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Weather Journal

with Kevin Myatt

Don't worry about Tropical Storm Chantal

Tropical Storm Chantal is well east of Cape Cod, Massachusetts, heading northeast over the cold waters of the North Atlantic. Chantal will be absolutely no threat to the United States. Visit the National Hurricane Center Web site for more information on Chantal.

A wee little shower

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Just looked out the window of the Roanoke Times to see, to my surprise, a shower of heavy rain falling. I hadn't been following radar closely, so I zipped over to the National Weather Service radar on the Internet to see if there were any kind of large storm near us. Nope. Just this tiny little shower over the central and eastern part of Roanoke city, already weakening from what it was earlier. And now ... it's over and the sun's back out. Just a little summer showers, aided by afternoon heating and moisture converging against our mountain ridges, with no sign of a drought-breaker in sight. And so we move into August.

Drought moves into Roanoke Valley

If you look closely at the map linked here from the National Drought Mitigation Center, the beige color signifying moderate drought has spread eastward into the western half of Roanoke County and into Salem, while the city of Roanoke and eastern Roanoke County are still in the lesser yellow "abnormally dry" category. That's probably picking hairs a bit too much, but suffice it to say that seriously dry conditions have nudged eastward a tad despite the scattered showers and thunderstorms of the past week. It's just not raining enough in a wide enough area to reverse the drought.

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Though it was delayed last week by the werird cutoff low that brought unseasonably cool air to our region, it does appear that hot, dry high pressure is likely to build in later this week, increasing the likelihood that we will experience a prolonged period of hot and dry weather (Climate Prediction Center maps are linked) over the next couple of weeks. This will not be good news for our dry situation. We will continue to have scattered showers and thunderstorms, especially in the afternoons, but these may dwindle some after the next couple of days as a weak cool front moves in, then high pressure builds in, and we are left with only the typical mountain-induced thundershowers of mid-summer as hot, dry air builds in.

Another cold front is coming

As a weak cold front slides our direction out of the Great Lakes the next couple of days, expect showers and thunderstorms to break out in scattered to numerous fashion in the warm, humid air ahead of it. This front will have a hard time getting through, but probably will by early next week. Don't expect the unseasonably cool air of earlier this week, but temperatures will probably back off a few degrees and continue the recent trend by being slightly below normal. As next week rolls along, I think we may finally see a hotter, drier air mass building in. I don't know if we'll get to a true heat wave, but it would be nice to get some beneficial rains the next few days before a toasty summer period sets in.

Fury in a hurry

UPDATE, 2 PM: A severe thunderstorm watch has been issued for all of Southwest Virginia through 8 p.m. Click here for the watch area and statement from the Storm Prediction Center.

Beech Mountain in Watauga County, N.C., had 1-inch hail at 4:15 p.m. on Thursday, according to a law enforecement report turned into the National Weather Service in Blacksburg. Just 15 minutes later, the storm report went even more beserk.

"15 gravel roads watched out. Main highway to the mountain closed by debris. 2 to 3 inches of rain fell betwee 3:30 and 4:30 p.m. ..."

Just shows that while most folks will only hear a rumble of thunder and maybe get a little rain in the pop-up storm regime typical in the mid-summer heat and humidity that has re-established itself, a few people will get a tempest. The Storm Prediction Center has put our region under a slight risk of severe weather this afternoon. While things are hot and humid at the surface, it's still unusually cold higher in the atmosphere, and that could trigger some potent storms as the afternoon heating builds.

More organized storms developed in the Ohio Valley on Thursday and moved into West Virginia. A 76-mph wind gust was recorded at Charleston, W.Va., overnight and numerous reports of wind damage were received across West Virginia. The storm cluster died before it could reach us.

We'll again be in the pop-up storms today and Saturday while also watching to the west to see if any of the organized storm clusters can make it far enough east to affect us.

