Matt Lanza

Late Sunday afternoon Harvey forecast update

Good afternoon. Rain rates today have been more manageable in the area. We’ve even had reports of sunshine in spots. Over the next few hours, the weather is going to likely deteriorate once more. Current problems will continue and new ones will crop up, but we feel that we will probably see less rain overall tonight than we did last night in the Houston area. That being said, tonight’s rains come with a bit more uncertainty than last night’s. Let’s explain.

Now

Harvey is centered about 25 miles from Victoria. This is further east than Harvey was at this time yesterday. The setup has changed a bit, with a weak boundary along I-10 and flow that’s directed more southeast to northwest from the Gulf.

What does this mean? It means that varying intensities of rainfall are likely tonight south of I-10. Again, this isn’t optimal, but my hope is that the rains will remain manageable south and southeast of Houston. Folks in those areas will need to stay alert and keep the guard up overnight, but rain totals (and the hope is VERY importantly, the rain rates) should be less than last night.

Overnight HRRR model projects the heaviest rains near Beaumont/Port Arthur and north of I-10 in Houston. (Weather Bell)

North of I-10,it’s similar, but with more rain and fewer breaks. Expect occasional 1-3″ per hour rain rates in those areas. This will exacerbate already near-record levels of flooding on Cypress Creek and other bodies of water north of Houston.

On average, I would expect 3-7″ south and 4-8″ north, but there is most certainly a risk of higher amounts in spots. The heavy rains near Port Arthur and Beaumont should add up to 5-10″ or more.

Tomorrow & Tuesday

Looking ahead, no new news to report. After tonight, rainfall will continue sporadically and heavily at times through tomorrow, similar to what we saw today, perhaps with a few less breaks though unfortunately. Harvey will emerge back out over the Gulf near Matagorda, and a Tropical Storm Watch was reissued from Sargent to San Luis Pass with the National Hurricane Center’s 4 PM advisory. Eric will have a post shortly on that aspect of the storm, but please, use your bandwidth to deal with the rain and flooding around Houston right now. That’s the issue we have to focus on.

We’ll have another post on the forecast this evening. Stay safe.

Posted at 4:25 PM Sunday by Matt

Early Sunday afternoon Harvey forecast update

Continuing our theme of giving you the latest forecast information, here’s an early afternoon update.

Now

Some good news for some folks. Dry air has punched in west of I-45 as of 12:30, and in some areas, we’re getting a nice dry period. Other areas are still seeing rains, but they’re falling at manageable rates. We continue to see isolated tornado warnings pop up all over the area.

Radar around 12:30 PM shows breaks in the rain, but more localized heavy rainfall. (GR Level 3)

 

Rest of Today

Looking at high-resolution weather models, I think we’re going to see this pattern continue. Occasional drying moves around the area, with pockets of heavier rain at times. Some places may see 1-3″ in an hour. This will limit improvement, but outside of areas where runoff from last night is still flowing through the system, it shouldn’t make things terribly worse. Not ideal, but manageable for the most part. Tornado Warnings will continue to pop up across the region, so if you can safely find shelter if a warnings is issued, do so.

Tonight

A couple points. The setup is not identical to last night, but there are a number of similarities. And obviously that concerns us. Yesterday, we could say with high confidence that Houston was going to have a rough night. Tonight, we can only say that someone in the Houston area is going to have a rough night. Our highest resolution, shortest term model, the HRRR, has the heaviest rain tonight between Baytown and Beaumont. The Texas Tech WRF model develops another period of heavy rain west of Houston and progresses it eastward across the city (not as intense or permanent as last night, but still bad). The NAM models tend to like the heaviest rain over the Inner Loop, and the GFS has the heaviest west of Houston. Last night, they all had Houston getting hammered. So tonight’s forecast is a shrug forecast. I’m hoping we’ll gain more clarity with our mid to late afternoon update in a few hours.

Tomorrow

Right now, despite the model disagreements, I would expect a repeat of today’s weather after sunrise on Monday: Rain, heavy at times, with occasional breaks. And a continued isolated tornado threat. More on this later.

Posted at 12:45 PM Sunday by Matt

Mid-morning Sunday Houston area weather update

As of this morning, not much has practically changed, with widespread flooding continuing and heavy rainfall continuing. Please see our previous post for a re-hash of safety information I think everyone has heard to this point.

