Forecast for Central Texas

Friday Saturday Sunday Monday Tuesday
Fri Sat Sun Mon Tue
86 °F / 73 °F 84 °F / 70 °F 84 °F / 70 °F 87 °F / 73 °F 87 °F / 73 °F
86 ° / 73 ° 84 ° / 70 ° 84 ° / 70 ° 87 ° / 73 ° 87 ° / 73 °
60% 70% 50% 30% 40%
60%Chance Rain/T-Storms 70%Chance Rain/T-Storms 50%Chance Rain/T-Storms 30%Chance Rain/T-Storms 40%Chance Rain/T-Storms
Updated September 21, 2018

Bob's Blog on Central Texas Weather

Periods of Rain and Thunderstorms Expected this Weekend and Much of Next Week.
Friday, September 21, 2018 2:45 PM

A wet weather pattern has returned to Central and South Texas.  Rain showers and thunderstorms developed across the region Thursday as a plume of tropical moisture spread north from the Gulf.  According to LCRA's Hydromet, the highest gauged totals so far have been in and around the Austin/Travis County area, where several locations have recorded between 1 and 1.5 inches.  Another area of heavy rain is ongoing  across the western Edwards Plateau where an area of heavy rain has been slowly spreading east out of the Concho Valley.  An LCRA gauge near Eldorado in Schleicher County, has recorded 5.05 inches of rain since midnight (as of 1 pm).  The Schleicher County sheriff's department reports numerous roads flooded in the central part of the county. 

The current wet and unsettled pattern is the result of the summertime ridge of high pressure moving from Texas to the southeastern US and a trough of low pressure setting up over northern Mexico and the Desert Southwest.  Circulation around both of these features is pulling an area of deep, tropical moisture from the Gulf of Mexico north into Texas.  At the same time, considerable middle and high level moisture is also spreading into Texas out of the eastern Pacific, causing the atmosphere to become very moist and unstable.  Atmospheric disturbances moving through western trough and tracking across Texas are helping to initiate waves of rain showers and thunderstorms across the region.  This same set up is forecast to hold in place through the weekend and early next week, creating an ongoing chance for rain showers and thunderstorms.  An additional feature that will be enhancing the development of rain this weekend is a weak cold front currently snaking from southern Oklahoma into Far West Texas.  The cold front is predicted to sag slowly to the southeast, reaching the Central Texas region sometime Saturday afternoon or Saturday evening.  The front is forecast to stall and move back to the north on Sunday.  

As of midday, a strong disturbance was pushing east out of West Texas, causing a large area of rain and thunderstorms that stretched from Northwest Texas to the western Edwards Plateau.  This area of rain and storms is predicted to slowly spread east across the Hill Country this afternoon, reaching the Interstate 35 corridor sometime this evening and into parts of Central Texas overnight.  Due to this system's slow movement, there will be the potential for significant totals of rain across the Hill Country this afternoon and the Interstate 35 corridor this evening and overnight.  Out ahead of this disturbance, there will be a 50 percent chance for scattered rain showers and thunderstorms from the coast, northwest to the Interstate 35 corridor.  Afternoon temperatures should generally reach the middle 80s.

There will be another good chance for rain and thunderstorms across the Hill Country and Central Texas regions Saturday into Saturday evening as the weak cold front over West Texas slowly tracks to the southeast.  The probability for rain will be near 70-80 percent.  Significant totals of rain will have the potential to develop along the slow-moving boundary.  To the south of the boundary, there will still be a 50 percent chance for scattered rain showers and thunderstorms.  Saturday's temperature will only reach the middle 80s.

A slightly decreased coverage of rain and thunderstorms is predicted for the Hill Country and Central Texas regions Sunday as the weak frontal boundary weakens.  The probability for rain will be near 50 percent.  A good coverage of rain and thunderstorms is predicted for the coastal plains region.  Sunday's temperature is forecast to be mostly in the middle 80s.

Rain totals over the weekend are forecast to be significant.  The National Weather Service's outlook through Monday morning is calling general totals of 1-3 inches, with isolated totals of 5-6 inches.

Weather Prediction Center Rainfall Forecast for the Period 7 pm Friday through 7 pm Sunday:
Rain10.png

For next Monday and Tuesday, the chance for rain and thunderstorms is expected to decrease to around 30-40 percent as the set up for widespread and significant rain temporarily weakens.  High temperatures both days look to be in the upper 80s.

