Serious severe weather outbreak likely across SouthPosted Feb28, 2007 at 07:11 PM
This is all part of a large and powerful storm system moving east out of the Great Plains. It will bring heavy snow to the nothern Plains, Great Lakes and eventually parts of New England. Farther south, where cool, dry air and warm, moist air collide, abundant rainfall and thunderstorms will erupt. Strong winds aloft moving in different directions will cause some of those storms to spin, fueling the possibility of large hail, high winds and tornadoes. For our area ... it just looks like quite a bit of rain, particularly Thursday night. Click here for projected rainfall amounts, as of this afternoon. Click here for the latest local advisories and warnings. Click here for the latest severe weather information locally, regionally and nationally Click here for the latest rainfall and flooding potential information Weather service helps you keep tabs on the next threatPosted Feb27, 2007 at 04:45 PMThe National Weather Service in Blacksburg has a neat new feature on what has been its current events page on its Web site that helps you keep track on upcoming severe, flooding, winter, fire, and heat/drought threats locally, regionally, nationally. Just click on the tabs at the top of the page for the latest "briefing pages" on these different types of inclement weather. Not only will you see a local map of warnings/advisories and clickable images of radar, satellite and surface map images, but also maps from national forecast office depicting broad areas of inclement weather threat. I have linked these maps quite often on this blog. So let's use this new feature for the upcoming system, which looks like a fairly rainy one for us on Thursday. Click here for the latest on the severe weather threat and the heavy/rain flooding threat from the upcoming storm. Hail of a problem for space shuttlePosted Feb27, 2007 at 04:32 PMA hailstorm is keeping the space shuttle grounded. Click here for story. Elsewhere ... this storm system was a very big dealPosted Feb25, 2007 at 09:20 PMA powerful tornado devastated much of the town of Dumas in southeastern Arkansas on Saturday, injuring 40 people ... but killing no one, miraculously and thankfully. (Click here for story) Meanwhile, 1 to 2 feet of snow buried much of the Plains and Upper Midwest, with Eastern U.S. areas north of us getting a lesser but still potent blast of winter. (Click here for story) This flirtation with winter weather is overPosted Feb25, 2007 at 09:15 PMThe winter weather advisories have all been cancelled. A few places got a little ice, but not much. Most places are just cold and damp. Will this be the last flirtation with winter precipitation this season? Always hard to tell, as March pulls some quick winter punches quite often. This week is looking mild, but there seems to be some indication that winter may make another run at us by the following week. I'll keep an eye on it. Winter precipitation threat easingPosted Feb25, 2007 at 12:57 PMThe bulk of the heavier precipitation is slipping east of the area, and temperatures at most locations are hovering a little above freezing. So the winter storm warning in the counties to the north has been reduced to a winter weather advisory, and some spotty freezing drizzle appears like it will be the only real threat left. This was not anything close to a typical winter storm setup, with the main low way up in the Great Lakes pulling warm, moist air from the south overhead. But enough of a wedge of cold, dry air forced its way southward along the eastern slopes of the mountains to make this a borderline winter weather event. Once again, the Roanoke Valley escaped by the margin of 1-3 degrees, other than the early-morning sleet that slushed the grass up some. You don't have to go far to find warmth: Bristol, Tenn., was reporting 55 degrees at noon, and temperatures on that side of the mountains, even into far southwest Virginia, may shoot up to 60 this afternoon. On this side, though, it will be a chilly, damp afternoon and evening. 'Chaotic mix' prompts winter weather advisoryPosted Feb25, 2007 at 07:42 AMI awoke to find a white ground from a light, slushy sleet accumulation here in south Roanoke County, though air temperatures are hovering a little above freezing. The sleet fell hard enough and the ground and exposed objects cooled enough to accomodate some accumulation. Streets are just wet here at this time, but that may be different where you are. In a morning forecast discussion, the National Weather Service in Blacksburg described the precipitation as "a chaotic mix of rain ... sleet ... freezing rain and snow falling across the forecast area this morning." The mix changed the wording of the advisory for the Roanoke and New River valleys from "freezing rain advisory" to "winter weather advisory." The