Weather conditions are currently quiet across Central and South Texas. A broad ridge of high pressure in the middle and upper atmosphere stretching across the southern US is causing a very typical late August pattern: dry, hot and humid. However, some changes in the pattern are beginning to appear on the horizon that look to bring our region scattered rains and less hot temperatures. These changes are forecast to take place as early as Sunday.
For today and Saturday, mostly sunny and dry weather conditions are forecast across the Hill Country and Central Texas regions. High temperatures both days will generally be in the upper 90s, although a few spots may see readings up to 100-102 degrees. Expect a light southeasterly wind at 5-10 mph. There will be a 40 percent chance for scattered rain showers and isolated thunderstorms across the coastal plains region both days as an area of tropical moisture holds in place over the area. Spotty totals to around a half inch are forecast. High temperatures both days will be in the low 90s.
As mentioned earlier, changes in the pattern are forecast to take place across the entire region beginning Sunday. The area of high pressure over Texas is forecast to shift to the east as a broad trough of low pressure pushes inland out of the Pacific and sets up over the Southwestern US and the southern Rockies. Circulation around the western trough and the ridge of high pressure to our east is expected to steer very moist air off the Gulf of Mexico inland across Texas. This will cause increasing atmospheric moisture levels across the region, leading to a more unstable atmosphere. Meanwhile, weak disturbances moving through the western trough and out of the Gulf of Mexico are forecast to help kick of areas of scattered rain showers and thunderstorms. The probability for rain will range from near 60 percent along the coast to near 30 percent along the Interstate 35 corridor to 20 percent across the Hill Country. Sunday's sky will be partly cloudy. High temperatures will generally be in the mid to upper 90s, with lower 90s expected along the coast.
Scattered rain showers and thunderstorms are forecast across the entire region Labor Day through Friday as considerable moisture continues to spread inland off the Gulf of Mexico. The probability for rain each day will be around 30-40 percent across the Hill Country and Central Texas regions and near 40-50 percent across the coastal plains region. Due to the scattered nature of the rain, none of the days next week are expected to be a total washout. The rain will be the most widespread in the afternoon and evening hours. Light to moderate rain is forecast, but due to the high moisture levels, some tropical downpours will also be possible.
Rain amounts over the next week are forecast to be highest towards the coast, with lower totals expected across the Hill Country. The National Weather Service's 7-day rainfall forecast, for the period from 7 am Friday through 7 am next Friday, calls for totals of 1-2 inches across the coastal plains, between 0.5 and 1 inch for areas along and east of Interstate 35 and between 0.25 and 0.5 inches across the Hill Country.
Due to more clouds and the scattered rain showers , high temperatures next week are forecast to generally be in the middle 90s.
Forecast solutions indicate the weather pattern will remain somewhat unsettled next weekend, continuing into the following week as our region remains under the influence of a very moist flow off the Gulf of Mexico. A slight chance to a chance for rain looks to continue across the region. High temperatures are predicted to remain mostly in the middle to upper 90s. Friday's data does not show the high pressure ridge returning and setting up again across Texas over the next couple of weeks. As a result, temperatures are predicted to stay below 100 degrees.Tropical Weather Update
National Hurricane Center forecasters are monitoring an area of disorganized clouds and showers extending from Hispaniola northeastward to the adjacent Atlantic. These clouds are associated with a tropical wave interacting with an upper-level trough of low pressure. This activity is forecast to spread westward to west-northwestward this weekend into early next week, enhancing the rainfall across portions of Hispaniola, the Bahamas, the Turks and Caicos Islands and Florida. Strong upper-level winds will prevent any development of this system during the next 2 to 3 days, but environmental conditions could become less hostile when the system reaches the eastern Gulf of Mexico during the early to middle part of next week.
We will need to watch this system as it moves westward across the northern Gulf. NHC forecasters are giving this system only a 10 percent chance for development over the next 5 days. RAMMB-CIRA 08/31/18 1:00 pm CDT
Forecasters are also monitoring a strong tropical wave in the far eastern Atlantic which pushed off the coast of Africa Wednesday. Although the system appears to be getting better organized, the system still lacks a well-defined center, and has not quite met the qualifications to be a classified as a tropical depression at this time. The National Hurricane Center is currently referring to this system a Potential Tropical Cyclone. As of 10 am CDT, the disturbance was centered about 135 miles southeast of the southernmost Cabo Verde Islands. The system is moving toward the west-northwest near 13 mph, and this motion with a slight increase in forward speed is expected to continue for the next three to four days. On the forecast track, the disturbance is expected to move near or over the southern Cabo Verde Islands as a tropical storm later today and tonight.
Maximum sustained winds are near 35 mph with higher gusts. Strengthening is forecast during the next several days, and the disturbance is expected to become a tropical storm later today or Saturday. The system is forecast to strengthen into a hurricane in about 5 days. Forecasts call for this system to turn north into the central Atlantic the middle of next week. It should not pose a threat to the Caribbean or the Gulf of Mexico.
NHC forecasters are giving this system a 90 percent chance for tropical development over the next 5 days.Orion and Sirius the Dog Star
In late August and early September, there is a hint of the changing season in the predawn sky: Orion the Hunter and Sirius the Dog Star. The very noticeable constellation Orion the Hunter rises before dawn at this time of year, recognizable for the short straight line of three stars that make up Orion's Belt. And the sky's brightest star Sirius – sometimes called the Dog Star because it's part of the constellation Canis Major the Greater Dog – follows Orion into the sky as the predawn darkness gives way to dawn.
Have you noticed a very bright, madly twinkling star in early morning sky? Many do – around the world – at this time of year. That star is Sirius. It's so bright that, when it's low in the sky, it shines with glints of red and flashes of blue – very noticeable!
Orion and the nearby star Sirius will become visible in the evening by northern winter (or southern summer). But presently the Hunter and the Dog Star lord over the sky at dawn's first light. (Courtesy Earthsky.org)
Have a safe and happy holiday weekend.