Good Evening Folks. We have a lot to talk about today with the main story being the major flooding for the southwestern and central states.
A Dangerous Flooding Threat Takes Shape Across the Southwest
Graphic depicting the Monday, Sept. 28, 2026 Moderate Flood Risk.
The Southwest is facing a significant flooding threat today as tropical moisture, saturated soil, and the potential for slow-moving thunderstorms come together across the region. The Weather Prediction Center issued a Moderate Risk (level 3/4) of Excessive Rainfall across much of the desert southwest, while a Slight Risk extends in the surrounding areas. Precipitable water values are expected to reach 2 to 3.5 standard deviations above normal across much of the region.
Rainfall of 1 to 3 inches remains possible across portions of the region.. The latest Weather Prediction Center update notes that much of the rain currently falling across Arizona has been stratiform because of limited instability, keeping the immediate flooding threat somewhat lower. However, clearing skies are allowing more heating across the Colorado River region, which could destabilize the atmosphere enough for slow-moving thunderstorms to develop later this afternoon.
The most vulnerable areas include southern Utah, the San Juan Mountains of Colorado, and portions of New Mexico, where saturated soils, burn scars, steep terrain, and slot canyons can greatly worsen the flooding threat.
Graphic depicting the Tuesday, Sept. 29, 2026 Moderate Flood Risk.
On Tuesday the flooding threat shifts eastward as the remnants of Hurricane Polo move northward from Mexico, passing near El Paso and then somewhat following the New Mexico-Texas border. The heaviest rainfall is expected to track near the center of the remnant system, while a much broader area of rain continues across the Southwest. The Weather Prediction Center has once again highlighted a Moderate Risk of Excessive Rainfall from southeastern Arizona through southeastern Colorado and into southwestern Kansas.
The most concerning area will extend from central New Mexico into the northwest Texas Panhandle, Cimarron County, Oklahoma, and southeastern Colorado. Here, 2 to 4 inches of rain, with some localized pockets seeing higher amounts, could fall on soils that are already nearly saturated. Low flash flood guidance, additional moisture flowing northward from Mexico, and instability near Polo's center will create a particularly dangerous setup. The east-facing slopes of the Sangre de Cristos could also see significant rainfall as easterly flow develops ahead of the system.
Farther east across the Plains, the flooding threat becomes more conditional. The latest guidance has shifted the heavier rainfall area somewhat south and east from Nebraska into Iowa, but limited instability along the warm front should keep much of that rainfall stratiform. That should limit rainfall rates and reduce the potential for widespread flash flooding in those areas.
Graphic depicting the Wednesday, Sept. 30, 2026 Moderate Flood Risk.
By Wednesday, the remnants of Polo will have been absorbed into a strengthening low over the High Plains, producing a much broader storm system. Wednesday will feature a double threat with one extending from southern Colorado northeastward toward the Upper Great Lakes while the other axis of heavy rain develops across Texas and Oklahoma. Moderate Risks remain in place across portions of the Central and Southern Plains.
The greatest concern across Texas and Oklahoma will be a potentially slow-moving line of thunderstorms extending from around Wichita Falls southwestward through San Angelo and into the Hill Country. Where this line ultimately develops will depend partly on how the dry slot interacts with the storm system, but repeated thunderstorms over the same areas could produce significant flash flooding. Farther north, heavy rainfall from southeastern Nebraska through central Iowa could also become substantial, although limited instability should keep rainfall rates lower and favor more scattered flooding rather than widespread flash flooding.
There is at least some good news for areas hardest hit on Tuesday. The dry slot associated with the strengthening Plains low is increasingly expected to move across eastern New Mexico and the Texas and Oklahoma Panhandles, allowing those areas to finally begin drying out. Meanwhile, moisture will remain abundant farther east, with precipitable water values around 2.25 inches and a low-level jet producing moisture transport several standard deviations above normal.
Graphic depicting the Thursday, Oct. 1, 2026 Moderate Flood Risk.
On Thursday, the storm system will begin to weaken as the upper-level trough stalls over the central and southern Plains. Weakening does not mean it is over however, as a Moderate Risk still remains in effect across portions of southern Texas and southeastern Oklahoma, where 2 to 2.25+ inches of precipitable water and favorable upper-level forcing. The biggest concern will be areas that receive heavy rainfall on Wednesday and then see additional rain on Thursday, as runoff problems could quickly worsen.
A broader Slight Risk extends northward into parts of the Central Plains and the mid-Mississippi Valley. Rainfall totals are expected to be lower here, but moisture pooling ahead of a southward-moving cold front could produce widespread moderate rain with pockets of heavier rainfall. This should generally be a less significant threat than farther south, but soils that have already received several days of rain could still produce localized flooding.
Graphic depicting the Friday, Oct. 2, 2026 Moderate Flood Risk.
By Friday, the system should continue weakening, and the potential for widespread heavy rain across the Southern Plains should decrease. A lingering Slight Risk remains from South Texas into southeastern Oklahoma, where abundant moisture and slow-moving energy could still produce organized thunderstorms. Farther east, moisture will increase across the Southeast as the front moves toward the Ohio Valley, potentially bringing another round of heavy rain from the Gulf Coast into parts of the Southeast. While the overall threat is expected to gradually diminish, the long duration of this event means flooding concerns will persist in some areas well into Friday.
The Tropics
Graphic depicting Category 4 Hurricane Nolo.
Switching over to the tropics, we still have Nolo and Polo active in the Pacific. Nolo currently sits as a Category 4 hurricane. Yesterday evening, Nolo underwent a period of rapid intensification, during which it strengthened to an upper-end Category 4. However, it failed to breach the Category 5 threshold, remaining 2 mph short.
Graphic depicting Category 3 Hurricane Polo
Meanwhile, Polo has weakened to a Category 3 hurricane and is expected to continue weakening as it makes landfall in Baja California Sur late this evening into the overnight hours.
Graphic depicting Tropical Storm Rachel.
Currently hugging the coast of Mexico is the newly formed Tropical Storm Rachel. For most of the current forecast, it appears that Rachel will remain mostly parallel to the Mexican coastline. As the storm will be traversing waters that have recently been churned up by Hurricane Polo, along with the addition of wind shear, it is not likely that Rachel strengthens much over the next day or so. However, even with these factors, Rachel is likely to strengthen into a hurricane over the next few days.
As we look at the Atlantic, things are definitely still quieter and look to remain that way for the foreseeable future. Our only tropical systems are currently Fay and Hanna.
Graphic depicting Tropical Depression Fay
Fay is continuing its weakening trend as it moves toward the southwest. The storm is expected to fully dissipate over open water without posing any threat to land.
Graphic depicting Tropical Storm Hanna
Hanna is forecast to remain over open ocean for its full lifespan. It is currently a strengthening tropical storm but is expected to begin declining in strength over the next 48 hours or so.
Temperature
Now, as we talked about in our last forecast, we are going to have a cold front come through the central and southern U.S. later this week, and it also happens to coincide with the ongoing flooding threat. The forecast hasn't really changed much. Temperatures are still expected to initially drop from the low to mid 90s down into the mid to upper 70s before climbing slightly back into the low 80s.
That second cold front we talked about previously is, unfortunately, not forecast to come quite as far south as it was in earlier forecasts. That means Dallas might not get in on anything cooler than the 70s. But honestly, considering how hot it has been, 70s and even low 80s would feel wonderful.
And with that, its time to wrap up another forecast
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Thanks for reading, and I’ll catch you next time!