Back on April 22, I wrote I was less confident than the National Weather Service Climate Prediction Center/CPC that our summer temperatures would run above average, both in June and for June through August. CPC was projecting about a 40 percent probability summer temperatures would run above average for our region in their outlooks at the time. Some of CPC's confidence may stem from the persistent warmth that has been dominant for some time. Eighteen of the last 20 months have been warmer than average.
I questioned this confidence because of excess soil moisture in the east. Air is harder for the sun to heat over moist soil than over dry soil. We all recall the muddy yards and fields we suffered earlier this month from weeks of excessive rainfall. That moisture surplus has declined but it most certainly has not gone away. As of Monday this week, Buffalo rainfall/liquid was at 19.92 inches, 6 inches above average for the year. And just since March 1, the surplus for that time period is larger: 6.49 inches.
I'm not countering with a prediction of cooler-than-average temperatures instead of warmer. I'm suggesting we are more likely to have typical ups and downs in our temperatures that may end up equating to average temperatures when all is said and done. In case anyone forgot, average means typical summer temperatures. There will be some chilly days and some warm and humid days.
Frankly, I've read CPC's reasoning for their warmer-than-average probabilities, and I just can't buy their reasoning. Let's start with soil moisture. As of May 22, here's the picture.
Our soil isn't just a bit moist. It's running well above average. That surplus isn't going to quickly dissipate unless we head back into a droughtlike pattern. Even CPC sees no clear indication of drier or wetter anomalies for precipitation. They indicate on their maps "EC." EC means equal chances for above or below average rainfall. We have nothing to hang our hats on for rainfall.
It would take a more fundamental change in our pattern to ditch the excess soil moisture-related capping on heating. We would need to see a more persistent warm ridge of high pressure anchored near the SE and Middle Atlantic coasts, or a Bermuda high to more consistently pump up warmer-than-average air into the eastern Great Lakes. That may happen eventually, but there is no sign of it right now becoming persistent.
As far as temperatures, here is a long-range model called the Climate Forecast System/CFS:
The CFS is far from foolproof, but it offers no signs of a pattern reversal. In fact, it shows little excess warmth for the vast majority of the nation.
The European/ECMWF model has a 46-day product which explores trends but, as I've written before, I'm not permitted to display that product due to licensing requirements. However, I've examined it and the trends in that product are not very different from this ECMWF product that goes out to June 3.
If you click on the play button to animate, you'll note a tendency in the ECMWF for systems to keep moving right along, rather than a persistent warm ridge in brighter reds setting up in the east. This is what meteorologists call a progressive pattern. Progressive patterns lend themselves to ups and downs, rather than persistence. Catch my drift?
My thinking is we'll have our share of warm days, even warm and humid days – especially with the moist soil adding water vapor to the air – but we'll also have our share of cooler days following passage of cold fronts, as we had on Monday this week. For those of you strangely attracted to lengthy periods of sultry, sticky weather, you may be disappointed. For those of you who prefer some periodic relief from sultrier periods, you may be just fine with this progressive pattern.
Either way, it doesn't matter what any of us prefer. Nature's laws of physics will do what they do regardless of huzzahs and/or boos from us earthlings.
Story topics: By Don Paul