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Kevin Myatt grew up in Arkansas to the tune of tornado sirens and the rhythm of hailstones. Chasing twisters like he did in 1999 and getting within a quarter-mile of one was exciting, but he finally tired of 5-month-long summers and 2-inch snowstorms and moved to the cooler climes of Southwest Virginia's mountains in 1999. Kevin thought he was going to be a meteorologist growing up but he credits divine intervention with continually detouring him to a newspaper career instead, landing him in an managing editor job of a small Arkansas paper before coming to The Roanoke Times as a copy editor in 1999. But his love of weather continues to this day, and at the beginning of 2003 he began this weather column in addition to the hiking page he has updated occasionally on Roanoke.com since early 2000. He now works the copy desk for The Roanoke Times and is its principal weather geek, offering weather reporting training classes to reporters and advising the newsroom on upcoming weather stories. He updates this column most Tuesdays and Fridays -- and other times as conditions warrant. Email your weather or comments questions to kevin.myatt@roanoke.com For more on Kevin |
WEATHER JOURNAL
February 27, 2004 8:15 a.m. DOUGHNUT HOLE  February 27, 2004 STRANGE PATTERN OF SNOW The Danville area has up to a foot of snow. So does Charlotte, N.C. Parts of North Carolina have had up to 18 inches, with snow still falling. I'm quite sure some isolated area has topped two feet. The Tazewell area managed to squeeze out 4 inches. February 26, 2004 4 p.m. WATCH AND WAIT It's pretty much a radar watching game now, as the precipitation area slowly works northward, destined to run into a firewall of dry air somewhere tonight. As of now, returns are as far north as Wytheville and Martinsville, but a lot of the initial charge of moisture is not reaching the ground. Looks pretty good for 4-6 inch snows from Wytheville and Martinsville and points south, but less in the Roanoke and New River areas. About 2 inches looks good here. An upper level low will be pulling from the west as well, and this will help trigger a wider outbreak of snow later tonight. But the surface low is tightening off the coast, and this is pulling a lot of the storminess eastward. Lost in our obsession with whether or not it snows here is the fact that this is is now a true blue nor'easter, with 50-plus mph winds possible along the Outer Banks tonight. It's one of the roughest storms of the season. Whatever falls tonight won't last long. We should see 60s by Monday. February 26, 2004 11 a.m. TIME TO FOLD ’EM? The government's Hydrometeorological Prediction Center is noting stronger winds aloft and expanding its heavy snow zone a bit northward. But the National Weather Service in Blacksburg is noticing drier air at the surface being pulled southward as the low on the coast takes shape. February 26, 2004 8:30 a.m. CAROLINA CRUSHER Bottom line: This will be a snowstorm of historic proportions for North Carolina. Before it ends Friday, somebody in the western half of the state will have 2-3 feet of snow. Yeah, that's right, I said FEET. Widespread 1-2 foot amounts will occur. Wouldn't rule out a 4-footer on some high mountain peak where no one lives. For our area, it will be the ultimate game of brinkmanship figuring out who gets snow and who doesn't. Conceivably, the margin between a foot and nothing could be 50 miles or less. It all depends on where the edge of the snow sets up across our area, similar to the Sunday, Feb. 15, storm except this storm is much more powerful. I think the forecast map by private meteorologist David Tolleris shows vividly the possible narrow margin we're dealing with ... notice how the line between 4-8, locally 10, and less than 3 goes right across Roanoke. Also remember that the Feb. 15 storm left up to 5 inches on the south side of the Roanoke Valley, while the north side got as little as 1 inch. The National Weather Service is calling for less than that, 1-4 inches in Roanoke, 3-7 in the New River Valley. My best guess: a solid 5 inches in Roanoke from about 6 hours of heavy snow tonight. More to the south, maybe as much as a foot in places like Abingdon, Damascus and Martinsville, perhaps 8 inches up through Wytheville, Rocky Mount and Pulaski. The cutoff line falls from Clifton Forge to Lexington to Amherst. North of there, almost nothing. We'll update again later today as this severe winter storm comes together. Feb. 25, 3:30 p.m. LIVING ON THE EDGE North Carolina looks like it is going to get hammered. Models are showing incredible amounts of moisture with the upcoming storm. Somebody in the western mountains will top a foot, easy. Maybe lots of somebodies. For us, it's a razor-thin margin between the glancing blow expected now and a really big snow. It depends on how fast and deeply the moisture can penetrate the cold, dry air settling over us. With a tendency for storms to track northwest of expected tracks and still 24 hours til showtime, it is a shaky forecast at best. The National Weather Service has issued a winter storm watch up to as far up as Wytheville, for 3-6 inches of snow, with 6-10 expected in North Carolina. That may be undercutting it a bit down there. The depth of the dry air is the only thing really keeping me from disagreeing with the NWS call and expecting snow to spread farther north. I've seen such dry air eat away many potential snowstorms, here and elsewhere. Somewhere there will be a sharp line between several inches of snow and not much. Where that falls is critical, and we might not know until the radar shows us -- like two Sundays ago, which is in the back of my mind. Like this storm, it was supposed to cut off near the Virginia-North Carolina line. My advice to you: Pay attention closely to the forecast throughout Thursday. It could change rapidly. I discourage travel south of Roanoke, especially into North Carolina, late Thursday where severe winter storm conditions could develop quickly. For Roanoke, just hang on to your seats right now. I'll take a crack at a guess on it tomorrow morning. This could become the "nickname" storm of 2004, especially with a strong coastal low forming later Thursday. LET THE NAIL-BITING BEGIN Sure enough, right on cue, computer forecast models are beginning to show what every weather geek and meteorologist east of the Mississippi instinctually feels to be the right thing, and that's to bring the Gulf low northeastward instead of shipping it straight out to sea. The models now paint a serious snowstorm over North Carolina and a developing low off the Atlantic coast that could become a full-fledged nor'easter. To be watched henceforth is whether this northwestward jump in the