Pacific system could produce thunderstorms

A Pacific low-pressure system has made its way into the desert Southwest, and as it moves in our direction, it will provide the energy to fuel strong thunderstorms across parts of Texas overnight Sunday and into Monday morning.

A widespread severe weather outbreak is not expected. However, a few isolated storms could become severe. To be considered a severe thunderstorm, a storm must produce quarter-sized hail or larger or wind gusts of at least 58 mph.

Sunday’s forecast

Dry weather is expected throughout the day in San Antonio. But the western low-pressure system will bring some changes.

Moisture levels will increase, resulting in mostly cloudy skies throughout the day. Wind speeds will also increase, reaching close to 20 mph by noon. Some wind gusts could reach up to 30 mph.

Temperatures will be pleasant, starting in the mid to upper 50s before 9 a.m. They’ll steadily rise, reaching the upper 60s by noon and topping out in the low to mid 70s during the late afternoon.

Storms develop late

Just like San Antonio, most of the state will stay dry through much of Sunday.

It’s not until after 8 to 9 p.m. that storms are expected to develop in westcentral Texas, on a line from San Angelo to Abilene to Wichita Falls. This area, mainly west of the I-35 corridor, is the region most likely to see severe weather, including damaging hail and wind gusts late Sunday night and early Monday.

Overnight, storms will develop into a line and move east. They’ll weaken a bit, meaning that the severe weather risk is not as high through the I-35 corridor, in cities including Waco, Austin and San Antonio.

Still, you may wake up to rumbles of thunder in San Antonio early Monday morning.

The greatest chance of storms will be between 4 and 8 a.m., and overall rain chances stand at 40%.

By mid-morning Monday, storms will move out of South and Central Texas. Severe weather will be possible in far East Texas through the early afternoon, before storms finally move into Louisiana and Arkansas.

This week’s forecast

Once the rain clears out Monday morning, drier air will move into San Antonio from the west. It’ll bring sunshine, wind and warm temperatures rising into the upper 70s.

The weather will remain quiet on Tuesday as highs reach the mid 70s, very close to average for late March.

By Wednesday, a weak low-pressure system will pass through Texas, delivering slightly cooler temperatures, in the upper 60s and low 70s.

It will also bring a slight chance of showers and storms, but rain chances are only 20-30% in San Antonio. It’s the best chance San Antonio will have to pick up some rain for the rest of the week.

Temperatures will rise slightly through the end of the work week and into the weekend.

Highs will reach the upper 70s and possibly the low 80s at times, but no significant storms are expected.