A somewhat wet weekend has come and gone in Houston. Parts of the city, such as the area between Memorial City and Katy, received almost no rain, whereas separate locations near Alvin and Bush Intercontinental Airport received up to 3 inches. The sunshine on Sunday afternoon felt pretty nice.

For this week, we can expect some more wet weather—although frankly, the scattered reports I’ve seen of a “tropical wave” or other language to suggest a serious flooding threat is headed this way are significantly overstated—before drying conditions later in the week. See below for a full outlook for the July 4th holiday.

Monday

Conditions today should be fairly mild for the first day of July, with highs of around 90 degrees and partly to mostly sunny skies. With daytime heating we may see some isolated showers and thunderstorms pop up later this afternoon, but coverage probably will only be in the 10 to 20 percent range. Lows tonight should get into the mid-70s.

Tuesday and Wednesday

The region will fall under the influence of a more moist air mass from the Gulf of Mexico, and this will lead to increased rain chances for Tuesday, Tuesday night, and most of the day Wednesday. Right now there doesn’t appear to be too much to drive organization of these storms, and models indicate most of the area will see 0.25 to 1.0 inch of rain, with a few bullseyes of heavier rain where 1 to 3 inches may fall fairly quickly given the tropical nature of the moisture. These will be partly to mostly cloudy days, and the intermittent rain showers should limit highs to the upper 80s for most areas.

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Well, so much for the high pressure that was supposed to tamp down on rain activity Thursday. Despite the influence of a ridge to the west of the region, some pretty strong showers still popped up over Houston, dropping as much as 1.5 inches near the Waller-Harris County line Thursday. I think we’ll be in for a similar pattern this weekend in which perhaps only 30 to 40 percent of the Houston area receives rainfall in any given day, but those areas that do see showers could experience some briefly heavy rainfall. Welcome to the game of rainfall roulette.

Friday

Mostly sunny skies this morning should allow temperatures to push up into the low- or even mid-90s by early this afternoon, and this will be warm enough to help generate some scattered showers and thunderstorms.

High resolution modeling suggests these storms will initiate around 2pm or 3pm and then wane by or before sunset with the loss of this daytime heating. Rainfall could be briefly heavy under some of these storms, potentially making something of a mess during the evening commute. However, we don’t have any flooding concerns beyond the usual mess on streets. Lows Friday night should fall into the mid-70s.

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It has been a wet week for much of coastal Texas, with the combination of moist air moving inland, and the absence of high pressure to keep rainfall at bay. The Valley was hit especially hard, with areas near Harlingen and McAllen receiving in excess of 10 inches and experiencing some pretty significant flooding. Closer to home, parts of the coastal Houston region saw 3 to 5 inches of rainfall. We’ll now mostly dry out for a few days before the potential for some heavier rain returns early next week.

Thursday

Today should see the return of mostly sunny skies to Houston, although we can’t entirely rule out the possibility of a few isolated, pop-up storms. But for the most part, we’re just going to see a warm, June summer day with highs in the low 90s and moderate southerly winds. Overnight temperatures may lower into the mid-70s—if you’re lucky, and live far enough away from the coast.

Friday

This should be a similar day to Thursday, although we’ll probably see rain chances on the order of 10 to 20 percent, again in the form of some pop-up showers. Otherwise, expect mostly sunny skies with highs in the low- to mid-90s.

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If you missed it, Eric and I have decided to start doing tropical updates for you every week or two through hurricane season. We had our first one last week, which was rather detailed. This week, we’ll be a little more succinct!

Tropical outlook in a sentence

The Atlantic basin continues to be void of much interesting tropical activity, and it will likely continue that way for the next week to 10 days.

Near-term summary

Dust, dust, dust. And shear. Those two things are characterizing the Atlantic basin today. Dust from the Sahara Desert continues to roar across the Atlantic. This tends to be a fairly common feature in the early parts of hurricane season. We’ve noticed it a lot more in recent years, and I’m not sure if that’s because of some functional change or just because our observational capabilities have gotten so much more sophisticated. Either way, the last few years have seen a lot of Saharan dust in the basin in June and July.

From the satellite image above, you can see where dust (yellow/orange/red) is located, as well as cloud cover (gray). Virtually the entire Atlantic basin is littered with Saharan dust right now. This includes the Gulf of Mexico. Some of that thicker dust is likely to appear in Houston’s skies in the days ahead.

Why does this matter? Well, Saharan dust is extremely important globally. It’s a major source of nutrients for phytoplankton, and it helps to fertilize the Amazon. It obviously doesn’t come without problems, as the dust can irritate those who have sensitive respiratory systems, allergies, or asthma. It reduces air quality, and we may well see that here in Houston for late this week.

But from a tropical point of view, Saharan dust can help hinder systems from developing. The dust is indicative of dry air in the atmosphere. Obviously, hurricanes need moist air. Think about our weather here in Houston. On days with a “cap” in the atmosphere, there’s a barrier that exists preventing or limiting how high cloud tops can go. That reduces our thunderstorm chances. The Saharan air layer can act as a “cap” as well, preventing storms from billowing up. It doesn’t entirely prevent tropical storms or hurricanes from developing, but it can severely limit how well developed they can become. So curse the dust when it irritates your sinuses, but thank it for helping to keep the early part of tropical season under wraps.

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