models' tracking of the storm is the start of a trend or whether they're now adjusting themselves to what will end up being close to correct. If it's the start of a trend, the track may continue being shifted northwest until suddenly the I-81 corridor is in the snow game. Not unprecedented for that to happen. Not at all unusual, in fact. The time frame here is Thursday night-Friday. If the upper level low pressure approaching from the west is stronger, it could serve to deepen the storm and pull it farther north. But it may run out to sea before that has a chance to develop. It's nail-biting time for forecasters. There's only about 24 hours to really commit on this storm, and no one wants to have a surprise nor'easter on their scorecard. Probably, for now, this is more North Carolina's storm than ours. But that's what we said a couple of weeks ago. Tune back in this evening and on Thursday for additional updates. February 24, 2004 A HOLDING PATTERN As a cold front moves through bringing rain showers today, we're still in sort of a "wait-and-see" mode regarding the late-week storm. Computer forecast models are split this morning between a deeply suppressed storm that misses us far to the south -- even farther south than some of yesterday's runs were showing -- and a more intense system that rides northeastward from the Gulf and spreads a snow threat closer to us for Thursday. A lot depends on whether a high pressure building in from Canada, and bringing the cold air necessary for snow, will be strong enough to force the whole thing south. Hopefully, the weather pattern will offer more clarity on this situation over the next 24 hours. Feb. 23, 2004 ANOTHER STORM TO WATCH Another week, another complex weather situation to watch. I'm not sure I ever properly followed up on last week's expected "bomb" off the East Coast. It did indeed bomb into a powerful low pressure system, but too late for a severe winter storm anywhere in the United States. Some places on the New Jersey coast got a few inches of snow, but it certainly was not nickname material. Don't tell that to the folks in Nova Scotia, though, who got snow measured in feet and hurricane-force winds out of it. This week's complexities are a different animal, focusing more on the Gulf of Mexico initially rather than the Atlantic. That alone should raise some eyebrows, because we get more of our significant winter storms from low pressure systems rising out of the Gulf than from those bombing in the Atlantic. There was a bit of a buzz last week when some computer forecast models showed a perfectly phased system, bringing pieces of northern jet stream and southern jet stream energy together, developing in the Gulf and riding up the East Coast as far as Cape Hatteras before angling out to sea. This scenario, provided enough cold air, would bring the shovels and the snowblowers out in force in Southwest Virginia. This has proven to be fantasy as the different upper level systems are coming through at different times rather than working together. A wave on the northern branch will be coming through Tuesday, bringing some light rain and then a cold front, with maybe a snow shower or two. No big deal, except that it will reinforce the cold air. But it still leaves the wet southern storm, coming out of the Pacific across California, to deal with later in the week, probably on Thursday. The slower arrival takes care of the cold air issue. Questions abounded about whether a big system coming through Tuesday would have enough cold air to work with, but a system that late in the week would be well supported by high pressure to the north and a developing cold air damming effect on the east side of the Appalachians. From this distance, it appears it would be pretty much all snow for us by Thursday. The questions now surround the track of the storm and the available moisture. A lot of the computer models want to suppress the storm to the south, scooting it out to sea harmlessly for us. Not a few meteorologists, however, are noting that the pattern in the Atlantic may be conducive for a storm to ride at least part of the way up the East Coast. I don't have enough space or time to explain all that right now, but perhaps I will later in the week as we get a better handle on whether this system is a threat. Last week, I said the coastal bomb in the Atlantic was not a favorable pattern for us to get much snow out of; that proved to be true. On the flip side, the Gulf Coast low is a favorable pattern. The early instincts of many weather-involved people have it to override a literal interpretation of computer modeling and expect something to come out of this storm for us late this week, based on historical and climatological norms. Beyond this episode, there are some signs the southeastern U.S. high pressure ridge may intensify, and this may bring a longer respite of semi-spring over the weekend and into early next week than last week's two-day break. The breaks will keep getting longer and longer until one of them catches on and becomes spring itself. That should be some hope for you winter-haters. February 20, 2004 ON THE HORIZON Enjoy the sunny warmth today. Somebody might clip 70 today. The next big feature on the horizon occurs in the Tuesday-Wednesday time frame next week, as a strong low pressure system crosses the southern U.S. on the Pacific jet stream. Many models are showing this as a particularly strong and slow-moving system. It is a very interesting feature, but there are lots of questions -- the biggest being how much cold air will play into the storm. A cold front will come through Saturday to end the springlike break, and cold air damming may very well develop early next week. Will it be enough and timed right for snow with the upcoming system? Or is it just a big soaking rain? This will be something to keep me occupied early next week. February 18, 2004 SNOWBREAK It's a taste of spring, at last. Highs today are likely to be in the 60s as a warm air mass continues to build in from the southwest, aided by downslope winds flowing off the mountains that push things upward a few more degrees. But alas, it will be short lived. Another cold front sweeps in on Saturday, bringing familiar northwest winds and snow showers to the mountains, and we return to a colder, stormy pattern over the next week to 10 days. Still, today's warmth is a sign that the coming arrival of spring is as inevitable as the sun coming up each morning, quite literally. The days are getting longer and the sun angle is getting higher. What this means is more warmth upon the Earth's surface in our hemisphere. More and more of that warmth is absorbed or transferred into the atmosphere and the oceans each day, and slowly but surely, the large-scale patterns shift