Expect an Increasing Chance for Rain this Week. Temperatures Trending Just Slightly Cooler. - LCRA Expect an Increasing Chance for Rain this Week. Temperatures Trending Just Slightly Cooler. - LCRA


A mostly cloudy, wet and unsettled weather pattern is beginning to take shape across Central and South Texas, and this pattern is forecast to persist through late week and possibly the upcoming weekend.  This week’s big weather maker involves an unusually strong trough of low pressure in the upper atmosphere that is diving south across central Rockies.  It’s this trough that is expected to bring Denver and much of Colorado an early taste of winter today through Thursday.  The trough is forecast reach the Four Corners region tonight and stall over the Southwest Wednesday and Thursday.  The trough is then forecast to lift northeast into the Plains state Friday into the weekend.  Today through Friday, small waves of low pressure rotating around the main trough are forecast to move across Texas, causing periods of rain and thunderstorms, with the western half of Texas expected to see the best chance for rain.  The first of these waves of low pressure is lifting north across our region today, causing mostly light rain showers and scattered thunderstorms.  Heavier rains have developed toward the coast.

Another important factor in this week’s weather picture will be a cold front connected to the Southwestern trough.  Forecasts from late last week called for the front to blast through Texas this week, bringing an early taste of fall.  But subsequent forecasts now indicate the front is going to have a much tougher time making it through the state.  As of late Tuesday morning, the cold front stretched from southeastern Kansas to the northern Texas Panhandle, to north central New Mexico.  Forecasts call for the cold front to reach Northwest Texas and the Big Bend regions Wednesday morning, with the front sliding southeast across the Hill Country Wednesday afternoon and Wednesday evening.  The front is expected to push east of Interstate 35 on Thursday where it will pull up stationary.  It will be important to note the position of the front as it is expected to become the focus for concentrated areas of rain showers and thunderstorms.

For this afternoon and tonight, there will be a 50 percent chance for scattered rain showers and thunderstorms across all of the region.  Totals through 7 am Wednesday are forecast to average around a half inch, with isolated totals 1-2 inches possible.  Today’s sky will be mostly cloudy.  The temperature will warm to around 88-90 degrees.  Lows Wednesday morning will include the upper 60s to low 70s across the Hill Country, with mid-70s expected at most other locations.

For Wednesday and Wednesday night, a widespread coverage of rain showers and thunderstorms is forecast across the Hill Country beginning early in the morning.  Additional showers and storms will continue Wednesday afternoon into Wednesday night.  Across Central Texas, showers and thunderstorms will increase in coverage late in the morning and continue through the afternoon and Wednesday night.  Across the coastal plains regions, there will be a 50 percent chance for rain showers and thunderstorms Wednesday afternoon, decreasing to 30 percent Wednesday night.  Rain amounts Wednesday morning through Thursday morning are forecast to average between 1 and 2 inches across the Hill Country and around 1 inch along the Interstate 35 corridor.  For locations east of I-35, totals should average around a half inch.

High temperatures Wednesday will include the low 70s across the western and northern Hill Country, the upper 70s across the eastern Hill Country, the mid-80s across Central Texas and be close to 90 degrees across the coastal plains.  Lows Thursday morning will be near 58-60 degrees across the Hill Country, the mid-60s across Central Texas and the low 70s towards the coast.

For Thursday and Thursday, there will be a 70 percent chance for additional showers and thunderstorms across the Hill Country and Central Texas regions and a 50 percent chance for rain across the coastal plains.  Totals are not expected to be quite as heavy, with most amounts around a half inch, with isolated heavier totals.  High temperatures Thursday will include the mid-70s across the Hill Country and most of Central Texas but will still be near 90 degrees towards the coast.  Lows Friday morning will include the low 60s Hill Country, the mid-60s Central Texas and the low 70s towards the coast.

NWS Rainfall Forecast for the Period 7 am Tuesday through 7 am Friday:

For Friday through Sunday, expect a partly to mostly cloudy sky along with a 30-40 percent chance for mainly afternoon scattered showers and thunderstorms.  Although the upper trough will be exiting to the northeast, a very moist and moderately unstable atmosphere is expected to continue across our region.  Totals each day are forecast to average around a quarter inch, with isolated heavier totals.  High temperatures are forecast to be in the mid and upper 80s across the Hill Country and Central Texas regions and in the lower 90s towards the coast.

Looking ahead to next week, no significant changes are expected as our region comes under the influence of a weak ridge of high pressure out of the southeastern U.S.  There will be a slight chance for scattered showers and thunderstorms each afternoon, but significant rain is not expected.  Temperatures should remain warm, but not excessively hot, with high temperatures generally around 88-90 degrees and low temperatures in the low and mid-70s.

Tropical Weather Outlook

Weather conditions across the Gulf of Mexico and the Caribbean Sea are currently quite, with no systems of interest at this time.

Two new tropical storms developed over the central and eastern tropical Atlantic Sunday into Monday.  Tropical Storm Paulette is located about 1295 miles east of the northern Leeward Islands, with top winds of 65 mph.  Paulette could become a hurricane tonight.  Paulette is moving to the northwest in the direction of Bermuda and poses little threat to the Gulf of Mexico.

Tropical Storm Rene is located in the far eastern tropical Atlantic and is bringing tropical storm force winds and heavy rain to the western Cabo Verde Islands.  Top winds are currently 40 mph but is forecast to strengthen into a hurricane in a couple of days.  Rene is forecast to turn north over the open Atlantic and appears to pose no threat to the Gulf of Mexico.

National Hurricane Center forecasters are monitoring a strong tropical wave that is forecast to emerge off the west coast of Africa by Thursday.  Gradual development is expected once the system moves over water, and a tropical depression is likely to form late this week or over the weekend while the system moves generally westward across the eastern tropical Atlantic.  Given this tropical wave is moving into the Atlantic at a lower-latitude position compared to Paulette and Rene, this next new tropical wave may eventually become a greater threat to the Caribbean sometime next week.  NHC forecasters are giving this system a 70 percent for tropical development over the next 5 days.


NOAA/NESDIS-GOES 16 09/08/2020  11:05 am CDT

Tropical Storm Rene has broken the record for the earliest-forming “R” storm in the Atlantic hurricane season.  This record was previously held by Hurricane Rita on September 18, 2005.

Only four more names remain on the 2020 Atlantic list: Sally, Teddy, Vicky, and Wilfred.

Bob