Bob Rose on the weather | LCRA Bob Rose on the weather | LCRA


Forecast for Central Texas

Thursday Thu Friday Fri Saturday Sat Sunday Sun Monday Mon
106 °F / 78 °F106 °F / 78 °F106 °F / 78 °F106 °F / 78 °F101 °F / 77 °F
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Sunny, Very Hot!!!Sunny, Very Hot!!!Sunny, Very Hot!!!Sunny, Very Hot!!!20% Chance Rain and T-Storms
Updated August 14, 2020

Rainfall summary
Temperature summary
Humidity summary

Bob's Blog on Central Texas Weather

Thursday, August 13, 2020 4:31 PM

In a discussion released Thursday, forecasters at NOAA’s Climate Prediction Center indicate the odds for the development of La Niña this fall have increased to approximately 60 percent.

CPC forecasters noted that during August, sea surface temperatures (SSTs) in the equatorial Pacific, from the Date Line to the west coast of South America, were observed to be below average.  The four Niño indices were negative during the latest week, with the Niño-3.4 and Niño-3 indices at -0.6°C.

In addition to cooler than normal surface waters, water temperatures below the surface in this same region which had warmed some during June and early July, began cooling again in mid-July.  In early August, below-average subsurface temperatures re-emerged in the east-central equatorial Pacific.  Observations during July showed low-level wind anomalies were easterly across most of the equatorial Pacific while upper-level wind anomalies were westerly over portions of the far western, central, and eastern Pacific.  Tropical convection was suppressed over the western and central Pacific, and was near average over Indonesia. Putting all of these factors together, the combined oceanic and atmospheric system remains consistent with ENSO-neutral.  (Neither El Niño nor La Niña).

CPC forecasters noted the latest long-range climate models are split between La Niña and continued ENSO-neutral conditions (Nino-3.4 index between -0.5°C and +0.5°C) for the fall and winter.  However, the models slightly favor La Niña from the August-October through the November-January seasons.  Based largely on dynamical forecast model guidance, the forecaster consensus favors La Niña development during the August-October season, lasting through winter 2020-21.

In summary, the Climate Prediction Center is calling for a ~60% chance of La Niña development during Northern Hemisphere fall 2020 and a ~55% chance for La Niña to continue through winter 2020-2021.

La Niña Nina’s typically bring a drier than-normal and milder than-normal weather pattern to much of Texas during the fall and winter months.  The latest Climate Prediction Center rainfall outlook for this fall and winter calls for increased odds rainfall will average below normal through both seasons.

Stay tuned for additional updates.

Bob

 

Previous Blog Entries

Tropical Storm Josephine Develops in the Western Tropical Atlantic.

Thursday, August 13, 2020 10:17 AM

Tropical Depression Eleven strengthened into Tropical Storm Josephine Thursday morning.  A weather satellite utilizing a type of radar to measure wind speed and direction around Josephine showed an area of 35-40 knot winds about 70 nautical miles to the north of the center of the Depression.  Based on this new data, the cyclone was upgraded to Tropical Storm Josephine, with an initial intensity of 45 mph.


RAMMB-CIRA 08/13/2020 10:00 am CDT

At of 10 am CDT Thursday, the center of Tropical Storm Josephine was centered about 975 miles east-southeast of the northern Leeward Islands.  Josephine was moving toward the west-northwest near 15 mph, and this general motion is expected to continue for the next few days, followed by a turn toward the northwest late this weekend or early next week.  Recent satellite wind data indicated that maximum sustained winds have increased to near 45 mph along with some higher gusts.

Some additional strengthening is forecast during the next 48 hours as Josephine moves through an environment of light vertical wind shear.  After that, however, the cyclone is expected to encounter moderate to strong southwesterly wind shear as it approaches an upper-level trough over the southwestern Atlantic.  The increased shear is expected to cause some weakening.  In fact, National Hurricane Center forecasts call for Josephine to weaken to a tropical depression by Monday.

Josephine is forecast to track to a position just east of the Bahamas early next week.  Josephine poses no threat to the Texas Gulf coast or the Gulf of Mexico.

Josephine is the earliest tenth tropical storm of record in the Atlantic, with the next earliest tenth storm being Tropical Storm Jose on August 22, 2005.