The chance for rain and thunderstorms is forecast to increase Wednesday into Thursday when a weak cold front sags south and stalls over the area.  This is the same front that was originally forecast to bring autumn-like temperatures to our area for late next week.  Current data now indicates this front won't be nearly as strong and it will stall over the region, enhancing the chance for rain.  The probability for rain both days will be near 40-50 percent.  High temperatures look to stay in the middle 80s.   

Longer-range forecasts call for more scattered rain showers across the region Friday into next weekend as our region remains under the influence of very moist flow off the Gulf of Mexico.  No significant change in the temperature is expected through next weekend.

Tropical Weather Update

National Hurricane Center forecasters are monitoring 4 different areas of disturbed weather across the central and far eastern tropical Atlantic.  However, none of these systems pose a threat to the Gulf of Mexico or the Texas coast.

First Day of Autumn

The autumnal equinox arrives Saturday, September 23, 2018, at 8:54 pm CDT.  At the equinox, days and nights are approximately equal in length.  The equinox marks the beginning of fall in the Northern Hemisphere and the beginning of spring in the southern Hemisphere.  Saturday's sunrise in Austin will be at 7:19 am.  Sunset will be at 7:27 pm.

The Full Harvest Moon

The September Full moon will occur Monday evening at 9:52 pm CDT.  Traditionally, the Harvest Moon designation goes to the full moon that occurs closest to the autumnal (fall) equinox.  Usually, the moon rises an average of 50 minutes later each night, but for the few nights around the Harvest Moon, the moon seems to rise at nearly the same time each night: just 25 to 30 minutes later each night.  Historically, Native Americans took advantage of the Harvest Moon to harvest corn, pumpkins, squash, beans and wild rice — the chief Native American staples.

Have a good weekend.

Bob
 

Previous Blog Entries

A Wet Weather Pattern is Setting Up for the Next Seven Days
Thursday, September 20, 2018 6:02 PM

Several factors are coming together that will are expected to cause a wet and unsettled weather pattern across Central and South Texas for the next several days.  A series of low pressure troughs tracking north out of Mexico, combined with a very moist air mass spreading north from the Gulf and a weak cold front sinking south out of North Texas will combine to produce waves of rain showers and thunderstorms.

The probability for rain is forecast to be near 60 percent Friday.  But the chance for rain looks to increase to near 80 percent Friday night through Saturday night when a weak cold front sags close to the Hill Country and Central Texas regions.  There will be a continued chance for rain Sunday through Tuesday as additional waves of rain and thunderstorms move over the area.  The probability for rain each day looks to be near 50 percent.

Forecast solutions call for a good chance for rain next Wednesday when a Canadian cold front tracks south through Texas.  The chance for significant rain is predicted to decrease Wednesday night as drier air spreads in behind the front.  However, forecasts call for at least a slight chance for light, overrunning rains next Thursday and Friday as a trough of low pressure hangs up over northern Mexico.

Rain amounts over the next 7 days are shaping up to be significant.  The Weather Prediction Center's 7-day rainfall outlook calls for totals of 2-3 inches, with higher totals across the Hill Country.

NWS rainfall forecast for the period 7 pm Thursday through 7 pm next Thursday:
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I'll have more details on this wet weather pattern in Friday's discussion.

Bob

Rain Chances Increasing Late Week. Watching for a Decent Cold Front Next Week.
Tuesday, September 18, 2018 5:18 PM

Forecasts continue to point toward the development of a wet weather pattern beginning Thursday and continuing through the weekend.  The stable ridge of high pressure currently in place across Texas is forecast to shift to the east beginning Thursday.  This will allow a series of low pressure troughs to begin lifting north out of Mexico and move across South and Central Texas.  These troughs are predicted to draw abundant moisture north from the Gulf of Mexico, causing the atmosphere to become increasingly moist and unstable.

Forecasts call for a 30 percent chance for rain showers and thunderstorms Thursday, increasing to around 50-60 percent Friday and Saturday.  The chance for rain should begin decreasing Sunday.  Due to the tropical nature of this moisture, some locally heavy rain will be possible.

The latest National Weather Service rainfall forecasts through Sunday evening call for widespread totals of 1-1.5 inches.  Isolated heavier totals will be possible as well.

