In brief: Yes, you are not crazy. Monday did feel incredibly hot outside, and the smoky haze from agricultural fires in Central America did not help. We’re now going to see a pattern change that could bring storms into the metro area as early as this afternoon. Today will be a day to be weather aware and we’ll update the site again by around noon.
Memorial Day madness
Houston did not set record high temperatures on Monday. The official high at Bush Intercontinental was 96 degrees, two degrees shy of the all time high of 98 degrees for May 27. However, it felt extremely warm thanks to incredibly high dewpoints. For example, at Houston’s Hobby Airport the heat index reached 115 degrees. This is a combination of temperature and relative humidity.
Even if you don’t have context for how hot that is—and believe me, it’s hot—Houston has never had a heat index of 115 degrees in May before. Moreover, Hobby Airport did not have a heat index that warm during all of last summer, which was excruciatingly hot. You’ve got to go all the way back to August of 1998 for a reading that high. Last summer recorded much hotter temperatures, but the humidity was somewhat lower, in part due to drought-like conditions. Fortunately, we’re now going to step back from the abyss of extreme heat for awhile.
Tuesday
Today will not be nearly so hot. Partly cloudy skies will help to moderate temperatures a bit, although we are still likely to see highs in the low 90s with plenty of humidity. The difficult question is severe weather potential, with the possibility of storms this afternoon, and then again overnight. As of 6:30 am CT there was a cluster of storms near Dallas, moving southward. The question is what happens to this system, and whether it holds together long enough to affect the Houston area. There has been a lack of consistency in our guidance.
Right now my sense is that this system will hold together as it approaches our northern areas, such as Conroe and College Station, shortly after noon. Then we could see this line of severe weather move from north to south, with strong thunderstorms, wind, and hail pushing into Houston during the afternoon hours. It could reach the coast by 4 or 5 pm. The usual severe storm risks are there, with heavy rainfall, damaging, winds, hail, and possibly a few tornadoes. We will update the site by around noon when we have more confidence in this forecast.
Then there is the potential for a second round of storms tonight after midnight. However, this is probably conditional on what happens this afternoon. I.e. if we get a fairly pronounced line of storms this afternoon, things will be quieter tonight. But if storms peter out later today before reaching Houston, a more pronounced line of storms could pass through tonight.
Wednesday and Thursday
These should be a pair of partly to mostly cloudy days, which will help limit highs to the upper 80s. Each day will also see a healthy chance of showers, although the likelihood of severe weather appears to be considerably lower. Nights will be warm, in the upper 70s.
Friday, Saturday, and Sunday
The end of the week and the weekend look slightly warmer, with daily highs of around 90 degrees and partly sunny days. The atmosphere will remain somewhat unsettled, but daily rain chances will drop to perhaps 30 percent, so if you have outdoor plans this weekend I don’t see anything like a total washout at this point. Let’s see how the forecast evolves.