The much discussed cold front is advancing toward the Houston metro area, and will push through the region this morning. It is producing a squall line of strong thunderstorms. This line of storms, presently along a line from Victoria-to-Sealy-to-near-The Woodlands, should reach areas such as Sugar Land, Tomball, and downtown Houston by around or before 7 am CT; League City and Baytown by around 8 am, and have exited the area shortly after that.
Houston radar at 5:12 am CT on Tuesday. (RadarScope)
The good news is that, as these storms have moved eastward overnight across Texas, they have lost some of their severity. Therefore, while there remains a chance of hail and tornadoes, that threat should diminish somewhat as the storms moves through our region this morning. Probably the biggest severe weather worry at this point is straight-line wind gusts of 50 or possibly even 60 mph.
HRRR model forecast for radar activity at 7 am CT on Tuesday. (Weather Bell)
The other concern is heavy rainfall as the squall line moves in. Some areas may quickly pick up 2 to 4 inches of rainfall this morning, flooding streets for a short time as high rainfall rates overwhelm roadways. Again, this threat should end quickly as storms exit to the east.
HRRR model forecast for radar activity at 8 am CT, showing the major storms clearing central Houston. (Weather Bell)
Unfortunately, the Houston metro area will be affected this morning as people are heading to work, and children going to school. If it is possible to delay travel until the squall line as passed your area, that would be for the best.
Beginning later this morning, high pressure will ensure that our weather is fair for the remainder of the week, with plenty of sunshine and pleasantly dry air.
I am writing this at 9 PM, and we’ve had confirmed tornadoes this evening in Round Rock, Jarrell, Elgin, Taylor, and Snook, all to the west of the Houston area.
Each red dot represents a report of a tornado today. Multiple tornadoes were reported just east of Austin this afternoon and evening. In addition strong winds and large hail have also occurred. (NOAA)
Thus far in Houston it has been quiet. Some of you are likely prepared to shout “BUST!” at us, but as we’ve been discussing, this was expected to be a nighttime affair in Houston and not everyone is expected to see severe weather. Here’s what we can tell you about the rest of tonight.
Radar as of 9:20 PM shows one supercell exiting the Brazos Valley, some non-severe showers north of Houston, and a developing squall line along I-35 near and north of Austin. All this will expand in coverage and slowly slide east overnight. (College of DuPage)
First off, a Tornado Watch is in effect for most areas north of Spring and west of Brookshire. The majority of the Houston area is not in any severe weather watch as of 9 PM.
Through Midnight
No issues are expected aside from scattered showers, possibly becoming more numerous on a line from Lake Livingston through Katy. Severe weather is unlikely in Houston before midnight. As I write, there is currently a tornado warning through 9:45 PM northeast of College Station, but there are no other supercells on track for Houston. Good news for sure.
Midnight through 6 AM
This will be when the vast majority of the action occurs around here. Look for showers and some thunderstorms to become more numerous as the overnight hours progress, mainly on the north and west sides of Highway 59/I-69. So folks in Galveston and Lake Jackson will likely see minimal activity through about 3 AM or so. All this will eventually get picked up by a developing squall line that’s currently located in the Austin area, along I-35. That will expand and shift east. Look for this line to progress across the Houston area between about 4 AM and 8 AM. As this occurs, we will be at our highest risk for strong winds, hail, and perhaps an isolated tornado. In other words, that will be the time of our highest odds for severe weather.
I do not want to minimize the tornado risk, as there is still going to be a healthy amount shear around, but these types of scenarios typically produce brief, lower-end tornadoes. So we are probably not going to see larger supercells with long-track tornadoes like we saw this afternoon and evening east of Austin. That said, given the potential for severe weather occurring overnight, you absolutely should have a way to be notified of weather warnings, be it using your phone or with a weather radio. Have a way to be notified and woken up should a tornado warning be issued for your area. And even if there aren’t tornadoes, damaging winds and potential for hail warrant your attention too.
In addition, flash flooding remains a possibility, as even non-severe storms will be capable of producing 1 to 2 inches or more an hour. We maintain a Stage 1 flood alert for the area, north of I-10.
After 6 AM
The good news is that once this line punches across the area by 8 AM or so, we’re done. We will see clearing and increasing sunshine with highs in the 70s and lower humidity.
Unless something ridiculous changes, Eric will have our next update for you a bit earlier than usual tomorrow morning. Try to get some sleep if you aren’t working the night shift, and if you are, please stay safe!
Good afternoon. Overall, the forecast remains on track. Houston will experience scattered showers and a few thunderstorms this afternoon and early evening. The threat of severe weather will increase after sunset, and peak overnight, before storms clear the area on Tuesday morning. Let’s examine the dual threats tonight: Severe storms and flooding.