Bob

Tropical Depression Eleven Develops in the Central Tropical Atlantic.

Tuesday, August 11, 2020 3:31 PM

Visible satellite imagery has shown that the area of low pressure being monitoring over the tropical Atlantic has developed a less-elongated circulation with a well-defined center.  For the most part, deep convection has persisted with the system since about this time yesterday, save a brief period of warming cloud tops this morning.  According to the National Hurricane Center (NHC), the low now meets the criteria of a tropical cyclone, and the NHC is now issuing advisories on Tropical Depression Eleven.

As of 5:00 pm CDT, the e center of Tropical Depression Eleven was located about 1450 miles east of the Lesser Antilles.  The depression is moving toward the west near 16 mph and this general motion is expected to continue through Wednesday.  A west-northwestward motion at a similar forward speed is forecast to begin Wednesday night and continue through the rest of the week.

Maximum sustained winds are near 35 mph with higher gusts.  Some strengthening is forecast during the next 48 hours, and the depression is expected to become a tropical storm by Wednesday night.

NHC forecasters point out that by Sunday and Monday, westerly or southwesterly wind shear is forecast to develop and increase to around 20-30 knots, which is likely to induce significant weakening.  Conditions may become hostile enough such that the global models are showing the system opening up into a trough near the northern Leeward Islands by Sunday, which is a plausible scenario.

Bob

Monitoring a Strong Tropical Wave in the Central Tropical Atlantic.

Tuesday, August 11, 2020 2:18 PM

National Hurricane Center (NHC) forecasters continue to closely monitor a strong tropical wave and low pressure system located in the central tropical Atlantic, more than a thousand miles east of the Lesser Antilles.


RAMMB-CIRA 08/11/2020 12:50 pm CDT

Although shower and thunderstorm activity decreased somewhat Tuesday morning, new activity was forming near the system’s center of circulation Tuesday afternoon.  According to the NHC, if these storms persist, advisories will be initiated on a tropical depression Tuesday evening or Tuesday night.  Even if a depression does not form by Tuesday night,  a tropical depression is forecast to develop over the next couple of days as the system moves into a favorable environment.  The low pressure system is moving to the west-northwest at around 15 mph and this motion is expected to continue for the next couple of days.  NHC forecasters are giving this system a 90 percent chance for tropical development over the next 48 hours and the next 5 days.

Environmental conditions are expected to become less conducive for tropical development by the end of the week when the system approaches the northern Leeward Islands.  Stay tuned for further updates.  The next name of the list of tropical storms and hurricanes for this year will be Josephine.

Bob

 

Little Day-to-Day Change in the Weather Expected through Late Week.

Monday, August 10, 2020 4:14 PM

The August doldrums are definitely upon us.  A stagnant ridge of high pressure in the middle and upper atmosphere continues to produce a very persistent pattern of sizzling hot and dry weather.  Unfortunately, this pattern is showing no signs of breaking down anytime soon, so get ready for more of the same.  In the longer-term outlook, the high pressure ridge is predicted to shift more to the west next week and this should have a moderating effect on the streak of triple-digit temperatures.  While a few showers may enter the forecast next week, no widespread rain is expected anytime soon.

Monday’s weather maps showed a broad, stable ridge of high pressure covering Texas and the southern U.S.  The ridge was centered over southern Louisiana, with another center located across northern Mexico, to the south of El Paso.  Forecasts call for the ridge of high pressure to remain over our region throughout the week and the upcoming weekend as the ridge center near El Paso becomes the dominant feature.  For the Hill Country and Central Texas regions, this means more of the same.  Sunny, hot and dry weather will be in place all week and through the weekend.  High temperatures look to be very consistent near 100-103 degrees.

Fortunately, a moderate pressure gradient is causing breezy south winds across much of the state.  South winds at 10-15 are forecast to continue through late.

Across the coastal plains region, there will be a 20-30 percent chance for spotty rain showers and isolated thunderstorms each day through Sunday as the Sea Breeze fights off the ridge and pushes north from the coast.  The spotty shows are forecast to extend as far inland to just north of Interstate 10.  For locations that happen to see rain, amounts are forecast to average between a quarter and a half inch.  Overall, weather conditions will be partly cloudy and hot with daily high temperatures in the middle 90s.

