With an official reading of 96 degrees Sunday at Dallas/Fort Worth Airport — and even hotter elsewhere — it may have felt like a record-breaking day.
But the record still belongs to 1947, which posted 100 degrees on May 4 in Fort Worth, according to data kept by the National Weather Service.
Sunday, however, managed one distinction: It was the hottest day in Fort Worth since Sept. 26, when the mercury reached 95 degrees, the weather service said. The normal average temperature May 4 in Fort Worth is 80 degrees, according to the weather service.
The toasty weather Sunday resulted from weak high pressure aloft, coupled with dry winds out of the southwest, said Dennis Cavanaugh, meteorologist at the weather service in Fort Worth.
With those kinds of winds, Cavanaugh explained, the air “gets squeezed, and as it does, it heats up.”
Monday should be warm and dry too, with a high around 92 degrees, according to the weather service.
Rain returns to the forecast on Thursday, but first, a couple things must happen to set the stage, Cavanaugh said.
On Tuesday, winds will shift from the southwest to the south and will drag moist air across Texas from the Gulf of Mexico, he said. The high will be around 90, according to the weather service.
This trend will continue Wednesday under mostly cloudy skies and a high of about 87. Next, an upper-level disturbance from the Pacific Northwest will roll into North Texas. Also, a “dry line” will form over the region.
“A dry line always comes from the west, and it represents a boundary of very dry air, compared to the moist air to the east,” Cavanaugh said. “It results in strong westerly winds on the High Plains, and it sloshes the moisture to the east.
“In the middle, where the dry air reaches the moist, it resembles a front, and that’s where thunderstorms develop.”
Exactly when they’ll develop, and their potential severity, won’t be known until Thursday, Cavanaugh said.
On Sunday, the weather service was predicting that a half-inch might fall west of Interstate 35W, while 1-2 inches may be recorded in areas farther east.
“Not a drought buster,” Cavanaugh said, “but it would help us catch up.”