UPDATE 12 NOON: Severe storm risk increases for today; Roanoke may hit 100 by Saturday, as it gets hotter before it gets cooler
National Weather Service-Blacksburg review of June 29 derecho linked here
UPDATE 12 NOON: Severe thunderstorm watch until 7 p.m. Roanoke and westward/southwestward. Clusters of storms continue to move southward through West Virginia and the I-77 corridor of Southwest Virginia. They may expand and/or intensify in peak afternoon heating. Click on Radar / Future Cast in right margin for latest location of storms. END UPDATE
UPDATE 8:45 AM: Western half of Virginia just upgraded to a slight risk of severe weather today by the Storm Prediction Center. Concern is upper-air cold pool associated with overnight storm cluster in Great Lakes drifting southward into the Appalachians today, which could lead to clusters of strong to severe storm with afternoon heating. Also note the link added above for the National Weather Service-Blacksburg’s review of the June 29 derecho. END UPDATE
UPDATE 8:30 AM: A small storm cluster just east of Beckley, W.Va., and a larger storm cluster in northern Ohio are drifting southward and may affect some or all of Southwest Virginia today, with some clouds and outflow breezes if not directly. Forecast models favor locations west of I-77 for more organized storms today, with pop-up afternoon/evening storms possible anywhere. This may hold afternoon temperatures a few degrees cooler than they otherwise would have been today. Some storms may become strong to severe with locally strong winds and hail possible. Latest radar linked here. END UPDATE
The core of the “heat dome” has relocated from the Southeast U.S. to the Midwest — St. Louis/Chicago area. You can see its location fairly well from the excessive heat warnings/heat advisories on the map linked here. It is expanding eastward again into the Ohio Valley and Great Lakes, and toward us. The result will be another push of very hot temperatures — not that they’ve cooled down a whole lot — aided once more by those northwesterly downsloping winds that aid in heating locally. Those breezes coming down the mountain slopes compress, adding a few degrees to the afternoon temperatures — Roanoke is often a major bullseye for this effect, lying on flatter terrain east of the slope of Catawba and Fort Lewis mountains. As a result, 100-degree temperatures are again possible any of the next three days in Roanoke, always depending on how much and where any afternoon showers and storms may form. A small storm this evening dropped some hail on the east side of Roanoke, and kicked out enough cooling outflow breezes to drop the official Roanoke Regional Airport weather station from a high of 97 degrees to 83 by 8 p.m. It probably didn’t deliver enough rain over most of the Roanoke Valley to affect Thursday’s temperatures all that much. Roanoke has hit 97 on four of the last seven days, going higher on two days (Friday’s 104 and Saturday’s 102) and cooler once (Monday’s 94). 97 may well be the floor of what to expect Thursday through Saturday in Roanoke, with widespread 90s across Southwest Virginia below 3,000 feet (including Blacksburg) and some 100-105 readings in lower elevations to Roanoke’s south and east.
The weather pattern is changing, though. The location of the heat dome has moved the main steering winds for major thunderstorm complexes to the north. The convection that develops and moves around a strong summertime 
high pressure system is sometimes called the “Ring of Fire.” We were in the middle of the “Ring of Fire” last Friday when the derecho roared through, but now it appears that large storm complexes rocketing toward us from the northwest will be less likely (though not entirely zero chance, with some northwesterly component to the upper winds continuing) through at least Saturday. (There is one storm cluster in Ohio tonight that may have some chance of working southward, perhaps into West Virginia later tonight, close enough for Southwest Virginia to keep an eye on.) A larger change appears to be in the works for next week, as the core of the heat dome is expected to shift all the way to near the West Coast by the middle of next week. Follow the shift of the yellow-green colors, depicting above-normal temperatures from Friday to Sunday to Wednesday on the European forecast model. The Wednesday map linked again here leaves a little dab of blue “below-normal” coloring on western Virginia amid a sea of white, signaling near-normal temperatures. I don’t think we’re headed for a major cool spell next week, but some days of 80s highs and 50s-60s lows appear likely. A cold front arriving Sunday will introduce the change — but also could trigger some strong thunderstorms, continuing into Monday.