to those that take us between sunny days and thunderstorms in spring and summer. Winter will not go quietly. There's still a deep and widespread snowpack over most of the northern half of North America, all of Canada, extending to the North Pole and down the other side into Siberia. The collisions of reticent winter and advancing spring can create some vibrant and treacherous weather, in the form of thunderstorms, tornado outbreaks, floods and snowstorms. Think of a lightly flowing stream that's frozen over. As warmth begins melting the ice, pieces of it break off and flow downstream. That's sort of like the atmosphere. As spring gets closer and more solar energy warms the atmosphere, chunks of cold air break off and flow with the jet stream. The chunks of cold air are the upper level lows that you hear about, and they can trigger thunderstorms or snowstorms, depending on the conditions underneath and around them. March is often a chaotic month of weather in our neck of the woods. It's sometimes 65 degrees and sunny one day and 30 degrees and snowing the next. It's been a month for some massive nor'easters, such as the 1993 Superstorm and Ash Wednesday storm of 1962, both of which buried inland areas under mountains of snow while rearranging coastlines with wind and high waves comparable to many hurricanes. The short-term pattern leading into March looks similar to what has brought us such a persistent round of winter storms. We'll have a strong Pacific jet stream traversing the country, bringing in a series of storm systems, and the presence of cold air masses dipping down from the north. The trick, once again, is the timing, whether the storms and the cold air will mingle just right. I doubt that we are done with snow this winter. There's just too much energy in the pattern and still too much cold air entrenched atop an unusually widespread snowpack to the north for them not to collaborate at least once more. The question still lingers whether 2004 will produce an East Coast storm powerful enough for a nickname. The energy is available in this pattern; it's just a matter of the day-to-day specifics getting lined up right. That said, we will see more respites like today, and probably no more weeks where the ground stays covered in ice and snow. I urge you to enjoy both the warmth and the snow. I do. February 17, 2004, 9:26 a.m. NO CHANGES With precipitation developing in the Carolinas and the low beginning to form off shore, right now it still looks like this storm will slip east of us, maybe a bit farther east than earlier expected. The low will not really get wrapped up until this evening, when another piece of upper atmospheric energy arrives. You can see that on the radar this morning coming through Louisiana. (Call up this radar loop.) By then, it will be farther north and too far east for us. Maybe some light snow from Roanoke east. There's still time for this forecast to go wrong though. If you don't hear anything else from me today, assume that this will stand. NOW BATTING We whiffed on a sinker Thursday, then fouled off a curve ball Sunday. So with two strikes against us, the greater community of weather-involved people is now staring at a mean knuckle ball today. It could easily be strike three in a tough week of winter forecasting. Today is one of those intriguing but nerve-wracking days for forecasters. That a powerful low pressure system will develop rapidly, or "bomb", on the U.S. East Coast seems nearly certain. Little else does. The early calls are that this is a glancing blow or a complete miss to the east for us. But Sunday night was supposed to be a miss to the south. The stakes are even higher this time, as this will be a much stronger system. One technique forecasters sometimes use is finding an "analog" to a given storm. This means looking back in the record books to find a weather pattern similar to the current one, and looking at what that storm did to look for clues on what this one might do. Two or three different possible analogs have been offered, but the most recent is Jan. 25, 2000. This was a strong low that bombed off South Carolina coast and tracked north-northeast along the coast. Snow spread rapidly northwest. Raleigh got two feet. Richmond about a foot. Lynchburg 9 inches. Roanoke -- not a flake. The thinking now is that similar to the 2000 storm, this one develops too far north along the coast and tracks too far east to give us much snow here -- farther north and east in fact than the 2000 storm. But had the 2000 storm been but 50 or 60 miles farther west, or developed maybe 100 farther miles south, we might have got the 8 inches in Roanoke, while Blacksburg might have been left high and dry. The margins can be that thin in a tightly wound coastal low throwing moisture back into cold, dry air. Though the consensus is an eastward storm, there are some whispers of a more westward development, or a larger precipitation shield to the west. There are others that see this as a very eastward storm that goes out to sea and doesn't do much to any landlubbers. The computer models aren't a lot of help -- they've been all over the board with this thing, just like they were in 2000. In fact, in 2000, many forecasters literally took their eyes off the ball, watching a second upper level low as the expected trigger for the coastal storm, when the first ended up doing the trick. This resulted in a storm developing more than 24 hours ahead of expectations, and much farther south. We don't have the dueling disturbances this time, but we do have lots of uncertainty. Bombs like this often seem to have a mind of their own. We'll probably start the day with middle-range probabilities of snow in the forecast during the afternoon and evening and light accumulation expectations. As the day wears on, do not be surprised to hear forecasts going decisively one way or the other, toward more snow or none at all, as the scene begins to unfold. Historically and climatologically, this setup is not usually a big snow-maker for Roanoke. Until something convinces me otherwise, I have to defer to that. But by the time we see where the ball is going, it'll be too late to swing. February 16, 2004 ROUND 3 Sunday night's storm did what I thought Thursday's storm would do. Thursday night's storm did what I thought Sunday night's would do. Two very similar systems that played out slightly differently with hugely different results. Up to 8 inches of snow fell in Southwest Virginia on Sunday night from a storm that I really, really doubted. In Roanoke, we got 3-4 inches, with about 5-6 in the New River Valley. By 6 p.m., it was becoming obvious that it was going to be a bigger snow night than just about anyone thought. The National Weather Service, though bitten a