Drought Busting Rain Event coming to the southern plains?

A Potential Drought-Busting Rain Event Is Taking Aim at Texas and Oklahoma

After months of intense heat and worsening drought conditions across Texas and Oklahoma, a major change in the weather pattern is taking shape.

A slow-moving storm system is expected to interact with an unusually deep supply of tropical moisture across the Southern Plains from approximately September 30 through October 3, bringing the potential for several rounds of heavy rain and thunderstorms.

For areas suffering through extreme and exceptional drought, this rainfall could provide substantial relief. However, too much rain falling too quickly can create an entirely different set of problems, including flash flooding.

There is also the potential for strong to severe thunderstorms as the system moves through the region.

Here is what is happening, why this system has the potential to produce so much rainfall, and what it could mean for Texas and Oklahoma.

Texas and Oklahoma Desperately Need Rain

The drought across the Southern Plains has become serious.

According to the September 22 U.S. Drought Monitor, exceptional drought — the highest drought classification — covers a significant portion of northern Texas and western and southern Oklahoma.

Both short-term and long-term drought are contributing to the situation.

West-central Oklahoma has experienced its driest year on record over the referenced period, while southwest Oklahoma has experienced its second driest.

Pastures, agricultural areas, ponds, creeks and soil moisture have all been affected by the prolonged lack of meaningful rainfall.

That makes the approaching weather pattern particularly important.

What Is Causing This Rain Event?

Several atmospheric ingredients are coming together at the same time.

A significant upper-level storm system is expected to move into the Southwest before progressing slowly toward the Southern Plains.

At the same time, tropical moisture associated with the remnants of Polo in the eastern Pacific is expected to become incorporated into the larger storm system.

That Pacific moisture will combine with moisture flowing northward from the Gulf.

Essentially, the atmosphere will have access to an enormous reservoir of water vapor.

The Weather Prediction Center has described the developing pattern as a major heavy-rain and flooding threat for portions of the south-central United States.

One reason is that this does not appear to be a simple cold front that produces a line of thunderstorms and quickly exits the region.

The upper-level system is expected to slow considerably.

That matters.

A slow-moving weather system allows multiple rounds of rain and thunderstorms to move across the same general region over a period of several days.

And that is where rainfall totals can begin adding up quickly.

An Extremely Moist Atmosphere

One of the meteorological parameters forecasters watch during heavy-rain events is called precipitable water, commonly abbreviated PWAT.

PWAT measures the amount of water vapor contained through the entire atmospheric column above a location.

Think of the atmosphere as a giant sponge.

The higher the PWAT value, the wetter that sponge becomes.

When PWAT values become unusually high, thunderstorms can become extremely efficient rainfall producers.

But there is an important misconception about PWAT.

If the atmosphere contains two inches of precipitable water, that does not mean two inches is the maximum amount of rain that can fall.

Moist air is constantly being transported into thunderstorms.

If strong southerly winds continue feeding extremely moist air into a storm complex for several hours, the atmosphere essentially keeps replacing the moisture being converted into rainfall.

That is how locations can receive four, six, eight or even more inches of rainfall from an atmosphere containing roughly two inches of precipitable water.

The Low-Level Jet Will Help Feed the System

Another important ingredient is the low-level jet.

The low-level jet is a relatively strong current of wind typically found around 850 millibars, or roughly 4,000–5,000 feet above the ground.

Across the Great Plains, it frequently transports warm, humid Gulf air northward.

During this event, unusually strong low-level moisture transport is expected to feed the developing storm system.

Think about the setup this way:

PWAT tells us how much moisture is available.

The low-level jet continuously transports additional moisture into the system.

The approaching upper-level storm provides the lift necessary to produce thunderstorms.

And if those thunderstorms repeatedly move across the same locations, rainfall totals can become excessive.

That repeated movement of storms over the same area is called training.

It is one of the biggest things we will be watching as this event develops.

How Much Rain Could Fall?

Exact rainfall totals and the location of the heaviest corridor will continue changing as higher-resolution weather models begin resolving the event.

However, confidence is increasing that widespread significant rainfall will occur.

The National Weather Service in Fort Worth currently expects widespread rain and thunderstorms beginning Wednesday and potentially continuing into the weekend.

Forecasters have also indicated that there is currently a low probability — around 25% — that some locations could exceed seven inches of rainfall.

Meanwhile, the Weather Prediction Center has placed portions of Texas and Oklahoma within a Moderate Risk of excessive rainfall during portions of the event.

A Moderate Risk is Level 3 of the Weather Prediction Center’s four-level excessive-rainfall scale.

That is noteworthy several days before an event.

It does not mean everyone will receive extreme rainfall.

There will almost certainly be substantial differences from one location to another.

