The heat is on, likely reaching some numbers we haven’t seen in years. However, the entire stretch won’t feel horrid thank to dewpoints being modest from Wednesday in to the weekend. The daytime dewpoints/air temp spread gives a low relative humidity. Making your “reel feel, apparent temp, heat index” not that much different than the actual ambient air temp. So, while hot is going to be the theme, the stretch will not be consistently oppressive. Monday and Tuesday may feel the most oppressive. However, the media will jump all over the max temp numbers as it’s a big headline. Rightfully so, but as far as oppressive goes. Its not much different than our typical hot summer days as far as that goes.

With the relstively comfortable dewpoints from Wednesday in to the weekend

GFS DEWPOINTS Afternoons at peak heating

ECMWF (Euro Dewpoints) afternoons at peak heating

So, most of that time will feature a “semi dry heat” in the afternoon. Night time dewpoints will come up slightly, so as temps fall, meet the dewpoints, relative humidity climbs, a typical night-day, night- day process.

When the air is drier, our sweat can evaporate into the air, drying our skin and letting our body heat escape and our body cool off. The drier the air, the less it feels hot to us. The opposite is true, when things become more humid.

Now Monday and Tuesday. A muggier, humid feel is present

GFS DEWPOINTS peak heating afternoon Monday and Tuesday

ECMWF DEWPOINTS peak heating Monday-Tuesday

Now let’s look at temps off the modeling and take these with a little grain of salt or 3 because modeling does NOT handle extremes well and the typical bias is too hot. Even today the modeling was several degrees off. Keep in mind phone apps are model outputs.

GFS afternoon temps this week

GFS with showers and storm potential Monday and Tuesday with the heat, high dewpoints, those slow moving sometimes stationary downpours occur with no great mechanism to move them along. Raining themselves out in one place while a mile away is dry.

onward

Now on to the ECMWF for the week which is hotter.

Euro also on board with pop up storms, Monday and Tuesday

onward

With the low afternoon dewpoints, and high temps, that spread gives a lower relative humidity.

(localized factors will vary DP and RH with evapotranspiration in the peak heating)

RH off the ECMWF

Thats all courtesy of a strong 500mb ridge. Western US like

With the dry air, reel feel temps will not vary much midweek on from the actual ambient temp in the afternoons.

The dry air allows the max afternoon temps to heat up more efficiently vs the typical humid air masses we get with summertime heat. The more water molecules in the air, the more energy it takes to heat it up. The less water molecules in the air, the easier and faster it is to heat up. So, while numbers will potentially be higher than we’ve seen in potentially years, it really won’t feel any worse with the dry air. That said, it’s still hot.

With the ridge overhead, winds for the most part will be rather light all week. Perhaps stirring up at times during the afternoons. Or blow off from a few showers and storms. With the calm factor in place, as soon as the sun goes down, the valley areas will still cool off rather pleasant while the ridgetops remain 60s. I’d still expect 50s at nights, mid to late week across the high valleys, and potentially a upper 40 even in the coolest spots.

Weather Service Temps for Garrett County Airport.