UPDATE 10 AM: This heat wave isn’t quite over — and even when it is, the heat will return
UPDATE 10 AM: Scattered storms and showers — probably even more than Friday, especially east of Interstate 77 — are likely to develop this afternoon with the heat and humidity. Some storms could be locally strong to severe with gusty winds, hail and some intense rainfall in localized areas. s As is typical in midsummer, some locations will see little rain and others will miss entirely. Keep an eye on the storms with the latest weather service Doppler radar linked here. END UPDATE
This was not the first day in history that Newark, N.J., was warmer than Wichita Falls, Texas — but it was the first time that Newark was 4 degrees hotter when Wichita Falls was at 104 on its 30th straight day of temperatures 103 or above. Newark’s 108 and Dulles International Airport’s 105 (Sterling, Va., in DC suburbs) were among the impressive all-time records set in the Mid-Atlantic and Northeast today. Scattered showers and thunderstorms sytmied the afternoon heating some in our neck of the woods, so what looked to be an obvious 100-degree day at Roanoke by mid-afternoon stalled at 98. Still plenty hot and sticky.
We’re not quite done with this heat wave. Saturday and even Sunday have the potential to produce temperatures in the mid to upper 90s from Roanoke south and east, and 100 still isn’t out of the question for Roanoke, especially Saturday. Roanoke’s record high temperature for July 23 is a mere 99 degrees, set in 1952, so it would not be shocking at all for that 
record to be tied or even broken. Blacksburg’s record of 93, set in 1991, is reachable, too. That’s all dependent on not getting showers and storms moving through the area at peak heating time, as happened on Friday. July 23 records for warmest low of 76 in Roanoke and 71 in Blacksburg, each set in 1999, may also be challenged as humid air holds the nighttime low up.
After the weekend, temperatures will retreat a little back to near-normal/slightly above-normal readings in the mid 80s to low 90s a few days, as the big hot high contracts back to the central U.S. where several long streaks of triple-digit temperatures will be extended. But there is every indication it will expand again by late next week. The Climate Prediction Center is already coloring the dark reds over Virginia and neighboring states in the 6-to-10 day outlook, signaling 70 to 80 percent chances of above-normal temperatures in the July 28-August 1 timeframe. I’ve said before that the dark colors reflect probability, not intensity, but it does appear this could be another run of potential triple-digit temperatures — and maybe aimed more squarely at our region rather than going more toward the Northeast the way this week’s heat wave did. The 8-to-14-day outlook also shows a 50 percent chance of above-normal temperatures. That’s all still several days away, and we have a sticky weekend to get through. But there is no real cooldown on the horizon, yet, and strong signals of multiple waves to this heat. Just because it didn’t hit 100 in Roanoke on Friday doesn’t mean it won’t do so later this summer.
July 22, 2011 - 10:10 PM
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Kevin: If a big tropical storm or hurricane somehow got into east Texas or Louisiana and then moved north over land, could that provide at least some relief to this huge dome of heat? Or could it merely push it more easterly? If I can get through August 2nd — just like many politicians may be thinking!! — I will be in clover until August 16th. Not working for those two weeks.
A big tropical system moving west into Texas (I’m thinking more like all the way to west Texas, and stalling there) would help in the long term by bringing extremely needed rain to parched regions where this heat is continually recharging. In the short term, it might nudge the hot high a little more north and east — highs shove most tropical systems around, while most tropical systems can only nudge highs. So it might be a short-term loss, long-term gain situation.
Somebody needs to summon the subtropical jet out of its slumber that started when the snow stopped flying in early March 2010. A solid southern branch of the jet stream in the fall pumping a series of Pacific storms over Texas and the Southern Plains would be the best long-term remedy for their drought. If La Nina comes back, that would be doubtful.
To heck with autumn, I am talking about in mid-August!! LOL No big cold fronts up in Canada or off the Washington State or British Columbia coast? I wasn’t asking so much about the drought or central USA problems — which I realize are mammoth in size and intensity — as about some possible help in cutting off this heat dome at its source. If that could somehow happened, I bet our weather and especially our temps would get back to roughly normal shortly afterwards.
The drought and central US problems ARE the source of the heat dome, Doug. That’s got to be dealt with or the heat will keep recharging itself into October, no matter how many cold fronts come south.
A tropical system would be the best short-term relief but it’s going to take a full-fledged major pattern change for a prolonged period to make any real headway against what has built up there. The 1930s are a prime example of the central U.S extreme drought dominating the weather over much of the country not just for a season but year after year.
