Weather Post by Dr. Ryan N. Maue
As the ridge of high pressure slowly edges eastward over the eastern USA, dewpoints in the 80sF and temperatures over the century mark are creating heat index values typically seen in Iran, Yemen, or Saudi Arabia. Along the Persian Gulf and Arabian Sea, sufficient moisture combines with the oppressive desert heat to generate heat indices in excess of 130F. As of 1 PM Eastern on Friday, parts of the DelMarVa peninsula are feeling the effects of Northern Hemisphere summer Middle-Eastern style.
From coolwx.com/extreme “Extreme Weather Site“, which keeps track of crazy global METAR or station data, Baltimore MD has a HI of 129F. An unofficial “records” site co-authored by myself shows current temperatures compared to daily and monthly records going back between 30-60 years. While some stations have much longer historical records, this quick-look is indicative of record high/low temperatures, and inspires the reader to cross-check the local National Weather Service office daily climate page to verify the “all-time” high. For instance, Newark NJ (KEWR) is going to test it’s all-time high temperature, currently sitting at 104F…
At my Florida State weather maps site, I plot up a variety of useful quantities from the brand new NAM/WRF 4-kilometer mesoscale forecast model which runs four-times daily over the Continental USA. These include simulated radar reflectivity, 2-meter temperature, and heat-index. It is cool to watch the near-surface temperatures wax and wane with the daytime heating or plunge as a thunderstorm cools an area with its outflow pool.
Historical Heat Index and 2-meter Temperature from the RTMA 2.5 km mesoscale analysis: 2-meter temperature (last 48-hours), heat-index (last 48-hours)
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Last year this happened in Russia, this year the USA, could we be seeing a pattern emerging or are we still in the “it’s just weather” phase?
When it breaks it’s going to rain like there’s no end.
Mike Abbott says: Let’s assume, for the sake of argument, that “consensus” AGW theory is correct and global warming is the cause of the current U.S. heat wave. By what mechanism would global warming, which amounted to about 1 degree from 1980 to 1998 and little or none since then, cause a heat wave averaging about 15 degrees above normal over a region comprising just 2.7% of Earth’s land mass (i.e, the eastern half of the continental U.S.)? Do the climate models predict this? Is Michael Mann’s “loaded dice” analogy the best explanation the Team can come up with?
I don’t know Mann’s “loaded dice” analogy, but it sounds like it might be similar to what I’m about to say. Do you know what a normal distribution curve (bell curve) looks like? The temperatures for a given date or a given period, same date or period in each of many years, are very likely distributed like that. If you shift the curve to the right (hotter), you get a disproportionately great increase in the number of years near the right end of the curve, because you’ve shifted a “bulkier” part of the curve to every temperature on the right side. “Disproportionately” is somewhat hand-waving unless we know how steep the curve is, and it’s not clear what a “proportional” increase would be, anyway, but it’s true that if you shift the curve to the right, you’ll get an increase in the number of cases near the right end that would surprise someone who had not studied statistics. By the same token, a small increase in average IQ would produce a surprisingly great increase in the number of geniuses.
I don’t know what to say about the 2.7 percent.
“US heatwave raises climate complexity”
http://www.bbc.co.uk/news/science-environment-14254856
He’s at again
See that very blue area out west? That’s where I live. S.West BC, 60 miles east of Vancouver. It is 7 degrees on my front porch right now, where I sit shivering in front of my laptop, sipping hot coffee. Daytime temps have not exceeded 26 degrees this year, (we hit 26.7 earlier this month for one day) This cold stretches all the way down to LA and at times as far as San Diego. It is particularly cold off the west coast of Vancouver Island, where a friend is trying to earn a living catching Salmon. I am told that the temps dive down to 3-5 degrees most nights, and the days are cold and blustery. He has never seen a summer like this one, and he has been fishing for 40 years.
What are the odds of anyone reporting the record cold we are having? Zip is my guess.
Thanks for the article Dr Maue. And thanks very much for the weather map pages! I have been running ~80% in my forecasting this year, thanks to your hard work!
Tom T.;
Try this: http://www.intellicast.com/National/Temperature/Current.aspx
As posted above – here in the UK its around 55F and with a nasty breeze and a lot of showers. But – hey – any day now our Minister for Propoganda (aka the Secretary of State for Energy and Climate Change) will come out with something like: ‘Exceptionally high temperatures in North America are evidence of climate change…’
I absolutely guarantee it….
Here in the middle of the mid-Atlantic, but in a rural area, the high Thursday was — wait for it — a whopping 97F (36C)! Big deal. That’s the typical high summertime temp here. Yesterday’s high was less as small local thundershowers knocked it down 10F in minutes & it never got back up to 90F. The only thing of remark were the overnight lows that were above 70F — now that is a bit unusual, but very comfortable for viewing the stars at night.
