Eric Berger

In brief: Storms are firing up to the west of Houston this afternoon, and the region will face an unsettled pattern through Wednesday morning, at least. This post describes our latest thinking on timing and impacts from these storms.

Good afternoon. Some fairly strong thunderstorms have developed near Brenham, and they are part of a system that is slowly moving to the east, and therefore toward the Houston metro area. I have some doubts about how much of this activity is going to hold together later this afternoon, but it is possible that some parts of the Houston region, including Montgomery County, will experience thunderstorms late this afternoon or this evening before midnight. After this we should experience a reprieve over night.

Tuesday and Wednesday

It is difficult to forecast the next couple of days with high confidence, so I’m going to share what we’re thinking now. But this is a fluid situation. (Both literally and figuratively). Tomorrow morning a fairly strong line of storms is likely to develop along the I-35 corridor around sunrise and then progress eastward across the state. A lot of our modeling suggests this line of storms will remain rather strong as it reaches I-45 late during the morning or around noon-ish. All of the threats are in place here: heavy rainfall, damaging winds, hail, and possibly tornadoes.

Here’s the tricky part. I’m fairly confident in strong storms for places like College Station and Huntsville, but the further south one goes, the less chance of inclement weather. It is possible that much of Harris County, and points south, see only scattered showers and thunderstorms on Tuesday, rather than a seriously disruptive and severe event.

However, that won’t be the end of it. The atmosphere will be supportive of a second round of showers and thunderstorms that are more likely to impact central and southern regions of the Houston area. Whether this occurs late on Tuesday evening, overnight, or on Wednesday morning simply is not something I can say with confidence right now.

The bottom line is that from now through Wednesday morning you should be prepared for the possibility of strong thunderstorms and heavy rainfall. We have put a Stage 1 flood alert in place to account for street flooding, but there is also the threat of hail, damaging winds, and tornadoes.

We will continue to keep you posted.

In brief: Monday will be calm, but you should anticipate the potential for showers, thunderstorms, and heavy rainfall on Tuesday and Wednesday in the Houston metro area. We don’t have high confidence in the timing yet, but with the atmosphere in place we can be pretty confident in disruptions, and have put a Stage 1 flood alert in place through Wednesday. Things calm down after that.

Weekend review

You would be hard-pressed, I think, to expect a finer weekend in early May than we just experienced. My wife and I were at a choir event on Sunday evening at the Willowynn Barn in Santa Fe—a gorgeous place for events by the way, I joked with Amanda that I would like to have my next wedding there—and you just had to stand outside and soak it up. Summer is on the horizon.

Inland areas got into the 50s on Sunday morning in Houston, and most of the rest of the area enjoyed the lower 60s with drier air with dewpoints in the 40s. That’s really pleasant for May. I do think we’re going to see another weak front for next weekend, but unfortunately it’s unlikely to pull as much drier air with it. And first we’ve got to get through another stormy pattern.

Monday

Humidity is already on the rise this morning, and we’ll see southeasterly winds gusting up to 25 mph that will set the stage for more moisture in the air. We’ll start out with partly sunny skies this morning, but by some point this afternoon we should see mostly clouds. High temperatures will reach the vicinity of 80 degrees. By this afternoon and evening we will see some scattered showers, mainly located to the west of Interstate 45. A chance of light rain will spread into the entire region during the overnight hours as lows fall to around 70 degrees.

Tuesday and Wednesday

The moisture that moved inland on Monday was a “warm” front, and it will set the stage for the possibility of heavy rainfall and storms on Tuesday and Wednesday in the Houston metro area. Our various high resolution models still have some discrepancies, but right now I would predict that the greatest potential for inclement weather will occur from late Tuesday morning through Wednesday morning across the region.

There will be the usual threats: damaging winds, hail, and possibly a tornado. We are also concerned about the potential for heavy rainfall. Most areas are likely to pick up 1 to 3 inches of rain through Wednesday, but we could see some higher bullseyes of 5 inches or more. For this reason we are going to institute a Stage 1 flood alert from Tuesday at noon through Wednesday. In terms of temperatures, Houston should reach the lower 80s on both days with plenty of humidity. We’ll have more on this later today and plenty of coverage the rest of the week.