NWS rainfall forecast for the period 7 pm Tuesday through 7pm Sunday:
Rain7.png
 
Tuesday's forecasts are showing increased confidence a fairly strong cold front will push through the region next Wednesday.  There will be a chance for rain along the front, followed by dry and almost fall-like weather late week into next weekend.  High temperatures are predicted to fall into the mid and upper 80s while low temperatures should fall to the 60s.

This is shaping up to be our first significant cold front of the fall season.

Bob

Drier Weather through Wednesday Followed by Another Chance for Rain Late Week
Monday, September 17, 2018 3:27 PM



The pattern of widespread rain which set up across the area late last week has come to an end.  That area of disturbed weather which pushed inland out of the Gulf of Mexico late Friday was located Monday morning over northern Mexico.  While much of the deep, tropical moisture has shifted to the west with this system, Monday's analysis showed a fair amount of moisture still remaining across the Central and South Texas.  Due to this lingering moisture, there will be a slight chance for a few isolated rain showers and thunderstorms across the region this afternoon and evening.  The probability for rain at any given location will only be near 20 percent.  Rain totals, if any, will average less than a quarter inch.  Today's sky will be partly cloudy and conditions will be warm and quite humid.  Today's temperature will generally warm to the low 90s.

For Tuesday through Wednesday, little change in the pattern is expected.  A couple of isolated rain showers and thunderstorms will be possible each afternoon, but the probability for rain will be less than 20 percent.  Conditions will be mostly sunny, warm and humid with high temperatures generally in the low to middle 90s.

A change in the weather pattern is predicted to take place Thursday when the broad ridge of high pressure over Texas shifts to the east, allowing a series of low pressure troughs to begin lifting north out of Mexico.  These troughs will pull moisture north from the Gulf of Mexico, resulting in the development of scattered rain showers and thunderstorms.  The probability for rain will be around 30 percent Thursday and near 40 percent Friday.  A partly to mostly cloudy sky is forecast both days, with daily high temperatures of 88-90 degrees.  Rain amount over the 2-day period are forecast to total less than a half inch.

The wet and unsettled weather pattern is forecast to continue Saturday through Sunday as additional low pressure troughs lift north out of Mexico.  These systems will cause the sky to remain mostly cloudy.  There will be a 30-40 percent chance for rain showers and scattered thunderstorms on both days.  Rain amounts over the weekend are forecast to total close to a half inch.  High temperatures will be in the upper 80s.

Forecast solutions indicate the unsettled weather pattern will continue into early next week, with at least a slight chance for rain showers and thunderstorms forecast for Monday and Tuesday.  Rain amounts are not shaping up to be very heavy, with most totals staying below a quarter inch.  High temperatures both days will be near 90 degrees.  Partly cloudy and warm weather is forecast next Wednesday and Thursday.  There are signs a Canadian cold front will attempt to push south into Texas sometime late next week or the following weekend.

One item to watch for late this week and into the upcoming weekend will be an area of disturbed weather currently located in the eastern Pacific Ocean, a few hundred miles south of Baja, California.  National Hurricane Center forecasters state this system will likely become a tropical depression later this week as it tracks north toward Baja, California and northwestern Mexico.  Depending in the eventual path of this system, it is possible some of this system's moisture could be pulled northeastward into Texas. Stay tuned for more details on the progress of this system.

Tropical Weather Update

The tropical Atlantic basin has quieted down from the very active pattern that was in place last week.  Tropical Depression Florence was located along the border between Kentucky and Ohio, about 240 miles west of Charlottesville, Virginia.  Florence is moving to the northeast at 15 mph and is forecast to become extratropical late today while accelerating to the east-northeast.

Tropical Depression Joyce was located over the northeastern Atlantic, about 285 miles south-southwest of the Azores.  The depression is moving toward the east-southeast near 8 mph and this forward speed is expected to continue while turning toward the southeast today, south on Tuesday, and southwest on Wednesday.  Maximum sustained winds are near 35 mph.  Some weakening is forecast during the next 48 hours and Joyce is expected to become a remnant low tonight or Tuesday.

National Hurricane Center forecasters continue to monitor an area of disorganized showers and thunderstorms extending from just west of Jamaica to eastern Cuba and Hispaniola.  This activity is associated with the remnants of Isaac.  Environmental conditions are expected to remain unfavorable for re-development while the system moves westward to west-northwestward across the northwestern Caribbean Sea.  NHC forecasters are giving this system only a ten percent chance for development over the next 5 days.