It would help our region if the high would shift WEST for once instead of spreading east. Then we’d get on the cool side of it for several days with a constant northwest flow out of Canada. But that wouldn’t do much for the bigger issues.
Yes, I knew that the drought was causing the heat dome, but thanks for explaining just how serious this whole thing is!!
Massively heavy rains in and around Chicago metro area overnight, 6-12 inches. Too bad we can’t spread that out farther south.
Was up at Mt. Lake Friday hiking to Bald Knob. The heat wasn’t too bad but the thick, humid air was! And the bugs! What bugs bite at 4363 feet? I put Burt’s Bees bug stuff on my legs but not on my arms and that is where I am suffering. The view from the Knob was very hazy. The lake has lost all its June rain gains and the ‘peninsula’ spit is reappearing as the water recedes. As someone who remembers the lake full pond, it seems strange to see tall grass, roads and trails where there was once water. Kevin, what is our rain outlook the remainder of summer?
Rain outlook: Sporadic. Not a total drought, but general, widespread rainfall will be hard to come by short of a tropical system.
Mountain Lake will probably need a couple of years or more of above normal precipitation to fully recover. It went dry in the early 2000s, recovered quite a bit toward the middle of the decade and then went very dry the last few years, bouncing back somewhat for a while after the wet/snowy winter of 2009-10.
Wow, what a depressing thread.
So Kevin, what was causing the heat dome to stay more or less in place over the central plains since late-Spring? In other words, what is causing it to expand East all of the sudden?
So we’re enjoying our 2nd day of rain in a row. Nothing really significant, but given the alternative of sunny and highs near 90, I’m pretty happy (it’s overcast and in the 70s again this afternoon here). Carol- I was looking in your direction and saw some pretty dark clouds- hope you had your rain barrels ready!
Afrog strangler here on the Knob at 1:45 PM. Didn’t see that one coming and still don’t see it on radar. But I’ll take it, water puddles and all. Also tkae that 20* temp drop in less than 15 minutes. 73* here as I post.
Heat really builds up in the mid-summer sun and allows it expand more. Also, the seasonal retreat of the jet stream into Canada gives it less resistance. Persistent low-pressure troughiness near the Pacific coast has caused the dome to expand eastward rather than westward so far this summer.
With time, the seasonal southward return of the jet stream in fall will erode the heat dome, but because it has the midsummer heat in it, it usually hangs around well into fall. In 2007 we had summerlike heat off and on into October.
We had a brief rain shower a little after noon, but now the sun is out and boy is it sticky out. I hope we get a good storm later to cool it down, the humidity and heat are making today pretty miserable outside.
Had another brief, but heavy rain shower. I’d like for some longer rains, but I’ll take what we can get. And it just started raining again. It’s at least knocking the heat back a bit each time.
Talking about this big heat dome, really gets me back into my niche with the weather. It’s truly pretty incredible how much a heat wave like this can effect the national weather pattern for the next several months, well into winter.
The Texas/Oklahoma area has been exceptionally dry, dating back to winter if I’m not mistaken. The lack of a real subtropical jet stream this last winter really set the stage for this heat wave to build. When it doesn’t rain, the air basically cooks. This is why parts of interior PA and NY were hotter than the South these past couple of days, due to the lack of rainfall over the past few months. The air is easier to heat when it is drier at the surface. So it makes sense, that this heat wave is going on, and will continue to go on until something can dislodge it over the South Central part of the country. I dare say it will take something. A tropical system from the Atlantic. Maybe a tropical system from the Pacific later on in August or early September, to really tear down the dryness and make a dent in the heat.
For snow lovers, this could be a bad omen for our coming winter. If the heat persists well into the fall, look for alot of storminess over the Central part of the nation. Where two air masses meet is where low pressures form. Just something to think about, how much this heat wave will affect the coming winter.
Just for fun, I did some checking. I believe that 95, and 66 were the last two major heat waves that can compare to this one in this part of the world. Take a look back at those winters if your interested, tell me what you see
I am glad that several of you got some nice rains lately, especially happy for you, Ralph. Now it’s my turn. We have had no appreciable rain since we were bombed with 1.7 inches on the evening of the 8th. Kirk to Khan: “Like a bad marksman, you KEEP MISSING THE TARGET!!” TWC Weekly planner places all of Virginia in the dark green (decent chances of rain) for both tomorrow and Monday, but after that it will be dry (according to them) through at least Thursday. I gotta invoke Kirk while there is a reasonable chance ….. :>) :>) :>) Will it work yet again??
