TheClimateChanger

Been hearing of a heat wave in Puerto Rico, so figured I'd take a quick dive into the data. Easily the hottest start to June on record in San Juan:

I've seen a little chatter on Twitter that the recent warming may be related in part to a reduction in sulfur emissions from shipping and/or water vapor from the 2022 Hunga Tonga eruption. I don't buy either of these theories - First, aerosol optical depth across the northern Atlantic has been much higher than typical due to the intense plumes of smoke from the Canadian wildfires. Moreover, wildfire smoke has a greater cooler potential by mass than sulfate aerosols emitted by shipping, and can be lofted into the upper troposphere and lower stratosphere by pyrocumulonimbus and even downstream convection. The North Atlantic heat wave is happening IN SPITE OF very high levels of climate-cooling aerosols, not DUE TO low levels of aerosols. As for the volcano theory, this theory is basically akin to a "volcanic summer" - i.e., a brief, but rapid, warming due to stratospheric water vapor. Doing some research, I could find zero evidence that this phenomenon has ever been observed prior to 2022. There can be warming from volcanoes, but it's usually due to a series of volcanoes or a few intense eruptions emitting large amounts of greenhouse gases and follows an intense volcanic winter. Obviously, Hunga Tonga is not the first explosive undersea volcano - nearly 70% of earth's surface is covered by water, so there's likely been a lot more of those type of eruptions than explosive terrestrial eruptions. Despite this, there is zero evidence of a volcanic summer ever occurring, which would be easy to detect. They've detected numerous volcanic winters. Any impact from Hunga Tonga is likely minimal, and if anything more likely to have resulted in some cooling of the climate system. In my opinion, the warming is more likely the result of continued, record-breaking, emissions of greenhouse gases, rapidly developing El Nino conditions, and perhaps positive feedback loops being triggered, with the two mechanisms proposed above a very small part of any observed warming.

For reference, here is what the 21z RAP is showing for hour 51. As you can see, this is a massive plume, enveloping all of Saskatchewan, most of Alberta and Manitoba, western Ontario, and even parts of Nunavut.

Both the RAP and HRRR agree that another massive pall of smoke will form and cover all or most of Alberta, Saskatchewan, Manitoba, and western Ontario early next week. Many of these areas look likely to experience degraded air quality and limited sun. A bit concerned we could see this intrude into the upper Midwest and perhaps elsewhere as we head into the middle of the week, with a northwest flow aloft west of the Great Lakes upper low. Regardless of whether this enters the US airspace, many places in Canada look likely to see unhealthy to hazardous air quality. This is the 00z HRRR depiction of vertically integrated smoke and near surface smoke. We see the south end of a dense pall of smoke, including a substantial near surface component. The RAP gives the true size of the smoke pall, as much of it lies outside of the HRRR grid.

This is why I always use to say I’m a climate skeptic. Skeptical that it wasn’t much worse than the mainstream view, not that it wasn’t happening. They say it’s warmed 1C since preindustrial, but in fact it’s warmed nearly 1C just since the 1981-2010 average. This should be a smoking gun that they’ve been downplaying this, but I doubt that’s how many will report it.

Driest and warmest year to date at IAD. For the record, DCA with a much longer POR, is 4th driest & 2nd warmest on record YTD.

Looking back at the last 31 days, can certainly see the flash drought. Temperature rankings are based on mean maximum temperatures, which mitigates the urban heat island effects. I didn't realize it had been so warm, since a lot of the heat has been disguised in the means by somewhat cooler minima due to the dryness. Just by way of example, Moline is 2nd warmest by mean maximum temperature in the last 30 days, but would only be 13th if measured by mean. Chicago is 8th by mean maximum, but only 15th if measured by mean. For more extreme examples, Lansing is 7th warmest by mean maximum, but only 19th if measured by mean. Detroit is 9th warmest by mean maximum, but only 33th if measured by mean. Toledo is 6th warmest by mean maximum, but only 32nd if measured by mean. Moline, IL: Driest on record, 2nd warmest on record Minneapolis, MN: 6th driest on record, 4th warmest on record Chicago, IL (16th driest on record, 8th warmest on record) Green Bay, WI (Driest on record, 3rd warmest on record) Duluth, MN (2nd Driest on record, 5th warmest on record) Lansing, MI (Driest on record, 7th warmest on record) Detroit, MI (2nd driest on record, 9th warmest on record) Toledo, OH (Driest on record, 6th warmest on record)

Looks like MSP is off to an absolutely scorching start to summer. Second warmest on record for first eight days of June, and would have been first if it occurred during or before 2020. Third warmest when measured by mean maximum to minimize impacts of growing UHI. Wouldn't have expected this with the northerly flow and wildfire smoke limiting insolation.