Bob2.pngRAAMB-CIRA 09/17/18 2:30 pm CDT 

The First Day of Autumn

The autumnal equinox arrives this coming Saturday, September 23, 2018, at 8:54 pm CDT.  At the equinox, days and nights are approximately equal in length.  The equinox marks the beginning of fall in the Northern Hemisphere and the beginning of spring in the southern Hemisphere.  On the equinox, the sun shines directly overhead at the equator.  It's interesting to note, the sun will rise due east and set due west on the equinox.  This fact makes the day of an equinox a good day for finding due east and due west from your yard or other favorite site for watching the sky.  Just go outside around sunset or sunrise and notice the location of the sun on the horizon with respect to familiar landmarks.  The equinox is a seasonal signpost in Earth's orbit around the sun.

14-Day Rainfall Totals

Pasted below is map showing the estimated rainfall accumulation beginning September 3rd.  The highest totals of rain during this period occurred near and to the west of San Antonio, with totals of 16-20 niches.  Another area of very heavy rain occurred along the coast between Corpus Christi and Galveston, with some totals in excess of 20 inches.  LCRA's Hydromet gauge located at Matagorda, recorded a 2-week total of 17.97 inches.

NWS Rainfall Acccumulation for the period 7 am 9/3/2018 through 7 am 9/3/2018
FF.pngMap courtesty National Weather Service West Gulf River Forecast Center 

Much of the Hill Country received between 5 and 8 inches of rain.  LCRA's highest gauged total across the Hill Country region was 13.22 inches in southeastern Burnet County, roughly 8 miles south-southwest of Bertram.

Across Central Texas, totals generally averaged between 3 and 5 inches, with the lowest totals occurring across Fayette and Colorado Counties.  LCRA's highest gauged total was 15.48 inches, occurring in western Bastrop County, about 3 miles west-southwest of Cedar Creek.

Across the coastal plains, totals were generally in the range of 6- 8 inches, although amounts were considerably higher across the southern half of Matagorda County.

Bob

Periods of Rain Expected through the Weekend. Generally Dry the First Half of Next Week.
Friday, September 14, 2018 3:33 PM

The persistent area of disturbed weather located over the western Gulf of Mexico has changed little in organization since Thursday.  Midday satellite images showed a large area of disorganized cloudiness associated with an elongated trough of low pressure over the western Gulf of Mexico.  Satellite data indicated the disorganized area of clouds was beginning to push inland over the lower Texas coast.  With the system moving over land, there is little chance now the system will organize into a tropical depression.
 
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RAMMB-CIRA 09/14/18 2:30 pm CDT

Early this afternoon, a large area of tropical moisture associated with the area of disturbed weather was pushing inland along the lower, middle and upper Texas.  Weather radar showed a large area of light to moderate rain occurring between Corpus Christi Victoria and Conroe.  LCRA's Hydromet gauges as of 3 pm showed totals to around three quarters of an inch across Matagorda County, with much lower totals to the north.  LCRA's gauge on the coast at Sargent has recorded 1.62 inches since midnight.  Scattered rain showers and isolated thunderstorm were beginning to develop across the rest of the region. 

The rain showers occurring across the coastal plains region are forecast to spread northwest through Central Texas this afternoon, reaching the Hill Country late this afternoon and evening.  A widespread coverage of light to moderate rain along with a couple of isolated thunderstorms is predicted for the entire region Friday night through Saturday.  The probability for rain will generally be near 60-70 percent.  The heaviest and most persistent rains look to occur across the coastal plains region, generally to the south of Interstate 10.  Totals Friday night through Saturday evening are forecast to generally be between 1 and 2 inches.

The area of widespread rain showers is forecast to decrease from east to west Saturday evening into Saturday night as the area of deep tropical moisture shifts west towards Mexico.  Saturday night through Sunday, scattered rain showers and isolated thunderstorms will likely continue across the area due to lingering tropical moisture.  The probability rain at any given location will be near 30-40 percent Sunday, decreasing to 20 percent Sunday night.  Rain amounts Sunday are predicted to average between 0.25 and 0.5 inches.

The National Weather Service has posted a Flash Flood Watch for most of South Texas, including Gillespie, Blanco, Hays and Caldwell Counties through Saturday evening.

