Good morning. It’s been a mostly wet week to bring July to a close, and yesterday we saw some much needed rain just to the north of the city of Houston. As a result most of the area has seen 0.5 to 2.0 inches of rain during the last three days, a nice reprieve from what was otherwise a sweltering month. This rather wet interlude may soon draw to a close, however, as drier weather looms.
Fortunately that does not mean we are going to climb back toward the 100-degree temperatures we experienced last weekend. Houston continues to fall between two high pressure systems—one over the western United States and one along the east coast.
Texas lies between two high pressure systems at the moment. (Weather Bell)
As we approach the beginning of August we’re about to begin the most active period of the Atlantic hurricane season. This is because low pressure systems start to move off the African coast and into the eastern Atlantic ocean, into what is known as the “main development region.”
And right on cue, the Atlantic is delivering, with a large low that has developed into a tropical wave just off the coast of Africa. According to the National Hurricane Center this system has a 40 percent chance of becoming a tropical depression or storm during the next five days.
The 1pm CT, Wednesday, advisory from the National Hurricane Center.
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)
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.