bit in its earlier expectations, did a good job adjusting forecasts to meet the changing situation. There's little time to contemplate what's past for a third larger situation is at hand. The upper level low sweeping across on Tuesday could trigger a "bomb," or a suddenly developing low pressure off the coast. This could be a big, big snowstorm for someone, if it doesn't go out to sea. Most forecasters expect this to be east of us, possibly Tidewater or the Delmarva, but considering the batting average of late, that's little to rest on. A more westward track, or a low developing farther south, could spell bigger trouble for us. No rest in this pattern. Hope you enjoyed the snow on Sunday night. It was gorgeous, clinging to every single twig. And there was no freezing rain and very little sleet involved. That alone made it notable. February 15, 2004 PROBLEMS? Radar returns are indicating a more serious precipitation shield advancing farther north than expected. This could mean that some areas, particularly from Roanoke south, may top expected light accumulations. There are reports of heavy snow with huge conglomerated flakes in the Martinsville-Danville area. That area is in for much more snow than expected, it would seem. For Roanoke, we're still on the north edge right now, but that north edge is nudging north. The reverse of last week's bust that was less snow than expected? It sure looks like it might be.
DEJA VU? THEN AGAIN? As an upper level low pressure area spins across Tennessee and Mississippi this morning, the forecast looks eerily similar to what happened last week when a significant snowfall failed to materialize. And with my expectations that the storm will almost entirely sneak south of us, and the National Weather Service calling for an inch or less, the worry this time is that this thing will lob a band of snow just far enough north to do the reverse of Thursday's bust -- more snow than expected. The critical difference in this storm and last week's is that a legitimate Arctic air mass is building in -- cold air damming, again. This has two effects that seemingly contradict one another: (1) it will provide plenty of cold air that will ensure that this is all snow, with temperatures going below freezing rather quickly once it starts and (2) it provides dry air that the incoming storm must overcome with moisture before it can begin snowing at all. I hope I'm not just being gun-shy after last week's miss, but I just can't buy into tonight's storm for us. It's too far south and quite possibly weakening. So while we may see some flakes, I don't think they stack up much tonight. I like the Weather Service's call of no more than inch, and really, I would be surprised if we got that. Then, we have the third pitch thrown at us late Tuesday. This strong upper low coming in on the jet stream is expected to cause a large surface low to form off the South Carolina coast. Someone in the eastern U.S. may get their largest winter storm of the season with this one, but I don't think it will be us. I think it's going to be wide right, out to sea, more of a storm for Richmond and Virginia Beach. But Tuesday's storm is potentially a "bomb" -- a suddenly developing very strong surface low -- and for that reason has its own uncertainties and concerns. Stay tuned. February 13, 2004 WHAT'S ON THE PLATE (1) A system with a couple of pieces swings across the South over the weekend. Winter storm watches are up in Texas today -- and I'm not talking the Panhandle areas that get snow fairly regularly. We're talking places like Waco and Longview. The presidential ranch at Crawford will probably be a winter postcard. All in all, this looks like a Deep South storm that will scrape south of us. As the upper low pressure drags across Sunday night, there is a better chance that it could kick some snow into our area, but it still looks more like a Carolinas event. The cold air supply will be much stronger than this past forecast debacle. It's something to consider, though forecasters may be a tad gun-shy. (2) Some weather analysts are latching onto a midweek possibility of a significant storm again headed across the South and up the coast. Some of that reticent Arctic may be building in, and this could turn into a large storm. It's many days out, and some forecasters are not even mentioning it, so let's leave it there. I'll update Sunday if there seems to be a decent snow or ice threat for Sunday night. Meantime, have a happy Valentine's Day. February 12, 2004 SOMETIMES YOU FEEL LIKE A GOAT Sometimes you just happen to be reading something that seems so appropriate for the moment. A colleague handed me an article Wednesday off backpackinglight.com by a Western outdoors writer named Ryan Jordan who is documenting his hike on the Appalachian Trail. He offers the following observation on weather forecasting: "I've learned time and time again that billions of dollars of weather forecasting equipment placed in strategic locations across land, sea and space, providing data to sociologically peculiar scientists (who the ... chases tornadoes?) and presented to the public by less interesting forecasters, really don't work well at all. Forecasters seem to report accurate weather only in real time, and even then, that is not often, because they often fail to look out the window of their studio buildings, relying instead on computerized databases of numbers that were something on the other side of meaningful not less than a few hours before." A stinging rebuke. I'd hate to see where weather geek newspaper columnists fit on Jordan's meteorological feeding chain if he thinks so little of television forecasters. But today his words seem oh so fitting after, for the first time this season, the weather forecast community experienced pretty much an across-the-board, area-wide forecasting bust on an alleged snow event for Thursday. There are misses in almost every storm. Someone gets more snow than expected, someone gets less. Someone gets ice instead of snow, someone gets snow instead of ice. But this was a miss for just about everyone, with calls of anywhere from 1-4 inches in our area (I guessed 2-3 for Roanoke) and speculations of up to 8 or 10 down in North Carolina. You might have seen some snow falling out your window Thursday morning, but you didn't get what was called for. (Let me hear from you if you did). This storm system unraveled faster than Howard Dean after the Iowa caucuses. It was too fast, too warm and too dry to be a significant winter storm. Some people got rain instead of snow, and where it did snow, it didn't snow hard enough long enough to pull the cold air down with it from the upper atmosphere, so ground temperatures hovered above freezing and not much stuck. Only some North