It would have been catchier if this was titled “The Heat Goes On.” Alas, other than Wednesday’s mugginess, what lies ahead doesn’t cut it – in my book – as true heat, even by mid-September standards. We will be holding on to above-average temperatures most days for some time to come, even though this Thursday was almost unseasonably chilly.
The warmup gets going even before the weekend begins, with an increasing downslope/southerly breeze boosting temps back up above average. By late night, some scattered showers and thunderstorms will be approaching from the west, continuing on and off into Saturday morning.
A fresh, breezy Pacific air mass will arrive for the afternoon with more sunshine and seasonably mild temperatures reaching the mid 70s. (“Seasonably mild” would mean a little above the average of 72-73.) By Sunday, we’ll be experiencing another mild day, with plenty of sun and readings creeping up into the upper 70s. If you’re headed to the Bills-Giants game at MetLife Stadium in New Jersey, it will be warmer yet with temps reaching the low 80s. Some Saturday night New York metro showers should be gone by mid morning and for the game.
As for next week, my colleague Dr. Michael Ventrice of IBM’s the Weather Company is a little dramatic with his title for the European ensemble temperature trend, but the graphic’s legend does convey a clear-cut warming trend continuing.
The peak warmth is in the Midwest and the east, with the only cold departure in a smaller portion of the west. As for how that warmth projects into actual forecast high temps next week, the numbers are warm but not so dramatically above average as the European ensemble suggests. Here are Tuesday’s highs, as forecast by National Weather Service HQ.
By next Thursday, the numbers edge up:
The trend holds into the end of the week:
But by the end of the following weekend, we are seeing sign of the warm upper level ridge in the east migrating to the west. This would allow more of a NW flow aloft in the Great Lakes, and would be a harbinger of some change from the excess warmth.
Nothing here portends, at least not yet, a dramatic change over to real, lasting autumnal chill.
Dr. Judah Cohen, a scholarly long range specialist who lives in New England put out an interesting tweet Thursday morning. He would readily admit, as do many of us meteorologists who live in snowy climes, we enjoy the anticipation in advance of winter. In fact, I’ve never met a New England meteorologist who didn’t look forward to the start of winter.
— Judah Cohen (@judah47) September 11, 2019
I should quickly add, however, he is no “wishcaster,” nor am I or almost any experienced forecaster. That is, we make every effort to forecast with good scientific practices, and not with what gets our adrenaline flowing. If you scan his answers to comments on his tweet, you’ll note Cohen is quite restrained and circumspect. If he sees signs of a mild trend in the winter, he will be the first to tell you so.
As for the polar vortex, no one needs to say “Oh, no … not that polar vortex jazz again!” The polar vortex redevelops every year in varying strengths and locations, and has been around in the scientific literature the better part of a century. Some elements of the media make it seem as if it’s something recently discovered, which is not the case at all. Its development has become more erratic and less predictable due to arctic warming weakening the polar jet stream, and allowing it to buckle southward into a high amplitude blocking pattern from time to time. None of us can predict those blocking episodes more than a couple of weeks in advance. That means, in my opinion, advance winter outlooks have become even a dicier proposition than they already were.
In the meantime, we’ll be watching a new tropical system developing in the Bahamas that will threaten the northwest Bahamas and Florida with at least heavy rains and gusty winds, probably reaching tropical storm force. As of this writing, this potential tropical cyclone had not yet become a depression. It is forecast to become a tropical storm and, after 48 hours of moving northwest, it should recurve to the northeast. It will not become a monster hurricane or produce the kind of destructive storm surge as what Dorian produced in the northwest Bahamas, with a less favorable environment for rapid intensification. Intensity forecasts being what they are, however, hurricane strength cannot be ruled out.