Nothing much changing in our weather over the next few days: Warm, sticky with scattered afternoon showers and storms.
It was just about as flawless a Memorial Day weekend weatherwise as it could be in Southwest Virginia.
UPDATE 8:30 PM: Memorial Day (thanks to all who have served!) still looks warm in the upper 70s to mid 80s across Southwest Virginia, with a little bit more humidity than the weekend. Hotter, stickier weather is on the way for later in the week. I'll take a look at that in my next Inclement Conditions Index, which I will post on Tuesday morning, a day later than normal due to the holiday. In the meantime, check out the blogs of Virginia Tech student storm chasers Jordan Pegram (first-timer) and Trevor White (3rd-time returnee as grad student). They've had some pretty good success after a major automotive breakdown in one of the vans. END UPDATE
Thursday will begin with some light rain across the region as an upper-level storm system quickly moves across from the northwest. As the National Weather Service in Blacksburg notes, this is more like a winter-type rain system, not the muggy summerlike sporadic storms we've seen in recent days, so it will mostly be light (a quarter-inch or less), with no thunder, and cool temperatures hanging on for a while. It may not get above 60 in some locations until after midday, when the rain will move out and the sun may start breaking through.
You probably felt something different in the air on Tuesday, and that will be even more obvious on Wednesday, as much drier air behind a cold front has pushed out the mugginess of the weekend. Dew points, which have been in the 60s to low 70s, may be as low as the 30s for some by Wednesday afternoon, certainly in the 40s. Temperatures will also be cooler on Wednesday, 70s highs for most, maybe barely scraping 80 in the Roanoke Valley and Southside. Even that is considerably cooler from back-to-back highs of 82 in Blacksburg Monday and Tuesday and 87-86 those two days at Roanoke.
Sometimes it's amazing how repetitive the weather can be on the same days in consecutive weeks. Roanoke's temperature has hit 88 with muggy conditions on consecutive Mondays. And now Tuesday looks to be very similar to last Tuesday, as a cold front passes through that at first won't be a "cold" front. Instead it will serve two purposes today: (1) bringing in drier air to quell the humidity of recent days and (2) producing westerly winds that will actually heat up as they blow down the Appalachian slopes this afternoon. So we may see a bit of heat surge today, but less humid, with highs similar to Mondays -- and I wouldn't even rule out a degree or two higher in some spots, possibly near 90. Showers and thunderstorms will not be as numerous as recent days, but a few may pop up along the front in the afternoon heating especially east and southeast of Roanoke.
May has already been an active severe period in the Plains states, the latest coming Friday/Saturday with 47 tornado reports. The first of two groups of Virginia Tech storm chasers -- primarily meteorology students -- begin heading to the Plains on Monday for 10-12 days or so in the field forecasting and observing severe storms. A second group heads out June 1 -- I'll be with that one, but until then, I'll post some interesting things the first group catches on its journeys. (It's usually easier for me to post from the trip I'm not on rather than the one I am on, as most of my day is consumed driving and forecasting on the trips I am a part of.) You can also check out the Hokie Storm Chasers blog, Hokie Storm Chasers Facebook page and @hokiestorm on Twitter, all linked here, for updates during the trip. (Pictured above, an up-close-and-personal look at a supercell in southeastern New Mexico last May.)
UPDATE 12:25 AM, 5/16: There isn't much to add or change about the weekend weather. It will be warm and increasingly sticky with a chance of afternoon showers and storms -- similar to those that occurred on Friday afternoon. Overall, not a washout this weekend, but do have an umbrella or a place to go inside in mind if you're out and about. Another "cold" front moves through early in the coming week with a temporarily raised chance of showers and storms, then a slight cool-off. END UPDATE
After some summerlike weather early in the week, we've had a little taste of fall in May the last couple of days, with cool breezes and low humidity. But the pattern continues to look more summerlike for us, and the warmth and accompanying humidity will gradually build back over the next few days, along with some showers and storms.