Current National Weather Service-Blacksburg radar


Record cool at the hottest time of year

According to the National Weather Service in Blacksburg, the five days from July 21 to 25 was the coolest such period on record in Blacksburg and the second coolest in Roanoke, edged out by the July 21-25 period in 2000. Even in Lynchburg, where records go back more than 100 years as opposed to a little more than 50 years in Roanoke and Blacksburg, it was the third coolest July 21-25 on record.

As I wrote on Wednesday, this period of time is typically the warmest of the year, but has been made cool this year by an "cutoff low" that trapped cool air over the area for a few days.

Humidity has returned now and that is gradually buoying temperatures upward again. We may get back in the 80s today.

Deja vu dampness

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This radar shot from midday today looks a lot like the one for Tuesday morning. Once again, bands of showers and few thunderstorms are moving through Southwest Virginia, with the greatest concentration west of I-81. West of I-81 is also the area of Southwest Virginia that has had the worst of the long-term dryness, reaching moderate to severe drought in a few areas. So these rains are welcome. Some of these bands will also continue to move through the Roanoke and New River valleys today, so it will be another unseasonably cool, dank day.

Click here for the latest National Weather Service-Blacksburg radar.

Below are some rainfal totals from Tuesday, many of which are being added to today.

Continue reading "Deja vu dampness" »

It's not been this cool since ...

Roanoke's high of 72 today was the coolest high we've had since June 15, when on a foggy, dank day it only made 64.

The three days of lows in the 50s -- 59 on Saturday, 58 on Sunday, 59 on Monday -- was the first time we had three consecutive days below 60 degrees since May 17-21, when we had four consecutive days with lows 50, 50, 45 and 59.

Going into Tuesday, the month was exactly on its average temperature through the first 23 days of the month, at 76.0 degrees. It appears that we are likely to end the month very near normal in temperature, if not a tad below normal.

We only got 0.16 inch of rain through 5 p.m. in Roanoke, with some more showers occurring this evening. We could use more, but places to our west that are even more dry than us did get more, some more than an inch.

Some needed rain on another mild summer day

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A blob of showers and thunderstorms entering Southwest Virginia may provide many areas some much-needed rain today, as temperatures once again act more like late September than mid-July. A large cold pool of air high in the atmosphere is helping keep our temperatures down and also causing any little bit of moisture and heating to bubble up into showers and storms. Weak disturbances rotating around this cold pool, centered in the Ohio Valley, are enhancing shower and storm development. With so much cold air aloft, it won't take much of a storm to spit out a little hail, since the freezing line for the rain will be very low and moderate updrafts will be abel to carry rain into the freezing air. Mostly, though, at least some parts of still-very-dry Southwest Virginia will get some blessed rain today.

July chill

Blacksburg tied a record low this morning at 50 degrees, equalling the previousmark for July 23 set in 2001.

On Sunday morning, Roanoke's low was 58. That was 3 degrees above the previous record, also dating back to 2001.

This week overall looks to be cooler than normal, with lots of highs in the 70s and low 80s and lows in the 50s and low 60s. It will gradually get warmer and more humid toward the weekend, and next week still looks pretty darn hot.

A beautiful sunset leading to a beautiful weekend

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David Gravell of Shawsville captured the orange-red glow of Friday's sunset against some mid and high-level cloudiness. (Click here for bigger version of inset photo) This gorgeous skyscape has kicked off a July weekend of rare beauty and comfort, with cool nights, warm but not hot days, bright sunshine and white puffy clouds filling blue skies. Enjoy it again on Sunday. A better chance of thunderstorms moves in Monday, as modest surface heating will be enough to bubble some storms in the unseasonably cold air aloft. It still looks we're in for several days of below-normal temperatures through at least mid-week, when a steady climb of hotter weather may eventually lead to a heat wave, which will set in for the northern tier of the U.S. during the next few days.

A record low?

The forecast low for Sunday morning for the Roanoke Valley is the mid 50s. The record low for July 22 is 55 set just a few years back in 2001. So we have a shot at it.

