A large and deepening low crossing southern Canada has caused a sharp drop in temperatures over the N Plains with Pierre, SD going from 104 Saturday to the 60s today.

As for points further east within the SW flow and strong August sun, temps are on the rise with widespread 90s up and down the East Coast today. Tomorrow will mark the first official heat wave (three straight 90-degree days) in New York City since 2013.

However, temps take a drop mid to late this week as the very system gives then takes away, also sparking severe weather over the Heartland as the front lights up as it pushes into hot, humid air.

US highs yesterday. Note the drop over the Dakotas from 100s the day before.

Highs around the NYC area yesterday.

The warm, humid air mass in place has led to the typical muggy nights, especially in the Big Cities. Note the cooler temps outwith the urban areas.

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500mb height anomaly today (below). Note the digging trough down the Plains that’s bringing a 20-30 degree slash in temperature while they rise on the East Coast.

In the wake of the westward shift in 594 ridge, a trough has formed over east Texas, introducing cooler air and increased rain chances, easing the intense heat over Dallas and Houston. An all-time record 95F+ streak at Houston’s Hobby Airport and the streak 80F+ nights in Galveston has ended but a high of 96 at Houston’s main site (Bush Intercontinental) means the 95+ streak continues and now sits in 3rd place.

Streak comes to an end but both set new all-time records.

Streak continues.

Rain chances increased!

 

The heat didn’t just disappear but indeed has been focusing on the Desert Southwest, even causing Phoenix to tie the all-time August record back on Saturday (117F). The Texas ridge eventually joins the trough coming out of Canada.

With the phasing of both troughs, we have a deeper single trough over the Plains during Wednesday.

This will spark a severe weather outbreak.

It has indeed been hot in the Southwest of late thanks to the high that baked Texas shifting west. Upper 90s made it to LA while it soared well beyond 110 to the east of the coast range.

Over 100 in the San Fernando Valley.

Here are the projected high temperatures according to the GFS over the next few days for the Northeast and Mid-Atlantic.

Eventually the front pushes into the East, causing showers and storms to break out as well as creating a fall in temperature.

GFS surface shows the deepening of the low, setup supporting the severe weather as well as the eventual break in East Coast heat late week.

Interestingly, during the weekend, we saw temps soar to 90 degrees all the way to the shores of James Bay, perhaps not that odd for mid-August but what is unusual is the fact there’s still ice on James Bay and especially over eastern Hudson Bay where fuel supply to the village of Iqaluit is all but impossible at the moment.

See this morning’s video for more!

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