INCLEMENT CONDITIONS INDEX
FOR THE ROANOKE AND NEW RIVER VALLEYS
Thursday, 5/14/2015 to TMonday, 5/18/2015
(Scale of 0 to 10 based on both likelihood and intensity of weather events. 0 indicates no chance of even a minor event. 10 indicates a high-impact event is nearly certain.)
Extreme temperatures: 4
UPDATE 9:45 AM, 5/13: Expect some genuinely cool temperatures -- 40s lows -- for Thursday morning and a couple of days with highs in the 60s and 70s, near or even a tad below mid-May normals. But it won't last long. END UPDATE
INCLEMENT CONDITIONS INDEX
UPDATE 8:15 AM, 5/10: Tropical Storm Ana has come ashore near Myrtle Beach, South Carolina, still spinning bands of squally rain, but weakening. On Saturday, there ended up being 50 reports of tornadoes in the central U.S., most in open terrain, but at least one fatality in Texas. More severe storms are expected today, a bit farther east. And blizzard conditions are blasting western South Dakota this morning. So the three-ring circus has happened, and continues in many locations. For Southwest Virginia, daytime warmth combined with perhaps a little extra moisture edging westward from Ana may trigger a few scattered afternoon showers and storms, but for the most part it will be another sunny, warm day for Mother's Day, once the morning low clouds with the inland marine air burn off. END UPDATE
What we've talked about as a possibility this week has happened: Subtropical Storm Ana has formed off the southeast U.S. coast, according to the National Hurricane Center. This would signify a storm with at least 39 mph sustained winds that has a closed circulation and a mixture of tropical and non-tropical characteristics, and the Atlantic hurricane season's first named storm 24 days before the season technically begins. Tropical storm watches are from Edisto Beach, South Carolina, to Cape Lookout, N.C. -- including Charleston, Myrtle Beach and Wilmington -- for potential wind gusts of up to 50 mph and, possibly, a ton of rain. Ana was pulling in quite a bit of dry air on Thursday, but new squalls may develop around the circulation center as it spins over the warm waters of the Gulf Stream.
Thunderstorms made some impact on Southwest Virginia on Wednesday evening, including a storm that rolled through the Roanoke Valley with about 3,000 power outages related to lightning and wind, as well as reports of pea-sized hail and quick but intense downpours. I took the photo above as it was getting organized north and northwest of Roanoke, before it intensified and enlarged and moved over the Roanoke Valley a bit later.
UPDATE 9:35 AM, 5/6: The National Hurricane Center gives the system off the Southeast U.S. coast -- currently disorganized -- a 60 percent chance of developing into tropical or subtropical cyclone as it drifts north. Further discussion about the potential subtropical/tropical storm threat for the coast of the Carolinas is in today's Weather Journal column, linked here. For Southwest Virginia, a weak "backdoor" cold front will push through from the north over the next 24 hours, possibly enhancing the chance of afternoon/evening thunderstorms. There is not much cooler air behind the front, and it will barely affect the above-normal daytime highs on Thursday, before the front washes out entirely. END UPDATE
When I left for vacation a week ago, the coming week's pattern looked a little more like winter than spring. Now, upon my return, this new week looks more like summer, with stagnant high pressure, above-normal temperatures for early May, the possibility of scattered afternoon and evening thunderstorms, and maybe even an Atlantic storm system with some tropical characteristics to watch.
Got to go on vacation sometime. I usually don't take vacation time in winter when interest is high for snow potential, so they get scheduled in other seasons. I'll be off the blog through Monday, May 4, with no new blog posts or updates. I will return on that date with a new Inclement Conditions Index.
Our frequent visitor the cool-air wedge is making another return this weekend, with plenty of Gulf of Mexico being lifted up and over it by a strong low-pressure system in the central U.S. After a sunny, mild but still a bit breezy Friday, this will result in a cool, damp weekend, with periods of rain especially the latter half of Saturday into Sunday. Temperatures probably will not reach 60 in Southwest Virginia east of Interstate 77 and may not reach 50 in some spots throughout the weekend -- mid 60s to low 70s are the normal highs this time of year in our region. One impact of the cool-air wedge -- that is, cooler air trapped by easterly winds against the Appalachians -- is illustrated in the map above from the National Weather Service. The trapped cool, stable though very moist air will just about entirely eliminate any severe storm risk we might otherwise have. Over the mountains, in the Tennessee Valley and much of the South, there will be a much higher risk of severe storms, where it is warm and unstable. Most of the rain will be light to moderate, but could be quite persistent Saturday afternoon and evening, with some periods of showers continuing into Sunday as the system only slowly pulls away.
