A dose of common sense from Marshall Shepherd
As I browsed the social media, I saw claims of climate change, “end of times” language, and sheer awe that hail fell in Mexico during the Summer. I thought that it would be instructive to provide context and perspective on this event before things get too carried away.
Hail is not uncommon during the summer. In fact, it is quite likely. For many people, it is counterintuitive that large chunks of ice can fall from the sky during the hottest season of the year. Hail forms in cumulonimbus clouds, which are quite common during the warm season.
Later in the article he drills down into regional points.
It is not surprising that higher elevations would experience a greater number of hail days. Florida receives more thunderstorms than most states in the U.S., but “hail alley” Colorado, Nebraska, and Wyoming. These states receive 7 to 9 hail days per year according to NOAA because the freezing levels (32 degrees F or less) in those regions are closer to the ground. Guadalajara, Mexico sits at an elevation above 5,000 feet. Hail is not necessarily abnormal at this geographic location. What about the vigorous amount of hail seen in photographs all over social media?
And the real sanity check.
It was clearly a dramatic and extremely impressive event with major local impacts–but I think the physical characteristics have been fundamentally mischaracterized. I have no doubt there were 1-2 meter hail drifts in some spots (photos attest to that)–but those drifts were clearly created by flash flooding down streets and culverts in a highly urbanized area. (A strong clue are the cars stacked on top of each other–water did that, not hail!). Come to think of it, the physical constraints of a single storm dropping 6+ feet of actual solid ice would probably be prohibitive anywhere on Earth, I would think. I don’t know the exact numbers, but even just considering the amount of column water or the vertical forces required to loft that much solid water…well, suffice it to say it would stretch credulity.
Shepherd is a mainstream scientist, so the rest of the article puts the episode in consensus perspective, but without the hysteria, hyperbole that is so common these days.
I want to close by dealing with the climate change question. Even officials in Mexico were so stunned by the hail drifts that they mentioned climate change. It is quite common after extreme weather events for some people to say “see climate change caused this.” The other partner in this very familiar social media “waltz” is the”things happen naturally or are not unprecedented” narrative. Climate change is very real, and humans are a significant cause of our crisis. Virtually every credible scientific organization and peer-reviewed report affirms this point. A 2016 National Academy of Science report even explored the emerging science of attributing current extreme events to climate change. Concerning severe convective storms that produce hail or tornadoes (SCS on the graphic below), linkages are not nearly as compelling (right now) as they are for heatwaves, drought, extreme rainfall, and lack of extreme cold events
“Climate change is very real, and humans are a significant cause of our crisis. Virtually every credible scientific organization and peer-reviewed report affirms this point.”
If they don’t agree that humans are a significant cause are they then simply not “credible”?
“Significant” – does that mean may be causing or may be contributing to or only “definitely is”? I’d like to see a complete list of these organizations with their exact statement. Do they all say or mean exactly the same thing?
Then there is the “humans are a significant cause” problem. Which human actions specifically are a “significant cause” or is it only a combination of all human activities? More to the Carbon Dioxide emission discussion, what is specifically said about the contribution of those emissions.
I’m sure we could pick this apart more, but the absurdity of it to the well=informed is overwhelming.
As a U.K. friend put it, “I also know that this year there were floods in Sussex, which has never happened before, ever. Apart from every year for the last two thousand.”
– Weather, not climate…
The sheer arrogance of the author is revealed by saying that only research that agrees with him is “credible”. So much for his credibility as a scientist.
Any hail storm I have ever been through where the ground is covered with hail stones also strips the trees bare. I saw lots of pictures with mounds of hail on the ground, but the trees still had most of their leaves. For me, that was a non sequitur. Maybe I just did not look at enough of the photos.
Yeah, I noticed that too (the palm trees look unaffected)). Perhaps the hailstones were small, but the total amount was huge.
I find it fascinating that ONE event can so shift an average, which is what climate is, enough to declare “climate change”. You take 6,000 red balls, through in a blue one, and suddenly, the balls all turn purple. Fascinating, absolutely fascinating.
Nicholas and Mat
A long time ago I recall hearing or reading about “Ayre’s Law”.
If it has happened it can happen.
Gully-washer downpours and in this case hail have likely been happening over geological time.
You sure it wasn’t Sayre’s Law that springs to mind?
https://en.wikipedia.org/wiki/Sayre%27s_law
At an even more general level, if it has a name, it is not a new thing.
“There is nothing new under the Sun.”
“Climate change is very real, and humans are a significant cause of our crisis. Virtually every credible scientific organization and peer-reviewed report affirms this point.” “…linkages are not nearly as compelling (right now) as they are for heatwaves, drought, extreme rainfall, and lack of extreme cold events.”
Significant? Crisis? Virtually every? Compelling as? No skepticism allowed.
There’s the legend of hailstones in the Indian Himalayans the size of small elephants. Yeah, grain of salt.
The Earth is huge. Weather can be violent. There’s almost always someplace at a given time where sh*t is happening.
