Baby cold front brings chance of rain this week for Valley

HARLINGEN — Brace yourselves, but there’s a cold front on the move.

Meteorologists with the National Weather Service in Brownsville say your kids won’t need their winter jackets, and the cold front probably won’t even reach the Rio Grande Valley before it stalls out for good sometime early Wednesday.

But it brings a potential break in the weather by helping increase the chances of rain this week.

“Believe it or not, and I’m not sure if it is a late-season or an early-season cold front, but there is a cold front that is coming down,” said Robert Frye, a meteorologist with the weather service in Brownsville. “It should not push through the area, unfortunately, so it’s not going to do anything to lower our temperatures that much.”

Frye said yesterday such a weak cold front is referred to by weather gurus as a “density boundary,” and he predicts the deepest south it comes will be somewhere along a line between Corpus Christi and Laredo. If it does drop farther down, it would be “very odd” for this time of year, the meteorologist said.

“The only thing that’s going to happen to us here in the Valley is an increase in precip, increased rain chances,” he said.

Highs this week will range from 96 along the coastal areas to 104 farther up the Valley, perfectly normal numbers for the cusp of August.

But the chances of rainfall are increasing, from 20 percent tonight as the density boundary approaches and 30 percent on Wednesday. The next-highest possibilities will be 20 percent both Friday and Saturday.

“Definitely the increase in precip is there,” Frye added. “And that is a change from what we’ve been seeing.”

The chances of rainfall will lessen the possibility of setting any records for high temperatures in the Valley this week, and will keep highs within normal ranges.

Yet those conditions also mean higher humidity levels, particularly for McAllen and points east.

“Not to make a really bad pun here,” Frye said, tossing all restraint aside, “but the relative humidity’s all relative.”

Summer humidity in the Valley generally hugs the coastal area, where gulf moisture is more likely to build up. Frye said these conditions usually are found east of the I-69C corridor near McAllen.

Heat indices, the feels-like temperature, will range this week from around 105 degrees to 110 degrees, although Frye said he doesn’t envision any official heat advisories being necessary.

“There may be isolated areas up to a 112 heat index, especially where you have the warmer temperatures juxtaposed over the higher humidity values where you have them come together,” he said. “Which is generally right alongside the I-69E corridor — from Olmito to Harlingen up to Raymondville, that’s where we usually have a bit higher heat indices because it’s where you start getting away from the coast … but still close enough to the coast to have relatively high moisture content.”