Blacksburg's July 22 record low of 47 in 1974 appears to be safe.

What's down the road

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We've gotten just enough rain this week to stymy the drought a little ... it didn't advance much this week.A few areas -- like parts of Bedford County on Thursday -- have gotten copious rain for a day here or there. But the overall state is still pretty dry. We're going to have a really nice weekend -- cooler than normal, and mostly dry -- once the cold front passes early today. But the overall pattern over the next couple of weeks points to a lengthy hot, dry period as high pressure that has been cooking the West slips eastward across the northern half of the country toward the East. Above-normal temperatures are likely in the 8-14-day period, as is below-normal precipitation, according to these maps from the Climate Prediction Center. It might take something tropical to break down this dry pattern in the long run. But in the meantime, enjoy a nice weekend.

Between the watch boxes

UPDATE 8:35 p.m.: A band of storms has just moved across the West Virginia border into part of Craig and Giles counties and is likely to move across the Roanoke and New River valleys within the next couple of hours. Some of these storms have had severe thunderstorm warnings issued for them. The latest from the National Weather Service in Blacksburg.

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One severe thunderstorm watch was just east of Roanoke, the other was to the west.

One group of storms fired in higher instability just to our east and rocketed off the coast ... the other formed with greater lift and wind shear far to our west and will slide our way after dark, probably in a weakened state as the cold front approaches. As a result, Roanoke was left between the watch boxes. Bedford and Botetourt counties are under one of the watches, and Bedford County saw some severe thunderstorms during the afternoon. While we can't rule out a few gusts and small hail with the storms coming out of West Virginia, it's no guarantee we'll even hear thunder overnight. Hopefully, we'll get some rain for our dry ground, as the next week's weather looks to be milder, drier days giving way to hot, dry days.

Latest National Weather Service-Blacksburg radar.

Hot day could lead to stormy night

Expect hot temperatures this afternoon in the low to mid 90s before a strong cold front moves toward the region tonight and early Friday. Strong to severe thunderstorms are expected to develop ahead of the front as it plows into warm, moist air, and we might even get a squall line through the area during the evening or overnight. Behind the front, a cooler, drier weekend is on tap.

Did you miss anything today?

There was no thunder or spotty showers or storms today. Drier west winds downsloping off the mountains prevented development. By Thursday, winds will switch back to the southwest, pumping moisture back into the area, and the combination of daytime heating (well into the 90s) and an approaching cold front from the Ohio Valley will again increase the chances of thunderstorms.

The weekend is looking really nice -- dry and cooler than normal -- before what may be a long spell of hot weather sets in next week.

Another day of scattered severe weather

Today brought another round of storms similar to Monday, firing in the afternoon heat but then blowing their wad pretty quickly. The Storm Prediction Center's storm reports map highlights a number of hail and wind reports in Southwest Virginia, including trees blown down at Troutville in Botetourt County and 1-inch hail near Montvale in Bedford County.

Catching a severe storm in Bedford County

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The structure of a severe thunderstorm in northern Bedford County on Monday

Noting a somewhat heightened risk of severe weather on Monday, and maybe just enough upper-level wind support that they wouldn't all collapse as soon as they fired, I decided to head out to see if I could catch up with one in our area. I headed north along the Blue Ridge Parkway, expecting storms to fire along the ridgeline with the moisture converging there. Before I left Roanoke, big cumulonimbus clouds were bubbling into the sky, and many more were firing either side of the Blue Ridge as I headed north along the Parkway.

The best looking storm developed to the west of the Parkway along I-81 just north of Buchanan. (You can see Purgatory Mountain near Buchanan in this photo from a parkway overlook.) This storm drifted eastward near the Peaks of Otter, where I caught some heavy rain and gusty winds along the Parkway near Flat Top. Heading down Route 43 on the east side of the Peaks, I heard a severe thunderstorm warning issued for northern Bedford County. I was not surprised, considering the solid structure of the storm, including lowerings that might have indicated weak rotation, (click here and here for photos of that structure) and the frequent lightning.

