Eric Berger

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.

In brief: Today’s post reviews an unseasonably warm April and then looks ahead to some dynamic weather on Friday. Much of the region should see storms between Friday afternoon and Saturday morning as a slow-moving cool front moves into the region. After this, the weekend looks quite nice for early May.

May arrives

If April seemed rather warm, you’re not wrong. The month ended last night, and for the greater Houston region it was a seasonably sizzling one. The city’s average temperature was 74.6 degrees, which is nearly 5 degrees above normal. This ranks as the fourth warmest April of all time in the city’s history. One reason is that the city saw no real fronts during the second half of the month. But that does not mean summer has quite yet arrived in Houston. A modest front will reach the city this weekend, and another one is possible about 10 days from now. These won’t be strong fronts, as such things are rather rare for May. But any dry air this late into the spring season is welcome.

Thursday

If you’re wondering about those storms on Wednesday night, they essentially remained north of Highway 105, with only a smattering of rain making it down into the Houston metro area. Plenty of moisture remains in the atmosphere so we may see a few showers and thunderstorms today in Houston, but I expect most of us to stay dry. As skies clear out this afternoon, it should be rather warm day, with a few inland locations probably reaching 90 degrees this afternoon. Winds will be from the south at 10 mph, gusting perhaps to 20 mph. Lows tonight only fall into the low 70s for most locations.

Friday and Friday night

In terms of temperatures and humidity, I expect Friday to be similar to Thursday, however I do expect to see less sunshine. The big thing to watch is the possibility (likelihood, really) of showers and thunderstorms on Friday afternoon, evening, and overnight. As a front approaches Houston we are likely to see a mass of showers and thunderstorms develop north of Interstate 10 by Friday afternoon or early evening, and we cannot rule out some hail or damaging winds with these. Although I believe the formation of tornadoes is unlikely, I cannot say none will occur.

Later on Friday evening, or perhaps around midnight, these storms should march southward toward the coast before the whole thing moves offshore some time on Saturday morning. Because we are still nearly 48 hours from all of this, we are just coming into the range of high resolution modeling. However I want people to be aware that the region could see 0.5 to 2 inches of rain on Friday evening and night, with the possibility of thunderstorms. If you have plans for Friday night, this is definitely something to take into account.

Saturday

Rain chances will likely end on Saturday morning, and we should see some clearing skies during the afternoon hours. High temperatures will likely reach about 80 degrees for most locations, with some modestly drier air. Lows on Saturday night will depend on how far you live from the coast, with areas south of I-10 maybe reaching 65 or the lower 60s, whereas some areas further inland have a chance to reach the upper 50s. It should, in any case, feel pretty nice.

Sunday

Dare I say this may be the nicest day the region sees until some time in October? Expect mostly sunny skies with a high temperature in the vicinity of 80 degrees. With dewpoints in the 50s, the air will feel reasonably dry. Although we cannot entirely rule out a few isolated showers at this point, I don’t expect much rain. Lows on Sunday night will, again, drop into the lower 60s for most.

Next week

Already on Sunday we’ll start to see the return of a southerly flow, and this will eventually nudge temperatures and humidity back up next week. The bigger story will be a lumbering low pressure system that is likely to be a rainmaker for the region. It’s hard to predict totals, but next Tuesday, Wednesday, and Thursday look to be fairly soggy ahead of possibly another weak front.

In brief: Houston will now enter a somewhat wetter period in which rain will be possible most days. In addition, after a couple of fairly hot days, a weak front should bring some slightly drier air into the region for this weekend, knocking humidity down a bit.

Wednesday

As noted in yesterday’s post, we’re now entering a period over the next week or so in which it probably will not rain every day, but rain should be possible most days. Today, an upper-level system will drive a chance of scattered showers this morning, followed by partly sunny skies this afternoon. Depending on cloud cover, highs today will likely reach the low- to mid-80s. We’re going to have one more day of pronounced southerly winds, gusting to 25 mph, or higher.

Tonight the pattern becomes more interesting, as a line of storms approaches the region from the north. But how far will it progress? These showers and thunderstorms, some of which could be severe, will likely approach the region around midnight and could push south of Interstate 10 by sunrise on Thursday morning. However, this is no slam dunk. While some ingredients are in place to support such a line of storms moving across Houston, I think there’s a 50 percent or less chance it actually materializes.