The outlook for next week calls for a few minor changes in the hot and dry pattern.  Forecasts call for the center of the high pressure ridge to migrate to or just west of the Four Corners region.  The ridge over Texas is predicted to weaken slightly and this will allow Gulf moisture to spread from the coast north into Central Texas and the Hill Country.  A few spotty afternoon showers will be possible across the region throughout the week.  Rain amounts, if any, should average less than a quarter inch.  In addition, high temperatures next week are predicted to lower a couple of degrees to near 98-100 degrees.

Across the coastal plains region, there will be a 30-40 percent chance for scattered rain showers and isolated thunderstorms each day as moisture levels slowly increase.  Spotty totals of 0.25-0.50 inches are forecast.  High temperatures next week will be in the low and mid-90s.

Long-range forecasts into the last week of the month call for a very similar pattern as Texas remains under the influence of a somewhat weaker ridge of high pressure.

Tropical Weather Outlook

Weather conditions are currently quiet across the Gulf of Mexico and the Caribbean Sea.

However, National Hurricane Center (NHC) forecasters are monitoring a strong tropical wave located in the eastern tropical Atlantic, about 700 miles west-southwest of the Cabo Verde Islands.  The area of shower and thunderstorm activity associated with the wave have changed little in organization since yesterday.  Environmental conditions are expected to be somewhat conducive for development, and a tropical depression could form during the next day or two while the disturbance moves generally westward to west-northwestward at 10 to 15 mph across the tropical Atlantic.  Conditions are forecast to become less conducive for development by the end of the week.  NHC forecasters are giving this system a 60 percent chance for development over the next 5 days.

Perseid Meteor Shower

The annual Perseid meteor shower is underway. Debris from giant comet 109P/Swift-Tuttle is disintegrating in Earth’s atmosphere, producing a nightly spray of shooting stars expected to peak on Aug. 11th and 12th.  But do note the Moon (in Taurus) rises around midnight, and its light will interfere an extent during the prime meteor hours from midnight to dawn. So you might do best before then, from about 11 p.m. through moonrise when the sky will be its darkest.

Bob

Very Hot and Dry Weather to Persist for Another Week.

Friday, August 7, 2020 3:15 PM

It’s early August and we’ve reached what is typically the hottest point of summer.  It’s at this time when the jet stream lifts far up to the north, causing most weather systems to slow way down.  Ridges of high pressure cover much of the southern U.S., causing a persistent pattern of hot and generally dry weather.

True to form, Friday’s weather maps showed a broad area of high pressure in the middle and upper atmosphere covering the southern U.S., with the ridge being centered over West Texas, just east of Midland.  Fortunately, this ridge is not quite as strong as the ridge that was in place during in the first half of July.  As a result, we’re not seeing the temperatures quite as hot as they were in July.  Sinking air under the ridge is causing a very stable and dry atmosphere.  Weather conditions are sunny, hot and dry.

Forecasts call for the ridge to continue to be our region’s dominant weather feature this weekend, and through all of next week.  The center of the ridge is predicted to remain over West Texas through the middle of the week, then shift west to northern Mexico and southern New Mexico late next week into next weekend.

With the ridge in place, sunny, dry and hot weather conditions will persist across the Hill Country and Central Texas regions through late next week.  In addition, daily high and low temperatures are expected to remain quite consistent.  High temperatures this afternoon through next Friday across the Hill Country and Central Texas regions are predicted to be near 100-103 degrees.  Across the coastal plains, daily high temperatures will be in the mid-90s.

Across the coastal plains region, an isolated rain shower or two will be possible each afternoon through early next week where the strength of the ridge won’t be quite as strong.  Forecasts call for a slight increase in the chance for scattered showers and isolated thunderstorms Wednesday through Friday as the ridge’s influence weakens further.  Rain amounts through late next week are forecast to be low—generally under a quarter inch.

The center of the high pressure ridge is forecast to shift west to the Four Corners region next weekend and continue over that location through the week of  August 17th.  With the center of the ridge further to the west, the ridge’s grip on Texas is predicted to be weaker.  Forecasts call for the development of widely scattered afternoon rain showers and isolated thunderstorms across the coastal plains region, with the activity also extending inland to the Austin/Interstate 35 corridor throughout the week of August 17th.   With the tropical moisture spreading inland from the Gulf, spotty totals of around quarter inch are forecast across Central Texas.  Totals between a quarter and a half inch are forecast across the coastal plains region.

