Tag: rain

Storms to return to Southeast Texas today

Posted by Matt Lanza at 11:10 AM

While we’ve mostly gotten off easy here in Southeast Texas the last couple days, areas to our north and east have been pummeled by storms. The maps below show estimated rainfall for Friday into Saturday and Saturday into this morning.

Rainfall estimates since Friday show Northeast Texas and Louisiana have been clobbered. (NWS)

Rainfall estimates since Friday show Northeast Texas and Louisiana have been clobbered. (NWS)

Areas in Northeast Texas saw tremendous rains Friday night, that unfortunately ended up being tragic in Palestine, TX. Yesterday morning and again this morning, the Lake Charles area was particularly hard hit as well, with totals of 6-8″ over a large area leading to widespread street and highway flooding.

So with all this in mind, today is a new day, and some changes will take place atmospherically that should lead to increasing storm chances. Read More…

Houston’s threat for storms kicks off again today

Posted by Matt Lanza at 6:27 AM

It looks like it’s going to be another one of “those” weekends here in Southeast Texas. We’ll have rain, storms, and potentially flooding to contend with, and all the while, we have a good deal of uncertainty still in the forecast. Here’s a short breakdown. I’ll follow it with an FAQ type section at bottom.

First, just a reminder: A Flash Flood Watch is posted for Houston and primarily the counties north and west of the city starting later today and going into Sunday morning.

TODAY

I don’t foresee a lot of issues this morning…if any at all. By mid-afternoon, storms should have started in Central Texas, along I-35 and points east. These will organize and spread east toward our area by late afternoon or evening. Storms this afternoon and evening will have the potential to be strong to severe. The main threats will be hail and damaging wind, and given how saturated the ground is, any sort of strong winds can be more problematic than usual. The tornado threat is low, though it isn’t zero (and as we sadly saw in Tomball the other morning, it doesn’t need to be a high risk or a strong tornado to be tragic, so please heed any warnings if issued). Obviously, our main focus will be flooding.

Simulated forecast radar for today. Storms fire along I-35 this afternoon & move toward Houston this evening. (Weather Bell)

Simulated forecast radar for today. Storms fire along I-35 this afternoon & move toward Houston this evening. (Weather Bell)

TONIGHT

This is where confidence drops and our risks for flooding begin to go up. I expect we will see repeated rounds of showers and thunderstorms around the region. It’s still a bit difficult to say exactly who will see the most persistent storms, but anywhere in the area around Houston (north, west, or even south of the city) stands the potential to see this happen. It’s simply too tough to say where with any specificity. We will update you on this again later today. But the Friday night timeframe is the one we’re most concerned with, namely because we’ll have a substantial amount of atmospheric moisture to work with.

GFS Precipitable Water (PWAT) forecast this evening shows summer-like levels of available moisture. (Weather Bell)

GFS Precipitable Water (PWAT) forecast this evening shows summer-like levels of available moisture. (Weather Bell)

Usually once you get over 2″, you’re talking considerable moisture, which means that any thunderstorms can produce torrential rain. The concern is that a boundary of storms could sit over one area and tap into this moisture. Hopefully this isn’t what occurs, but it’s something we have to watch.

Read More…

The National Weather Service said this afternoon that a Flash Flood Watch will go into effect for much of Metro Houston (basically along and north/west of US-59/I-69) beginning Friday afternoon and continuing through Sunday morning. This includes the areas hardest hit by last week’s flooding.

Counties under the Flash Flood Watch Friday-Sunday (Iowa State/NWS)

Counties under the Flash Flood Watch Friday-Sunday (Iowa State/NWS)

 

As Eric pointed out this morning, there’s good reason for this. Most bayous in the city (Buffalo Bayou an exception) are back at their baseline levels. But, outside the city, streams, creeks, and bayous are running a few feet higher than normal still. And with a soggy ground any additional rain is unwelcome and can cause flooding concerns depending on how quickly it falls.

Basically, at this point all you need to do is continue to watch the forecast. There’s a bit less certainty with this event than there was last week. Also, it can’t be underscored enough that the rain totals implied by all models with this event aren’t anything like the last one. We want you to be prepared but not to panic here. We still don’t know exactly where the heaviest rain will fall, but we know there will be a few spots that see a pretty substantial amount of rain (not 15-20″ like last week, but 4-8″ in a few spots isn’t impossible).

So just stay tuned in through the weekend, especially if you have to travel around the area or live in an especially flood prone spot. We will have you covered. Read More…

Note: This is the first in a series of reports by Matt Lanza that puts the Tax Day floods into perspective, and discusses what Houston should learn from this natural disaster.

On Monday afternoon the Harris County Flood Control District released its first official summary of the historic flooding that occurred last week in the greater region. I’ve read through it and compiled some highlights for here. (You can also view the report yourself in its entirety here). A serious thank you to Jeff Lindner at the flood control district who has worked tirelessly since last week to provide critical, useful, and interesting information to put this event into context and keep the region informed. He is also a must-follow on Twitter if you’re into weather, haven’t done so yet.

Report highlights

  • Rainfall rates of 1″ in just 5 minutes were observed in Harris County. The maximum hourly rate was 4.7″. The maximum amount in 12 hours was 16.7″
  • Harris County averaged 7.75″ of rainfall for the event. That’s equivalent to 240 billion gallons of water falling on the area. This exceeded Memorial Day (162 billion gallons) by almost 80 billion gallons of water. That event was more confined, whereas the Tax Day rains were much larger spatially.
Map of 12 hour rainfall totals and location/flooding description of significant waterways. (HCFCD)

Map of 12 hour rainfall totals. Click to enlarge. (HCFCD)

Read More…