Today ended up being a mostly quiet one again for most of the region, with just a few showers here and there. Rainfall since about 7 AM today has been more than manageable with most areas seeing minor amounts. A couple areas, notably up toward Conroe and south toward Santa Fe and Galveston have seen close to or in excess of an inch of rain since 7 AM today.

So we’ve done alright so far. Heading into tonight, I will level with you: Eric and I are scratching our heads a bit. Yesterday, it appeared we had a pretty favorable setup for heavy rain leading into the nighttime, and yes it materialized, but not in the way we were anticipating until late in the game. Tonight we are presented with a set of data that is different than yesterday but does offer up some risk of heavier rainfall in spots.

Brace yourselves, some serious nerd-speak is coming in this paragraph: I just dug through a lot of the meteorology here, and what I’m coming up with does make me think some areas could see some locally heavy rainfall tonight. For one, we have a weak upper level low over Southeast Texas. Those are notoriously fickle systems, and they can become more active at night. Second, it appears there is some sort of weak boundary at the surface that’s roughly along US-59/I-69 from Victoria through Houston that then arcs to the east toward Beaumont. Boundaries like this can act as focusing points for thunderstorms. Third, model parameters suggest a good bit of instability in the atmosphere tonight. Higher instability means thunderstorms can develop and sustain themselves. Fourth, models suggest plenty of atmospheric moisture is available right now. Observations back this up, as the weather balloon launched at 7 PM from Lake Charles shows precipitable water values in the 90th percentile for this time of year, which means if storms can get going, they can rain heavily. Lastly, it appears that winds about 5,000 feet above the surface are going to increase off the Gulf from south to north tonight, aimed east of Houston. Winds at that level can act to provide additional ingredients and moisture needed for heavy rainfall.

This is a long winded way of saying that the meteorology that’s showing up right now backs up the idea that we could see some heavy rainfall tonight.

The question, as always, is can the ingredients actually come together in such a way to allow this to transpire. I really don’t know. These are fickle, tricky situations, so there’s always a chance a few things don’t happen and you end up with a couple isolated showers and storms and that’s that. But, if things do come together, we could be talking about repetitive showers and storms for some areas.

So, for most of the area tonight, let’s just call it a few showers or a storm possible. Some folks will see nothing. Others some heavy rain for a time. Totals of a quarter inch to an inch.

Put a pin over downtown Houston and if you go south of there and east of there, you stand the chance of seeing perhaps some more sustained rainfall. In those places, I would say your odds of seeing a quarter inch to inch of rain are higher than northwest of Houston. There may also be a few isolated locations that see as much as 2 to 4 inches of rain or a bit more in a worst case scenario. The odds of that happening are not high, but as I laid out above, the ingredients are certainly in place. If I had to focus on an area tonight for the highest risk of this it would be from Baytown to Beaumont.

Anyway, we just wanted to provide some situational awareness for you this evening. Be safe!

Good morning. Houston’s wet pattern will continue through the work week, although the most organized heavy rainfall should wind down over the course of this morning after a storm system pushes through the area. Please take care if you have cause to be out and about this morning before conditions should improve later today.

Wednesday

Moisture continues to move in from the Gulf, combining with an upper-level storm system to bring heavy rains to the metro area on Wednesday morning. The heaviest rains are generally to the south of the city now, and this mess should slowly begin to slide generally eastward, exiting the area entirely by 9 a.m. or 10 a.m. In the meantime, these storms should put a manageable 1 to 3 inches of rain down for most of the metro area—with the heaviest rains coming and lingering near the coast.

Although this will end our Stage 1 flood event, the rain won’t be over. Even as the storm system rotates away from Houston, additional moisture will be pulled inland and more showers will likely develop this afternoon. We’re not sure about this, because the atmosphere should be somewhat stabilized after this morning. In any case, storms this afternoon should be less organized. Highs today will likely only reach the mid-80s with cloud cover and rain.

Thursday

Healthy rain chances continue on Thursday, with a higher likelihood of moderate-to-heavy rain along the coast where moisture levels should be highest. Accumulations should be less than on Wednesday, however. Temperatures should remain in the upper 80s for most with cloudy skies.

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Good afternoon. We’re continuing to monitor the threat of heavy rainfall during the overnight hours as a front sags into the Houston area, and stalls. And at this point, we believe this threat warrants a Stage 1 alert on the Space City Weather Flood Scale. However, we’re following the situation closely, and it may require an upgrade to Stage 2 this evening.

In anticipation of this threat, the National Weather Service has issued a flash flood watch for the entire metro Houston area, in effect from 7 p.m. tonight through 7 a.m. Wednesday morning. In terms of overall accumulations, they are forecasting widespread totals of two to four inches of rain through tomorrow morning, with isolated areas of six to eight inches possible. This is reasonable. However, these kinds of potentially heavy rainfall events, with a slow-moving system and very high levels of atmospheric moisture, are notoriously hard to predict.

At this time we do not have much confidence in where the rains will be heaviest—it could be anywhere from south of the city to the northeast. The good news is that we expect the storms to begin to clear the area by around sunrise, or shortly thereafter. By then the atmosphere will probably be pretty worked over, and we think storm coverage should be less during the daytime on Wednesday.

Good morning. While we anticipated widespread rainfall on Monday, the intensity of the storms that developed over central Houston—in one area near downtown rainfall rates briefly exceeded a rate of 4 inches per hour—was not expected. Overall it’s a good reminder of the potential of heavy rainfall from the kinds of moist air we can see during summertime along the Gulf Coast. The potential for heavy rainfall will continue through Thursday, after which it should slacken some due to the arrival of Saharan dust.

Tuesday

We have all of the ingredients needed for heavy rainfall today, but we think storms will develop a little bit later in the day than on Monday. The first thing we’re watching is a complex of thunderstorms currently near the I-35 corridor that will move east into the Houston region later today. We expect this to weaken. Later this morning, showers should develop offshore, and move inland. And finally, tonight, a weak front will sag into Houston. Sadly this won’t bring any cooling, but it will serve as a focus for additional storm development.

Some models show this front moving slowly, and then hanging up along the coast. This could lead to a scenario where coastal counties pick up a fair amount of rain tonight and into Wednesday morning. Widespread rain totals for today and tonight will probably be about 1 to 3 inches for most of the area, but some isolated areas—most likely between Interstate 69 and the coast—may pick up as much as 5 additional inches of rain.

Wednesday

After whatever mess of storms that develops overnight weakens or moves off by around sunrise on Wednesday, it is possible that any new development later in the day will be more scattered in nature due to a worked-over atmosphere. Mostly cloudy skies should continue to keep temperatures in the upper 80s.

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