Tropical moisture enhances rain on the southern High Plains (29-30 September 2026)

Tropical moisture enhances rain on the southern High Plains
29-30 September 2026

Wet roadways at the intersection of Quaker Avenue and 114th Street in southwestern Lubbock early Tuesday morning (29 September 2026). The image is courtesy of the City of Lubbock. 

The unsettled latter half of September didn't let up at the end of the month. Instead, following a brief reprieve from the widespread rain September 24th-26th, yet another storm system moved into the Desert Southwest. In advance of the system, abundant Gulf moisture streamed in from the south while rich mid-upper level moisture flowed in from the southwest off the eastern Pacific. The monsoon moisture was further "enhanced" by the remnants of Hurricane Polo after making landfall on Baja California early Tuesday morning (September 29th).

A relative lull in precipitation unfolded late Tuesday morning into the early afternoon, though breezy southerly winds continued to carry moisture into the region. As temperatures warmed into the upper 70s and lower 80s, scattered thunderstorms developed near a warm front across the southern Texas Panhandle and northwestern South Plains late Tuesday afternoon. Many of the individual cells began to rotate as they felt the influence of the relatively strong low-level wind shear in place. In addition to dropping brief bouts of heavy, one of the storms produced a documented tornado near Claude. Farther south, much of the South Plains and Rolling Plains remained dry Tuesday afternoon.  

Even greater moisture and lift, including from Polo's remnants, then overspread the region late Tuesday. This led to a rapid increase in shower and thunderstorm activity that spread into the South Plains region from the west Tuesday evening. A broad shield of rain and embedded thunderstorms advanced eastward across the Caprock late Tuesday evening/night. One storm generated a wind gust to 65 mph at the West Texas Mesonet (WTM) site 6 miles west-northwest of Denver City just before 10:30 pm. However, the most widespread impact was the heavy rain that, similar to the previous week, targeted the southwest Texas Panhandle and western South Plains with an additional 2 to 3+ inches of rain. 

The heavy rain, falling on already saturated soils, led to excessive runoff that caused flash flooding and inundation of low-lying and poor drainage areas. The flooding led to the closure of several County and Farm-to-Market roads across Parmer and Castro County, while TXDOT documented water portions of many roads from the southwestern Texas Panhandle into the western South Plains.

The rain continued eastward across the Rolling Plains and southeast Texas Panhandle early Wednesday morning (September 30th), though at a greatly diminished intensity. The rain then quickly ended, from southwest-to-northeast, as much drier air moved in aloft after daybreak. While locations on the Caprock experienced good to excessive amounts of rain over this 2-day event, locations off the Caprock didn't fare so well. Many locations in the Rolling Plains only tallied several hundredths to a couple tenths of an inch of rain from Monday through midday Wednesday (28-30 September).

Officially, the Lubbock Airport measured 0.84 inches over this 2-day stretch, which boosted the annual running total to 11.99 inches (though still over 3 inches below the average year-to-date precipitation). Farther east, Childress Airport officially measured 0.22 inches over this period, lifting their annual total to 12.53 inches (over 7 inches below the average year-to-date precipitation).

A list of the preliminary storm reports collected from September 29th to 30th can be found below.