An active weather pattern is taking shape across Texas this week. Very high atmospheric moisture levels are expected across the state, creating an unstable atmosphere that will help fuel showers and thunderstorms. In addition, a cold front will stall across South-Central Texas by the middle of the week, serving as a focus for daily storm development.
San Antonio storm chances will be relatively low on Monday, but the odds of heavy rain will increase during the middle and end of the week. Some storms could produce heavy downpours, large hail, and localized flooding. Here’s a day-by-day timeline of what to expect.
Monday: An extremely muggy day is expected across South and Central Texas. Morning low temperatures will hover in the upper 70s – more than 10 degrees above average for this time of the year. With mostly cloudy skies in place, temperatures will rise slowly, reaching the mid-80s by noon.
By the late afternoon, high temperatures are expected to reach the low 90s. However, with very high humidity in place, the “feels-like” temperature is expected to reach as high as 100 degrees.
A few isolated showers and thunderstorms are possible during the afternoon and evening. However, recent weather model data shows that overall rainfall coverage will be quite sparse, limiting rain chances in San Antonio to just 10%-20%. Most areas will stay dry throughout the day.
Tuesday: Another warm and very humid day is expected in San Antonio, as high temperatures once again rise into the low 90s. However, by Tuesday night, storm chances are expected to increase significantly as a cold front stalls north of San Antonio.
San Antonio’s best chance of storms will arrive between 9 p.m. Tuesday and 1 a.m. Wednesday, as overall chances rise to around 70%. Some of this activity could be strong to severe, capable of producing hail and damaging wind gusts. Additionally, the region has also been placed under a Level 2 of 4 risk of excessive rainfall, meaning that flash flooding may become possible for some.
Wednesday: The cold front will stall near or just north of San Antonio, but with a high humidity still in place, another round of showers and storms will be possible. The exact timing is uncertain, but San Antonio will have about a 50% chance of additional rainfall. Temperatures will fall slightly, with highs expected in the mid- to upper 80s.
Thursday and Friday: Storm chances are expected to rise even higher, with about a 70% chance of rain each day. Rain will not be constant throughout each day, as you can expect long periods of dry conditions interrupted by bursts of potentially heavy rainfall.
Memorial Day weekend: There is potential that the stormy conditions will continue into the upcoming holiday weekend as well. Because this is still several days away, many details in regards to timing and storm intensity are not yet known. Be sure to stick with expressnews.com/weather for daily forecast updates as those details become more clear.
The National Blend of Models – which takes into account input from 31 different weather models – shows that the San Antonio area could see between 3 and 6 inches of rainfall over the next seven days. Isolated totals of over 8 inches may also be possible in a few spots.
With potential rainfall totals so high, the flood risk across South Texas is expected to increase significantly late in the week, especially between Thursday and Saturday.