next few hours are crucial to whether this will end up being an oddball winter storm or just a cold rain in the Roanoke Valley. Temperatures are in the mid 30s, but dew points are still in the upper 20s, which means there is some room for the temperatures to drop a bit with evaporational cooling. It's already 32 at Blacksburg, but 34 at nearby Dublin. As with the Feb. 13 winter storm this may well be a situation where conditions are different within a few miles, with one area getting ice while someone a few miles away stays a little above freezing. It's likely most of the precipitation will change to rain or freezing rain later this morning. The margin is thin between an ice storm and a cold rain. Latest winter weather information from the National Weather Service It can sleet in the 40s ... but will it get cold enough for ice?Posted Feb24, 2007 at 11:37 PMThere have been some reports of sleet around the area tonight. Yes, it can sleet well into the 40s, even the low 50s on occasion. Sleet is a very dense ice pellet that doesn't melt as rapidly as the fragile crystals of snow. It usually can't snow much at the surface above 40, but sleet can sometimes penetrate a surface layer of temperatures well above freezing. It won't stick much though unless it's 32 or below. Temperatures are only slowly creeping downward tonight, still hanging in the low to mid 40s, so I'm doubting even more that there will be much significant ice along and south of U.S. 460. We do now have a northeast wind that may add a touch of cold-air damming to the evaporational cooling from the precipitation falling into dry air. I think most areas from Roanoke south will stop in the mid 30s, though I'm sure a few outlying areas will drop to 32 and develop a little ice. Don't let my doubts overrule caution, though ... it only takes one patch of ice to ruin your day, or even your life. With so much mild weather of late, ice is more likely to form on trees and exposed objects than on roadways, but bridges and overpasses can get slick quickly even it is just 32. Any travel to the north on Sunday shoud be done very cautiously, as more severe winter weather conditions will be developing "upstate." Click here for the latest local National Weather Service radar Click here for the latest updates on the current weather event We're a minor part of a huge stormPosted Feb24, 2007 at 09:03 PM
It doesn't get much drier than this ... but it will change quicklyPosted Feb24, 2007 at 04:18 PMAt 3 p.m., Roanoke's temperature was 52 degrees and the dew point was -4 ... making the humidity 10 percent. I have a hard time remembering a lower humidity during my 7-plus years in this area. (Click here for Roanoke's current conditions and those of the last 24 hours) That low humidity is one of the major reasons wintry precipitation is even on the menu for Sunday. With tons of moisture being pulled our way, that dry air will become saturated. In that process, it will cool rapidly during the evaporation of the first waves of precipitation. And that evaporational cooling, combined with a slight amount of cold air damming (cold air being pushed southwestward along the east slopes of the Appalachians), will drop temperatures very near where they would need to be for freezing and frozen precipitation by early Sunday. It's really an almost Western-type weather scenario ... it's not uncommon in many areas of the West to have highs in the 50s and then for temperatures to drop rapidly and snow to fall. We will see very little or quite likely no snow, but temperatures will be near freezing. I still have my doubts whether the Roanoke Valley will see much in the way of ice, but things will be worse just to the north. Botetourt, Alleghany, Rockbridge and all counties north and east along I-81 are now under a winter storm warning through midnight Sunday. A freezing rain advisory is in effect for Roanoke, Bedford, Montgomery, Craig, Giles, Pulaski, Floyd and Franklin counties. Click here for the latest from the National Weather Service in Blacksburg. Freezing rain advisories, winter storm watches issuedPosted Feb24, 2007 at 12:10 PMDon't let today's fairly mild temperatures fool you ... it's another borderline freezing rain situation similar to Feb. 13 late tonight and Sunday -- though probably not nearly as severe -- as some cold air drains down the east side of the mountains with a storm system spreading moisture from the west. A freezing rain advisory is in effect for most of the New River and Roanoke valleys, meaning less than one-quarter inch of ice is expected; Botetourt, Alleghany, Rockbridge and counties northeast from there are under a winter storm watch. Again, as on Feb. 13, it may be difficult to get the temperatures to below freezing and to stay there in the heart of the Roanoke Valley, but many surrounding areas will likely be 32 