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A tree blocks Route 122 south of Big Island in Bedford County

I followed just south and east of the storm and then actually got into the edge of a microburst along Route 122 to the south of Big Island. The winds were gusting from east to west blowing out of the storm, whipping the rain in sheets. I think I heard a few hailstones pelt the vehicle, and there were some reports not far from where I was. I parked at an abandoned old gas station and watched the tempest move mostly to the north of me. It's a good thing I did: A few miles up the road, a tree blocked Route 122. I turned around toward Bedford, and though there were other storms, I never caught up to another the rest of the day.

You can click on the continued line below to see a complete list of severe weather reports in the National Weather Service-Blacksburg's coverage area on Monday.

Continue reading "Catching a severe storm in Bedford County" »

Some stronger storms possible today

Thick moisture, strong summer heating, a weak disturbance moving in from Kentucky and West Virginia and the ever-present quirks in instability related to our mountainous terrain will likely lead to scattered to numerous thunderstorms firing this afternoon. Many will have very heavy rain in localized areas, some will have strong winds, a few may have hail, and one or two may become severe. There is a slight risk of severe weather, according to the Storm Prediction Center, to our east in central and eastern Virginia where conditions will be a little more favorable.

This is certainly not unusual weather for us in mid-July. While some of you may see flooded ditches and roads today, this will not be the widespread general rains we need to dig us out of the long-term near-drought we're in.

Web sites of interest

I promise in today's Weather Journal column that you can go to my blog and find links to the two Web sites I write about. We're working on getting them linked permanently here along the right rail, but for now, here are the links.

Kevin Ray's Roanoke Valley Weather

Chip Konrad's Climate Perspectives for the Carolinas and Virginia

And while we're at it, here's a bonus site that I didn't write about on Saturday but is quite comprehensive with its weather information.This one is particularly notable for its wide range of area Webcams.

Wally Mayo's Weather Roanoke

Doesn't look good if you want rain

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The brown color depicts expected below-normal precipitation during the next 2 weeks

Temperatures will back off a bit and it will be less humid the next couple of days ... but less humid also means our chance of dryness-alleviating rain is diminished. (Click here for latest national drought map.) Long-term, there are indications that we will move toward a hot, dry pattern as the big hot-air "balloon" of a high pressure system I referred to in Wednesday's Weather Journal column slowly drifts eastward to cover much of the central and eastern United States. As this high pressure systems drifts eastward, it is expected to bring hot, dry conditions to much of the country, including our region, as the 8-14-day temperature and precipitation maps from the Climate Prediction Center show. We may see the scattered afternoon showers and thunderstorms now and then, but unless something tropical fires up between now and then and moves our way, our chance of a widespread, general rain seems remote through nearly the end of the month.

Torrents of rain amid the dryness

I didn't see a drop of rain where I live in south Roanoke County. (UPDATE 10:45 p.m.: Not 5 minutes after I wrote this, we got a brief but intense shower of rain) But on the other side of the county there was a ton of rain. A flash flood warning was issued for parts of northern Roanoke city and Roanoke county, and some street flooding was reported at the intersection of Peters Creek and Cove roads, according to the National Weather Service.

Today, about half of you in Southwest Virginia saw some rain, and the other half saw nothing, though you may have heard thunder in the distance or saw a few lighning flashes. A few of you got a lot of rain. We'll continue to see this scattered pattern of rain and storms the next couple of days, though perhaps even more numerous as a cold front approaches. It won't break us out of the dryness bordering on drought, but every drop helps -- and every drop hurts in the few flood-prone areas that get a deluge.