One town might receive two inches while another location relatively nearby receives five or six inches because thunderstorms repeatedly track across the same area.

The exact placement of those training corridors will be extremely important.

Could This Actually Break the Drought?

For some areas, this event could dramatically improve drought conditions.

Several inches of rainfall spread over multiple days could replenish topsoil moisture, improve pastures, reduce wildfire danger and put water back into smaller creeks, ponds and stock tanks.

Agricultural areas desperately needing moisture could see significant benefits.

But the term “drought-busting” needs some context.

A major rain event can quickly improve short-term drought conditions, but long-term drought involves much more than dry grass and topsoil.

Groundwater, deeper soil moisture, rivers and major reservoirs can take much longer to recover.

There is also a major difference between receiving five inches of rain over three days and receiving five inches in three hours.

Slow rainfall has time to soak into the ground.

Torrential rainfall runs off.

When rainfall rates become excessive, the ground simply cannot absorb the water quickly enough.

So while this event could provide enormous benefits, the most extreme rainfall totals may actually become less beneficial because so much water could become runoff.

Flash Flooding Could Become the Biggest Concern

This is the other side of the equation.

We desperately need rain.

We do not need eight inches in six hours.

If thunderstorms repeatedly develop and move across the same locations, rainfall rates could overwhelm drainage systems, creeks and low-water crossings.

Urban areas are particularly vulnerable because pavement prevents water from soaking into the ground.

Rural areas can experience dangerous flooding as normally small creeks and drainage areas rise rapidly.

Drivers should take flash flooding seriously.

Never attempt to drive through a flooded roadway.

It is impossible to determine how deep the water is simply by looking at it, and flowing water can easily move a vehicle.

What About Severe Weather?

Heavy rainfall and flooding currently appear to be the primary hazards, but severe thunderstorms will also need to be monitored.

There are several ingredients present that can support organized thunderstorms.

The approaching upper-level system will provide strong large-scale lift and increasing wind fields, while abundant Gulf moisture will create a warm and humid air mass ahead of the system.

If sufficient instability develops, some thunderstorms could become strong or severe.

Potential hazards would include:

• Damaging straight-line winds

• Hail

• Frequent lightning

• Torrential rainfall

• Localized flash flooding

• A conditional tornado threat if sufficient instability, low-level shear and favorable storm modes overlap

The tornado potential is particularly dependent upon details that cannot be resolved confidently several days in advance.

Heavy clouds and widespread rainfall can limit instability and reduce the severe-weather threat.

On the other hand, if pockets of stronger surface heating develop ahead of the main system while low-level winds strengthen, the environment could become more favorable for organized storms.

That is why we will be watching the evolution of surface winds, dewpoints, instability, low-level shear and storm mode as we get closer.

At this stage, it would be premature to describe this primarily as a tornado event.

The much stronger and more consistent signal is heavy rainfall and flooding.

That could change as higher-resolution guidance becomes available.

Why Storm Chasers Watch Systems Like This Closely

Most people associate storm chasing with springtime supercells and tornadoes.

But fall can produce fascinating weather across the Southern Plains.

Large-scale troughs become stronger as we transition toward the cooler months, while the Gulf of Mexico can still provide tremendous amounts of heat and moisture.

When those ingredients overlap, significant severe-weather and heavy-rain events can occur well outside the traditional peak tornado season.

This particular system is especially interesting because of the tropical moisture connection.

Meteorology is ultimately about understanding how all of these ingredients interact — moisture, instability, wind shear, lift, storm motion and the larger-scale atmospheric pattern.

One ingredient alone rarely tells the entire story.

The Bottom Line

Texas and Oklahoma need rain badly.

We may finally be about to get it.

A slow-moving upper-level storm combined with deep Gulf moisture and additional tropical moisture from the eastern Pacific is creating the potential for a significant multi-day rainfall event across portions of Texas and Oklahoma from midweek into the end of the week.

For drought-stricken areas, several inches of rainfall could be tremendously beneficial.

But there is a line between beneficial rainfall and dangerous rainfall.

If thunderstorms repeatedly train across the same locations, rainfall totals could become excessive and flash flooding could develop quickly.

Strong to severe thunderstorms are also possible, although the magnitude and location of that threat will become clearer as the system gets closer and higher-resolution forecast data becomes available.

At Apex Storm Tours, we will continue monitoring the system as it develops, including rainfall forecasts, instability, wind shear, moisture transport and any potential for organized severe thunderstorms.

One thing is certain:

After an exceptionally hot and dry stretch across much of the Southern Plains, the weather pattern is finally changing — and it could change in a big way.

Forecast information reflects guidance available September 28, 2026. Weather forecasts, rainfall totals and severe-weather risks can change as new data becomes available. Always follow the latest watches, warnings and forecasts from the National Weather Service.