or below. The precipitation could even begin as sleet and some snow, especially to the north, before changing to freezing rain and rain on Sunday morning. Part of the reason freezing precipitation is even possible tonight is because the air is extremely dry. As the precipitation falls into the dry air, much of it will evaporate at first, leading to evaporational cooling through the atmosphere. This cooling will help bring temperatures to near the freezing mark even though we're in the 40s and 50s today. Click here for the latest from the National Weather Service in Blacksburg. If you are traveling toward Northern Virginia ...Posted Feb24, 2007 at 12:30 AMBe aware that much of Northern Virginia on up into Maryland and Pennsylvania is under a winter storm watch tonight and Sunday for the potential of freezing rain, sleet and some snow. I think most of our area is barely going to miss the ice early Sunday, other than a few sleet pellets bouncing off things. Click here for the latest information from the National Weather Service. How hard did the wind blow?Posted Feb23, 2007 at 10:06 AMThe National Weather Service in Blacksburg is estimating the wind gust that toppled the church steeple in Northwest Roanoke to be 66 mph. The highest measured wind gust at the Roanoke Regional Airport was 59 mph. Wind advisories, fire weather watches and high wind warnings continue today most of Southwest Virginia. The winds have calmed some but are still quite gusty. Click here for the latest from the National Weather Service. Below is a listing from the weather service of wind gust measurements and estimates, plus observed wind damage, across the area. (Click on continued line if you are viewing the full blog) A new ice threat?Posted Feb23, 2007 at 09:44 AMEnough cold air has creeped in behind this last, very windy cold front to give us a couple of chilly nights ... and to play touch and go with the next rain maker moving our way this weekend. Temperatures across the area are likely to be flirting with the freezing mark when precipitation arrives late Saturday or early Sunday. The result could be a period of freezing rain or sleet before warmer air moves in later Sunday. At this time, the Hydrometeorological Prediction Center in Washington expects the greatest threat for problem ice to be far north of our area, in northern Virginia and Maryland, as this map shows. As other maps on the HPC's Winter Weather page show, this looks to be a huge snowstorm for the upper Plains and western Great Lakes, regions that have been very cold in recent weeks but have seen below normal snowfall. For our area, the greatest threat of ice would be north of Roanoke. Unlike the last event, warmer air will be drawn in as the precipitation continues, not colder air. From this distance, I would expect the Roanoke Valley to get a brief period of sleet as the precipitation begins and then simply get rain. But it is something to at least keep an eye on. And the wind continues to roarPosted Feb22, 2007 at 06:11 PMIn case you're wondering ... the maximum wind gust at Roanoke Regional Airport today was 59 mph. Other maximum gusts around the area include according to the National Weather Service in Blacksburg include 61 mph at Hillsville in Carroll County, 59 mph at Conners Grove in Floyd County and 58 mph at Dublin in Pulaski County. Most of the area from the Blue Ridge westward, including the Roanoke and New River valleys, is under a high wind warning tonight and Friday morning. Also ... almost all of Southwest Virginia is under a red flag warning, for the threat of a high fire danger with the combination of high winds and dry air. For the latest on the situation, click on the National Weather Service's Current Event page. High winds may rock areaPosted Feb21, 2007 at 11:33 PMA cold front will zip through the area on Thursday, bringing with it a threat of high winds, possibly gusting over 60 mph, especially on mountain ridges. As of this writing on late Wednesday night, a high wind watch is in effect for much of the area for the afternoon and evening; that may well be upgraded to a high wind warning for some or all of the area. For the latest, click on the National Weather Service-Blacksburg's "Current Event" page. While the winds will be strong, this is not an Arctic front, but one of Pacific origin with some Canadian influence. Expect somewhat cooler weather for Friday, with temperatures back near normal (near 50 for a high, upper 20s to near 30 for a low). An early sign of springPosted Feb21, 2007 at 05:30 PM