July 4, 2012 - 8:53 PM
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Kevin, my neighbors continue to say our Sunday 11am storm was a tornado, people saw the funnel, etc. I was in Missouri, so I have no input. Is there a chance? Is the NWS going to investigate?
Sunday AM storms near I-77 were more discrete cells than Friday PM/Sunday PM storms, so there would be a better chance of a tornado in that than than other times.
Did it leave only a narrow path (less than a mile) with converging damage (trees pointed toward middle of path, not outward)? Tornadoes don’t leave miles-wide stretches of general damage pointed outward or in a straight line.
I have heard nothing about a storm survey in that region.
If the heat dome is shifting, how come it seem to be hotter in the Carolinas than in Virginia? I am sure the mountains contribute to the influence of temperature and overall weather pattern.
I recall this topic came up when the discussion of tornado was being discussed. The statement was made that the mountains doesn’t prevent tornado, it simply alter the flow of winds, which lead me to wonder if the derecho could have been somehow influenced by the Blue Ridge mountain range.
Thoughts?
By the way, there was no storm in Goldsboro, NC this afternoon. It did thunder, but nothing major happened. It was HOT, muggy, and my pant stuck to my legs when I was outside for a few minutes.
The “heat dome” is about temperatures relative to normal. The lower-elevation part of the Carolinas average hotter in temperature than western Virginia does — so it’s usually hotter there in summer even if they are normal and we are a little above (in this case, both locations are still quite a bit above). But evidence that it has moved is that NC is not running 100-105 statewide like Friday and Saturday. By Friday or so, it’s possible Roanoke, Raleigh and Charlotte will all be similar in temperature, as we may be running higher relative to normal than they are.
Atmospheric differences on each side of the Appalachians/Blue Ridge weren’t very great this time, so there wasn’t much effect. It’s possible the shrinking of the updraft crossing the mountain ridges did cause the bow echo cells to weaken as they approached Roanoke, leading to no rain, before they re-formed to the east. The mountains are much more of a factor when they divide much different air masses. The Ohio Valley tornado outbreak in early March, that ran into a brick wall of cold air crossing the mountains, is an example of that.
Kevin, The NWS in Morristown shows us with a 50% chance of storms, some severe, tomorrow. Is there a disturbance moving in and how widespread are they expected to be. Just wondering. Hoping no severe weather anywhere.
It appears to be the same disturbance working southward causing the Ohio storms tonight they’re concerned about. Blacksburg NWS thinks it skirts western counties of its forecast area.
Roanoke’s high of 97 today topped Phoenix (91 — actually at midnight, before a unseasonably cool day in the low 80s), Las Vegas (93) and tied Palm Springs, Calif.
I took down one satellite map with arrows I had linked earlier. The general idea is right but the map seemed to be a little misleading with how the upper-air flow is developing, especially with a storm complex tonight moving southward through Ohio. We do seem to have broken out of the Chicago-to-Southwest Virginia express that brought us the storms Friday night and Sunday night.
Kevin, The tree damage is not a narrow path and most of them seem to have gone over from west and NW winds. I’m sure the NWS would be investigating if there was a suspect tornado. I’ll just figure it was nasty straight line winds.
Rick, you can have your “treeless” situation. My lawn is fast becoming “greenless,” and would probably be there in all of the front if I had not watered on a few mornings. I may not yet be the Mayor of Brownsville, but just got elected to the city council. If we don’t get rain in the next ten days, our lawn will look like it did on 9-1-11, only this time it will be in mid-July.
The CEO of AEP, Chuck Patton, came on WDBJ7 news live during their 6 PM broadcast. AEP is making progress, but it seems to be at a snail’s pace. Some people are getting totally fed up. I fear there could be big protests here in Roanoke city by this weekend. I think Chuck gets high marks for being willing to come on tv and be interviewed. I can certainly understand their frustration, but protesting won’t solve anything, if it happens.
