The latest on late week Barry risk and current heat

I will jump into the latest on the potential for a tropical depression or storm named Barry in just a moment. I did go extremely in depth on where we stood last evening with regard to Barry, which you can check out as well. First, we do still have some important weather (heat) to get through before that.

Today & Wednesday

Heat and humidity will dominate today once more. We should shoot for the mid- to upper-90s again this afternoon. Look for potential heat advisories again this afternoon.

Exercise heat precautions today, stay hydrated, and try to stay in air conditioning if possible in the late afternoon. After some noisy, soaking storms in northern parts of the metro area yesterday evening, we could again see a handful of showers again today, though coverage and intensity should be a bit reduced.

Wednesday looks even worse with high heat and humidity. Expect upper-90s and risk for heat advisories again. There could be one or two showers around but nothing more.

Thursday

We should begin to feel some influence from the potential tropical depression or storm in the Gulf by Thursday, which would just mean a few scattered showers or storms at this point on Thursday afternoon. Otherwise, it will be hot and humid with solid mid-90s if not a little hotter.

Friday, weekend, and potential for Barry

The link in the first paragraph will get you to my in depth post from last night. I’m not going to repeat a whole lot this morning, but here’s where we currently stand. We still have a significant degree of uncertainty regarding the future of Invest 92L/future Barry.

The one sentence summary: Thunderstorms are developing in the northeast Gulf that will ultimately help determine where 92L goes and how strong it becomes, and while overnight guidance did shift back more to the east (focused in Louisiana), there remain a number of potential outcomes we should be prepared for.

The National Hurricane Center continues with an 80 percent chance of development over the next 5 days somewhere in the northern Gulf.

Just to clear up any misconception about NHC graphics, the hatched red area on the map above indicates where development could occur, not a forecast track. This risk is mostly unchanged vs. 12-24 hours ago.

The disturbance that we are watching is somewhere between southern Georgia and the northeast Gulf this morning. Thunderstorms have recently begun firing, and the question becomes, out of this mess, where will the action focus? That will allow us answers as to where 92L/Barry ultimately goes.

So has anything changed overnight? As it relates to what we should be doing in preparation and what we should expect, no, nothing I would say has changed: There is still a significant amount of uncertainty around this system and there remains potential we are impacted by it this weekend in Houston.

But there were some hints that perhaps model guidance has begun to halt or reverse the western shift we saw yesterday. For those that look at models, many have focused on the European model, as it has been the strongest of all the reliable guidance, bringing a borderline hurricane into western Louisiana or eastern Texas since Sunday night. That model shifted markedly east with things overnight, more toward Central Louisiana with track, minimizing impacts in Houston. Why? I believe a slightly deeper/stronger trough in the Midwest is exerting more northward “pull” on the system, allowing it to end up farther north over time.

More importantly, the European ensemble spread (50 runs of the Euro with different initial conditions) generally shifted a little further east as well. Worth noting, the GFS model continues to insist this will barely develop. Now, I have done this long enough to know that this could easily swing back hard the other way this afternoon when that data is updated. This is why we caution you about focusing too much on individual model runs. The takeaway here is that model trends overnight were not discouraging, but until we get a true center for models to focus on, don’t fall in love with any one model outcome.

With all that said, the NWS rainfall outlook has shifted a bit further east as well, with the 5 to 15 inch bullseye now centered over the Cameron and Lake Charles areas of Louisiana.

I’m not intending a pun here, but it is important to remember that this is a very fluid forecast, and as the system organizes and guidance comes in line, we will see this rainfall forecast shift. Bottom line, travel along the Gulf Coast Friday and especially Saturday will be difficult east of Houston. Scattered storms are possible elsewhere too.

So Matt, what is the forecast for Houston Friday through Sunday? Again, given that we don’t know for sure where 92L will go, we can’t say for sure what the forecast will be. But I try to be a reasonable person, so let me offer you three possible outcomes, in no particular order at all.

Scenario a.) Overnight model guidance, specifically off the Euro accurately shifted things east, and the system comes ashore in central Louisiana: Houston would be extremely hot and mostly dry. High temperatures would be in the upper-90s to near 100° and storm chances would be minimal Friday and especially Saturday.

Scenario b.) The GFS model is generally correct, and 92L will come more due west, disorganized: We would see high temperatures in the upper-80s to low-90s all weekend with higher end daily storm chances, capable of locally heavy rainfall. That would probably yield 1 to 3 inches on average, with higher amounts possible.

Scenario c.) The Euro and GFS trend toward one another or the center forms further south in the Gulf today and tomorrow, allowing a more westward track toward southeast Texas rather than central Louisiana: We would see tropical depression or tropical storm type impacts Saturday and Sunday in the Houston area. That would include wind, waves, and widespread heavy rain in this scenario.

All three of these scenarios or some hybrid of a couple are completely plausible right now. I don’t expect a ton more clarity this afternoon, but I do expect a decent boost in forecast confidence by tomorrow morning. I’ll update with the latest later today.