Of course, there is very much a wintry side to this storm, over the northern Plains, a region that has been plenty cold this winter but has not seen a lot in the way of snow. The Hydrometerological Prediction Center map found by clicking here shows the risk of 8 or more inches of snow. There's no "freezing" before rain this timePosted Feb19, 2007 at 10:41 PMThe chances of rain on Tuesday night and again near the weekend will not include any mention of freezing rain, sleet or snow ... the first time since mid-January we've had a precipitation event that has had no real chance of wintry weather. The Pacific flow aloft has taken over the weather pattern, so we'll be having milder weather fill all the layers of the atmosphere. Even after a new "cold" front passes on Tuesday night, temperatures will only cool back to near normal (upper 40s for highs, near 30 for lows) before we start warming to above-normal readings by the time the next rain chance arrives. The warmup starts todayPosted Feb19, 2007 at 01:12 AMDon't put on your shorts yet ... today's highs will be in the 40s. But the southwest winds that will be kicking in do signal a significant change in the weather pattern that will be ushering in milder weather, possibly surpassing 60 by late this week or early next week. The Climate Prediction Center believes the upcoming warm spell is likely to cover most of the next two weeks. Beyond that, we'll just have to wait and see how things develop. 14 1/2 inches of snow -- yes, for realPosted Feb19, 2007 at 01:07 AMDon't underestimate the power of upslope snow squalls in the localized areas that get drilled by them. Quinwood, W.Va., located to the northwest of Lewisburg in Greenbrier County, came in with 14.5 inches of snow Saturday and Sunday, mostly on the strength of nothing more than cold northwest winds squeezing Great Lakes moisture out as it was lifted up the west side of rise in elevation leading to the Appalachians. Amounts of 1 to 5 inches were much more common in a stripe south from there toward Bluefield, W.Va., and Grayson County, Va. Heavy snow not far away todayPosted Feb18, 2007 at 12:56 PMIt might be hard to believe in the Roanoke Valley's bright afternoon sunshine, but a stripe of counties from Lewisburg, W.Va., down to Bluefield, W.Va., south to Grayson County, Va., and on into North Carolina is under a heavy snow warning this afternoon for 3 to 8 inches of snow ... locally up to 12 in Greenbrier County, W.Va., northwest of Lewisburg. This is from persistent upslope snow squalls, as winds from the northwest carry mainly Great Lakes moisture up the western side of the Appalachians, squeezing it out as it's lifted. Some upper-level energy moving through later today may enhance the snowfall a bit. For the Roanoke Valley, there may be a few flurries this afternoon and evening, and maybe a dusting to locally an inch in the New River Valley. But the upslope counties will be getting a full helping of winter today. The caboose at the end of the Arctic trainPosted Feb17, 2007 at 12:34 PMThe Alberta clipper storm system that will bring some light snow to the area today ... more of it the farther west you go ... looks to be the caboose at the end of this long Arctic train that started on Jan. 17. It will usher in one final shot of Arctic air that will chill temperatures the next couple of days before Pacific air starts regaining a foothold and returning us to milder temperatures later in the week. The milder weather will probably mean that this month will not end as one of the two or three coldest Februarys on record, but it's not likely that the upcoming milder weather will be enough to keep the month from ending below normal in temperature. Somehow, I don't think we're done with winter quite yet, but it's probable that our one consistent long stretch of winter is wrapping up. Next clipper will struggle to get over mountainsPosted Feb16, 2007 at 06:53 PM
For the Roanoke Valley, expect to see flurries and sprinkles during the day maybe giving way to a few brief but heavier bursts of snow at night. For the New River Valley, maybe a dusting to an inch. A mid-week system headed our way may be plenty wet, but likely far too warm for any wintry precipitation. The overall pattern is looking milder the next couple of weeks, but I wouldn't be surprised to see Arctic air make one last short but sharp push come March. Yes, Rush Limbaugh quoted me on ThursdayPosted Feb16, 2007 at 01:32 PMSeveral of you have sent me e-mails noting that Rush Limbaugh quoted my Wednesday column on his Thursday radio program. The transcript is linked below. Let me state clearly that I did not intend in any way to make any statement on global warming, pro or con, in Wednesday's column. It merely points out that we have had unusual cold in Roanoke recently. In the transcript, Limbaugh did not make any assertions that I was making such a statement, but read it as a news item to support his own view that global warming hysteria is overblown. So, since he did not misrepresent my purpose in writing the column, I have no objections about his use of my material, and certainly don't object to being read for millions