Will the storms in Ohio make it into our region overnight?
I can’t believe how sick I am of this weather pattern. I don’t remember the last time I saw this much lightning in one week.
I have a very personal recollection of a completely non-weather item about a 4th of July many decades ago. Doppler Carol, Nurse Snow, Nick of Ellett Valley, Michael Hoback, Eva, Jared F., and Merle Spencer …. if any of you are a bit curious, simply get in touch with Kevin and he has my permission to give you my personal e-mail address and you can send me the fact that you want to read about it. It won’t be that long a message. it is a combination of something very noteworthy with a tiny amusing anecdote at the end of it.
Right now indications are the Ohio storms will stay west of Virginia and weaken overnight. I am a little more concerned about some kind of outflow boundary from them firing new storms on Thursday, though. Far SW Va/east Tenn. seems to be a little more favored for that.
Doug – did you by chance see the Fox 21/27 interview with Chuck Patton of AEP tonight? The interview got a tad testy with regards to how the cleanup/repair work is paid for. It’s an awful situation no doubt but it’s an awful lot of mess to clean up too.
Kevin – thanks; I thought that’s what you were saying in one of your previous comments but I wasn’t sure I understood 100%. I’ve learned a lot since following the Weather Blog in 2009 but I can’t say there’s not the occassional tidbit that flies right over my head.
Monday’s 94 is all that’s keeping Roanoke off this Top 10 record 95-streak list.
http://www.erh.noaa.gov/er/rnk/climate/top10s/ROA/consecGT95.txt
It would be 7 and counting with an extra degree on Monday.
Average high temperature over the last week has been 98.3.
July 1977′s 9-day period averaged 99.4. 1977′s run was 97-99-97-97-100-102-101-102-100.
August 1983 had a 7-day period averaging 99.1, including the 104-105-104 run on Aug. 20-22. THat appears to be the last time we had anything hotter than this run over a week or more.
And remember folks … we were having lows in the 40s/50s last Wednesday, and in the 50s last Thursday AM. Even Roanoke was 59 a week ago Thursday morning.
Went from 54 Wednesday morning last week to 104 on Friday afternoon.
No, Amanda, I did not see that Fox 21/27 interview. Who was the interviewer? I bet it was either Jay Warren or that young fellow whose first name is something like Jared or Jarrett.
I just checked the NWS forecast for my location next week and they have us (Elliston) at reaching only 80 by midweek. I’m not holding my breath but could it be possible? I’ll take the mid 80s over this horrid stuff. Although when we didn’t have power and were running our generator sparingly it seemed like 85 was cool to me, now that we have power and are running the AC more or less full time 80 seems a bit too stuffy inside.
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Doug, all you “Browns” may be ok in a few days. The HPC just gave us 2.00 rain for Sunday-Tuesday.
http://www.hpc.ncep.noaa.gov/qpf/95e12p48iwbg_fill.gif
My first child was born at the end of August 1983 in Hokieburg and I remember that hot summer and those last weeks in August. My blood pressure had gone up from the heat and I had to lay low and bored in the AC.
It’s wearing on those without power. But some older folks I know said they just moved down to the basement to sleep and are just dealing with the cold showers. The last time I remember such a power outage (and trees down) in our area was the Ice Storm of 1994.
Just added link at top of the blog entry with the review of the June 29 derecho from the National Weather Service at Blacksburg, also linked below.
http://www.erh.noaa.gov/rnk/events/2012/Jun29_derecho/summary.php
One event this is compared to locally is the August 2000 “double derecho.”
Our region just updated to slight risk of severe weather today as cold pools/outflow boundaries from overnight/morning storm complexes may trigger new rounds of storms today.
http://www.spc.noaa.gov/products/outlook/day1otlk.html
Kevin, I was re-reading your derecho article that I had shared with my dad down in Texas. The correct pronunciation would be “deh-reh-cho”. In Spanish, the ‘e’ vowel is always ‘eh’, not a ‘day’ sound. The nice thing about Spanish is that the vowels are all the same. They don’t change like English vowels.