Zach, what about 1980? Wasn’t that another summer that was exceptionally hot for large areas of the nation?
Rain!! I am right underneath a strong thunderstorm. It is really blowing and coming down hard. 1/2 inch already in just ten minutes. And yet the NWS is forecasting the brunt of it to pass over in about ten minutes.
I was thinking about 2007 and 2010 as hot summers — those were the two hottest on record, locally. 2010 was followed by a cold (for 2 months) but not particularly snowy or wet winter. 2007 was followed by a mild, very low-snow winter.
I’ve looked back trying to find a summer-winter correlation before. I can’t find anything remotely consistent. Hot summer sometimes are sometimes followed by cold winters, sometimes by mild winters. Cool summers sometimes lead to cold winters, sometimes to hot summers.
Just guessing now, my bet for winter 2011-12 would be slightly colder than normal and much drier than normal. That’s betting on 2 things: (1) some semblance of a continuation of that central US high into the winter, funneling cold air southeastward out of Canada toward us on the eastern side of its clockwise circulation, and (2) the return of La Nina, but weaker than last year. But that’s a very early guess that could change going into fall depending on what else develops.
Roanoke’s high of 97 today came at 1:18 p.m.– just 2 degrees short of the July 23 record of 99 from 1952. Once again, clouds moving through and showers nearby may have thwarted another potential 100-degree day.
This is now 4 days in a row Roanoke has been 95 or higher — 95-99-98-97 — so it definitely meets my personal arbitrary definition of a “heat wave” specific to Roanoke, which is 3 straight days of 95 degrees or higher, or 5 days within a 7-day period. Also, it is the hottest 4-day stretch, with an average high of 97.2 degrees, since July 5-8 averaged 98.6 last summer (96-98-100-100)
And it proves that WDBJ7 was a lot more accurate than The Weather Channel over the last 3 days. On Thursday early morning I commented that Channel 7 was predicting 98-100-97, which was remarkably accurate. TWC had it at 95-95-90 (!) Oh, I forgot to post what unbelievably oppressive mornings Wash. DC and NYC had today. TWC showed the 6 AM temps, and I was stunned. DC was at 85 (probably at Reagan National Airport) while NYC was at 84, which might have been in Central Park. If it was Central Park, that NYC temp was even more outrageous. This evening CBS News showed one of its reporters on the sidewalks of NYC during the afternoon. He focused some hand-held machine at the sidewalk in the sun, and it registered an astounding 147. Even in the shade another patch of sidewalk was 107. Like I and others have commented in the past, once extreme heat gets embedded within an enormous city, it takes a lot for it to relent. A windy rainstorm would do it, especially if it lasted for hours.
Kevin, I remember doing the same kind of analysis that you did comparing whether a hot summer was followed by a very warm or very cold winter, and conversely whether a cool summer (we haven’t had many in the past 12 years) was followed by a very warm or cold winter, and I came to the exact same conclusion that you did. There is no pattern. What I would like to see is whether a drought in summer and early autumn led to a certain type of winter. One year from way, way back that I knew was a bad drought year in Mass. was 1965, and we had an extremely snowy (and I assume cold) winter in 1965-66. But that was Mass. and many years ago. When we were having drought here from mid-1998 through Sept. 2002, none of those winters was snowy, except for 2002-2003, and that was no biggie, just a bit above the long-term averages.
TWC forecasts often seem to overplay higher elevation effects in the Roanoke Valley. They often show a higher probability of snow showers and 1-inch accumulations for the Roanoke Valley in upslope winter events that typically only produce flurries this far east, and also seem to trim our temperatures back a few degrees too much in summer, more like the New River Valley.
You are absolutely right about the TWC’s forecasts for ROA in the summer, although for a few days here and there during the days before the 18th, they were more accurate than WDBJ7′s temp forecasts for some reason.
With the various rounds of showers from nearby storms today, we got 0.20″ of rain…with the heaviest stuff again missing to our west and south. But it helps, and the grass is green at the moment. We’re up to 2.85″ for the month, which all things considered isn’t too bad, but I’m hoping for more in the coming days, especially if that blasted heat dome keeps persisting.
Thinking about winter gets me going.! haha