Let me rephrase my comment above if it wasn’t clear — “That’s the typical annual highest summertime temp here.”
And that has ranged from 95F – 99F here the last 7 yrs.
The Netherlands today; a fiery 14 C in the middle of summer.
I got out my sweater this afternoon before i went outside.
Neil Jones said on July 23, 2011 at 1:00 am:
In central and northeastern Pennsylvania, and many other places in the US, “Spring” was a long cool cloudy wet season, it delayed the normal Spring planting into the technical start of Summer. With the rain, right here in Central PA the undergrowth has exploded, the forest has nearly conquered our little property at its edge. The only “climate change” I’m wondering about is if this is becoming a temperate rainforest.
The current “heat wave” is, as far as I’m concerned, just averaging out the temperatures for the year. It’s just weather. If it is going to “rain like there’s no end” after it ends, either it’s going to take several years to average that precipitation out or we’re in for a very dry Fall and/or Winter. Either case, it’s still weather. We’ve had hot stretches before, and precipitation running low for years. If anything, all this “freakish weather” is doing is averaging out some locally cited “demonstrated effects of global warming.”
And to note it, after all those cool dim Spring days with some rainfall every day of a month, anyone around here with a solar photovoltaic system should really be considering doing some serious upgrading of their storage capabilities to get through those “rare” sunless periods.
Smoking Frog says:
July 23, 2011 at 1:42 am
I don’t know Mann’s “loaded dice” analogy, but it sounds like it might be similar to what I’m about to say. Do you know what a normal distribution curve (bell curve) looks like? The temperatures for a given date or a given period, same date or period in each of many years, are very likely distributed like that.
Yes, Mann was basically saying the same thing. (Here’s where I got it from: http://news.nationalgeographic.com/news/2006/08/060801-heat-waves.html) The problem is, how do they know how much of a “load” a 1 degree temperature increase puts on the dice? That’s the same thing as saying how much does 1 degree difference change the slope of the normal curve? Until you know that, it’s just a lot of hand-waving, as you noted.
I wonder how the older Bedouin folk in the desert manage without aircon?
A new article (Goldberg et al. Environmental Research 111:853-860) looks at mortality in Montreal as a function of temperature. The study finds a strong effect of heat above 27 C, not very strong for cold. However, the authors make the very interesting observation that Montreal homes are better equipped for cold than heat:
“A feature of the city and the province is that there is little air conditioning in homes (25.6%) in the Province of Quebec in 2008 (Statistics Canada, 2010) but that the buildings are well-heated during cold periods…”
Persons quoting just the main finding would do well to also include the caveat.
http://www.currentresults.com/Weather-Extremes/Canada/hottest.php
If the weather in France is so cold, why are there so many Tour de France spectators running alongside the race wearing only their budgie smugglers?
John,
Maybe they were trying to get a rise out of you. Looks like it worked.☺
Smoking Frog-“The temperatures for a given date or a given period, same date or period in each of many years, are very likely distributed like that. If you shift the curve to the right (hotter), you get a disproportionately great increase in the number of years near the right end of the curve, because you’ve shifted a “bulkier” part of the curve to every temperature on the right side.”
Faulty assumption here! That warming constitutes merely a change in the mean of the distribution. The standard deviation could also change, because you could get disproportionate warming in, say, the coldest days. Now someone could test this…Ah, here we go!
Knappenberger, P.C., P.J. Michaels, and R.E. Davis, 2001. Nature of Observed Temperature Changes Across the United States during the 20th Century. Climate Research, 17, 45–53.
The warming in the most recent period in the US was concentrated on the coldest days of the year. Meaning way fewer cold extremes, not a whole lot of heat waves.
Andrew says:
Faulty assumption here! That warming constitutes merely a change in the mean of the distribution. The standard deviation could also change, because you could get disproportionate warming in, say, the coldest days. Now someone could test this…Ah, here we go!
…
Yes, the assumption very likely is wrong, but I only made it for the sake of explaining a particular mathematical aspect of things to Mike Abbott. Quite possibly, I was wrong in thinking that he might not already understand it.
Mike Abbott says: Yes, Mann was basically saying the same thing. (Here’s where I got it from: http://news.nationalgeographic.com/news/2006/08/060801-heat-waves.html) The problem is, how do they know how much of a “load” a 1 degree temperature increase puts on the dice? That’s the same thing as saying how much does 1 degree difference change the slope of the normal curve? Until you know that, it’s just a lot of hand-waving, as you noted.
I thought you might not understand the mathematical question. If I was wrong about that, I apologize, but I’m not sure I was wrong, because in my explanation there was no change of slope at all. In reality, a change of slope may be likely, but I think this might depend on what is meant by “mean temperature” (e.g., mean of temperatures at which times of day?).