I was told by a Spanish language expert several years ago that it was “day-ray-cho” (with a rolled “r”). So that’s what I have repeated over the years. I can’t vouch for it personally one way or the other.
Actually, most weather folks call it “DUH-ray-cho” now.
But then again, tornado should really be “tor-NAH-do” not “tor-NAY-do” following Spanish phonetics.
Interestingly, there is some tendency for these storm clusters today to drift a little more southwest than due south. So that is why West Virginia and locations west of I-77 may have a little better shot at it than to the east. By afternoon, though, there will likely be some scattered thunderstorms at least here and there across the region.
Kevin,
I’ve read with interest the past week or so your comments about the heat dome retrograding to the west to allow us to get back to more normal temperatures. I’ve always been fascinated when weather patterns go in the opposite direction of where they normally go. In this case, will the NAO be responsible for this occurence?
It’s not too unusual in midsummer to see these “retrograding” features moving west instead of east. The fastest jet stream steering currents move into Canada, so air patterns over the U.S. kind of meander or outright stagnate at times. The NAO is a little negative even now, but usually has a pretty weak impact on summer weather. The building of a trough in the Pacific is one of the key triggers for the heat dome building in the West, as it kind of “snaps the garden hose,” if you will, with the southward dip out there leading to a similar northern rise in the jet stream farther east, which would be the high pressure ridge over the West.
I made a mathematical fix in my Comment 15 at 11:54 p.m. The average high over the past 7 days has been 98.3 degrees, not 99.3. So it doesn’t rank above 1983.
Storms are already moving into Giles county around Pearisburg.
Still Hot Kevin! High so far this summer has been 98 on Peakwood (elevation 1500) and 99 at the lake house, near the 4H Center. Never lost power at Peakwood and lake was restored on the 4th at 4P. Happy belated 4th to you and everybody.
Yep, Tina, that small cluster is sliding south toward Wytheville.
The line drifting south from Charleston looks a lot like the June 29 line.. just drifting more south than southeast.
Is there any forest fire nearby? I’m smelling a lot of smoke here in C’burg.
Check out the latest Charleston radar. The outflow is very apparent in front of the line of storms. Question Kevin.. from the NWS derecho page, the radar showed the storms to effectively “collapse” a bit as they got to Roanoke and here in Franklin County. Could the collapse have combined with the actual derecho to make the winds that much stronger around here?
It is miserably hot in Goldsboro, NC. I was outside with the GPS in desperate attempt to get the dang thing to pick up GPS signal. My head started to get oily when I get hot, and couldn’t bear it any longer. That was while I was standing under a tree!
The NWS has just issued a Severe TS Watch till 7pm for all of us here in Western and SW VA. The one storm moving through Wythe Co seems to be the predecessor of more up in WV.
Hearing thunder now up here in C’burg.
Weather channel has us posted at air temperature of 104 degrees at 1 pm! RIDICULOUS!!!! Poa on the greens are starting to puke out, in other words death. Oh well so much for those long range forecasters once again, calling for a cooler summer. Well guys, since June 21st its been nothing but HEAT!!! Its ok, you guys blew the winter forecast as well. Here is to trying to survive until October, have a good one and stay indoors if you can!
Storm just missed me a short time ago, Clarkdocvet might have gotten hit. I got a short shower and now the sun is out and the humidity is miserable as the steam rises from the driveway.
Right now I’m expecting Roanoke (97 degrees at 1 pm, btw) to miss bow echo storms in WVa. Blacksburg on eastern bubble. Big trouble I-77 area west into coalfields region. Smaller, slower moving, more rainy storms tham Friday night. More like Sunday night’s storms except moving south, even SSW at times.
NWS pegged this forecast in their discussion yesterday. They mentioned that western Va. would be the most likely area to get these storms.
Will there be hail Kevin?
Maybe you can answer this question. During the storm Friday night we noticed a very large cloud that would light up red with every lightning strike, while other clouds toward Vinton were lighting up whiteish as normal with lightning. What causes the clouds to turn red during the lightning strikes in the cloud we saw?