I remember a disastrous hailstorm in central India in the early 1960’s. Crops are planted after the rains and mature in Feb-Mar. That year hail beat the standing grain into the ground just before harvest, for the local people a serious disaster, but unlike similar events in Behar state, the central region has lots of transportation – rail and road – left by the British, so that there was grain available for those who could sell jewellry and purchase it. In Behar, they are only recently getting enough transportation so that the vagaries of the weather does not cause serious famine.
The most expensive hailstorm in U.S. history, to this point in time, was the June 1984 storm in the northwest Denver metro area. I lived there at the time. My home suffered $12,000 in damage, and 38th and 44th avenues had hail-drifts probably 4 feet deep with cars piled up in a jumble here and there. The storm produced $600 million in total damage, mostly to auto dealerships along Wadsworth.
This is not “end of days”.
How did hail pick up and pile cars into a jumble?
I think that someone above got it right: The aftermath seen was a result of flash floods.
Hail is just falling pieces of ice, and I am hard pressed to see how falling anything stacks cars into a heap.
I was living in Gallup New Mexico in the late 80s when we had a hailstorm that put down 3 feet of hail drifts in the middle of downtown on route 66. It was not unusual. It was given a single photograph and a paragraph long caption in the Albuquerque newspaper.
I suppose that depends on what one means by “unusual”?
It happens, every once in a while for any given location, almost never for other locations.
In addition to the hail forming aloft, it has to get to the ground w/o melting.
There was a summer fish kill from upstream hail in an arroyo in the desert, Texas best I recall. Fortunately it was recorded by Isaac Cline, a meteorologist of some note and sense as there was no evidence of hail with the fish. Not sure of original but reported by—-Larson, E. 1999. Isaac’s Storm: A Man, A Time, and the Deadliest Hurricane in History. Crown, NY. 323p.
This is weather. Big drifts caused by water running the dramatic hail volume into ever narrowing areas. If this had happened outside the urban area there would be no story.
Every time it is cold and people joke “where is that global warming now, eh?” warmists scold “weather isn’t climate, you idiots!”
They forget this every time it gets hot or there is a storm somewhere. Suddenly then weather IS climate.
I lived in Central Mexico for almost five years. It was not at all uncommon to have hail storms during the monsoon. I’ve not seen that much hail as the photos circulating but I’ve seen inches of it.
I’d have to take issue with Swain saying that a 6ft dump of hail isn’t possible. I remember something of that sort occurred in Colorado Springs CO sometime around 1998 or 99. There wasn’t a rainstorm at all, just some light drizzle that afternoon. It was an extremely localized hail event, right outside the front entrance of University of Colorado CS on Austin Bluffs Pkwy, when a cloud suddenly dropped its load of hail at least 5ft deep, catching several passing cars and encasing them in ice. The area was quite small, perhaps two city blocks. The CSFD and PD had to use picks to dig down to the cars to rescue the drivers, then brought frontend loaders and dump trucks to remove the hail to reopen Austin Bluffs.
As hail falls it melts and absorbs a huge amount of heat energy, cooling the air in the column of falling hail.
So the more localized the event, the more the column is cooled and this allows subsequent hail stones to fall and hit the ground while still frozen.
Also the dynamics of the inflow and updrafts lead to large amounts falling in a small area if a storm is stationary.
There is a good reason for the name Guadalajara. Wadi Al Jara Wadis are a dangerous place to be in a downpour. There are probably some orographic precipitation effects involved I suspect. I have seen a foot or more of fast running water, that was able to move cars, in the streets of Guadalajara. I have also seen highway underpasses filled in minutes.
Don’t think that low altitude Florida just can’t have significant accumulating hail. I very well remember seeing pictures of a hail event in central Florida, near Orlando, if I remember right, where hail accumulated at least a half a foot or more. The ground and parking lots looked like a northern snow. Cars were slipping around, putting deep tracks in the ice. Ice on the ground like that in central Florida blew everyone’s mind. Seems like it was 10-15 years ago.
I imagine the low altitude kept it to the lower amount compared to the recent event. The earth is big, and there is always something happening for the first time somewhere, even in the past. I’m tired of hearing, “Oh, a new temp record” must be climate change.
See above.
Apopka is northwest of Orlando.
Due west of Altamonte Springs.
Just north of west of Maitland.
I can recall reading many years ago that hail is so common in the US (and I am sure anyplace with thunderstorms) that a certain percentage of some crops will be lost to hail every year.
In Cairo (Egypt), more than 60 years ago, the whole of the plaster on the West wall of the villa in which I was living was stripped. Some of the North wall was also pockmarked as if by bullets.
The culprit was a hail storm with stones the size of marbles which started at around eleven o’clock one night. These piled on the roads, the lawns, the flower beds and the balconies to a height of six to eight inches. The piles would have been even higher had it not been that, due to the summer heat, the hailstones were melting rapidly.
Next morning all the gardens in the immediate area had been stripped of their flowers. But gardens and houses less than a mile to the North were unscathed and their residents had not notice been aware of the storm