The National Weather Service's 3-day rainfall forecast, for the period from Friday morning through 7am Monday morning, calls for totals across the Hill Country, Central Texas and the middle Texas coast to generally average between 1 and 3 inches.  A couple of isolated totals of 5-6 inches will be possible.  The highest totals from this system are predicted to occur over areas to the south and west of San Antonio.

NWS rainfall forecast for the period 7 pm Friday through 7 pm Monday:
Rain5.png
 
The sky will be mostly cloudy this afternoon through Sunday.  High temperatures will be in the mid-80s today and Saturday, rising to near 90 degrees Sunday.

The outlook for next week calls for a partly cloudy sky with warm temperatures Monday through Thursday as a weak ridge of high pressure spreads over the region out of the southwestern US.  A few isolated rain showers will be possible each afternoon and evening due to residual moisture, but widespread rain is not forecast.  High temperatures will generally be in the low 90s.

The next change in the weather is forecast to occur Friday into next weekend when a trough of low pressure over the Plains states pushes a weak cold front south into Texas.  An area rain showers and thunderstorms is forecast to develop along and behind the cold front Friday through Sunday.  High temperatures are forecast to lower to the middle 80s behind the cold front next Saturday and Sunday.

Tropical Depression Isaac Update:

Isaac weakened to a tropical depression overnight as persistent wind shear weakened the system.  As of 10 am, Isaac was centered in the eastern Caribbean Sea, roughly 300 miles southeast of Santo Domingo, Dominican Republic.   The depression was moving toward the west near 16 mph and this general motion with some decrease in forward speed is expected over the next couple of days.  A turn to the west-northwest is possible early next week, if Isaac survives.  On the forecast track, Isaac will move over the eastern and central Caribbean Sea during the next few days.  Maximum sustained winds are near 35 mph (with higher gusts.  Isaac is forecast to gradually weaken over the next few days, and the system could degenerate into a tropical wave at any time.  A NOAA  Hurricane Hunter aircraft is currently en route to investigate the depression.  At the current time, Isaac poses little threat to the western Gulf of Mexico through the middle of next week.
 
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RAMMB-CIRA 09/14/18 2:30 pm CDT

Have a good weekend.

Bob

An Area of Disturbed Weather Expected to Bring Widespread Rain to Central Texas.
Thursday, September 13, 2018 4:34 PM

Here is an update on the area of disturbed weather located in the western Gulf of Mexico.  This system is shaping up to be a big rain maker for our region.  However, the threat for a high wind/organized tropical cyclone appears to be decreasing.
 
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RAMMB-CIRA 09/13/18 3:15 pm CDT

Satellite data and surface observations Thursday afternoon indicated a weak low pressure center has formed over the western Gulf of Mexico, a couple of hundred miles east-southeast of Brownsville, Texas.  In addition, showers and thunderstorms in association with this system have become more numerous today.  While upper-level winds are generally conducive for development of a tropical depression, the system only has about a day before it reaches the western Gulf coast.  An Air Force Reserve Hurricane Hunter aircraft was en route to investigate the low as of mid-Thursday afternoon.  The National Hurricane Center currently has the probability for tropical development down to 50 percent.  Regardless of development, this system is forecast to bring widespread rainfall to much of the South and Central Texas Friday and this weekend.

Forecast solutions call for the disturbance to come ashore across deep South Texas sometime early Friday.  An associated surge in moisture and lift associated with the system will lead to development of widespread showers and heavy rainfall across the middle and lower Texas coast Friday morning.  A fairly widespread coverage of light to moderate rain showers is expected to slowly spread northwestward to Central Texas and parts of the Hill Country Friday afternoon.  Widespread rain showers and isolated thunderstorms look to continue across the entire region Friday night through Saturday.  The probability for rain Friday afternoon through Saturday afternoon will be around 90-100 percent.

The heaviest and most persistent rains are forecast to shift to the western Hill Country and the Rio Grande Plains Saturday night as the disturbance tracks west towards Mexico.  Occasional light to moderate rain showers will likely continue across much of the Hill Country, Central Texas and the middle Texas coast Sunday into Monday due to lingering tropical moisture.  The probability for rain both days will be near 30-40 percent.  The chance for rain should drop to just 20 percent by Tuesday.

The latest National Weather Service rainfall forecasts call for widespread totals of 2-4 inches across the area between Thursday evening and early next week.  But due to the very tropical nature of this system, isolated total of 6-8 inches will be possible.   Since the soils are very wet and in some cases saturated from recent rains, this additional rain will increase the threat for flash flooding.  The National Weather Service intends to issue a Flash Flood Watch for parts of the area Friday into Saturday.