Carolina mountain areas got a few inches of slush out of it. The worst part about it is that every meteorologist and amateur forecaster within a 500-mile radius knew this system was an iffy proposition, but had to stake themselves to something on glorified guesswork. The computer models were trending northward and wetter with the storm on Wednesday ... then poof, the models on Wednesday night weren't showing that as the storm cranked up to the west. Bad model runs? Can't argue with them in retrospect. It's a maddening pattern right now, because nothing is clear-cut. We don't have well-formed low pressure systems crashing onto the West Coast, gliding across the country into well-defined zones of warm and cold air. Instead, we have half-cooked upper level disturbances racing erratically into an air mass that's sortakinda cold but not real cold. Sometimes these things ramp up into major storms; often they do not. The Arctic air intrusion that's been constantly threatening is always another week to 10 days out. Throw in the increasing uncertainties of seasonal climatology moving toward spring. Let's check back with our friend Ryan Jordan: "In retrospect, that forecast turned out to be right on the money, which of course is absolutely maddening for an analytical backpacker that depends on the inaccuracy of these forecasts for his careful planning." Well, forecasting is not always wrong, as Jordan admits. Another disturbance is moving our way late in the weekend. It's expected to touch off unusual snow in unaccustomed parts of Texas, but after that, its path and intensity are uncertain. It's another chance for weather people to be like NFL kickers: either the game-winning hero or the title-choking goat. February 12, 2004 NO BIG DEAL I awoke to see a few flurries in the floodlight at 5:30 a.m. There might not be much more than that. The moisture levels are not impressive, most of what is there is to the south, the system is moving fast and a lot of the precipitation is simply evaporating in the dry layers of air between cloud and ground. Air also is warmer than forecast, though still cold enough for mostly snow here in our area. Bottom line: This isn't going to be a big deal for most of us today. Maybe an inch of snow in Roanoke. Maybe. I really doubt it. Probably a pesky off-and-on light snow today that might even be mixed with light rain. Doubtful that roads become a problem except maybe in some higher elevations. This isn't going to be the winter storm we thought for North Carolina, either. In the high mountains, somebody might collect 6 or 8 inches, but not widespread down into the Triad and Triangle. By the time the atmosphere moistens up and chills out enough for good snow, it'll be pulling out. It happens. It's called a forecast bust. Now, we have to look ahead to other pieces of energy coming down the pike through the southern jet stream into a marginally cold air mass. Not confidently, I might add. February 11, 2004, 4.p.m. NUDGING NORTHWARD As expected, forecast models throughout the day are showing the approaching snow expanding slightly farther north — enough that it looks likely that Roanoke will see at least some accumulating snow on Thursday morning. CLOSE SCRAPE This season's winter storms have pretty much followed the climatological norms, in that areas to the north and west have gotten more and areas to south and east have gotten less. The storm coming at us late tonight and Thursday will probably be the first this winter to bend those rules. A low pressure area is developing in Texas and will move east-northeast over the next 24 hours. This one will not head up the East Coast. It'll shoot out to sea. However, its precipitation shield as it slides through our area and the upper-level dynamics look favorable for snow late tonight and Thursday. The mountains of northwest North Carolina are the most likely to see a heavy dump of snow. Southside Virginia, including Martinsville, seems to be in the bull's-eye for 3 or more inches of snow. Roanoke and the New River valleys might get an inch or two. Or so it looks now. I'm always a bit jumpy about systems originating in the Gulf of Mexico shooting across like this. Any little nudge to the north, or any minor strengthening, could turn what looks like a light snow into a real wallop for us. Moisture won't be lacking with this system, although it looks more focused on North Carolina. This could be a big storm for Greensboro and Raleigh, perhaps on up to the Tidewater. There will probably be a sharp cutoff to the precipitation on the north side, so the other forecasting danger is that the entire snow slips just south of your given location. It could be that Lexington gets no snow while Buchanan gets an inch. Or maybe it cuts off between Roanoke and Rocky Mount. Check back with the forecasts this evening and don't be surprised if they start changing, depending on how the system forms in Texas and what later model runs show. February 10, 2004 Many forecast models have been depicting a southern storm system developing over the next 48 hours and tracking across the southern tier of the nation, possibly bringing snow and ice to some Deep South locations that get such weather infrequently. Later model runs have begun shifting this system farther north, so much so that this is becoming something for us to consider in the Wednesday night-Thursday time frame. Probably, we would be talking about a chance of snow here. Almost certainly, we're not talking a big, big snow here, but it is something to watch to see how it develops. I'll get back with you Wednesday morning for the latest, to see if this will become a winter storm threat for us or if it will pass harmlessly to the south. Feb. 9 THE TWO MINDS OF WINTER From my conversations, I take it there are two groups of people out there -- and it really has nothing to do with political leanings or Victory Stadium. (1) Folks who would love to see an early spring. (2) Folks who are still feeling empty because this winter, for all its cold storminess, has not clocked us yet with a truly pure and powerful snowstorm. The sad thing is that I don't have much to say to either group to heal your depression today. You early spring people have it worst, though. As much as it grieves me to concede to a rodent, I concur with the groundhog. Spring is probably a good five weeks away (we're a week past Phil's prognostication now). We'll probably see a few warm days before mid-March, but not a whole string of them. The North American snow cover map shows a healthy white over all of Canada and the northern half of the United States -- including a little stripe down the Applachian spine in far southwestern Virginia. I haven't seen the grass in the front yard of my apartment since Jan. 24. That's 