One very hot ridge of high pressure stacked up in the atmosphere through the first half of the weekend looked like this aloft. I can’t help feeling even the “untrained eye” can capture the heated look in this ensemble graphic.
This steamy hot ridge with extraordinarily high dew points will begin to give way a bit with a first cold front on Sunday, and then make a real retreat to the south and west as we get into Monday and next week. Take a look at the difference in the upper air steering currents early in the coming week.
In meteorology, this is a dramatic shift. The hot ridge builds over the west and a deep trough sets up shop over the Great Lakes and the Midwest. Earlier in the season, this would be an alignment favoring genuinely chilly conditions. That will not be the case in midsummer. The trough will actually bring slightly below average (80 is the average high in late July) to average temperatures and good sleeping weather at night. At the surface, you’ll note the cold front has been pushed well to the south, evening bringing relief to desperately hot Washington, D.C. For us, this enormous Canadian high pressure system will bring a more northerly flow.
Our high temps will be comfortably cooler, accompanied by much lower humidity.
The overnight lows will certainly have an “ahhhhh!” factor with air conditioners shut down for a vacation.
There is some good news in the relative persistence of this upper air pattern. While it won’t be fully permanent through August, and will weaken somewhat later next week, extreme heat is absolutely out of the picture into next weekend in our region. The initially cool high will drift to our south, and a milder flow around the back of the high will boost our temperatures, though only a couple of degrees above average by the end of the week.
As we move into early August, the upper air ensembles are still showing remnants of the Great Lakes trough/western hot ridge in place. If this verifies, it would preclude the kind of sultry heat we’ve been experiencing from returning during the next 14-16 days.
The Climate Prediction Center, after showing a tendency toward slightly below average temperatures in the six- to 10-day forecast, keeps our temperature probabilities near normal in the eight- to 14-day forecast. Again, near normal at this time of the year means warm enough for any outdoor activities without excessive heat.
So far, July will be running about 3 degrees warmer than average as of Saturday, which is significant but not extraordinary. Rainfall at Buffalo has been only slightly more than half of average, giving yards and fields a chance to dry out. Drier soil allows the air to warm more quickly in the day, and cool a little more at night if skies are clear. Conditions have improved tremendously for agricultural interests after the frequently soggy spring and excessive soil moisture. Vegetable and fruit crops eat this kind of weather up, so we can look forward to eating them up as they ripen. Soil moisture in the central and eastern part of the U.S. is still above average in most places, including Western New York. However, the change this month from those excess anomalies has been for the better.
As for how August may be shaping up for temperatures, I’ve been reading some private sector forecasts for a return to anomalous heat in the east. On the other hand, I’m not personally seeing any clear cut signs of that hot ridge migrating back to the east, at least not in the first part of the month. Even the extended range model with the warmest bias (called the CFS v2 if you’re curious) has the bulge of the warmest part of upper level ridge staying out west.
Not a bit of this is to suggest a cool August. I’m simply not detecting strong signals of a prolonged return to the kind of heat finishing up by the end of this weekend.
Our regional heat is far from unprecedented. Globally, it may be a different story, with continuing growing evidence of a climate tie-in. Much of the warming at high latitudes has been extraordinary since the winter, as it was the previous winter. Here is the global summary, from NOAA.