With the ridge losing some of its grip, high temperatures are forecast to lower slightly beginning next weekend, continuing through the week of the 17th.  High temperatures across the Hill Country and Central Texas regions are predicted to generally be near 97-100 degrees.  Across the coastal plains, high temperatures are predicted to be in the low and mid-90s.

No significant change in the temperature or rainfall pattern is predicted through the fourth week of August.

Tropical Weather Outlook

Weather conditions are fairly quiet across the tropical Atlantic, the Caribbean Sea and the Gulf of Mexico.

However, National Hurricane Center forecasters are monitoring a tropical wave located in the eastern tropical Atlantic, several hundred miles west-southwest of the Cabo Verde Islands.  This system is currently accompanied by minimal shower activity.  Slow development of this system is possible during the next couple of days as it moves slowly westward.  After that time, environmental conditions are expected to become less conducive for development.  NHC forecasters only give this system a 10 percent chance for development over the next 5 days.

Elsewhere, there are no systems in place which pose a threat for development over the next 5 days.


RAMMB-CIRA 08/07/20 1:00 pm CDT

The Perseid Meteor Shower

The Perseid meteor is typically one of the two best displays of “shooting stars” all year. The meteors are caused when little bits of grit, shed by a comet called Swift-Tuttle, slam into our atmosphere at 37 miles per second. Every August, like clockwork, we cross the comet’s orbit and plow right through this dusty debris. The good thing is you don’t need any special equipment to enjoy the Perseids, so this annual sky show makes a wonderful activity for the whole family.

The Perseid meteor shower should be at its strongest Tuesday night, August 11th.  This year, however, the Moon rises around midnight, and its light will likely interfere somewhat during the prime meteor hours, from midnight to dawn.  So you might do best watching before then, from about 11 pm through moonrise.

The best direction to look is wherever your sky is darkest, usually overhead.  The shower’s radiant (the meteors’ perspective point of origin, if you could see them coming from far away in space) is in northern Perseus under Cassiopeia.  But the meteors only become visible when they hit the upper atmosphere, anywhere in your sky.

While the meteor shower will peak on the night of August 11th, you may see the occasional Perseid on any night this weekend or next week.  With a mostly clear sky expected this weekend, give it a shot.  For more information, check out Spaceweather.com

Have a good weekend.

Bob

Updated Outlook Calls for an “Extremely Active” Hurricane Season to Come.

Wednesday, August 5, 2020 2:02 PM

The heart of the hurricane season is just around the corner and according to a leading hurricane expert, we haven’t seen anything yet.  On Wednesday, meteorologist Phil Klotzbach and his forecast team at Colorado State University released an updated prediction for this year’s Atlantic hurricane season.

“We have increased our forecast and now call for an extremely active 2020 Atlantic hurricane season,” Klotzbach said.

In all, Klotzbach and his team predict a total of 24 named storms in 2020. This includes the nine named storms that have already formed: Arthur, Bertha, Cristobal, Dolly, Edouard, Fay, Gonzalo, Hanna and Isaias.  Of those, the team expects 12 to become hurricanes (including the two hurricanes that have already formed, Hanna and Isaias).  The team predicts 2020 hurricane activity will be about 190% of average according to the new forecast.  By comparison, 2019’s hurricane activity was about 120% of average and it was classified as a hyperactive season.

Twelve hurricanes is the most the forecast team has ever predicted in its August forecast.  This updated outlook is an increase from the early July seasonal forecast which predicted 20 named storms, nine hurricanes and four major hurricanes.

Klotzbach stated there are three main reasons for his “extremely active” forecast.  First, sea surface temperatures averaged across the tropical Atlantic are much warmer than normal and warmer waters mean more fuel for storms.

Another reason for the very active seasonal forecast are observations showing vertical wind shear across the Atlantic is well below average.  Having less shear generally aids in tropical storm development and intensification.

Finally, neutral ENSO conditions currently in place across the Pacific may transition to weak La Niña conditions by later this summer.  According to Klotzbach, La Niñas often increase hurricane numbers in the Atlantic.

