Early Monday morning Harvey Forecast Update

Good morning. Since about midnight, while it has continued to rain, totals have been held down a bit. Most of Harris County has seen less than an inch in that time, while a few spots west of Harris County and to the northeast, especially into Chambers and Liberty Counties have seen 1-3″ of rain. No rain helps, but these sorts of rains don’t hurt quite as badly.

Now

Radar this morning is opening up on a mostly positive note for us. Yes, again, more rain in the area, but a better view than 24 hours ago, and much better than some forecast models had indicated even 8-12 hours ago.

Radar as of 6 AM shows the heaviest rains oriented from about Beaumont and Lake Charles northwest to Livingston and Madisonville. (GR Level 3).

Scattered showers persist west of Houston and in other parts of the area.

Monday

Harvey has re-emerged in the Gulf near Matagorda. We, along with the National Hurricane Center, continue to believe that while Harvey will travel over the Gulf the next couple days, only modest re-organization is expected. Eric covered this in detail last night, and I see no reason things have changed much overnight. We don’t want you worrying about that, and everyone’s focus should continue to be on the rainfall forecast and ongoing flooding.

So what about rain today. Radar isn’t too alarming this morning, but we do expect rains to fill back in a bit as the day progresses. This is certainly not what folks want to hear, but I do believe that in most cases, the rainfall *rates* will be manageable enough to limit substantial new problems from occurring. What this will likely do is lead to some rises again on area bayous that have crested and are dropping now. Those that haven’t crested will continue to rise, albeit hopefully at a slower pace, despite new rains.

Tonight & Tuesday

As we go into tonight and tomorrow, expect continued periods of rain. Most of the time, rates should continue to be manageable so that things don’t worsen, but I can’t entirely rule out some heavier rainfall at times until Harvey comes ashore in Louisiana again on Tuesday night or Wednesday morning.

We figured this would be at least a four or five-day event for Houston, with the worst rains front-loaded in the first two or three days. Today begins day three, so we’re past the halfway point, and hopefully past most of the worst of the rains. That’s not to say we don’t have additional problems ahead, but our hope is that we can manage what is to come. We’ll have more for you a bit later this morning.

Posted at 6:20 AM Monday by Matt

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