Month: July 2016

The last 48 hours have brought some welcome change to Houston’s hot and (mostly) rain free summer as Gulf of Mexico moisture has surged into the region amid a weakness in high pressure. Those conditions will more or less remain the same today, with one key difference.

So far the heaviest rains have been more clustered over the southern half of the metro area, in places like Fort Bend, Galveston and southern Harris counties. Although we’re likely to see some coastal rains again today, there’s a better chance of development further inland later this afternoon.

Accumulated rainfall for Houston from 5am Monday through 5am Wednesday. (NOAA)

Accumulated rainfall for Houston from 5am Monday through 5am Wednesday. (NOAA)

Read More…

Good morning. After a wet Monday brought as much as 3 inches of rain to some of the Houston metro area (see map below), it looks like we’re in for part two today, with lowering rain chances through the rest of the week.

Rain accumulations across the Houston area on Monday. (National Weather Service)

 

The upshot of this is that the region could really use the rain after a very dry month of July.

Today

As of 6:15am CT rain showers have spread over most of the western metro area, south of Interstate 10. Northwestern Fort Bend County is already under a flood advisory for minor street flooding due to these rains, and there may be some delays along low-lying roads.

It looks like the greatest amount of moisture today will be closer to the coast, leading to greater rain chances for those areas, and less further inland, for Montgomery County and to the northwest of Houston. Additionally there is enough moisture to produce some locally heavy rainfall, although I am not expecting any significant problems. Overall I am expecting a day similar to Monday—with some areas receiving 2-3 inches of rain, and other areas getting perhaps a tenth of an inch. On Monday the rains didn’t start until later in the day so high temperatures still had a chance to rise into the upper 90s for most areas. Today, with earlier rains, I expect highs to remain confined to the low 90s.

Click to enlarge. This image shows precipitable water value forecasts for today, Wednesday and Thursday. Note the decline in available moisture for rainfall.

Click to enlarge. This image shows precipitable water value forecasts for today, Wednesday and Thursday. Note the decline in available moisture for rainfall.

Read More…

After two consecutive 100-degree days are you ready for a bit of a reprieve? I thought so. And fortunately, cooler and especially wetter weather is at hand. Change is coming.

Today and Tuesday

Much of the area is likely to see rain showers today, Tuesday—or both. We’re seeing increased atmospheric moisture levels in combination with some lower pressure that should lead to much-needed rain. The most likely time for showers is after about 1pm through the late afternoon hours.

wpc_total_precip_tx_13

NOAA rain accumulation forecast for now through Wednesday. (Weather Bell)

Although with these moisture levels we can’t rule out some locally heavy rainfall, with rates of 2-3 inches per hour, conditions aren’t going to be ideal for these kinds of deluges. As a guess I’d say most of the area will receive about 1 inch of rain, plus or minus, over the next two days. High temperatures, accordingly, should only rise into the low 90s.

Read More…

I’m back—and I bring some good news. First of all I want to thank Matt for holding down the fort while I grabbed some vacation. It was nice to unplug for awhile. But now I’ve returned, and I’ve come with much more promising rain chances and relief from the heat.

Yes, some areas of Houston received a very good dousing last week, particularly central Houston. But most of the area has seen 1.0 inch of rain or less during the month of July, at a time when temperatures have consistently been in the mid- to upper-90s. (This leads to a very high pan evaporation rate, meaning soils dry out very quickly). So some rain is welcome, both for our trees and green spaces, but also to moderate daytime temperatures. And some is coming.

This weekend

The sprawling high pressure system that’s been anchored over the south-central United States, including much of Texas, is moving off to the west. But there’s likely going to be a modest capping inversion today and Sunday, and moisture levels aren’t the highest, so I think we’re only going to see some scattered rain showers this weekend, primarily during the afternoon hours. Rain chances are best to the east of Interstate 45. Lacking widespread rain, most areas will likely see highs in the mid-90s.

Monday and Tuesday

By Monday we’re likely to see atmospheric moisture levels climb above 2.3 inches of precipitable water—which is very good for rain chances.

Precipitable water levels  are likely to surge on Monday and Monday evening in Houston. (Weather Bell)

Precipitable water levels are likely to surge on Monday and Monday evening in Houston. (Weather Bell)

 

This, along with some low pressure moving into the area from the Gulf of Mexico should be enough to bring some fairly widespread rain showers into the metro area. I think much of Houston can probably hope for 0.5 to 1.0 inch of rain, and there’s the potential for heavier, more localized rain showers. Clouds and intermittent rain should hold high temperatures for both of these days to the low 90s, if not 90 degrees.

Wednesday and beyond

Pressures appear to rise beginning Wednesday, but it doesn’t look as though we’re going to see dominant high pressure. This should hopefully keep daytime temperatures in the low 90s, with at least some scattered rain showers most days.

Posted by Eric on Saturday at 6:55am CT

Yesterday was a bonafide scorcher for Houston, with another 98° day. Really, it was a scorcher almost everywhere in the Eastern and Central U.S. We’re squished under a heat dome here in Texas. Fortunately for us, the heat dome will begin to break down, or at least move around enough this weekend to open the Gulf back up a bit for some showers. It’s going to be hot, but hopefully some of us see a little relief at least.

WEEKEND

Rain chances will still be on the lower side today, with most activity likely south or east of Houston (most, but not exactly all). The majority of the area should stay dry and hot and humid, but rain chances aren’t quite zero. As we go into Saturday and Sunday, a surge of precipitable water, not too uncommon for this time of year, will come our way from the south and east.

The forecast for precipitable water lurches upward this weekend, increasing our chances for daytime storms. (Weather Bell)

The forecast for precipitable water lurches upward this weekend, increasing our chances for daytime storms. (Weather Bell)

This sets the stage for more “juice” available to fuel daytime storms. So I think coverage of thunderstorms on both weekend days will be more than we see today. Think about what happened on Sunday, Monday, and Tuesday of this past week, and I think that’s a reasonable analog case to what we see this weekend: A scattering of storms that dumps on a few folks, but leaves others high and dry.

Read More…