Cool San Antonio before Thanksgiving, but how rainy will it be?

After the passage Monday of a strong cold front, Tuesday kicks off several days of cool weather, including a chance of rain, that will bookend the Thanksgiving holiday in San Antonio, forecasters said. So just how likely are we to get rain, and if you’re road-tripping for Turkey Day, when should we expect to see those droplets?

Gusty winds will trail behind the cold front in South and Central Texas, and “the highest gusts will likely concentrate across the Hill Country,” according to a National Weather Service forecast bulletin. In San Antonio, northerly winds will blow at 15 to 20 mph, with some gusts as strong as 35 mph.

On Tuesday, San Antonio International Airport, site of the city’s main weather station, should see morning temperatures start out as low as 45 degrees. Under sunny skies, temperatures will rise to an afternoon high near 65 degrees, which is about 5 degrees cooler than normal for Nov. 21 in San Antonio.

Skies will remain mostly clear at night amid weaker winds of 5 to 15 mph, but still with gusts as strong as 20 mph.

Meanwhile, a rain-producing system of low atmospheric pressure was moving away from East Texas and into the Lower Mississippi River Valley. But another trough of low pressure will continue to develop in northern Mexico, according to the weather service.

“Tuesday night into Wednesday will see an upper-level disturbance across Mexico start to get pinched off from the flow and the main upper-level trough energy moving through the Ohio and Mississippi valleys,” the weather service said.

Temperatures in San Antonio on Wednesday should start in the low 40s, with sunny skies helping to push them to an afternoon high near 61.

“Precipitation chances increase from south to north during the evening hours Wednesday as this low (from Mexico) progresses into southern Texas, although there is still some uncertainty about its exact track,” the weather service said. “This low will continue to move across the area through Thanksgiving with precipitation chances continuing into the morning hours before drier conditions are seen in the afternoon.”

In San Antonio, rain chances on Wednesday night will be only as high as 20%, and mainly after midnight.

Weather forecast models disagree about how this low pressure system from northern Mexico will move through Texas, forecasters said, “but it’s worth noting that there’s at least a low potential for a freeze Thanksgiving morning in a few Hill Country areas should skies remain clear.”

The National Blend of Models, a composite forecast used by the weather service, “is still picking up on this potential with a 40-50% chance for freezing temperatures in west-central Llano County, though these chances are much lower elsewhere across our region.”

Thanksgiving in San Antonio includes a 20% chance of rain before noon on an otherwise partly sunny Thursday, and an afternoon high temperature of 61 degrees.

“A few areas may see some light showers, but rainfall amounts will be paltry even in areas that do see any rain,” the weather service said. “Another cool day is expected and some eastern areas will likely struggle to reach the mid-50s.”