10/24/2025
Bottom Line
Showers and storms are expected to develop ahead of and along an upper level disturbance and associated cold front starting late tonight and continuing into Sunday morning, with the potential for periods of moderate to heavy rainfall leading to localized street flooding. A Flood Watch is in effect for most of Southeast Texas from early Saturday morning to early Sunday morning.
What Has Changed Since Previous Email?
• A Flood Watch will be in effect for most of Southeast Texas from early Saturday morning to early Sunday morning.
• The slight risk for severe weather for Saturday has been expanded to include all of Southeast Texas.
Overview
An upper level disturbance with an associated cold front is expected to move through Southeast Texas late tonight through Sunday morning. Widespread moderate to heavy rainfall and strong to severe thunderstorms will be possible in two main windows in the form of two lines of storms: late tonight into Saturday morning and Saturday evening into early Sunday morning. Expect the first line of storms to push into the Brazos Valley around 12am tonight-4am Saturday, the Houston metro area around 2am-6am Saturday, and near the coast around 5am-9am Saturday. Keep in mind that these storms could speed up their timing. There will be discrete storms developing out ahead of the first line of storms, and we'll be monitoring where these storms merge with the line for potential flooding impacts.
Heavy Rainfall:
• Expecting widespread 2-4” of rainfall totals throughout the event, with isolated higher amounts of 4-6”.
• The most likely impact of the heavy rainfall will be localized street flooding in urban and low-lying areas (areas with poor drainage), but instances of flash flooding are also possible.
• The main drivers for flash flooding would be high rainfall rates and heavy downpours occurring over the same areas. Rainfall rates could be upwards of 2-3+” per hour in the strongest storms.
There is a marginal to slight risk (level 1-2 of 4) of excessive rainfall today and a slight risk of excessive rainfall for all of Southeast Texas Saturday.
Severe Threat:
• Strong to severe thunderstorms will be possible throughout the event, but the greatest risk is associated with lines of thunderstorms that will move through late tonight into Saturday morning, and again Saturday evening into early Sunday morning.
• All severe weather hazards will be possible, but damaging wind gusts and isolated tornadoes will be the greatest risks.
There is a marginal to slight risk (level 1-2 of 5) of severe weather today and a slight risk of severe weather for all of Southeast Texas Saturday.
Urban Flash Flood Messaging
Heavy rainfall is forecast for portions of Southeast Texas, including highly urbanized areas like the Houston metropolitan area. Based on forecast conditions, NWS Houston will be utilizing the following urban flash flood messaging for this event:
- Turn Around, Don't Drown. Isolated underpasses or low-water crossings may be life-threatening.
- Pay attention to the weather. Monitor the NWS, your local media, HCFCD and other official weather information sources.
- Rain may move repeatedly across the same area, causing a rapid rise on creeks and bayous. However, creeks and bayous are not likely to exceed their banks.
