A sharp divide between early fall air in the North and oppressive late-season heat farther south is expected to hold for several more days, but meteorologist Ryan Hall says a stronger cold front may finally break through into the Ohio Valley around the start of astronomical fall.
Hall, host of the Ryan Hall, Y’all weather channel, said the current boundary is stalled because a strong ridge of high pressure over the Southeast is blocking cooler air from pushing farther south.
“The next cold front is about to change everything,” Hall said as he explained that the first front is not really the one many people are waiting for. In his view, the more important change comes with a second wave late this week into early next week, when both American and European ensemble guidance begins pushing cooler air farther into the Midwest and Ohio Valley.
That does not mean everyone gets relief at once. Hall said confidence is much higher from Chicago through Indianapolis, Cincinnati, Columbus and Pittsburgh than it is farther south in places such as Nashville, Memphis and Dallas.
Extreme Heat Hangs On Across the South
The contrast across the country remains unusually strong.
Hall said Memphis could reach 100 degrees Tuesday and again Wednesday, while Louisville may reach 96 and Dallas around 101.
Nashville could also touch 100 Tuesday, which Hall said would be exceptionally late in the year.
He cited the National Weather Service office in Paducah, which said there was “nothing typical about this level of heat and humidity” for this point in September.
Hall also noted that heat advisories this late in the season are unusual for the region.
The heat is being reinforced by the strong Southeast ridge, which he described as acting “like a hand on a door” and keeping the cooler air bottled up farther north.
That image fits the pattern well because the cold air is not absent. It is already sitting close by, but the atmosphere has effectively built a wall between two very different seasons.
By Saturday, Hall still expects Louisville to be around 91 and Indianapolis near 86, showing that the first push of cooler air will struggle to make much progress.
Repeated Rain Raises Flooding Risk
The stalled boundary is also creating a prolonged corridor of heavy rain.
Hall said northeast Kansas and Missouri face a flash-flooding concern Tuesday, followed by renewed problems in Iowa Wednesday, Nebraska into Iowa Thursday, and then from Iowa toward Michigan Friday.
That puts many of the same areas under repeated rainfall for several days.
Hall said parts of the corridor from Kansas through Iowa and into Michigan could receive between 3 and 7 inches of rain, with localized totals even higher.
Some places are already saturated after receiving up to 8 inches last week.
The setup is fairly straightforward: warm, moist air keeps flowing northward and running into the stalled front, allowing thunderstorms to repeatedly form along the same zone.
That kind of pattern can be more damaging than one violent storm because it keeps hitting the same ground over and over.
Hall stressed that the cruel part of the setup is where the rain is not falling.
Memphis, Little Rock and Oklahoma City are all expected to receive less than an inch over a much longer period, even while drought conditions continue to worsen south of the main rain corridor.
Drought Worsens Where Rain Is Scarce
Hall said 59% of the Lower 48 is now experiencing drought conditions, compared with 36% a year earlier.
He also said Missouri’s drought coverage jumped by roughly a quarter of the state in one week, while Kentucky and Tennessee both saw major increases.
Oklahoma, he added, has more than half the state in extreme drought.
“The places that need the rain aren’t getting it,” Hall said, while areas that do not need additional water could receive several more inches.
That imbalance is one of the most important parts of the forecast because it shows how the same large-scale weather pattern can create two opposite problems at once.
One region gets too much moisture, while another remains hot and dry only a few hundred miles away.
Hall also warned that the next cool push may not solve the drought either, because the high pressure expected behind it looks relatively dry.
Stronger Front Expected Early Next Week
Hall said the more important front should arrive as the Southeast ridge begins weakening late this week.
At the same time, a trough is expected to drop out of Canada toward the Great Lakes.
That combination could finally allow cooler air to move into the Ohio Valley Monday into Tuesday.
Hall reviewed 82 model runs and said every one of them had Indianapolis, Cincinnati, Columbus, Pittsburgh and Chicago below 80 degrees by Monday.
Louisville and St. Louis showed more uncertainty, though most guidance brought them below 80 by Wednesday.
Farther south, confidence drops quickly.
Hall said fewer than one in 10 model runs had Nashville below 80 by Monday, while Memphis and Dallas had almost no support for that kind of cooldown yet.
His conclusion was simple: the Ohio Valley is likely to get meaningful relief with this next wave, while much of the South may have to wait for a third push.
Fall Could Arrive Right on Schedule
Hall highlighted Sept. 21 into Sept. 22 as the key period for that next change.
Astronomical fall begins Tuesday, Sept. 22, at 8:05 p.m. Eastern Time, and Hall said the cooler air may arrive almost perfectly on cue.
By next Wednesday, he expects a broad area from Kansas City to Pittsburgh to be in the 70s.
Louisville could fall from the mid-90s to around 79, while Indianapolis may go from near 90 to the mid-70s.
Nighttime temperatures should also become much more comfortable.
Hall said low 60s could spread across the Ohio Valley by the middle of next week, with upper 50s possible in Indianapolis, Columbus and Cincinnati.
Louisville may even see its first night below 60 since June.
That would be a noticeable change after a long stretch of warm nights, and perhaps a more meaningful sign of fall than the daytime highs alone.
South Still a Major Forecast Question
Hall was much less confident about what happens farther south.
He pointed to a huge disagreement between the European and American models.
The European model had Dallas at 74 next Wednesday, while the American model had it at 99.
For Memphis, the European solution showed 77, while the American model kept the city near 93.
“Somebody is very wrong,” Hall said.
He added that he was not ready to believe a dramatic drop into the 70s for Dallas, even though he felt much more confident about the Ohio Valley cooling down.
That kind of model spread is a useful reminder that long-range temperature forecasts can still swing sharply, especially when a stubborn ridge has to break before cooler air can move south.
Hall said he believes the European model has recently performed better, but the gap is still too large to place much confidence in the Southern forecast.
Birds and Winter Offer Clues About the Pattern
Hall also pointed out an unusual radar signal across the Ohio Valley that was not rain at all, but migrating birds.
He said tens of millions of birds crossed Kentucky and Tennessee, with hundreds of millions more expected in the air as they take advantage of northerly winds behind cold fronts.
The next major migration wave may come when the stronger front finally pushes through next week.
Hall used that same stalled-front pattern to make a broader point about winter.
Cold air bottled up to the north and moisture sitting to the south can produce flooding in September, but in January the same type of collision can help create major snowstorms.
He said El Niño is reaching historic territory and believes the current pattern offers a small preview of how much more intense winter systems could eventually become.
For the immediate future, though, the main story remains simpler: heavy rain continues along the stalled front, dangerous heat holds farther south, and a stronger push of cool air looks increasingly likely to reach the Ohio Valley around the first day of fall.
The South remains the uncertain part.
Hall’s confidence is much higher that cities from Chicago to Pittsburgh will cool down first, while Nashville, Memphis and Dallas may have to wait longer for their real break from summer.
Growing up in the Pacific Northwest, John developed a love for the great outdoors early on. With years of experience as a wilderness guide, he’s navigated rugged terrains and unpredictable weather patterns. John is also an avid hunter and fisherman who believes in sustainable living. His focus on practical survival skills, from building shelters to purifying water, reflects his passion for preparedness. When he’s not out in the wild, you can find him sharing his knowledge through writing, hoping to inspire others to embrace self-reliance.