15 days now. The sun, a few days in the 40s and last week's rain have cleared off most of the south-facing banks here in the Roanoke Valley, but there's still a crusty white shellack on nearlly all the north-facing hillsides. The North American snow cover is much more widespread and thicker than it's been during most of the last 20 years. Cold air masses early in the season helped build that snowpack, and the snowpack now gets to return the favor by helping hold in cold air masses late in the season. With that kind of mini-glacier covering North America, it's going to be hard to sustain a widespread warmup any time soon. For the weekend and into next week, a high pressure ridge in the West is expected to push northward and dislodge a chunk of frigid arctic air southward. This arctic air mass probably will be the most widespread of the season to date, and may cover the U.S. from the Rockies to the East Coast. The coming arctic air does give you snowstorm fans some hope. You've got to know that one of the best opportunities for a large snowstorm was missed Thursday and Friday -- so much moisture and atmospheric energy wasted on ice and flooding rain. The arctic air could suppress the southern jet stream such that the storm track speeds west to east across the Gulf of Mexico. But with the cold air likely hanging around into late February or even March, the blizzard-wishers haven't had their dreams snowed under just yet. Feb. 6 2004, 2 p.m. SMORGASBORD OF WEATHER Many counties to the west of Roanoke, including Craig, Bath, Montgomery and Giles, are under a flood warning now as rain continues to pour down on frozen, snow-covered ground. Although isolated areas are still at the freezing mark and experiencing ice accumulation, temperatures have risen just above freezing across most of the area. It's not hyperbole to say that a couple of degrees have separated us today from a nasty, chilly, wet day and a multimillion-dollar ice storm catastrophe. It's a weird day for temperatures. It's 33 in Roanoke, while Hot Springs is now at 42, the spread reversed from its usual arrangement. The warm air continues to surge aloft. There's a 40-degree spread between the Tidewater area, where they're basking in 70-plus degree warmth, and Richmond, which is barely above freezing. The cold air wedge is obvious from those numbers. Flooding rains are the main issue now, as the warm, moist air aloft surges north in front of advancing cold front. The front arrives this evening, and it will bring renewed chilly winds from the northwest, which will in turn kick off snow showers in the mountains. It's a two-day smorgasbord of weather with this powerful storm system. February 6, 2004 CLOSE CALL Heavier rain is moving across the area this morning with temperatures at or slightly below freezing. Rain will help mix warmer air above to the surface, eventually warming us above freezing, but freezing temperatures will linger just long enough in some areas that downpours may cause problems with ice accumulation on trees and powerlines. The problem with terrain like Western Virginia is that subfreezing temps can hang on in some valleys hours after surrounding temperatures have gone above freezing, and these localized areas can continue to collect ice. Unusual this morning is that Hot Springs, whose airport reporting station is on a mountaintop at nearly 4,000 feet, is reporting 33 degrees while it's still 32 here in the Roanoke Valley. Usually, Hot Springs is 5-10 degrees colder than we are, but the warm air is moving in aloft first. I would not be surprised to see temperatures warm above freezing in some parts of the Roanoke metro area while ice continues to collect elsewhere in the Roanoke Valley. Also, it may continue to collect on tree tops while surface temperatures go above freezing. With the expected warmup, rain is expected to continue throughout the day and into tonight as a low pressure system to the west pulls in copious amounts of moisture. Expect 1-2 inches of rain, and the concern is that combined with the melting snowpack in the mountains, there will be some flooding. That's why a flood watch is in effect. That's something we'll have to keep watching as the day unfolds. This morning's problem is ice. Most of it is on the trees here in the Roanoke Valley, but there is some on the roads here and there. February 5, 2004 IT HAS BEGUN Sleet and freezing rain have already begun in much of the area and there are reports of accidents in outlying areas. In Roanoke, we may not catch the heaviest part until much later tonight when the main precipitation band drags through from Tennessee. The early rounds are heaviest to the north, so Lexington and Bath County may get real slick real fast. The northern areas are under a winter storm warning for potentially heavy ice, while we're under a winter weather advisory here in Roanoke. It is a close call, though, whether we'll get to a quarter-inch of ice before the warmup comes early Friday. Temperatures are hovering a little above freezing in Roanoke now, but additional precipitation will bring us to the freezing mark or below later this evening. The warmup early Friday should take us above freezing rather quickly at some point, and then we wait to see if flooding rains will become an issue. February 5, 2004 BAIT AND SWITCH? The storm moving in begins as a winter storm worry -- then morphs into a spring storm for us. It's a left jab followed by a right uppercut, and it's hard to tell right now which, if either, will be the knockout punch. The National Weather Service is going more with the flooding threat on Friday and Friday night as the chief concern. All of Southwest Virginia is under a flood watch for that period, as possibly heavy rain occurs on top of mountain snowpack. Meanwhile, only a few northern counties are under a winter storm warning for the ice threat tonight, while counties farther south including the Roanoke and New River valleys are under a winter weather advisory for what is slated as just a touch of ice. As a low pressure area moves west of our region tonight through Saturday, it will sweep Gulf moisture over cold air at the surface. This cold air will be enough at the start for sleet -- maybe even a little snow -- followed by freezing rain. However, it looks nearly certain that it will warm up enough for precipitation to become all above-freezing rain by sometime during the day Friday. The questions of exactly when that changeover occurs and how much rain falls before it does are the pivotal points between a major ice storm, nuisance icing, or no ice at all. My icing concerns are raised this morning. We have total cloud cover this morning, so we will not have a lot of solar warming at the surface. Precipitation is advancing faster than