NWS rainfall forecast for the period 7 pm Thursday through 7 pm Tuesday:
Rain11.png

Tropical Storm Isaac 

Forecasters continue to monitor the progress of tropical storm Isaac, located Thursday afternoon near the Leeward Islands, about 220 miles south-southeast of St. Croix.
 
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 RAMMB-CIRA 09/13/18 3:15 pm CDT

Isaac is moving toward the west near 16 mph.  Isaac is moving to the west at 16 mph and this general motion with a decrease in forward speed is expected for the next few days.  On the forecast track, Isaac should move farther away from the Lesser Antilles tonight, moving across the eastern and central Caribbean Sea through the weekend.  Maximum sustained winds have decreased to near 40 mph with higher gusts.  Isaac is forecast to generally weaken over the next few days, and could degenerate into a tropical wave during that time.  Tropical depression Isaac or the remnants of Isaac are forecast reach a position over the northwestern Caribbean Sea by Monday.  We will need to keep a close eye on Isaac as the system could push north into the Gulf of Mexico in the early to middle part of next week.

A Historical Note:  Today marks the ten year anniversary of Hurricane Ike making landfall along the north end of Galveston Island.

Bob

A Rainy Pattern is Forecast through the Weekend and Early Next Week.
Friday, September 7, 2018 3:26 PM

It has been a wet week across Central and South Texas, with scattered to numerous rain showers and thunderstorms.  The highest totals have primarily been across the Hill Country where totals since Saturday have generally averaged between 2 and 4 inches.  Rainfall across the far western Hill Country over Schleicher and Sutton Counties has averaged between 5 and 7 inches.  An LCRA Hydromet gauge located near Eldorado has recorded a 7-day total of 7.89 inches, as of 2 pm.  Soils across parts of the Hill Country are beginning to become saturated.  For areas east of Interstate 35, totals this week have been considerably lower—generally around an inch, or less with some isolated heavier totals.  Towards the coast, totals this week have generally averaged between 2 and 5 inches, with the highest totals occurring across Matagorda County.

Friday's analysis showed the atmosphere across the region being very moist and fairly unstable.  In the upper atmosphere, a trough of low pressure was tracking east across the southern Plains states.  This feature was helping draw a very moist air mass from the Gulf of Mexico inland across the region.  With the atmosphere so very moist, scattered to numerous rain showers and isolated thunderstorms are forecast this afternoon.  Light to occasionally moderate rain is expected.  The probability for rain at any given location will be around 70-80 percent.  This afternoon's sky looks to stay mostly cloudy and today's temperature is forecast to only reach close to 90 degrees.

The trough of low pressure moving across the Plains states is helping to push a weak Canadian cold front south out of the Plains states.  This feature will be very important over the next couple of days as it will serve as a focus for widespread and potentially significant totals of rain.  As of midday Friday, the front was located over Northwest Texas, stretching just east of Wichita Falls to Abilene to near Fort Stockton.  Radar showed a widespread area of rain occurring along and behind the cold front.  Forecasts call for the cold front to sag south into the Hill Country Saturday and toward the coastal plains region Sunday afternoon.

High-resolution forecasts call for a widespread area of rain showers and thunderstorms to spread into the northern Hill Country around midnight and across the rest of the Hill Country Saturday morning.  Rain is forecast to persist all day Saturday into Saturday night.  There will be a 40-50 percent chance for additional rain and thunderstorms Sunday.

The large area of rain and thunderstorms is forecast to spread across Central Texas around midday Saturday, with the rain continuing Saturday night into Sunday.  The probability for rain both days will be near 70 percent.

Scattered to numerous rain showers are forecast across the coastal plains region Saturday, followed by a more widespread coverage or rain and thunderstorms Saturday night through Sunday night.  The probability for rain will be near 70 percent.

The threat for widespread rain is expected to decrease across the Hill Country Saturday evening and across Central Texas around midday Sunday.  The widespread rain should diminish across the coastal plains region around midday Monday.

A light to moderate rain intensity is predicted with most of this weekend's rains.  However, due to the large amount of tropical moisture in place, some locally heavy downpours will also be possible.  Rain amounts across the region between this afternoon and Monday morning are forecast to generally total between 2 and 3 inches, with isolated totals of 5-7 inches possible.