Klotzbach’s updated outlook also stated an above-normal probability for major hurricanes making landfall along the continental United States coastline and in the Caribbean.

NOAA and the National Hurricane Center will release their updated outlook for the hurricane season Thursday.

Observations Wednesday afternoon showed weather conditions were generally quiet across the tropical Atlantic, the Caribbean Sea and the Gulf of Mexico.  NHC forecasters are watching a small but well-defined low pressure system located a few hundred miles southwest of Bermuda. This system is producing an area of disorganized showers and a few thunderstorms.  Although the low has remained nearly stationary today, NHC forecasters call for the low to drift west-southwestward during the next couple of days.  Any development of this disturbance should be slow to occur due to dry air and increasing upper-level winds by the weekend.  NHC forecasters giving this system just a ten percent chance for development over the next five days.


RAMMB-CIRA 08/05/2020 1:10 pm CDT

Bob

 

A Persistent August Heat Wave Taking Shape

Monday, August 3, 2020 2:16 PM

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

A Slight Chance for Showers through Early Next Week but the Heat Continues.

Friday, July 31, 2020 2:16 PM

A rare, weak cold front is predicted to sink south through our region this afternoon and tonight, providing a focus for the development of scattered rain showers and thunderstorms.  Friday morning’s weather maps showed the persistent ridge of high pressure in the upper atmosphere has shifted away from Texas and the south central U.S to the western US.  This has allowed an unusually strong trough of low pressure to develop south into Texas out of southern Canada.  A cold front associated with the trough pushed into Texas Thursday night.  As of early Friday afternoon, the cold front stretched from Longview, to Temple to near Fort Stockton.  While certainly not a “blue norther”, the air behind today’s cold front is drier and just slightly cooler.  Forecasts call for the front to reach the Austin/Interstate 35 corridor region around mid-afternoon Friday and the Interstate 10 corridor Friday evening.  The front is predicted to stall across the coastal plains region Saturday, then weaken and wash out on Sunday.

As temperatures warm into the 90s this afternoon, scattered rain showers and thunderstorms are forecast to develop along and to the south of the cold front.  The probability for rain will be near 40-50 percent across the Hill Country and Central Texas regions and be less than 20 percent across the coastal plains.  Today’s atmosphere will be structured in such a way that some of the developing storms may become strong to marginally severe.  Today’s primary severe weather threat will be strong, potentially damaging winds.  The Storm Prediction Center has placed the area north of Interstate 10 under a Marginal Risk for severe thunderstorms this afternoon and evening.

Widespread rainfall is not expected.  However, spotty totals of 0.25 to 0.50 inches are forecast across the Hill Country and Central Texas regions through midnight.  Isolated totals of 1-2 inches will be possible.  High temperatures this afternoon will be in mid and upper 90s.  Lows Saturday morning will include the low 70s across the Hill Country with middle 70s at most other locations.

On Saturday, the chance for rain and scattered thunderstorms will shift to the coastal plains region, in the vicinity of the stationary front.  The probability for rain will be near 30-40 percent.  Spotty totals of 0.25-0.50 inches are forecast.  Further inland, there will be just a slight chance for a few scattered rain showers across Central Texas through the afternoon.  Little to no rain is forecast across the Hill Country.  Expect a mostly sunny to partly cloudy sky.  High temperatures are forecast to be in the mid and upper 90s, with lower 90s expected towards the coast.

Sunday’s weather is shaping up to be mostly sunny.  There will be a slight chance for a few spotty rain showers across the coastal plains while most other areas will remain dry.  High temperatures are predicted to be in the upper 90s.

Forecasts call for a second cold front to sink south out of North Texas Monday, pulling up stationary across Central Texas Monday afternoon into Tuesday.  This next front is expected to cause a slight chance for rain showers and thunderstorms across the region both days.  For locations that do happen to see rain, totals should average around a quarter inch or less.  Otherwise, weather conditions will be mostly sunny to partly cloudy and hot.  High temperatures both days will be near 98-100 degrees, with mid-90s expected towards the coast.