DuBois received 0.11" of rain this morning. This is the first rainfall since May 20, and only the second since May 9 when a trace was recorded. The last measurable rainfall prior to May 20 was on May 7.

I think I can smell the fires now, unless it’s a local fire.

Not sure if it runs a bit cool, but the AWOS at Zelienople Municipal Airport is down to a chilly 36 this morning: https://w1.weather.gov/data/obhistory/KPJC.html

Pretty close to the record hourly minimum dewpoint at KPIT right now.

Impressive to see a 6 degree temperature drop right around local solar noon just two weeks before the summer solstice. Like a miniature nuclear or impact winter.

Well, don't quote me on it. Was just soliciting Tip's thoughts. I did some research last month, because I was curious and I think I read where Australia's Black Summer produced up to 0.17C cooling in the southern hemisphere. That's also how I happened upon that curious event in September 1950. Not saying there's a link, but 1950 was the coldest year in the U.S. since 1929, and 1951 was even colder. There's only been a handful of years since that were colder than either of those years - which obviously mainly due to climate change. There was record breaking cold and snow in November 1950, and 1950-51 remains the snowiest winter on record in Pittsburgh. Ant Masiello seems to be the only met who dives deeply into these issues:

Do you really think it will get that hot this summer? Aerosol optical depth was off the charts in May over North America and looks to be even worse in June. There have been numerous pulses of pyroCb lofting the burnt biomass aerosols into the stratosphere already, and its only June 7. Would expect at a minimum regional cooling, if not hemispheric wide cooling, from this event. Wildfire season is just starting.

Wow - that's Black Sunday stuff right there. The Day the Sun Disappeared—September 24, 1950 - Burchfield Penney Art Center Black Sunday: Darkness falls in the PA Wilds - Pennsylvania Wilds darksunday (the-red-thread.net)

Syracuse, looks like visibility is actually 1/2 mile: National Weather Service : Observed Weather for past 3 Days : Syracuse, Syracuse Hancock International Airport

Why is dense smoke advisory criteria so much lower in the east than the west? In the western US, they routinely issue dense smoke advisories for 1-3 mile visibility, yet there are none issued even for less than one mile visibilities in the eastern US.

Unfortunately, the next two days look just as bad as today. Tomorrow looks to be the worst, maybe a slight reprieve on Thursday. Of course, that's contingent on additional fires not breaking out between now and then inserting additional smoke. I don't know what the weather is like in Quebec, presumably dry. But there have been bouts of pyrocumulonimbus in recent days, which can be accompanied by dry lightning. Near surface smoke at 5 pm on Wednesday: Near surface smoke at 5 pm on Thursday:

While we've unfortunately grown accustomed to these extreme wildfire smoke events in recent years, in 1950, it was without precedence. 911 dispatchers were flooded with calls. Many ascribed various theories ranging from the end of the world, atomic bombs, flying saucers, toxic clouds from government experiments, to a non-forecast solar eclipse. From the Weather Bureau's Pennsylvania Monthly Weather Review for September 1950:

Interesting. The wildfire smoke last month prompted me to do some research. I wanted to see how unusual it was to have wildfire smoke, and what effects wildfire smoke has on the weather and climate. I came across a peculiar event on September 24, 1950 known as "Black Sunday" or "The Great Smoke Pall of 1950." Here is the article from Hazleton from that event:

I mean, it's not ideal. But when the alternative is a guaranteed blue ocean event and the permanent loss of the Arctic as we know it, what other choice do we have?

Wow, this is an impressive pall of smoke tomorrow - keeps intensifying on the models. Which makes sense the earlier runs saw only the existing fires, and didn't factor in additional fires breaking out in the extreme conditions today. Now showing a widespread area of dense smoke with surface visibilities under a mile, perhaps locally under 1/2 of a mile. Looks like a potentially dangerous situation on portions of the New York State thruway.

I see a lot of media reporting this as "it's too late to save Arctic summer ice." I'm not so sure. I think a targeted system of solar radiation management by spraying aerosols in the atmosphere over the Arctic each summer could buy us sufficient time to draw down GHG levels. But none of our do-nothing politicians want to have that discussion!

Doubtful, likely a net negative. Cools the surface, and warms the upper atmosphere, which reduces instability. The presence of wildfire smoke does brighten and thicken cumulus clouds, producing additional cooling; however, the presence of more, but smaller, droplets means the resulting clouds are actually less conducive to rainfall. There is some research, however, that suggests wildfire smoke and aerosols can lead to more lightning - particularly dangerous positively charged bolts. If anything, the case can be made that the unusually smoky atmosphere contributed to the ongoing regional dry spell. https://www.nationalgeographic.com/environment/article/wildfire-smoke-is-transforming-clouds-making-rainfall-less-likely#:~:text=It does indeed%2C according to,likely to fall as rain. https://news.mit.edu/1998/smoke-1007