Temperatures top 105 in Texas as early heat wave expands into Southeast

A quick-hitting but intense surge of heat for this time of year is expanding across the South and will peak Wednesday into Thursday. Numerous records for warmth are anticipated from Texas to Florida and northward into the Mid-Atlantic.

Temperatures - up to 10 to 20 degrees above normal - will feel more like midsummer than early May.

Already, temperatures surpassed 105 degrees near the Rio Grande in the southernmost parts of Texas on Monday and Tuesday. Heat indexes - a measure of how hot it feels after factoring in humidity - soared to 110.

Records fell in the swelling hot-air mass. Widespread afternoon highs above 90 are forecast for several days across much of the Gulf Coast, while highs of 105 to 110 may continue scorching southern areas of Texas. Heat indexes could rise above 115 in the most stifling locations.

“Those spending a prolonged period outside will need to take necessary heat precautions to avoid heat-related illnesses,” wrote the National Weather Service office serving Brownsville, Tex., and its surrounding area.

The newly operational HeatRisk product from the Weather Service and Centers for Disease Control and Prevention indicates moderate to major (Level 2 or 3 out of 4) health effects from excessive heat through Friday from Texas to the northern Gulf Coast and Florida. Locations near Brownsville, where a heat advisory is in effect Wednesday, may see “extreme” (or Level 4) heat risk at times.

Unseasonable warmth began swelling northward Monday. Several record-warm nighttime lows were established Monday along the Gulf Coast and into the Southeast, including in Corpus Christi, Tex., and Charlotte. The number of records is projected to increase Tuesday and Wednesday.

Although this bout of heat is unusual for early May, it should be mercifully short-lived.