Sunny, dry and hot weather is forecast Wednesday through next weekend as the trough of low pressure exits east and the ridge of high pressure over the Southwest begins to spread back over Texas.  Fortunately, the ridge is predicted to only be moderately strong, so extreme temperatures are not expected.  A few isolated rain showers will be possible towards the coast, but areal coverage will be less than 20 percent.  Daily high temperatures are forecast to be close to 100 degrees, with middle 90s expected towards the coast.

The outlook for the week of August 10th calls for little change as the center of the high pressure ridge remains parked over New Mexico.  Sunny, hot and dry weather will continue with daily high temperatures staying close to 100 degrees.

Tropical Weather Outlook

As of 1 pm Friday, the center of Hurricane Isaias was located by an Air Force Reserve Hurricane Hunter aircraft and Bahamas radar about 245 miles southeast of Nassau, Bahamas.  Isaias was moving toward the northwest near 16 mph, and a general northwestward motion with some decrease in forward speed is expected for the day or so followed by a turn toward the north-northwest.  On the forecast track, the center of Isaias will continue to move near or over the Southeastern Bahamas today.  Isaias is forecast to be near the Central Bahamas tonight, and move near or over the Northwestern Bahamas Saturday and near the east coast of the Florida peninsula Saturday afternoon through Sunday.

Data from the reconnaissance aircraft indicate that maximum sustained winds are near 75 mph with higher gusts.  Strengthening is expected later today and tonight, and Isaias is forecast to remain a hurricane for the next few days.

Isaias poses no threat to the Gulf of Mexico.

National Hurricane Center forecasters are keeping an eye on a tropical wave in the west-central tropical Atlantic, located about 950 miles east of  the Lesser Antilles.  This system is producing disorganized showers and thunderstorms as it moves to the west.  Some slow development of this system is possible while it turns northwestward over the western Atlantic by early next week.  NHC forecasters are giving the wave a 30 percent chance for development over the next 5 days.

NHC forecasters are also monitoring an area of showers and thunderstorms that remain separated from the center of a small area of low pressure located in the far eastern tropical Atlantic, a couple of hundred miles east of the Cabo Verde Islands.  The system is moving northward toward less favorable environmental conditions, and significant development of this system appears unlikely.  NHC forecasters are giving this system just a 20 percent chance for development over the next 5 days.

Elsewhere, tropical cyclone development is not expected over the next 5 days.

Catch Mars in the Late Evening Sky

Brilliant Jupiter and Saturday are now quite visible in the eastern evening sky.  But now, the planet Mars rises in the eastern sky around 11 pm CST.  It will be quite bright (magnitude –1.2).  It will appear yellow-orange in the constellation Pisces, like a far-off bonfire.   Where will it come up?  Watch the eastern horizon below the Great Square of Pegasus.  By dawn Mars shines grandly high and bright in the southern sky.

In a telescope this week Mars grows from 14½ to 15½ arcseconds in apparent diameter, as big as it appears at some oppositions!  But we’re still speeding toward it along Earth’s faster orbit around the Sun, and we have a long way to go. Around this year’s opposition in early October, Mars will be 22.6 arcseconds wide!

Have a good weekend.

Bob

 

Just a Slight Chance for Rain this Week. Hot Temperatures to Close Out the Month.

Monday, July 27, 2020 2:15 PM

Hurricane Hanna made landfall Saturday afternoon as a category one hurricane along the lower Texas coast, at the Padre Island National Seashore, about 50 miles south of Corpus Christi.  Highest sustained winds at landfall were 90 mph.  A wind gust to 68 mph was measured at Corpus Christi and gust to 81 mph was measured at Baffin Bay Padre Island.  Interestingly, Austin-Bergstrom Airport recorded a wind gust to 59 mph Saturday afternoon when a thunderstorm associated with the hurricane passed over the airport.  Hanna produced torrential rains of 10-15 inches across the Lower Rio Grande Valley and adjacent areas of northeastern Mexico.  As of Monday morning, Hanna was still designated as a tropical depression and was located over northeastern Mexico, to the southwest of Monterey.   The system was moving to the west at 5 mph and is predicted to bring additional heavy rain to northern Mexico and the Rio Grande Valley this afternoon and Tuesday.