projected to our west and may arrive sooner -- though the first waves of it will evaporate before hitting the ground. And some forecast models show us getting as much as a half an inch of rain before the changeover, with heavier amounts than that not far away. Plus, sometimes if you get a good layer of ice at the surface, it's hard to get the temperature to rise that last critical degree or two. The cold air dam will eventually burst, but maybe grudgingly. The flooding is a serious issue, too. The one thing missing is that, unless we get warmer than expected and jump into the 50s across the area on Friday, I doubt we get the extremely fast mountain snowmelt. The slow snowmelt plus heavy rain, plus a frozen ground that will not soak up much of the moisture, will be enough to push many rivers to bankful or above, and some creeks in tight valleys may experience flash flooding if heavy rain showers or thunderstorms move in. So, waiting for this match to unfold, it's my hope that we'll get two glancing blows, but my fear that we'll get two hard punches. Stay tuned as we watch it's arrival. February 5, 2004 STORM TRACKS Often it seems as if storm systems are like trains on rails, following the same tracks over and over again. While low pressure areas can and often do find new and creative ways to move, there are two common tracks forecasters look for in storm systems moving northeastward from the Gulf of Mexico: (1) along the coast and (2) along the western side of the Applachians. The storm we are dealing with today, if it's does what we expect it to, is of the second category. When a storm system takes this track, we are on the east side of the center. South and southeast winds in the counterclockwise circulation pull in warmer, moister air off the Gulf and Atlantic. Sometimes, this is called the "warm sector." An "inland runner" like this often leads to thick moisture and potentially heavy downpours. In spring and summer, when the low is dragging a cold front into the warm, moist air mass, it can be a prescription for thunderstorms. In winter, if high pressure to the northeast has wedged cold air at the surface along the mountains, the warm air overriding it produces the sleet and freezing rain we've become so accustomed to this winter -- until the warm air becomes thick enough to mix down to the surface and turn everything to rain. That is exactly the scenario that is suppose to unfold tonight into Friday morning. You can be the judge of whether it pans out. A coastal storm keeps us on the north and west side of the low, where counterclockwise winds keep cooler air circulating. As a result, when they hit in warm seasons, we tend to have a damp, cloudy, cooler-than-normal day with persistent light rain rather than the heavy downpours we get from a system that moves west. In winter, this is the ideal snow track, as it keeps us on the cold side while circulating in just enough moisture for snow to form. Our big 1993 and 1996 snowstorms were examples of coastal track storms. Geography does play a role in storm tracks. A coast is frequently a natural place for air masses to clash. In the case of the East Coast, there is a constantly warm current of water called the Gulf Stream offshore that can be quite a contrast to the cold air masses working over the land to the west. Similarly, the Appalachians are often a natural divide between dissimilar air masses. Just a storm systems tend to follow fronts where cold and warm air masses meet, they may follow geographic boundaries that divide the air masses. There are other tricky tracks that can stump forecasters. One is the "coastal transfer" where the low begins heading northeast into Tennessee as if it's going to ride up the west side of the Appalachians, then a low develops off the coast somewhere to the east and steals the energy from the original storm. Then there's the "suppressed" track that just barrels west-to-east and out to sea without turning. If it's not too far south, we can collect a big snow out of suppressed storm while D.C. and New York miss out. Everything hinges on the exact track of a storm, and a difference of 50 or 100 miles from expectations can make a huge difference in our weather. Every once in a while, a storm will jump the tracks and take an altogether different route than expected. That's when all weather people end up looking foolish. February 4, 2004 TRY, TRY, TRY AGAIN Two major ice storms have gone by the boards in the last 10 days for different reasons. The first, early last week, missed us when the moisture failed to surge northward as had been feared. Tuesday morning's ice storm dwindled because of too much cold air being present, allowing for more sleet and snow than ice. So now, one more time, the weather map is showing a severe ice storm threat for Thursday night and Friday. An upper level low pressure area rides in on the juicy southern jet stream, throws tons of moisture over us just as high pressure builds in cold air along the east side of the Appalachians It seems nearly certain that the warm air will eventually so overpower the cold air this time that we'll go above freezing and have just plain rain. But how much ice can collect before that happens? Big question, no easy answer. It's a razor-thin line this time between plain rain and a truly destructive ice storm. Though it's not impossible to see some sleet or snow as it begins, we won't be saved by the depth of the cold air this time -- the approaching storm is too strong and will override us with warm air. It seems doubtful that we'll miss this moisture, as this is likely to be our wettest system so far this year. So this time, to miss an ice storm, it has to get warmer faster than expected. The high building in the cold looks pretty strong though. Warm air will not end our problems. So much rain is expected this weekend, probably more than inch across the area with locally 2 or 3, and so much snowpack remains on the mountains that a warmup combined with heavy rain could create flooding problems. Ugh. Storm train '04 rolls on. February 3, 2004 SAVED FROM A BIG ICE STORM The snow and sleet came through, unexpectedly sparing much of our area from what could have been a major ice storm. Instead, most of us have a couple inches of snow/sleet slush this morning with just a little glazing. Roanoke appears to be the pivot point; places north and east have more snow, places south and west more ice. In the Star City all night, it was a constant tug of war between half-dollar size clumps of snowflakes, window-pecking sleet, and glazing ice. I would say the snow won most of the night. Not only was the cold air damming a bit thicker than anticipated, allowing for deeper evaporational cooling as precipitation fell through cold, dry air, but