A fall-like chill has descended upon the country from the Rockies to the Appalachians, and it will be slow to ease the rest of the week into the weekend.
A deep upper-level trough of low pressure is caught in between two strong upper-level ridges, locking cool weather into Plains to the Appalachians and beyond.
A much cooler air mass will expand from the northern Plains this weekend to the Deep South and into the East by Tuesday, pushing temperatures much below normal.
Intense heat and oppressive humidity surging out of the central Plains will cause severe weather from the Midwest to the Ohio Valley in the next 72 hours, followed by much cooler weather next week.
Despite the heat and humidity in the East today and a surge of intense heat and humidity coming out of the central and southern Plains for a brief period of time, cool air will dominate the pattern through the end of July from the Plains to the Appalachians.
A pattern of extremes is once again unfolding across the country over the next week, with two shots of cool air interspersed with intense heat.
Despite the heat over the central and southern Rockies this week, an amplified pattern means cool air will dominate in much of the country for the rest of July.
Heat will resurface over the eastern Rockies and Plains this weekend and early next week, but the warming in the East will be much slower.
In the wake of the deep upper-level trough over the Great Lakes to the Tennessee Valley, a strong upper-level ridge is poised to blossom over the Rockies, one that will bring on the heat this weekend into the start of next week.
Beyond the big chill now engulfing the Plains, it will turn warmer and more humid in the East back into the Ohio Valley. The heat will be turned up in the northern and eastern Rockies and northern Plains into the Midwest this weekend into early next week.