It doesn't look like we'll pull out even a single sunny, dry day out of this coming weekend, as a cooler-than-normal pattern continues to set up that is likely to last at least a week, maybe 10 days to two weeks. And there may be some temperatures cold enough to threaten some outdoor vegetation on Friday morning. (UPDATE 8:45 AM: A freeze warning has been issued Friday morning along and west of the Blue Ridge for pockets of sub-freezing temperatures. END UPDATE)
Warmth is ridging in western North America over the next several days, and that means that cooler air will be digging into the eastern U.S. We've seen this pattern repeatedly over the last couple of years, and it's happening again. The cold front passing through later on this Wednesday will continue our trek toward a significantly cooler pattern, triggering some showers and perhaps a few thunderstorms as it pushes into somewhat warm but not terribly moist air today. It will be cold and a bit windy aloft, though, and that might allow for a few storms capable of localized strong wind gusts. (It may also be a little gusty even without storms at times -- a wind advisory has been issued for possible 40+ mph gusts.) This most likely will not be any kind of widespread severe weather outbreak, and there isn't nearly enough moisture to pull off anything close to the widespread heavy rain of Sunday or the localized intense downpours of Monday.
Storms produced streaks of heavy rain, gusty winds and hail in Southwest Virginia on Monday afternoon and evening, dumping some downpours on some areas that were already inundated by Sunday night's rain. I took advantage of the severe setup to do some regional storm chasing, focusing on a supercell near Yanceyville, North Carolina, (south of Danville) that split into two pieces. The right-splitting cell, as is often the case, developed stronger rotation for a time, and briefly a tornado warning, though no tornado appears to have occurred. I saw broad rotation within a lowered cloud mass called a wall cloud. For me, it's good practice preparing for the annual Virginia Tech storm chase I help lead, this time in June.
INCLEMENT CONDITIONS INDEX
UPDATE 5PM: Above is the map for the flood watch that continues into the night for much of western Virginia. Periods of rain, some heavy, will continue much of the evening, lessening toward morning. Storms may develop in the area on Monday. END UPDATE
The two-day cool, damp wedge is finally letting go on this Friday morning, and a partly cloudy, warm day with many highs in the 70s is expected. As a barely perceptible upper-level trough crosses the region, there will be some chance of showers and thunderstorms developing with the effects of daytime heating. You can never entirely rule out an isolated storm becoming strong to locally severe in this situation, but it is not likely to be a widespread severe weather situation, or even a widespread rainy situation, this afternoon and early evening.
Lots of rain in the days ahead for Southwest Virginia ... but substantial hope for Blue Ridge Marathon runners Saturday that you won't get soaked.
We have a winner in the 2014-15 Weather Journal snowfall prediction contest: Erinn Hokanson of Roanoke. The difficult part of predicting this snow season was that Blacksburg and Roanoke had first 1-inch snowfall dates nearly 3 months apart -- Nov. 26 and Feb. 16, respectively. Most entrants didn't split their dates nearly that far apart. Hokanson split hers just far enough (Nov. 30 and Jan. 25, respectively) and got close on her snow totals (guessing 20 inches for Roanoke and 24 for Blacksburg when 22 and 28 fell) for a total of 32 points (days and inches missed) in the lowest-score-wins contest. That was 13 points better than second place. You can read about how the contest went down for several top entrants in today's Weather Journal column linked here.
