FORT WORTH -- Forecasters say there's a 70 percent chance for rain Monday afternoon and evening that is not expected to be severe.
But don't let your guard down because there's some nasty stuff in the works Wednesday.
Monday's rain is expected to result from an upper-level disturbance combined with low pressure at the surface and a ready supply of moist air from the Gulf of Mexico.
Tara Dudzik, meteorologist for the National Weather Service in Fort Worth, said that no damaging wind or hail is expected Monday.
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"But we are expecting heavy rainfall," she said Monday afternoon, "so flash flooding could be a concern."
Most of the showers are expected after 7 p.m., the weather service said. The expected high temperature was 73 degrees, although the mercury had only reached 70 degrees at 2:30 p.m.
Tuesday holds a similar forecast, but the chance for showers and thunderstorms is 40 percent, mainly before 1 p.m., the weather service said. The expected high is the near 81, beneath mostly cloudy skies.
And then comes Wednesday, when the low pressure system already in place, along with the moist gulf air, gets bumped, or rather slammed, by a dry line boundary pushing from the west, the weather service said.
This line separates dry desert air and the moist gulf air, but it sparks storm activity as it pushes east, mingling the dry air with the moist.
"We have a pretty good shot at some severe weather -- large hail, damaging winds," Dudzik said.
What about tornadoes?
"It's a little early to say if there is going to be tornadoes," Dudzik responded.
But Thursday through the weekend will bright and shiny, she said.
"It will be clearing up with highs in the mid to upper 80s," Dudzik said.
POSSIBILITY FOR RAIN
National Weather Service officials attach a percentage to their predictions for precipitation, but the system they use involves a "12-hour probability of precipitation or POP12." This refers to the likelihood, expressed as a percent, of a measurable precipitation event (1/100th of an inch or more) during the 12-hour period in a particular area.
In our case that generally means Tarrant and Dallas Counties -- the Metroplex.
The POP, usually for rain or snow, can be illustrated by an example, so let's use Monday, which calls for 70 percent probability of rain in the Metroplex. This means that there's a seven-in-10 chance that any location in the Metroplex will receive at least 1/100th of an inch of rain.