Kevin – did your Spanish expert give you the pronunciation written out that way? It may be your person’s written phonetic interpretation of the Spanish ‘e’ using the word ‘day’ which makes it a really broad ‘a’ sound, as in saying the letter “A” but it should be closer to the ‘eh’ sound. I checked with the Cuban-born person in our office and it should be “deh-reh-cho”. She said it has been making her crazy hearing it as “day-ray-cho” and pointed out that the word means ‘straight ahead’.
HokieBurg weather has us a 0 degrees on their site with a -19F windchill. ???
Bill: So far just 1 report of significant hail in the storms today. Wind continues to be the primary issue. Hard to get a lot of hail to the surface when it’s this hot.
Hokie Trax: It may also have been my audibile interpretation of what she said. I might have Arkie-ised it a little bit in my mind.
I will ask The Roanoke Times’ Spanish columnist about “derecho” and go with that.
Rick, comment 19. thanks for the info!! But I’ll believe it when I hear about it. I am outta here (vacation)!!
Almost fainted while doing the monster today. It was brutal. I took a break and went to a local business for a “comfort stop,” looked at my face in the mirror, and wondered “Who the H— is that??” My face was bright, bright pink.
Once again Goodview was hit with a pop-up storm (as we did Tuesday) within the last hour or so, dropping temps some 15 degrees and dumping .40 inches of rain. We now have over an inch this week. We only got drops and thunder from the Vinton/Hardy storm yesterday.
Pretty darn cool to see how the evaporation over Smith Mtn. Lake has caused quite the thunderstorm.
Where it stormed yesterday — Buchanan to Vinton to Burnt Chimney — and dumped moisture also likely played a role. That’s where storms fired today. Also, the outflow boundary from the storms to the west interacted with these storms.
Michael: Just got off the phone with Dave Wert, meteorologist in chief at the NWS-Blacksburg, talking about the derecho. He agreed with me that dust picked up into the clouds by the wind could have caused the red lightning you talked about.
Not likely fokks around the lake would get evaporative effect off SNL…it would have to be a pretty still day for that…maybe at Niagara Falls …they have a nice micro climate there…!!
I went to Missouri a week ago and missed the big storms. Before I left some bloggers were talking of going camping up on White Top, the Mt. Rogers area, and other high places to beat the heat. I wonder if any of those campers have “wind blew me out of my tent” stories?
Well the storms blew through the Chapel around 3 pm today. Rain, wind and severe lightening and thunder. No damage in the immediate vicinity but several trees down in Abingdon and I saw a couple of bradford pears destroyed. Had .50″ of rain. That gives us a total 1.95″ since Sunday and we are loving it. We pray all will get the rain and not the storms.
Here’s what you want, Michael:
http://www.hpc.ncep.noaa.gov/qpf/95e00p48iwbg_fill.gif
Thanks Kevin and I will be listening for you tomorrow on WVTF.
HokieTrax, I have to argue with your Cuban friend. I used to be fluent in Spanish, and learned it at one of the finest secondary schools in the nation, from two teachers who spoke Spanish as their native language. They had us pronouncing it as day-ray-cho. Perhaps not quite as much of a long A sound for the Spanish “e”s, but definitely not “deh-reh-cho.” One doesn’t say, “Si, si, sehnyor,” but “Si, si, saynyor.”
Unless formal Spanish pronunciation has become altered over the years.
From several different sources I would consider knowledgeable, I have the following pronunciations:
* day-RAY-cho
* deh-RAY-cho
* duh-RAY-cho
* deh-WRETCH-o
And a humorous one suggested by a reader looking at his yard:
* duh-WRECK-o
Derecho does mean “straight ahead”, which is the whole point — winds blowing straight ahead, not rotating.
The storm cluster that came through WVa and far SW Va. is still going — in Alabama and Georgia. And still moving just a hint west of due south. South-southwest isn’t a direction we see very often for storm movement, and a big sign of weakening summer steering currents.