of listeners. Transcript of Rush Limbaugh that includes him quoting my column On deck, another Alberta clipper?Posted Feb15, 2007 at 12:19 PMAnother Alberta clipper will be diving southeastward our direction on Saturday. Big questions remain as to whether any significant energy or moisture can cross the mountains. The western upslope areas of the mountains to our west appear likely to get hit decently, as usual. East of there, from the Roanoke Valley eastward, its a big question mark. Right now, expect at least some snow showers on Saturday. This might be the last crack at snow for a while, maybe for the season. The warmup for next week is looking more and more likely. Spring at the end of the tunnel?Posted Feb14, 2007 at 04:11 PM
So this map (bigger version here) I've posted from the Climate Prediction Center may be a relief to everyone: A strong chance of above average temperatures in the 8-14-day period throughout much of the eastern U.S. This map looks a lot like things did back in late December and early February, with cooler than normal weather in Alaska and the western states and above normal temperatures here. This map reflects probability of occurrence rather than intensity, so redder doesn't necessarily mean warmer ... it just means a greater probability of warmer than normal temperatures for the last week of the month. Before that pattern change can come about though, we have another shot of Arctic air the next few days, a possible Alberta clipper brush with snow over the weekend, and then another lesser shot of Arctic air behind that clipper. The long-awaited pattern change begins developing next week. There's always a threat of big precipitation makers near a pattern change, so we'll have to watch that. But if this pattern shift comes about as planned next week, spring may indeed come early as the groundhog has predicted, and this long, weird, freaky, nearly snowless winter can finally be brought to a merciful ending. New problem: High windsPosted Feb14, 2007 at 09:29 AMA high wind warning is in effect for much of Southwest Virginia today. Winds being pulled behind the departing storm system, ushering in a new round of Arctic air, could gust over 50 mph at times. Where there is ice accumulation, those high winds could cause additional damage to trees and power lines. Click here for the latest from the National Weather Service in Blacksburg. Ice accumulation reports for Feb. 13-14Posted Feb14, 2007 at 09:16 AMMost locations in and near the New River and Roanoke valleys outside of the Roanoke city center received significant ice accumulation from Wednesday's ice storm, ranging from a thin coating to as much as 1.25 inches. Below is a listing from the National Weather Service in Blacksburg of ice amounts in the area (click on Continued line if you are viewing the full blog). Continue reading "Ice accumulation reports for Feb. 13-14" » A big ice storm for some, nothing for othersPosted Feb13, 2007 at 11:46 PMIf you live high on the Blue Ridge in Floyd County tonight, this definitely lived up to its billing as a major ice storm. If you live in downtown Roanoke in the shadow of concrete, it was just a long, cold rain. For most of the rest of us, it was somewhere in between. I live about 6 miles south of downtown Roanoke, in south Roanoke County, and I've got about 1/8 inch of ice covering all the trees and the cars and anything metal. The roads and sidewalks here are not in bad shape. Some other places, they're slick and hazardous. In less than half an hour, I could drive to ice 1/4 or more thick, or to places where there is no ice at all. By area coverage, more areas got ice than did not. By population, the margin between haves and have-nots would be closer, since ice is spotty across the Roanoke metro area this evening. When you wake up Wednesday morning, you may have a shimmering, silver landscape outside, or just gray, dead winter trees. The wind will whip through them later in the day, and a new round of Arctic air will gush in. Whether this was your storm or not, winter blows on, and I'm sure there will be another maybe, maybe-not, borderline snow-ice-rain encounter not very many days out. Ice buildup on treesPosted Feb13, 2007 at 09:47 PMI'm noticing a lot of ice buildup on trees here in south Roanoke County, as well as on exposed objects like car tops. The rain has been coming down moderately to occasionally heavily for a couple of hours with temperatures near the freezing mark. I would think that in areas where ice has been building most of the day, that there could be some big problems soon. National Weather Service-Blacksburg is noting in its evening discussion the presence of an urban "heat island effect" holding temperatures just a touch above freezing near downtown Roanoke. This may prevent a lot of ice from building up in the core of the city. |
