A Persistent August Heat Wave Taking Shape - LCRA A Persistent August Heat Wave Taking Shape - LCRA


There will be a slight chance for scattered thunderstorms this afternoon and Tuesday before a dry and hot weather pattern settles in for spell.  Monday’s weather maps showed an unusually strong trough of low pressure in the upper atmosphere stretching from southeastern Canada to southern Louisiana.  The familiar ridge of high pressures was located over the Desert Southwest.  The maps showed a small wave of low pressure in the upper atmosphere located over the Permian Basin region of West Texas that is moving to the southeast.  This system has helped produce an area of showers and thunderstorms over the area between Del Rio, San Angelo and Abilene Monday morning.  High–resolution forecasts solutions call for this area of rain and thunderstorms to spread southeast across the Hill Country this afternoon, with the activity reaching the Austin/Interstate 35 corridor in the late afternoon and early evening.  The probability for rain will be near 40 percent across the Hill Country and near 30 percent across the Austin/Central Texas region.  While most of today’s thunderstorms are forecast to remain below severe threshold, a couple of the storms may produce strong and potentially damaging winds.  Most, if not all of this activity is forecast to diminish after sunset.  For locations that happen to see rain, totals should average between 0.25 and 0.5 inches, with isolated totals of 1-2 inches possible.  Across the coastal plains region, there will be a slight chance for isolated to scattered rain showers and thunderstorms across the area this afternoon and early evening.  Spotty totals to quarter inch will be possible.  High temperatures this afternoon will include the mid to upper 90s across the Hill Country, the upper 90s to low 100s across Central Texas and the mid-90s towards the coast.

The outlook for Tuesday calls for a generally sunny and hot day.  However, a few isolated afternoon showers and thunderstorms will be possible across the region due to lingering moisture and instability.  The chance for rain at any given location will only be 20 percent.  Temperatures will be quite hot with readings reaching near 100-102 degrees across the Hill Country and Central Texas regions and the middle 90s across the coastal plains.

Sunny, dry and hot weather conditions are forecast Wednesday, continuing through the upcoming weekend as the ridge of high pressure over the Desert Southwest slowly spreads east over Texas. In fact, the center of the high pressure ridge is forecast to set up over Northwest Texas this weekend.  With the high pressure ridge in place, it is going to be quite hot!  Daily high temperatures across the Hill Country and Central Texas regions are forecast to be near 100-103 degrees.

The outlook for next week calls for more of the same as Texas remains under the grips of the broad, stagnant high-pressure ridge.  High temperatures are predicted to be near 101-103 degrees across the Hill Country and Central Texas regions and in the mid to upper 90s across the coastal plains region.

Long-range forecasts indicate the ridge may shift a little more to the west the weekend of August 15th.  This might allow an area of moisture to spread inland, causing some isolated to scattered rain showers across the coastal plains region and possibly as far inland as Interstate 35.  High temperatures look to drop about 2-3 degrees at that time.

Tropical Weather Update

…Isaias is expected to make landfall tonight as a hurricane along the Carolina coast.  Strong winds and heavy rainfall is likely from the eastern Carolinas to the Mid Atlantic coast tonight and Tuesday…

At 100 pm CDT, the center of Tropical Storm Isaias was located by an Air Force Reserve reconnaissance aircraft and NOAA Doppler weather radars about 115 miles south of near Charleston, South Carolina.  Isaias was moving toward the north near 13 mph, and this general motion is expected to continue this afternoon.  A turn toward the north-northeast along with a slight increase in forward speed is expected by early this evening, followed by a faster motion tonight and Tuesday.  On the forecast track, the center of Isaias will pass well east of the Georgia coast through this afternoon.   The center of Isaias will then approach the coasts of northeastern South Carolina and southern North Carolina within the hurricane warning area this evening.  The center will then move inland over eastern North Carolina tonight, and move along the coast of the mid-Atlantic states on Tuesday and into the northeastern United States Tuesday night.


RAMMB-CIRA 08-03-2020 2:20 pm CDT

Data from the reconnaissance aircraft and NOAA Doppler weather radars indicate that maximum sustained winds remain near 70 mph with higher gusts.  Some strengthening is forecast this afternoon or early evening, and Isaias is expected to regain hurricane strength just before the cyclone reaches the coast of northeastern South Carolina or southern North Carolina tonight.  Only slow weakening is anticipated after Isaias makes landfall in the Carolinas and moves across the U.S. mid-Atlantic region tonight and Tuesday.

National Hurricane Center forecasters are also closely watching the area a few hundred miles south of Bermuda where a  surface trough of low pressure is producing disorganized showers and thunderstorms.  Marginal environmental conditions could allow for some slow development of this system during the next few days, with a tropical depression possibly forming later this week.  This system is forecast to move northwestward at about 15 mph over the southwestern Atlantic today and Tuesday, then stall several hundred miles southwest of Bermuda by the middle to latter part of the week.

NHC forecasters are giving this system a 60 percent chance for development over the next 5 days.

July Climate Wrap Up

Data shows the month of July was much warmer and drier than normal across the Hill Country and Central Texas regions.  Temperatures generally averaged 2-4 degrees above normal and rainfall average 1-2 inches below normal.  Rainfall was above normal across Matagorda and southern Wharton Counties due to Hurricane Hanna.  Rainfall was also above normal across Schleicher and Sutton Counties in the western Edwards Plateau.

In Austin, Camp Mabry recorded an average monthly temperature of 88.9 degrees, which was 3.9 degrees above normal.  The average high temperature for the month was 100.3 degrees!  July 2020 ranks as the 3rd hottest July on record behind 2009 and 2011.  Rainfall measured 0.65 inches, which was 1.23 inches below normal.  July 2020 ranks as the 37th driest July on record.

Austin-Bergstrom recorded an average monthly temperature of 86.5 degrees, which was 3.1 degrees above normal.  The average high temperature for the month was 97.6 degrees.  July 2020 ranks as the 13th warmest July on record.  Rainfall totaled 1.18 inches, which was 1.26 inches below normal.

Wednesday, August 5th marks the midpoint of astronomical summer.

Spot the International Space Station Each Evening this Week

There will be opportunities to see the International Space Station each evening this week.  Wednesday looks to a particularly good pass around 9:15 pm when the ISS will be traveling high above the horizon.  Find out the times and directions to look for your particular location at  https://spotthestation.nasa.gov

Bob