HARLINGEN — Heat records for June 5 tumbled down in Brownsville and McAllen, and Harlingen came up a few degrees short.
Brownsville recorded a temperature of 98 degrees, breaking the city’s 97-degree record for the day set in 1942. In McAllen, the heat hit 106 degrees, shattering the 102-degree record for the day set in 1998.
In Harlingen, the 97-degree high was three degrees shy of the record of 100 set in 1955.
What is shaping up as an abnormally hot year is expected to continue, and forecasters at the National Weather Service in Brownsville say summer will most likely bring us more of the same, they write in their 2017 RGV Summer Outlook released yesterday.
May turned out to be 1 to 3 degrees above the 1981-2010 average, forecasters say, ranking among the Top Ten all-time for temperatures in Brownsville and McAllen. The month ended “in a super-sweaty and dangerous close to the month with three days in a row with heat index, or ‘feels like’ temperatures, soaring to or above 111 degrees along the Rio Grande.”
Imagine what it will be like when summer actually begins later this month.
La Canicula
In the Rio Grande Valley, the generally dominant weather pattern for the summer season is “La Canicula,” a Spanish term indicating the dog days of summer, which generally occur from July 3 to Aug. 11. During this period, atmospheric high pressure “parks over northern Mexico and much of Texas, suppressing significant precipitation while allowing heat to build.”
“This was the case in 2015 and 2016; a third consecutive year of prolonged ‘Canicula’ would ensure a record warm 2017 for many, breaking the record set — in 2016.”
100-degree days for McAllen
Forecasters say McAllen in particular may be set up for a torrid summer season, and “practically guarantees the McAllen metro region will see at least 60 days of 100-degree maximum temperatures.”
“While too soon to predict whether the 2016 record of 90 days will be threatened, it is worth noting as of this writing that McAllen/Miller had already reached 10 days as of June 5, another 60 is almost guaranteed between June and August with the probability of above average sitting at 54 percent for the city this summer.”
Forecasters say if the current pattern holds through summer, McAllen could see 25 days of 100 degrees or more in July, and another 25 in August. Add those to a predicted 10 to 15 days in June and McAllen could be pushing around 70 triple-digit days for the year.
That would put 2017 among the top five years on record for the city when it comes to 100-degree days, forecasters say.
“While temperatures will be a little lower near the coast, a typical afternoon may see Harlingen top out at 98 degrees and Brownsville at 95 degrees — in all cases, 2 to 3 degrees above average … Sultry mornings in the upper 70s to around 80 would be some 3 to 4 degrees above average — similar to long periods during the summers of 2015 and 2016,” forecasters wrote.
Rain and possible drought
Spring rains across the Upper Valley and brush country have kept drought at bay there, and early June rains in the Lower Valley have eased what had been severe drought conditions in southeastern Cameron County.
But a strong La Canicula could quickly put severe drought conditions back into play.
“Across the Lower and Mid-Valley, however, conditions began summer 2017 as abnormally dry due to moderate drought, including nearly all of the heavily populated areas. A dry, hot summer would ensure expansion of moderate to severe drought, with the future status then resting heavily on whether September plays out as ‘normal’ (wettest month of the year).”
