enough cold air for some scattered freezing rain, sleet or snow in the morning. Maybe. Probably, this will just be another cold rain, and probably not much of it at that. But don't be surprised to see some flaky or bouncy stuff in the morning. * There are indications a low may try to ride south and east of the area for the period between Christmas Day and Thursday. Depending on the track, strength and level of cold air, there would be some potential for frozen precipitation. I'm still not expecting either of these to produce a true winter storm for our area, certainly not the one on Friday. But the cold air appears to have a little more staying power in the latter part of December than once was thought. There's something in the back of my mind that keep wondering if January will turn out colder and snowier than anyone expects. U.S. snow cover triples from a year agoPosted Dec19, 2007 at 06:05 PM(A quick note, 12/21/07: For some reason this blog entry has got stuck on the front of the Roanoke Times gateway page, but there have been more recent blog entries regarding our brush with snow/sleet early Friday morning. You can see those by viewing the entirety of the Weather Journal blog by clicking here. Comparing the snow cover over the United States today compared to the same date a year ago reveals a stark difference. Thanks to some recent storms crossing the country, snow covers nearly half the nation (47 percent) currently, compared to only 16 percent of the nation a year ago. It looks like the snow cover will be reinforced in the states north of us as a storm moves through this weekend. This increased snow cover could have some significant implications in a greater ability to hold in cold air masses as the season progresses. Don't expect much ice or snow the rest of 2007Posted Dec18, 2007 at 09:59 PMWe may well be done with snow and ice for 2007, not that we've had much of it. The two systems later this week look to bring rain, not snow, and probably not a ton of that, even. The long-term outlook the next couple of weeks still looks likely to be warmer than normal. It's starting to look a lot like La Nina, which generally brings mild and dry weather for most of the winter in our region. Two more systems to watch this weekPosted Dec17, 2007 at 01:16 AMHere we go again, maybe. There could be two more low pressure systems with precipitation-making potential this week, one about Thursday, the other during the weekend. As it looks now, each of them will encounter temperatures fliriting with the freezing mark, just like in Saturday's ice-above-1,500-feet storm. The early odds favor mostly rain in the first one -- with maybe some ice or snow on the highest mountaintops -- and perhaps a better chance of snow with the second one. But there are many atmospheric flips and flops to go before that time. One thing that may have changed at least temporarily is that the massive snow cover to our north from this weekend's storm and the cold circulation around the low moving away from us may pull down more cold air this week than appeared likely just a few days ago. So it looks to be a pretty chilly week, especially early. Whether it's rain, ice or snow, each of these systems is helping put some small dents in our drought. A La Nina-defying run of these systems through the winter could really help us make some headway before spring. Parched areas of Alabama and Georgia got some help this past weekend. Ice wasn't overly bad, but winds will howl later todayPosted Dec16, 2007 at 08:39 AMJust like last February, the Roanoke Valley missed the bulk of the ice storm by 1-2 degrees. There was some spotty ice around the rim of the valley and some glazed trees at slightly higher elevations, but not around most of the 900-1,000-foot elevation areas at the valley floor. The New River Valley had much more ice, and so did the high elevation areas along the Blue Ridge. Still, this doesn't appear to be a repeat of last February's storm that put thousands in the dark for days. The main difference this time -- it got warmer during the rain, not colder as it did during the Feb. 13-14 ice storm. All that said, there are areas of slick roads and trees hanging with ice not far away from Roanoke, so anyone traveling should take caution. The attention now turns from ice to high winds. A high wind warning, for gusts possibly exceeding 60 mph, is in effect this afternoon through the overnight. Anywhere that ice remains on trees, there will be even more potential for limbs to be blown down. The winds will be whipping through a few snow showers at times, especially from I-81 westward, but accumulating snow will be confined to the upslope areas of West Virginia and far western Virginia that always get it. Many are reporting ice tonight, but some are missing itPosted Dec15, 2007 at 09:36 PMI've been getting reports throughout the evening of ice forming in the New River Valley, Floyd County, south Roanoke County and Salem. Trees and exposed objects are getting most of the ice, but some bridges and higher-elevation roadways are getting a little slick. Here in downtown Roanoke, where I'm at work tonight, it's just a cold rain, but my wife tells me there is ice on metal objects where we live 5 miles to the south at a slightly higher elevation. As is typical in these marginal ice storm situations, Roanoke is hovering in the 32-34 degree range, and the temperature has fluctuated back and forth some this evening. You may have ice on your deck in one Roanoke Valley neighborhood, while someone you know blocks away has little ice. Temperatures are beginning to show a slight tendency to rise, but there is more rain headed our way. How much more rain will fall before the temperatures rise above freezing across most of the area? And can we get what ice has accumulated to melt off before high winds begin shaking the trees and possibly breaking off limbs Sunday evening? Icy situation likely to be developing very soonPosted Dec15, 2007 at 05:12 PMRoanoke's temperature is on the cusp of iciness now at 33 degrees as of 5 p.m.. Most surrounding areas are below freezing already. Rain is increasing in the area, as National Weather Service