After a briefly less humid Tuesday, and the redeveloping steam heat for the Fourth of July and Thursday, we’ll be over the heat hump as we head into Friday.
There are legions who enjoy the heat and even the humidity. Preferences aside, though, the heat wave is causing problems with power outages locally and regionally. The problems will likely worsen for the grid until a cold front arrives. The heat covers an extensive area, so a heavy power load is no doubt putting stress on systems from southern Quebec and Ontario to our region to parts of the Midwest and much of the middle Atlantic region.
Here is a 2 p.m. sampling of Monday temperatures, and you can see the extent of the heat, which hadn’t yet peaked for the day.
An enormous hot ridge of high pressure will be stacked up over a vast area on July 4, under which the atmosphere will be baking:
Under that ridge will be dew points like these.
Dew point temperatures of 70 or higher are oppressive, drastically reducing evaporational cooling via perspiration. The dew point will stay high into Thursday night, with showers and thunderstorms becoming more widespread as a cold front approaches. Here is the American GFS model depiction at 7 p.m. Thursday.
During Friday, the dew points will be tumbling back to the very comfortable low 50s, at which point many will be heard saying “ahhh,” including National Grid and NYSEG.
Take a look at the upper air pattern showing up in the European ensemble by late Friday. Note how the hot ridge has retreated to the west.
Our Saturday high temperatures will be seasonably cool-ish and, for many, will feel delightful. From the GFS model, check out the early afternoon temps Saturday.
This first shot of cooler air isn’t slated to last long, as the warm ridge moves east again during Sunday. We’re not heading back to where we are now, but we’ll be moving into the 80s for a bit.
However, by midweek next week, a longer-lasting retreat of that hot ridge will take place, allowing a moderate west/northwest flow to resume in the Great Lakes.
Seasonable warmth will be returning at regular intervals, but there are no signs at the moment of a heat wave in our future after this week for some time to come. This animation of the upper air pattern ensemble from National Weather Service HQ tells the story.