Across Central Texas, the Hill Country and the middle Texas coast, rainfall from Hanna ended up being much lower than was originally forecast.  Doppler radar estimates and gauge reports showed most totals since Friday were generally less than a quarter inch across the Hill Country.  Across Central Texas, totals ranged anywhere from a tenth of an inch to 1.5 inches.  And across the coastal plains region, totals generally ranged between 1 and 2.5 inches.  LCRA’s highest 72-hour gauge total was 3.65 inches near Garwood, in southeastern Colorado County.

NWS Radar Estimate of Rain Falling Between 7 am Friday and 7 am Monday:

Monday’s analysis indicated the atmosphere over Central Texas was still quite moist in the wake of Hanna.  In the upper atmosphere, a weak ridge of high pressure was located over Far West Texas and the Desert Southwest.  A small area of low pressure was in place over western Louisiana, drifting to the southwest.  Circulation around the low is forecast to pull additional tropical moisture into Central Texas this afternoon through Wednesday.  With warming afternoon temperatures,  scattered rain showers and thunderstorms are predicted to develop across the entire region.  The highest probability for showers will be across the coastal region, where the probability for rain will be near 60 percent this afternoon and Tuesday and near 40 percent Wednesday.  Across Central Texas, the probability for rain will be near 30 percent this afternoon and Tuesday and just 20 percent Wednesday.  The probability for rain across the Hill Country will be 20 percent all 3 days.

Rain amounts through Thursday morning are forecast to average between 0.5 and 0.75 inches across the coastal plains region and around a quarter inch or less across Central Texas and the Hill Country.

High temperatures Monday through Wednesday are forecast to generally be in the mid and upper 90s.  Highs near 90-92 degrees are predicted for the coast region.

Mostly sunny and generally dry weather is forecast across the region Thursday and Friday as moisture levels decrease.  Lingering  moisture may cause a few stray showers across the coastal plains region, but most other locations should stay dry.  High temperatures Thursday and Friday will be in the upper 90s.

A slightly unsettled weather pattern is forecast to develop across our region this weekend, continuing through the first half of next week, when an unusually strong trough of low pressure develops south from southern Canada to the lower Mississippi River Valley.  At the same time, the ridge of high of high pressure over West Texas is predicted to slide west to western Arizona and Northwestern Mexico.  A cold front associated with the trough is predicted to sink south to North Texas and pull up stationary.  The combination of a weaker ridge and the proximity of the stalled front to our north is expected to cause a slight chance to a chance for scattered rain showers and thunderstorms each day between Saturday and next Wednesday.  As of now, significant rain is not forecast, with most totals over this upcoming period remaining below  1 inch.  High temperatures will be mostly in the mid and upper 90s.

Mostly sunny, dry and slightly warmer weather is forecast late next week into the following weekend as the trough weakens and the ridge to our west moves to a position over New Mexico.  High temperatures are predicted to be in the upper 90s to 100 degrees.

Tropical Weather Outlook

Tropical Storm Gonzalo weakened into an open wave of low pressure when in entered the eastern Caribbean Sea Saturday.  Conditions remain unfavorable for this system to regenerate.

National Hurricane Center forecasters continue to closely monitor a broad area of low pressure located 1000 miles east of the Windward Islands.  Shower activity associated with this feature has changed little in organization since this morning.  Environmental conditions are expected to become somewhat more favorable for development during the next few days and a tropical depression or tropical storm is likely to form during that time frame. The system is forecast to move westward to west-northwestward at 15 to 20 mph and it could bring heavy rain to portions of the Leeward Islands by late Wednesday, regardless of development.  NHC forecasters are giving this system an 80 percent chance for development over the next 5 days.


RAMMB-CIRA 07/27/2020 12:40 pm CDT

Elsewhere, there are no systems in place which pose a threat for tropical development over the next 5 days.

One of the Hottest July’s on Record

As we move into the last few days of July, data so far this month shows July 2020 will likely close as one of the hottest on record across Central Texas.  While most areas have seen several triple-digit temperatures this month, the unusually warm nighttime temperatures have also been a big part of the very warm monthly average temperature.

At Austin-Camp Mabry, the average temperature through Sunday (7/26) was 89.0 degrees, 4.2 degrees above normal. July 2020 currently ranks as the 3rd warmest July on record, behind similar periods in 2011 and 2009.  Not exactly the “coolest” of summers to be keeping company with.

Have a good week.

Bob