radar indicates. It does appear that, at least for a few hours, this ice storm is going to happen as expected, and even some or all of the Roanoke Valley may be affected. Even if things appear just wet, approach bridges and overpasses with caution this evening. The farther out and higher up from the floor of the Roanoke Valley you get, the more dangerous things will become. Some higher elevations that have gotten freezing drizzle much of the day may already be getting slick. Additional counties have been added to both the ice storm warning and freezing rain advisories. Blacksburg and Montgomery County have been upgraded from a freezing rain advisory (less than 1/4 inch of ice) to ice storm warning (1/4 inch or more of ice). Click here for the latest from the National Weather Service in Blacksburg on the developing ice storm. Overnight warming may give Roanoke a breakPosted Dec15, 2007 at 10:47 AMI think tonight's ice storm will materialize and be significant for many higher elevation areas along the Blue Ridge -- say, locations at or above 1,500 feet. Lower than that, we'll probably be skating on the edge between cold rain and ice for a while. If you scroll down on the National Weather Service-Blacksburg's current events page to the ice accumulation map, you will notice that the colors are pretty dark to the north of Roanoke, and in a little stripe southwest of Roanoke (Bent Mountain-Poor Mountain area), but there are no colors on the city itself. Taken literally, this map suggests Roanoke could miss the ice entirely. Roanoke is at 36 this morning, with a dew point of 25. Once precipitation begins in earnest this afternoon -- rain mixed with sleet, probably -- the temperatures will drop some to meet the dew point as the air saturates. That will probably be about 32-34 degrees in the Roanoke metro area. It could mean ice for some hilly areas and not so much close to the Roanoke River. It could even be different neighborhood to neighborhood ... I remember last Feb. 13 there was a thin ice buildup on everything where I live in south Roanoke County but none less than half a mile away at a similar elevation. Besides the "urban heat bubble" effect -- concrete, asphalt and building materials holding in heat from the week's sunshine and releasing it to slightly warm the air over the city -- rain falling overnight thorugh a warmer air mass aloft will eventually pull some of that warmer air down with it. And, if you remember high school physics (I really don't, but I know this fact), the act of ice freezing on things releases a small amount of heat itself. Those effects will likely push temperatures up just enough overnight to bring temperatures above freezing in the base of the Roanoke Valley and to near freezing even in many higher elevations. The big question is: How much ice occurs before that slight warming happens? High winds are expected late Sunday, possibly gusting over 50 mph. Hopefully, even the places that get a lot of ice will see some melting during the day Sunday before those gusts arrive. Click here to see the latest National Weather Service-Blacksburg radar Ice storm warning includes Roanoke ValleyPosted Dec14, 2007 at 03:41 PMRoanoke County is included in an ice storm warning just issued by the National Weather Service in Blacksburg for the time period from noon Saturday to 9 a.m. Sunday. On this map linked here, you can seen an unusual pattern of counties in purple under the ice storm warning. The worst icing is expected along the Blue Ridge southward into Floyd County, in the Alleghany Highlands up toward Covington, Clifton Forge and Hot Springs, and in the southern Shenandoah Valley near Lexington and Buena Vista. This is because east winds will be banking cold air against the mountains in these areas, the familiar winter weather pattern known as cold air damming. Elsewhere, the New River Valley plus Franklin and Bedford counties are under the less ominous freezing rain advisory. Some warmer air may work into these regions and push the temperatures slightly above freezing. However, I would not be surprised to see some of these counties added to the ice storm warning once things get under way on Saturday. It does look like ice will be worse at higher elevations. The "urban heat bubble" kept Roanoke city barely out of the ice storm on Valentine's Day. We'll see if that can help us out in the valley once again. Ice storm threat grows; winter storm watch issuedPosted Dec14, 2007 at 12:36 PMWith increasing signals that a shallow wedge of cold air will be pushed southward through western Virginia as a low to the west drags warm, moist air over it, a winter storm watch has been posted Saturday for counties along the Blue Ridge, including the Roanoke and New River valleys. An ice storm is probably the worst of all options. Snow lovers miss the fluffly powder, winter haters get slapped with something undesirable, and everyone risks losing power and tree limbs. The roads may still hold some heat from this week's 70-degree temperatures, so ice may not build up immediately, but if it gets cold enough on the precipitation continues to fall, ice can start building up on roads, first on bridges and overpasses. Close brush between cold rain and ice stormPosted Dec14, 2007 at 08:25 AMBarring dramatic changes, it appears the die is being cast in favor of a low-pressure track to our west on Saturday evening. That path will sweep warm air in aloft, eliminating almost all risk of snow. The trouble, though, is that cold air will be present in a thin layer at the surface. Depending on the strength and location of high pressure to the north of us, that cold air could be just enough for freezing rain to develop across the area Saturday night. The Hydrometoeorlogical Prediction Center has considerably ramped up its ice probabilities for much of Western Virginia, as this map shows, calling for a 70 percent of at least a quarter-inch of ice from Roanoke northward and 40 percent for most of the rest of Southwest Virginia. This could be one of those borderline times when one location is 32 with ice collecting on the trees and another a few miles away is 33 with cold rain. As the low