Now & Today

As of mid-morning, we continue to see waves of rainfall push through the area.

Rain continues this morning. (GR Level 3)

 

Over the course of the afternoon, expect the pace of the rain to perhaps slow down a bit. This isn’t being optimistic…this is actually rooted in some of the weather models. We’ll continue to see widespread flooding problems, but any opportunity to slow added rainfall will help slowly drain a little bit of the water out of the region. Every little bit helps.

The heaviest rainfall today will occur north and east of the city it looks like. We’ll continue with isolated tornadoes.

Tonight & Monday

The nighttimes are when we are most vulnerable. Unfortunately tonight doesn’t look ideal. I don’t necessarily expect a repeat of last night, but even if half of what fell last night occurs tonight, there will be a recurrence and worsening of flooding in spots (perhaps not everywhere, but definitely in parts of the Houston region). Weather models indicate another substantial amount of rain is possible through tomorrow afternoon. Bottom line: You have to plan for another difficult night tonight and day Monday.

Beyond Monday

Harvey’s forecast track remains difficult to perfectly pin down, but a general drift south and east through Tuesday before it finally starts lifting north Wednesday and Thursday.

Forecast track of Harvey shows something of an end in sight. We just have to be patient. (NHC)

 

There may have been rumors circulating about Harvey pushing back out over the Gulf and reforming into a storm or, especially a hurricane. While the storm’s center may reemerge into the Gulf, we feel that significant strengthening is unlikely. For now, there is little need to worry yourself further about storm surge or very strong winds in an already awful situation.

As Harvey lifts north later Wednesday and Thursday, the rain won’t shut off, but it will become more sporadic and manageable. No, it doesn’t help, but we should hopefully begin the long road of recovering. Another update later this afternoon. Be safe.

Posted at 9:55 AM Sunday by Matt

 

Catastrophic flooding event will continue in Houston

Good morning. Heartbroken and sick over some of the news and stories this morning. Thoughts and prayers go out to everyone affected. Unfortunately we need to talk about the weather, as this will continue.

Off the top, we can’t tell you much more than to follow instructions of local government, NWS Houston, and Harris County Flood Control. Stay tuned to a media outlet using radio/TV.

A Civil Emergency Message has been posted regarding folks trapped in their homes.

Via NWS Houston and Jeff Lindner: Residents trying to escape rising floodwaters should go on their roof, do NOT go into the attic. Also if calling 911, stay on the phone until it is answered.

I am directly copying Eric’s words from overnight here:

“Speaking of that, for the first time ever, the National Weather Service just issued what it is calling a “Flash Flood Emergency for Catastrophic Life Threatening Flooding.” And not to sound too flippant, but that sounds really bad. You should probably heed their advice—WHICH IS SIMPLY DO NOT TRAVEL. DO NOT IMPEDE WATER RESCUES IN PROGRESS.

Is that clear enough?

(National Weather Service)

If you home has flooded, then we are truly sorry. No words from us can begin to address that problem. But we can say that millions of people have been through this before, and it can be done. Some good, basic advice, can be found here. And although this handbook from FEMA is dated, it provides detailed steps to take care of yourself, your family, and your property in the aftermath of a flooding event.”

Weather going forward

As of 6:30 AM rains continue to fall heavily, at a rate of 1-3″ per hour in spots.

No words. It continues. (College of DuPage)

 

Over the next 12-18 hours, expect this cycle to continue. Waves of rain, heavy at times. There will probably be breaks. What this does is both limit how bayous can drain and worsens flooding in spots. It’s bad and it’s going to likely stay bad through the day. Some folks may see another 6-12″ of rain today and tonight.

Rain will continue in similar fashion on Monday as Harvey drifts south and then begins to make the turn back north. The setup begins to change a bit on Tuesday, but at this point I still think periods of heavy rain are likely. Harvey should finally move far enough north on Wednesday to not shut off the rain, but reduce it to manageable levels.

In addition to the rain, Tornado Warnings continue cropping up from time to time. This threat will continue through the day today, with hopes that it will be at a slower pace than the last two days.

We’ll have another update around 9 AM or so. Please be safe.

Posted at 6:40 AM Sunday by Matt