Mid Summer finally here and with that high heat and humidity is often present. In this blog I’m going to go over how things are looking for the South East and give you an idea of what to expect. First lets take a look at the composite map showing the upper level heights ( thick blue lines) also showing where aloft (above) high and low pressure systems are located.
This map comes from the Storm Prediction Center in case you’re interested (lots of cool things on that site) So in the map above of the upper atmosphere we can see the 594 high pressure aloft over Oklahoma while an upper low sits over the Carolina’s and Virginia causing day time/evening storms there as the temps aloft are cool creating instability above the warm humid surface there. By this evening we’ll see the upper high expand.
Notice the lighter color over Oklahoma that is the summer heat ridge beginning to expand and create another hotter heat wave this time around. Tuesday surface map is below, notice the surface high and how large it is true summer heat dome (ridge)
Going into Wednesday and Thursday the heat only expands and things get dangerously hot with heat index in a lot of areas from the Central US to the Mid Atlantic and South east seeing heat index values over 100F and in some cases on the high end 110F this all depends on where you live as areas east of the Apps in VA and NC will see down sloping off the higher terrain causing not only the air to warm (compress) but also dry out leading to less moisture BUT at the cost of perhaps higher temps.
By mid week the areas seeing daily repeated rounds of storms (and intense at that) would be the upper Plains and western Great Lakes as a stalled front above the heat dome will help nocturnal storms form and ridge the top of the heat ridge. Wednesday’s Surface map above. Next is Thursday’s map showing just how expansive this ridge is.
The models are forecasting very high temps in the 95-100F range though not everyone will see 100 degree temps but this should give you an idea how the potential heat.
By late week (Friday in this case) I can see the heat peaking in areas of the Mid Atlantic and upper South. Check out these 5000ft temps on Friday (they help determine high temps at this level)
What I have circled is 5,000ft temps at or over 20C when translated down to the surface that comes out with temps anywhere from 95F to 105F in some areas. Again this is a great guide but if clouds are over any areas temps will be held back.
We’ll see this ridge become more flat over the weekend allowing or trying to allow a cold front to settle around the Mid Atlantic by early next week.
Notice the brighter colors in the North East and eastern Canada, that is cooler more dry air trying to work its way southward. We’ll look more into this over the weekend.
Lastly you may be wondering how the rain fall outlook looks. We’ll with a (what we call a heat dome) in pace across much of the central, eastern half of the Nation There’ isn’t much rain to be had expect those areas atop of the heat ridge and on the north east side of the ridge. Under the ridge forget about much help from mother nature in the rain department. Check out the Weather Prediction Centers outlook for Tuesday though next Sunday.
We see a dry area over the center of the nation thanks to that dome of high pressure keeping a “cap” on convection. We also see in the upper Plains and Great Lakes where rounds of intense storms will ride atop the ridge through the week into the weekend.