I was just talking yesterday about how the weather can change during the course of the four days of each Inclement Conditions Index period, and that has indeed happened for the heavy rain aspect -- which is now more like a 5 or 6 for the Roanoke/New River valleys rather than a 4. It now appears that heavier rain will make it farther north, centered over Kentucky, West Virginia and Southwest Virginia generally west of Roanoke. For that reason, a flood watch has been issued for Giles, Pulaski and Carroll counties and westward. This still doesn't look like a widespread flooding situation, but 1-2-inch rains now look to be for much of our region Tuesday into early Wednesday, perhaps more in spots, especially where easterly to northeasterly winds can lift and condense more moisture on eastern mountain slopes. Tuesday night into Wednesday morning, Gulf of Mexico moisture will be overrunning a developing "wedge" of cooler air banked against the mountains, and this will mean frequent to continuous rain with some locally heavy rain. By late Wednesday into Thursday there may be a break in the rain, at least reducing to showers, as a slow-moving cold front moves more to the south, focusing the rain farther south.
Before launching into the newest Inclement Conditions Index, a few words on the intent of the index, which I have been posting twice weekly since November.
Any threat of storms is past for Southwest Virginia, as a cold front is pushing through that will bring a dry, mostly sunny weekend with mild afternoons (60s to low 70s) and cool mornings (40s on Saturday morning, 30s to low 40s on Sunday morning).
Several days of severe storms have wreaked considerable havoc on the central U.S., including a large, powerful and much-photographed and video-recorded tornado in north-central Illinois on Thursday evening. At least one was killed in that storm, which hit a few towns and crossed a lot of prairie farmland west and southwest of Chicago.
Wednesday was the first 80-degree day in Roanoke and provided the first strong to severe storms in Southwest Virginia of 2015. Winds gusted between 40 and 50 mph at Blacksburg and Roanoke, with scattered reports of small hail (and one report of 1-inch hail at Peaks of Otter in Bedford County) and many locations got brief heavy rain and frequent lightning. Not everyone in our area did, though -- the nature of spring and summer storms. Kevin Struble of Lynchburg captured the striated shelf cloud on the Bedford County severe storm above ... and this video of the same storm seems to show some rotation.
UPDATE 8 PM, 4/8: Storms have cleared the Roanoke and New River valleys. There were some reports of 40-50 mph wind gusts and small hail -- larger hail up to an inch in diameter up at Peaks of Otter Recreation Area. Per the usual, some locations got very little rain or thunder while others got a few minutes of torrential rain and frequent cloud-to-ground lightning with booming thunder. But however it played out, it's over for now. Overnight additional clusters of showers and perhaps even a few rumbles of thunder are possible, but a cooler, more stable air mass will slowly be overtaking the region from the northeast. There may be another chance of severe storms on Friday as a cold front pushes into warm, humid air. END UPDATE
UPDATE 10:15 AM, 4/7: Rain is doing its part to help turn the tide against brush fires in our area. Cloudiness and intermittent showers today will likely keep the instability in check and not allow for many strong storms to develop this afternoon. It may get warmer with more sunshine, but still be just as humid, on Wednesday, so the storm threat may go up some. ... Do remember to take the wind survey linked below. END UPDATE
As I type this very early on this Saturday morning, a band of moderate to heavy rain is moving across the New River Valley into the Roanoke Valley -- after the showers and storms split around the valleys much of the early evening. But once this goes by, and the cold front pushing it does too, a breezy (wind advisories), mild and dry Saturday will be on tap with highs getting back close to 60. Be sure to dress warmly if attending sunrise Easter services on Sunday, as it may be a tad frosty in the 30s in the morning. Sunday afternoon, though, will vault back into the 60s with sunshine. As Easter weekends go, this one is pretty good, weather-wise.
UPDATE 6:20 PM, 4/3: Much of Southwest Virginia has been circled in the latest Storm Prediction Center mesoscale discussion for isolated severe thunderstorms -- mainly a few strong wind gusts -- this evening. But the threat is not expected to be great enough to warrant a severe thunderstorm watch. Instability is limited over Southwest Virginia by clouds and showers limiting daytime heating -- and surface dew points in the low 50s indicate significantly less dense low-level moisture than we normally have in severe weather situations. Still, don't be surprised to see a flash, hear a rumble or even notice a quick tree-bending gust this evening. The front pushes in behind the showers and storms early Saturday to bring about quite a nice Easter weekend. END UPDATE
Winds will be dying down from the breeziness of the last couple days, hopefully allowing progress against a few wildfires. The next couple of days will be mild to warm, but dry, as highs push into the 60s on Wednesday with many 70s by Thursday. This surge of warmth will set us for showers and thunderstorms by Friday -- but Easter is looking dry and mild behind the next not-all-that-cold front that arrives Saturday.