convection from thunderstorms that developed in North Carolina helped to bring more cold air down from the very high levels of the atmosphere to the surface. We'll probably see some more mixed precipitation, leaning a bit to freezing rain, off and on through mid-morning. With advancing warm air, we'll likely punch above freezing this afternoon and melt away some of the muck on the roads. A new cold front sweeps through later today, though, reinforcing the wintry air that we've had pretty consistently since our brief but sharp warmup right after New Year's. The new snow/sleet cover might raise the ante on keeping it cold at the surface for the next event on Thursday and Friday, which looks to be quite moist. It will be another nail-biter for forecasters, but the early lean is a significant freezing or frozen precipitation event similar to this one, probably larger. Just be sure and enjoy the Wednesday break in the action, though it will be cold. Feb. 2, 4:30 p.m. Radar shows moisture streaming up from the Gulf and developing across areas to our south. A few showers have moved into Southwest Virginia. This is the start of our potential ice storm tonight. The temperature is above freezing, 37 degrees officially, in Roanoke, but the dew point is 17 degrees. As precipitation falls, the temperature and dew point will meet in the middle as the air becomes more moist. This evaporational cooling will get us to below freezing fairly quickly. A winter storm warning is out for the entire area for expected heavy ice. The morning commute tomorrow may be hazardous, especially in non-urban areas. Be careful. February 2, 2004 ICE ON THE WAY We appear to be headed for a significant, potentially major, ice storm tonight across much of our area, with cold air at the surface and abundant warm, moist air set to override it. By significant, I would mean 1/4-1/2 inch of ice, enough to cause scattered power outages and slick spots on roads. By major, I would mean more ice than that, which could cause widespread power outages. I do not expect this ice storm to be a "catastrophic" one where almost all power goes out everywhere and nearly all trees are damaged. That would take well over an inch of freezing rain, and I think the system will be moving too fast to do that. An upper level is moving to the northwest of the area tonight, and this will stream Gulf moisture overhead. This should not be a prolonged event but probably several hours of precipitation into Tuesday morning as a wide band moves through. Early evening, 6-8ish, is my best guess at starting time for the precipitation. It'll be interesting to watch south and west of us and see how precipitation develops and moves today. Our saving graces could be if there is deeper cold air on the front end and more sleet and snow to start out than expected, or if it gets just a little warmer than expected and our rain doesn't freeze. The first of those options has a slight chance of happening, and one weather service to our south has alluded to that possibility in a forecast discussion this morning. I expect to see a period of sleet at the start, and then some mixed sleet with the freezing rain for a couple of hours after that. If at any time this evening it starts snowing pretty hard, that could be a good sign for missing at least some of the ice. The snow can't last too long in the atmospheric setup, but it would show deeper cooling instead of the shallow layer that's so dangerous for ice storms. The second option is looking really doubtful. With snowpack, frozen ground, and evaporational cooling with the beginning of the precipitation -- not to mention the slight cold air damming present -- it will be very hard to get temperatures to stay above freezing with this event. The cold air damming will break tomorrow, but just as the precipitation is moving out. The late week storm is a real conundrum right now. Multiple pieces of energy and computer model conflicts galore. We'll discuss it later. February 2, 2004 MORE TO COME? As you read this in the paper Tuesday morning, one winter storm will have probably left an icy muck on your doorstep. If it's more white or wet than icy, then the weather people are wrong about it. When the NAO is negative, that means there's a a low pressure system up in the north Atlantic near Greenland, and the polar jet stream crinkles southward around this block. When the PNA is positive, a steep ridge of high pressure forms in the Western U.S. and this causes storms to ride in atop the high and then southeastward toward us, bringing cold wet systems out of the northern Pacific and Canada. February 1, 2004 DANGEROUS ICE SITUATION DEVELOPING As you sit at home watching the Super Bowl this evening, we could be preparing for the Super Bowl of winter weather forecasting this week, with two very complicated storm systems. We'll leave Thursday-Friday alone for now. We have big trouble coming Monday night and Tuesday. A low pressure area will be moving northeastward toward the Ohio Valley. Typically, this is a warm rain track for us. There's just one problem: cold air damming. Enhanced by a still widespread snowpack in our area, and much greater to our north, the cold air looks like it will hang in tough at the surface as a high pressure area shoves it against the mountains. That means we'll have warm moist air streaming over a shallow layer of cold air at the surface. That's a prescription for freezing rain. If we're fortunate, the cold air's thicker and we get sleet, which is not nearly the problem on trees and power lines that freezing rain is. We may see some snow to start out, but this looks like more of an icer-sleeter. I am concerned about the potential for a major, widespread, damaging ice storm. Some models are showing anywhere from .5-1.5 inches of rain in our area. As freezing rain, this would cause major damage to trees and power lines. Again, the hope is we get sleet, or the surface temperatures rise just enough above freezing for no ice, or that we don't get nearly the precipitation expected. At 1:30 this afternoon, the National Weather Service in Blacksburg raised a winter storm watch for our area concerning the potential for an ice storm Monday night and Tuesday. From this distance, Thursday and Friday look like a very big deal weatherwise, and maybe the granddaddy of winter storm systems for the eastern U.S. this season. Where exactly we fit into the scenario is far from certain -- it could be anything from heavy rain to heavy snow, and many combinations in between. But there's many, many miles to trod before we get to that one, including an event that could upstage it on Monday night. Stay tuned this week as we dissect the difficult weather scenarios.
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