Katy-area residents should prepare for a cooler, wetter winter after the National Oceanic and Atmospheric Administration (NOAA) warned that a potentially historic El Niño is building in the Pacific.
NOAA's Climate Prediction Center has issued an El Niño Advisory and estimates a greater than 90% chance of a "very strong" El Niño during the fall and winter of 2026–2027, The Katy News reported. The agency also placed a 69% probability on the event exceeding every El Niño in records dating to 1950 during the October through December period.
The World Meteorological Organization (WMO) echoed that assessment on Thursday, Sept. 3, saying El Niño is "firmly established" and forecasting it will strengthen to very strong intensity before peaking toward the end of 2026, according to The Watchers. WMO forecasts show a nearly 100% probability that El Niño will persist through December 2026 to February 2027.
In an Aug. 19 assessment cited by The Watchers, 25 of 26 climate models placed the key Niño 3.4 index in the very strong category for October through December. Fifteen of those models forecast anomalies of at least +3°C.
What it means for Katy
A National Weather Service (NWS) Houston/Galveston historical analysis found that about 76.5% of El Niño winters brought above-average precipitation at Houston's Bush Intercontinental Airport. Roughly 70.6% brought below-average temperatures.
During a typical El Niño winter, the southern United States tends to see cooler and wetter conditions because the Pacific jet stream strengthens and extends farther across the region, according to NOAA.
Hurricane Harvey caused about $870 million in damages and affected roughly 155,000 structures in the Katy-Brookshire area alone, according to Harris County Commissioner Lesley Briones at a Sept. 1 regional flood-control ceremony reported by Covering Katy. The Katy area has grown to approximately 200,000 residents, Brookshire-Katy Drainage District General Manager Stan Kitzman said at the same event.
Katy Mayor Dusty Thiele spoke at that Sept. 1 ceremony about the personal toll. "The neighborhood that I lived in for 26 years flooded both at the Tax Day Flood and Harvey … And I always say, my old neighbors, anytime it starts raining one inch, or two inches, they have PTSD from that time …" Thiele said.
Winter flood risk
Flood risk in the Katy area does not end when hurricane season wraps up Nov. 30. Willow Fork Drainage District Director Alec Bray warned in the district's November 2025 newsletter that "some of the biggest floods have occurred during our cooler months and as we go into spring."
NOAA's long-range outlook shows the national precipitation pattern becoming increasingly characteristic of El Niño as winter approaches, with higher probabilities for above-normal precipitation across the southern United States.
Still, NOAA cautions that El Niño shifts probabilities. It does not guarantee a specific outcome. Two El Niño winters can behave very differently, and El Niño does not automatically mean the Houston area will see snow, freezing rain or an Arctic outbreak.
NOAA's next official ENSO Diagnostic Discussion is scheduled for Thursday, Sept. 10.
