A frontal system draped across the central Plains continues to result in areas of heavy precipitation across central US, including areas of severe weather.
Article continues below
A Slight Risk of Excessive Rainfall (level 2/4) and a Moderate Risk of Severe Weather (level 4/5) are in effect across portions of the lower Ohio River Valley into portions of Tennessee as a complex produces heavy precipitation, hail, and damaging wind gusts.
A warm and moist airmass to the south is helping to provide ample moisture for the current convective activity across the region.
On Thursday evening, the focus for heavy precipitation will shift toward portions of the north-central Rockies and High Plains as energy rounding the closed upper low over the West will interact with a surface boundary in the northern Rockies, which is forecast to produce heavy precipitation and severe weather across the region, including regions already saturated with recent heavy rains.
A Slight Risk of Excessive Rainfall and an Enhanced Risk of severe weather (level 3/5) are in effect over the Central High Plains due to the expected formation of convection overnight.
On Friday, this energy will progress eastward into the central Plains and Midwest.
Given the moist environment in place, widespread convection is likely to initiate across the region.
As a result, a Marginal Risk of Excessive Rainfall is in effect for much of central Plains on Friday.
On Saturday, the threat for excessive rainfall increases as southwesterly flow ahead of a surface trough will force ample moisture into a region of large-scale ascent over the Midwest, including areas impacted by heavy precipitation on Thursday and Friday.
As a result, a Slight Risk of Excessive Rainfall is in effect across the Midwest on Saturday.
A deep upper-level trough over portions of New England and the East Coast is forecast to continue lifting northeastward in the short term, providing a break from the convective activity that has impacted the region recently.
A slow-moving frontal system at the surface will continue to progress through eastern New England while slowly weakening.
The combination of modest forcing and terrain-induced lift resulted in a Marginal Risk for Excessive Rainfall to be issued in portions of northwestern Maine and the White Mountains of New Hampshire.
As the trough continues to lift northeastward, the threat for heavy rainfall shifts toward the next system approaching from the Midwest.
There are Marginal Risks for Excessive Rainfall on Friday and Saturday across the region as locally heavy rainfall amounts are possible ahead of a frontal system approaching from the Northwest.
On Friday, portions of the Ohio Valley and south-central Appalachians may see locally heavy rainfall ahead of this system.
On Saturday, the threat for heavy rainfall shifts northeastward into the north-central Appalachians and northern New England.
The risk for flash flooding is heightened in areas that have already seen localized heavy rainfall recently.
Temperatures across the region will remain relatively seasonal through the forecast period, with a modest warming trend expected heading into the weekend.
The upper-level ridge centered over the Mid-South is expected to begin moving east and gradually weaken through Saturday.
For portions of northern and interior Texas, this means that temperatures will be returning to near seasonal values, though still generally above average.
For the Mid-South and Gulf Coast, hazardous heat is expected through the end of the work week underneath the upper-level ridge.
Temperatures will near triple digits, with maximum heat indices likely exceeding 110F across portions of the Mid-South, low-mid Mississippi Valley, and portions of the Gulf Coast through Saturday.
Nighttime lows are expected to be extremely warm, and potentially record breaking, providing little relief for the heat at night.
In addition to the current weather activity, Canadian wildfire smoke is expected to continue impacting portions of the eastern U.S. over the next few days.
However, air quality is expected to improve in the short term as a combination of thunderstorm activity and dispersion of smoke will ultimately result in improving air quality conditions for much of the country heading into the weekend. ■