Prediction: We won't see lows as cold as Sunday (teens to low 20s) or highs as cold as Saturday (30s) again until at least November. Another frosty cold shot is probably inevitable in April or even early May, but I think we're done with anything that nippy this season.
UPDATE 9:40 AM, 3/29: Blacksburg tied its record low of 17. Roanoke's low of 23 came up a few degrees warm. A steady warmup begins today with highs climbing into the 50s for many, with 60s and some 70s expected most of the rest of the week ahead. END UPDATE
UPDATE 5PM, 3/26: A line of heavy showers and some thunderstorms is moving east out of West Virginia toward Southwest Virginia. This will move across the area through mid-evening with a brief period of heavy rain, perhaps some thunder and lightning, and possibly a few strong wind gusts. Most gusts will probably be under the severe level of 58 mph, but a localized brief gust above that is not entirely out of the question. You can follow radar on The Roanoke Times weather page linked here, or on the National Weather Service-Blacksburg web page linked here. END UPDATE
At some point Tuesday afternoon or evening, it is quite likely that the first tornado or severe thunderstorm watch of March 2015 will be issued somewhere in the general vicinity of the Arkansas/Missouri Ozarks in the central U.S. This is a noteworthy development because in the modern era of severe storm forecasting dating to the 1970s, it has never been 24 days deep in the month before the first such watch has been issued in the United States (there have been 4 previous watches in the U.S. since the start of the year, but none since March 1). There have also been no tornado reports yet in March anywhere in the U.S., when about 60 are normal by this point in the month (there have only been 28 since the start of the year when 150 or so are normal). It is far from certain whether there will be a tornado today or Wednesday in the central U.S. or perhaps Thursday in the Southeast (or even the Mid-Atlantic), as the overall parameters do not look highly favorable for tornadoes. But there will probably be at least one or two somewhere in that time.
High pressure pushing cooler air against the mountains on Monday may make it feel a bit nippy -- and there may even be some brief drizzle, even freezing drizzle in higher elevations. But overall, the next 4 days through Thursday offer nothing extraordinary in terms of late March weather, with fairly normal temperatures and some rain chances. There may even be an outside shot at thunderstorms by Thursday. Perhaps some colder weather after this period, but it still doesn't look likely to be an extremely cold period for our region, relative to normal. The early week Inclement Conditions Index is below:
With just a little bit deeper cold air, Thursday could have easily been a decent snow event in our neck of the woods. As it was, some of you in higher elevations and to the west and north of Roanoke will awaken to some white on Friday morning -- mostly under an inch -- but it won't last too long as temperatures, gradually at first and then a little more quickly, rise through the 30s into the 40s and low 50s. There may be a little more rain in the morning.
UPDATE 3:20 PM, 3/19: About 1,600 feet elevation appears to be the dividing line between rain and snow, at least over the Roanoke Valley. At 2:30 p.m. it was snowing on top of Mill Mountain but raining in the valley. It is possible the snow level will get lower this afternoon, so perhaps some flakes are possible in lower parts of the Roanoke Valley. Snow has been falling for hours in many parts of the New River Valley and the Blue Ridge south of Roanoke but with very little if any accumulation. Snow and some sleet may linger into the early evening before milder air aloft gradually changes it all to rain, possibly excluding higher elevations north of Roanoke. END UPDATE
Now that a cold front has pushed through, the reality that it is still March and not yet May will return to Southwest Virginia. And that reality may even include some snow on Thursday.