Some hot weather ... but it may not last too long

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Temperatures in the 90s are likely the next several days as some high pressure builds in overhead. That same high pressure will squelch most precipitation, except for anything that the daily heat and humidity, the temperature differential along the ridgelines, or any weak disturbances can fire up. If the Climate Prediction Center is correct, though, the heat might not hang on past this week. A cold front is expected to be forced southward late in the week, though computer models disagree on how fast this will occur. When it moves in, showers and thunderstorms will break out. After it moves through, it it does in fact get all the way through, cooler, drier air will re-establish itself. The CPC gives much of the eastern U.S. -- and especially the Great Lakes region -- a likelihood of below normal temperatures in the 6-to-10 day period, as this map shows.

Meanwhile, the West is expected to continue to broil.

Weird weather in other places

It's been pretty much a typical summer in Southwest Virginia ... but some other places are seeing some weird, wild weather.

Take for example:

Destructive tornadoes in New Zealand

Stifling heat throughout much of the West

Continued flooding in the southern Plains states

Keeping in mind that the southern Plains were parched this time a year ago, it's easy to see how quickly and wildly the weather pendulum can swing. What will the second half of 2007 bring us?

Storms firing in Southside Virginia

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Storms have indeed fired today, but they have mostly been occurring along a line to the southeast of Roanoke, now in Southside Virginia, as the inset radar shot depicts. Addiitonal showers and storms may develop this afternoon and evening as a cold front presses into warm, humid air present over the area. After today, a drying trend is expected, with only a few afternoon pop-up storms expected well into next week. Eventually, a warming trend will begin as well, and we could see temperatures well into the 90s next week. Check out the orange and red on this map from the Climate Prediction Center, depicting the likelihood of above-normal temperatures in the 6-10-day timeframe.

Strong -- maybe not severe -- storms are likely today

While the Storm Prediction Center is (as of late morning) targeting an area north of us for the best chance of severe storms (3/4 inch hail, 58 mph-plus winds) today, numerous storms are likely to fire this afternoon and into the evening as a cold front presses into warm, humid air. Some of these storms may be strong, with gusty winds over 40 mph, small hail, heavy rain and frequent lightning. While I would not be surprised to see a few severe storms in our area, the best chance of that will be farther to north with the best jet stream dynamics, including the greater D.C. area that saw rotating storms with large hail, damaging winds, and even a few funnel clouds and at least tornado report on July 4th. (Click here for Storm Reports map from Wednesday)

Risk of severe storms today and Thursday

UPDATE 10:20 PM: The watch was cancelled long ago. A blob of storms and rain is trying to move at us from the northwest, with the leading edge now near Beckley, W.Va. We'll see if this can hold together overnight. Click here for latest National Weather Service-Blacksburg radar

UPDATE 6 PM: A severe thunderstorm watch covers most of Southwest, Southside and Central Virginia through 10 p.m.


As I discuss some in today's Weather Journal column, there is a risk of severe thunderstorms in most of Southwest Virginia on Thursday ... but also today for areas north of Roanoke, according to the Storm Prediction Center. As the heat and humidity bubble this afternoon, not intensely, but enough, storms will begin to fire, and some of these could gain enough upper-level wind support to produce large hail or high winds.

Fireworks after the Fourth?

The buildup to the Fourth of July looks nice ... cooler and drier at first, then gradually warmer and more humid, just like it ought to be this time of year. After the Fourth, though, it could get interesting. The Storm Prediction Center is flagging this area for a significant threat of severe weather late this week (click here for the 4-8-day severe weather outlook) as a cold front moves southeast into the warmth and humidity. Something to keep an eye on this week.

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  • Power just went out in the Stoneledge area right on the Roanoke/Botetourt county line.more - Brandon R.
  • We had a pretty strong storm blow through early this afternoon that dropped hail 3 ...more - Other John
  • 1:14pm 6/22 We are getting a pretty heavy t-storm. Nickel sized hail in Radford/Christiansburg area ...more - Nathan
  • I'm greatful for chasers such as yourselves who actually got good video of this tornado ...more - CraigM
  • Thankfully that storm fizzled out as it crossed into Pulaski County, but we did get ...more - Other John

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