Thursday

By mid-morning on Thursday, at the latest, any residual storm activity should have moved off to the east, leaving us with a partly sunny and warm day. Some areas are likely to get into the upper 80s, and we can’t rule out a few 90-degree readings for areas well inland. Lows on Thursday night will fall to around 70 degrees with mostly cloudy skies.

Friday

This will be another warm-to-hot day, with temperatures in the upper 80s for most of the area. Beginning Friday afternoon, we’ll see increasing rain chances due to an approaching front. We’re far enough from this front to not have great details yet about potential storms, but the bottom line is that there will be a healthy chance of rain from Friday evening through Saturday morning, and possibly into the early afternoon hours on Saturday in Houston, as the front drifts in.

Saturday

The first half of the weekend, as noted above, will see a good chance of showers before the afternoon hours. Expect highs of around 80 degrees, with clearing skies later in the day. There is a fair amount of uncertainty about temperatures, but lows in the mid-60s are possible on Saturday night going into Sunday morning.

Sunday

I’m cautiously optimistic about Sunday being a really nice day. Humidity is not going to be low, per se, but it could be quite a bit lower than we’ve experienced of late. What would you say to high temperatures in the low 80s, partly sunny skies, and relatively low humidity in early May? It won’t be perfect, and there will probably be some isolated to scattered showers later in the day. But as we get closer to summer, beggars cannot be choosers.

Next week

Most of next week should see highs in the mid-80s. High pressure will likely shut down rain chances to start the week, but by Tuesday or Tuesday night we could see the return of some showers and perhaps a few thunderstorms. We shall see.

In brief: After several drier days, some rain chances will return to Houston’s forecast. We are not expecting any days really to be washouts, however. I’m also holding out some hope that a weak front makes it into the city this weekend, providing for some slightly drier and cooler air. Fingers crossed.

Overall pattern shift

The high pressure that has held sway since last Friday, and basically shut off rain chances since then, is now shifting to the east. This does not mean you will see rain every day from now on, but over the next 10 days there will be at least a slight chance of rain most days. Total accumulations over the next 10 days may only be 1 to 2 inches, so we don’t have any real flood concerns at this time. It just should be a pattern that provides the potential for spoiling a few outdoor activities, but also helps our trees and plants before the long summer days that lie in our near future.

Tuesday

With that said, rain chances today are rather slight, and anything that falls would be a quick passing shower. However that does not mean sunshine will be abundant. Rather we should see mostly cloudy skies, and this will help limit high temperatures in the mid-80s for most locations. With dewpoints in the 60s it will feel moderately, but not oppressively humid. We can expect southerly winds at about 15 mph, with gusts this afternoon up to 25 mph. Overnight lows will only drop into the mid-70s.

Wednesday

A weak front will move toward the Houston region on Wednesday, and it will spur a slight chance of thunderstorms to the northwest of the metro area. As of now, I think the chance of any serious storms getting anywhere close to the city of Houston or its surrounding suburbs is quite low. But we’ll keep an eye on things. Skies will again be mostly cloudy, with a fairly robust southerly wind as on Tuesday. Rain chances turn a little bit higher on Wednesday night, perhaps 30 percent. Some far inland areas may see lows on Wednesday night in the 60s due to the proximity of the front, but most of the region should remain in the 70s.

Thursday and Friday

These will be a pair of hotter days as we see an injection of warm, southerly air into the region. Thursday probably will be the warmest day of the week, with some locations potentially hitting 90 degrees as skies become partly sunny. Rain chances are are low, but non-zero. Friday will also be fairly hot, but another slow-moving front will spur better rain chances. I expect most of the region will see some showers, or possibly even thunderstorms later on Friday or Friday night as the front slowly moves in.

Saturday and Sunday

It is not possible to say for certain, but at this point I think that weak front will make it all the way to the coast. As a result most of the area should see highs in the lower 80s this weekend, with a smidge of drier air, and lows in the 60s. There will still be a healthy chance of rain on Saturday, but I expect Sunday to be partly sunny and fairly nice. Again, the weekend forecast is very much in flux because we just can’t be sure how much oomph that front is going to have, but I have some hopes for a nice day on Sunday. We’ll see.

Next week

I think Monday probably will see a fair amount of sunshine before rain chances return again next week during the Tuesday through Thursday time frame. I don’t think we’re looking at anything extreme at all, but just more rain to help our soils remain in good shape for nature.