UPDATE 10:15 PM, 3/16: Roanoke hit 77 and Blacksburg reached 73 on Monday for the warmest days since October. Tuesday's high will likely top 70 again in Roanoke and points south and east, maybe not quite that warm to the west, but colder air begins to move in behind a cold front for the rest of the week. Rain is expected by Thursday, and it might be cold enough for some spotty sleet and/or snow to start -- doesn't look like a big deal in our area, though, just a reminder that cold weather isn't quite over yet.
How times have changed: A cold front goes through with gusty northwest winds, and highs are expected to reach the 60s in Roanoke and 50s to the west behind it. Nothing shows the regime change in the weather pattern more than that. A wind advisory has been issued along and west of the Blue Ridge for some 50 mph gusts, mainly on ridgetops (worth a couple more points rise from 2 to 4 on my Inclement Conditions Index from Thursday). But these northwest winds aren't tapping the Arctic, they're tapping milder air of Pacific and continental origin. It's a typical spring cold front that brings breeziness, a mild day with sunshine, and then a chilly night (many 30s lows by Monday morning) as cooler, drier air moves in. But the temperature rebounds nicely on Monday with sunshine -- perhaps Roanoke's first 70-degree day since Nov. 24 -- and almost as mild on Tuesday before another cold front sweeps across.
UPDATE 12:30 AM, 3/14: Short update tonight, hope to post new Saturday evening. Showery weather will continue on Saturday, though there continues to be indications of a lull during the morning. Milder air will stream in with most spots making the 60s on Saturday afternoon, especially if there is peekaboo sun. A cold front only takes us back to 50s highs and 30s lows for Sunday -- much different than the cold fronts we were getting a couple of weeks ago. Some more mild days are ahead this week before colder weather toward late week. END UPDATE
After a brush of light rain on Tuesday, mostly during the morning, Southwest Virginia is likely to get a second wave of rain on Wednesday. This will be a direct flow of moisture from the Gulf of Mexico and temperatures will respond accordingly, pushing into the 60s. A rumble of thunder wouldn't be totally out of the question, especially in Southside.
UPDATE 8:45 PM, 3/9: A flood watch has been issued for some counties along the West Virginia border, and on into West Virginia, for Tuesday and Wednesday as periods of rain, some heavy, are expected to fall atop melting snowpack. Farther east in the Roanoke and New River valleys, most of the snowpack has melted away, and rain is expected to be light and intermittent Tuesday into Tuesday evening. I'm upgrading my Severe Storms rating below to 2 as there may be some chance of a few showers with thunder with warmer temperatures (60s to near 70) and a cold front on Wednesday, though no severe weather is currently expected. END UPDATE
Time for a weekend break from blogging. This has been pretty much a constant run for 3 weeks through a really impressive stretch of winter mayhem. I posted the snowfall total maps for our four winter storms during that stretch at left, just to give you something to look at (you can click on them to make them bigger).
Our region's fourth winter storm in 18 days on Thursday hit quickly, but generally dumped 1-4 inches of snow and sleet in the Roanoke and New River valleys, with more to the north and less to the south. Behind it, we will be waking up to temperatures Friday that may challenge record lows, which, for March 6, are 16 from 1960 for Roanoke and 7 from 1970 for Blacksburg. After sub-freezing highs or very nearly so on Friday, the weather turns milder, really throughout the foreseeable future.
Ronald Stuart Holasek, 82, died on Monday, May 25, 2015.
Donald Ray Brown, of Christiansburg, passed away Monday, May 25, 2015. Visitation will be 5 to 8 p.m. Thursday, May 28, 2015, at Horne Funeral Home, Christiansburg, Va., 540-382-2612.
Eva Spencer Claytor, 94, of Copper Hill, Va., passed away Tuesday, May 26, 2015. Funeral Service will be 1 p.m. Saturday, May 30, 2015, at Maberry Funeral Home, Floyd, Va., 540-745-2121.
Laura J. Compton, of Lakeland, Fla., passed away peacefully on Monday, May 25, 2015, from complications of a stroke. Services Saturday May 30, 2015. Condolences may be sent to the family at www.heathfuneralchapel.com.