...Dangerous Heat Expected Today... .An upper level ridge of high pressure has settled across South Texas this weekend. This ridge will continue to allow temperatures to warm into the upper 90s right along the coast to middle 100s across the middle and upper Rio Grande Valley. The combination of very hot temperatures and relatively high humidity values will cause heat indices to climb well into the 100s across much of the area today. ...HEAT ADVISORY IN EFFECT FROM 1 PM THIS AFTERNOON TO 6 PM CDT THIS EVENING... The National Weather Service in Brownsville has issued a Heat Advisory, which is in effect from 1 PM this afternoon to 6 PM CDT this evening. * TEMPERATURE...Heat index values ranging from 111 to 115 degrees can be expected this afternoon across the advised areas. * IMPACTS...An increased risk of heat related illnesses, including cramps, heat exhaustion, and heat stroke.