Thursday

Rain chances should diminish by Thursday, but will perhaps not go away entirely until the afternoon. Expect partly sunny skies and high temperatures in the low- to mid-80s. Lows on Thursday night should drop into the upper 60s.

Friday, Saturday, and Sunday

As a weak front drifts into the area we should see another nice weekend. I don’t know if we’re going to run it back and have things as nice as we just experienced, but as of now I anticipate mostly sunny skies with highs in the low 80s, overnight lows in the 60s, and modestly drier air. So if it is not cool as this past weekend, it will hopefully at least be somewhat pleasant.

In brief: Storms firing to the north and west of Houston will sag into the city this evening and down to the coast by around midnight. This system should also weaken with the loss of daytime heating, so the severe threat is diminishing. But it’s not completely gone yet.

If you live along, or south of Interstate 10 you may be wondering what the big deal is with storm forecasts today. So far the majority of the activity has taken place in the northern half of the Houston metro area. Some locations just north of Conroe have picked up in excess of 6 inches of rain, and areas near Kingwood have recorded upward of 4 inches. There also has been a fair amount of hail, some of it quarter-sized, within the stronger thunderstorms.

As of 6:45 pm CT two things are changing. The first is good news. The threat for severe weather, particularly hail and damaging winds is fading. That does not mean these storms cannot produce severe weather this evening, it just means that their ability to do so is declining. The second change is that, ahead of a cool front, the threat of showers and thunderstorms is now moving into central Houston and should reach the coast between 10 pm and midnight. Again, we expect the line of storms to weaken as it moves toward the coast.

So for areas that have been inundated with storms today, the finish line is sight. Things should clear out in northern areas over the next couple of hours. For areas that have seen nothing so far today, but may have heard the distant sound of thunder, showers and perhaps some stronger thunderstorms are inbound this evening. Closer to the coast I think rain totals will be hit or miss, but most of the region should see some rainfall between now and Saturday morning.

Saturday and Sunday both look like pleasant late spring days, with drier air and highs in the vicinity of 80 degrees.

In brief: Severe thunderstorms are developing in Houston as of noon on Friday, and will pose a threat for the next 12 hours across the region. We’ve got details about all of the threats in this update, with a particular concern for the evening commute.

As anticipated, with daytime heating, we are seeing severe thunderstorms developing in the Houston region. As of 12:30 pm CT there are large clusters of storms near Kingwood and just west of Katy. From this point forward we expect additional development throughout the afternoon and evening hours as the capping inversion over the region breaks.

From now until about 5 pm the majority of activity should be clustered along and north of Interstate 10, but that certainly does not preclude thunderstorms developing in the southern half of the region. Unfortunately we expect that the majority of the region is likely to see activity during the evening commute as the storms spread, making for a messy time on freeways. If you can leave earlier today, that’s probably for the best.

In terms of threats we have three major concerns right now.

RAIN: These storms will be capable of producing heavy rainfall, and under high rainfall rates we are likely to see street flooding. For this reason we have implemented a Stage 1 flood alert for the region through tonight. Essentially, you need to be weather aware on roads, take extra time, and do not drive into high water. Rainfall amounts will vary widely, with most of the area likely picking up 0.5 to 2 inches. I am concerned about a few bullseyes of 4 inches or more, which are possible.

WIND: There is a healthy chance of damaging winds with these storms, so anything you can batten down would be helpful. The threat of damaging winds is the highest we have seen so far this spring, so again this is another reason to stay off roads amid strong thunderstorms this afternoon and evening if possible.

HAIL: In some thunderstorms near Kingwood weather spotters have already observed quarter-sized hail this afternoon. So this is a distinct threat as well as these storms pass through.

Tornadoes are also possible, but the threat is on the lower end of the scale.

Over the next several hours the bulk of the storms will shift southward, ahead of a front rumbling into the area. Areas south of Interstate 10, accordingly, will likely face the greatest threat of severe weather from late this afternoon to late this evening. By midnight, or shortly afterward, the threat of storms should move offshore. After that, the weekend looks lovely.

We will update later today as warranted.