passes, colder air will sweep in by Sunday morning and some snow may fall. If there is significant ice, the strong winds wrapping around the low could add to any tree or power line damage that may occur. Could a tropical storm weaken our winter storm?Posted Dec13, 2007 at 11:01 AMThe first call on the winter storm from the Hydrometeorological Prediction Center is not impressive for our area. The winter weather forecast maps released this morning show the threat of heaviest snow way, way north of us with the threat of significant ice in a narrow sliver along the Virginia-West Virginia border basically from Roanoke northward. Questions that remain unresolved: Exact track of the low pressure system (now projected near or slightly west of us, transferring energy to a newly forming coastal low Saturday night), strength and movement of the cold-supplying high pressure to the north, and one of the most interesting, whether or not the computer models are correctly handling the moisture being pulled into the storm, and some other impacts, from what was Tropical Storm Olga. If they are in fact overestimating Olga's effect, the storm could end up being a little colder and farther southeast. I know that sounds weird, but the least little wiggles in the atmospheric data could produce dramatic forecast shifts as we enter the prime forecasting period (inside 48 hours) when, hopefully, the forecast can be zeroed in on. Meanwhile, areas of the Northeast are bracing for a winter storm today. Those same areas could get nailed again this weekend. Saturday forecast remains a messPosted Dec13, 2007 at 12:49 AMHopefully, there will start being some more clarity today as we get within 72 hours of Saturday's potential winter storm. The overall thinking now based on model runs is for a storm to lift northeastward toward us and then re-form off the East Coast. This would bring a mixed bag of snow, sleet, freezing rain and rain during the day Saturday, possibly changing back entirely to snow before ending Saturday night. But there are still big questions on the track of the storm and on the placement and strength of high pressure in southeast Canada, the feature that will be needed to hold the cold air in. At this time, it does not look like this system will fill any potential it may have had to be our "big 'un" but could still deliver a wintry mess and possibly a few inches of snow. Getting off easy with a little sleet changing to rain is more possible than getting a huge snowstorm. Expect some rain today and then windy, much colder weather to set in through Friday. Back and forth we go about weekend snowPosted Dec11, 2007 at 11:50 PMThe computer model runs are already in their tennis match stage, going back and forth between an inland track for the weekend's low and a coastal track. The inland track would bring more of a mix and maybe even rain, while the closer it goes to the coast, the more snow we would get. The one thing that seems likely is that a broad swath of the Mid-Atlantic and Southeast will get moisture in some form, and that's nothing but good news for all the regions suffering drought. Meanwhile, today should be the last really warm day with a high near 70 before showery weather introduces the cold front on Thursday that will usher whatever it is that happens this weekend. Some experts getting serious about storm threatPosted Dec11, 2007 at 12:07 PMThe Hydrometeorlogical Prediction Center's preliminary extended forecast discussion this morning includes this headline: "POTENTIAL FOR MAJOR STORM OVER THE EASTERN UNITED STATES AND WESTERN ATLANTIC" So they are starting to get serious, though still cautious, about the potential for a weekend winter storm in the East. Meanwhile, the Atlantic tropical season, thought to be over Nov. 30, has an encore with Subtropical Storm Olga moving through the Caribbean. A subtropical storm is one that has characteristics of both a tropical system and an extratropical system. (Click here for a column I wrote explaining subtropical storms.) This storm will not directly affect the U.S., but an intriguing question is whether the weekend storm forming near the Gulf Coast can pull in some moisture from Olga. The Midwest continues to be hammered by severe icing, with more than 20 killed in the storm. This is the storm system that, by moving northeast and eventually swinging cold air southward behind it, will set up any potential we have for snow or ice this weekend. For now though, it's more like spring. Blacksburg was already 70 degrees at noon -- breaking an old record of 65 set in 1971 -- while Roanoke was sitting at a seemingly cool 57. Wow, when is the last time Roanoke was 13 degrees cooler than Blacksburg? A wedge of cooler air has banked onto the east side of the mountains, while southwest winds continue to bring in balmy weather just a little to the west. Now that fog has burned off, the unusual gap between those temperatures will close this afternoon as sunshine prevails. Despite today's warmth, winter lurksPosted Dec10, 2007 at 05:19 PMRoanoke topped its previous Dec. 10 record high by 6 degrees today, hitting a balmy 73. Blacksburg beat its record more modestly, by 2 degrees at 67. The reason it's so warm is connected to the same reason that the Plains states and Midwest are experiencing a deadly winter storm. The strong low pressure system throwing moisture over cold air there is sweeping in warmth from the southwest into our area. Don't think we're too far our of winter's grip, though. After some more mild to warm days this week, cold air will return for the weekend, and there is some early indication of a storm system trying to form along the Gulf Coast and moving northeastward. If this materializes -- still too far off to get too excited about it, positively or negatively -- there could be an ice/snow threat for Saturday. With the next couple of weeks looking warm overall, it is possible that a storm system could catch a short gap in the warmth and bring a winter weather threat. If this transpired, it would be the opposite of last year, when even during the longer cold periods, storm systems always seemed to find the gap between cold waves. |
