Tuesday wasn’t the hottest day so far this year, but it was the steamiest. Dewpoints broached the 70-degree mark, with the lowest relative humidity of the day at a muggy 71%. Had temperatures moved higher into the 80s, most would have rated the day as oppressive. At least Buffalo only topped off at 81. If all this is reminding you how sticky it is, we have some change on the way. And, the final section of this article will focus on new evidence of accelerated warming in the Arctic having a better demonstrated link to periodic harsh wintry outbreaks, as counterintuitive as that may sound.
In just the first eight days of June, Buffalo’s mean temperature has been running 6.3 degrees above average, which is a large positive anomaly. Our rainfall for the month is just shy of average, but we remain about a third below average for the year. We need more rain. Distribution of what rain is coming will remain quite uneven, which is typical of summertime cellular convection. During Wednesday, a cold front will be sinking southward across Western New York and should be into Pennsylvania by early evening. This progression would favor any isolated heavier convective cells to occur well to the south, in the Southern Tier.
Because the front isn’t going to settle much farther south, the chances for additional weaker convective showers will return on Friday, but mostly well south of the metro area. Before that, Thursday will dawn a more refreshing day with dewpoints dipping from Tuesday’s 70 degrees back into the much more comfortable low 50s. You will definitely notice the difference, even with high temps in the low 80s. On Friday, humidity will creep back up to moderate, but then drop off to quite comfortable again on Saturday with more abundant sunshine.
Sunday gets trickier with the passage of a warm front followed by a cold front, bringing a chance for a few showers and thunderstorms for a portion of the day.
Temperatures will peak in the low 80s on Thursday, Friday and Sunday, but slip to the upper 70s on a beautiful Saturday. A somewhat lengthier transition to seasonably cooler readings will arrive by Monday, with passage of a couple of cold fronts.
The fronts will usher in readings in the low to mid-70s. The extended range upper air ensembles favor these seasonable to seasonably cool temperatures to dominate most days next week, out past midmonth, with the warm ridge retreating to the west. The Climate Prediction Center eight- to 14-day outlook has similar temperature probabilities.
Finally, it appears most of what inadequate rainfall comes in the next week will be south of the metro area, so frequent watering will still be in order.
On the winter side of the ledger, in this month’s edition of Physics Today comes one of the more convincing pieces of evidence linking accelerated Arctic warming with periodic cold and snowy outbreaks in the midlatitudes. Evaporated moisture from the Barents Sea, one of the few parts of the Arctic Ocean which has warmed sufficiently to remain ice free even in the winter, has been traced to snow which fell as far south as Rome, Italy, in 2018.
I’ve written a few Buffalo News articles highlighting strong but still inconclusive evidence of the high latitude warming leading to periodic southward shifts of the disrupted polar vortex.
But attribution of these periodic wintry outbreaks directly to Arctic warming has remained controversial, with some scientists believing the conclusive evidence just isn’t there. Now, there is some more concrete evidence.
The Barents Sea is fed by the northward extension of the Gulf Stream known as the Norwegian Atlantic Current. Until the last decade, this sea reliably froze over in the winter. In more recent years, accelerated high latitude warming has caused the Barents to remain open even in the winter. We now know this newly available Barents moisture was transported a long way. In 2018, snow fell in Rome for only the second time in 35 years. The proof of the Barents link lies in the molecular isotopes found in the snow.
A study led by Hannah Bailey of the University of Oulu in Finland found a fraction of water molecule isotopes found in the central European snow also contained a heavier atom of deuterium which was also attached to the H2O molecule. These heavier isotopes are common in seawater, not freshwater, and due to slower evaporation, build up in concentration over time in the seas. The chemistry gets very complex on these isotopes, but their presence provides more definitive evidence of a form of ocean-effect snow from the no-longer frozen Barents Sea. In other words, back in the cold, frozen days, such isotopes were trapped in the ice, and did not have a chance to evaporate in winter months and be carried by winds aloft.
Interestingly, the Physics Today article author, Johanna Miller, brought Buffalo into her prose as a roundabout analogy of the process: “An open body of water in an otherwise cold climate is potentially consequential because it can supply the atmosphere with large amounts of moisture that can later fall as snow. The same so-called lake effect explains the snowfall patterns around the Great Lakes in the US: Buffalo, New York, which is downwind of the lakes, gets more than twice the average annual snowfall as Milwaukee, Wisconsin, which is upwind.”
If you’ve forgotten how cold and snowy February was this past winter, that pattern was tied to a disrupted piece of the polar vortex slipping south, as I explained in my linked article above. It was quite extensive, and also led to the disastrous snow, freezing rain and bitter cold which paralyzed Texas.