Severe storm potential
NOAA has updated its severe storm outlook for Monday and Monday night, and upgraded some parts of our region to a “moderate” chance of severe storms. This is the second highest level of threat, and is indicative of the potential for supercell thunderstorms. Such storms can produce large hail, strong wind gusts, and tornadoes. The area with the most favorable conditions for these storms later today and tonight is northwest of Houston, and includes Austin and College Station. Most of Houston faces a lesser albeit still notable threat tonight, while the coast is at less of a risk.
Severe storm outlook for Monday and Monday night. (NOAA)
The bottom line is that strong and severe storms are possible tonight in the Houston metro area, particularly after 8 pm and continuing for about a 12-hour period. Not everyone will see severe weather, of course, and we cannot predict precisely where such storms will develop. So be weather aware, and take shelter in the event a tornado warning is issued.
Heavy rainfall potential
Later tonight the potential for heavier, training rainfall will also move into the picture. The problem is that as the cold front nears Houston early Tuesday it will start to slow down. This may cause storms to slow, and thus produce greater accumulations over certain areas. We’re still looking at 1 to 4 inches for most of the area, but bullseyes of 6 inches or more are possible for some locations, especially away from the coast. For this reason we’ve issued a Stage 1 Flood Alert for the metro are north of Interstate 10. Street flooding is possible in these locations.
Excessive rainfall risk for Monday and Monday night. (NOAA)
The good news is that this mess will clear out pretty quickly on Tuesday morning, taking its rainfall off to our east. But it could make for a stormy night, and potentially a messy commute to work on Tuesday morning before that happens.
Matt will have an update for you later this evening.
Good morning. Houston faces the threat of severe weather later today, and especially tonight, as a slow-moving cold front advances toward the region. This system will be bringing storms across central and east Texas during the next 24 to 30 hours before it finally moves east. During that period we face both the threat of severe thunderstorms, including hail and tornadoes, as well as heavy rainfall. To account for this heavy rainfall, we have instituted a Stage 1 flood alert for the Houston region for areas north of Interstate 10.
Monday
We’re not expecting too much action during the daytime. There will be some scattered showers, but nothing too extreme, as temperatures reach the low 70s beneath cloudy skies. Winds, however, will be noticeable out of the south, with gusts of 30 to 35 mph or even higher at times. For areas west and north of downtown Houston, conditions will start to become more favorable for strong thunderstorms around sunset. At that point storms are likely to sag southeastward, toward central Houston and the coast overnight.
Monday night and Tuesday morning
There will be an abundance of moisture and energy in the atmosphere tonight, which translates into the potential for vigorous thunderstorms. This system will be capable of producing large hail, briefly strong wind gusts, and tornadoes. While this system will be dynamic, and the details are to be determined, generally I think we can expect an initial round of strong thunderstorms during the overnight hours, to be followed by a band of heavier rainfall (with less potential for severe effects like hail and tornadoes) sometime around sunrise on Tuesday morning.
Severe storm outlook for Monday and Monday night. (NOAA)
Overall rain totals will likely be 2 to 4 inches for areas north of Interstate 10, and 1 to 4 inches for locations south of the freeway. Some inland locations will see more than 4 inches, and therefore we have placed areas north of Interstate 10 under a Stage 1 flood alert. Street flooding is the most likely outcome.
If this forecast gives you anxiety, please consider that NOAA’s forecast for storm activity locally is mostly in the orange or “enhanced” category (see above). This is relatively high, but there are two higher gradients of storm potential. So while our area is likely to see some severe activity, your personal chances of being directly affected by a tornado are really very low. With that said, due to the potential for inclement weather, this is time to pay attention. It is important that you have one or more ways to get weather warnings tomorrow night (such as you phone, a weather radio, etc.) Matt and I will provide additional updates today, tonight, and Tuesday morning.
Tuesday
As the front moves through on Tuesday morning it should begin to sweep away the rainfall, with rains likely ending mid-morning for most locations. Skies should clear out fairly quickly on Tuesday as drier air pushes in, with sunny skies in the afternoon and highs in the 70s. Lows on Tuesday night should drop into the upper 40s for Houston, with cooler conditions inland.
NOAA rain accumulation forecast for now through Tuesday morning. (Weather Bell)
Wednesday, Thursday, and Friday
The rest of the week should yield mostly sunny, pleasant weather with highs in the 60s and 70s, lows in the 40s and 50s. Look for a reinforcing shot of drier air sometime around Thursday.
Saturday and Sunday
At this vantage point, the weekend looks nice as well. Look for highs in the 70s or possibly low 80s, lows in the 50s, and partly to mostly sunny skies. Dewpoints will recover some, but the air should still feel pleasant dry outside.