NWS Rainfall Forecast for the Period 7 pm Friday through 7 pm Wednesday

Rain7.png 
For areas that have already seen significant totals of rain, this weekend's additional rain could lead to a large amount of runoff and flash flooding.  The National Weather Service has posted a Flash Flood Watch for the northern and western Hill Country, including San Saba, Mason and Kimble Counties, through late Friday night.  The rest of the region will also see a threat for flash flooding throughout the weekend.

On Monday, the most favorable area for rain is predicted to be across the coastal plains region where the front will have stalled.  There will be a 40-50 percent chance for scattered rain showers and thunderstorms Monday through Wednesday.  Additional totals of 1-3 inches will be possible.  Across the Hill Country and Central Texas regions, the chance for rain will decrease to 20-30 percent Monday through Wednesday as an area of tropical moisture lingers over the area.  Additional totals to around a half inch will be possible.  Expect a partly cloudy sky.

Longer-range solutions call for a slight chance for mainly afternoon showers late next week into next weekend as considerable tropical moisture spreads north from the Gulf. 

High temperatures are forecast to be in the middle 80s this weekend, warming to around 90-92 degrees Monday through Wednesday.  Low to middle 90s are forecast late week into next weekend.

Tropical Weather Update

The tropical Atlantic and Pacific are currently quite active.  At the current time, there are no identified threats to the Gulf of Mexico or the Texas coast.  However, we will need to keep a close watch on the disturbance currently located over the east-central tropical Atlantic.  Forecast solutions call for this system to track generally to the west over the next 5-7 days, possibly reaching the Caribbean region by the middle of next week.

Tropical  Storm Florence:  At 10 am CDT, the center of Tropical Storm Florence was located over the central tropical Atlantic, about 935 miles east-southeast of Bermuda.    Florence is moving toward the west near 8 mph and this general motion is expected to continue through Sunday.  A west-northwestward motion with an increase in forward speed is forecast over the southwestern Atlantic Ocean early next week.  Maximum sustained winds are near 65 mph (with higher gusts.  Little change in intensity is expected during the next day or so, but re-strengthening is forecast over the weekend.  Florence could become a hurricane again by Saturday night or Sunday.  Florence could pose a threat to much of the US East Coast around the middle of next week.

Forecasters are closely monitoring a tropical wave with a well-defined circulation located about 700 miles west of the Cabo Verde Islands.  Forecasters note this system's associated shower and thunderstorm activity has not been sufficiently organized to designate the system as a tropical depression.  However, only a slight increase in organization would cause this system to be designated as a tropical depression.  This low is expected to move slowly westward across the tropical Atlantic Ocean  during the next several days.  NHC forecasters are giving this system a 90 percent chance for tropical development over the next 5 days.

Hurricane Center forecasters are also keeping an eye on a second area of disturbed weather over the far eastern Atlantic, about 440 miles east-southeast of the southernmost Cabo Verde Islands.  The system is moving toward the west near 10 mph.  A westward to west-northwestward motion with a gradual increase in forward speed is expected during the next 72 hours. On the forecast track, the disturbance is expected to move near the southern Cabo Verde Islands on Sunday.  Maximum sustained winds are near 35 mph with higher gusts.  Satellite imagery indicates that the disturbance is becoming better organized, and it is expected to become a tropical depression or tropical storm later today.  This system is being designated as Potential Tropical Cyclone 8.

 
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RAMMB-CIRA 09/07/18 11:30 am CDT

In the central tropical Pacific, Major Hurricane Olivia was centered about 1465 miles east of Hilo, Hawaii. Olivia is moving toward the west-northwest near 16 mph, and this general motion is forecast to continue through Saturday.  A gradual turn toward the west is expected Saturday night or Sunday.  Maximum sustained winds have decreased to near 115 mph with higher gusts.  Olivia is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.  A slow weakening trend is expected during the next few days.  The National Hurricane Center's 5-day forecast calls for Olivia to weaken to a tropical storm early next week, but the system could move close to or through the Hawaiian Islands around the middle of next week.
 
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Four Bright Planets Still Visible

Four bright planets still shine during twilight, though one is getting very low and tricky. From right to left, they are Venus very low in the west-southwest, Jupiter upper left of Venus, Saturn higher in the south, and Mars well to the left of Saturn.  The best viewing time that includes Venus is around 30 to 40 minutes after sunset.

Have a good weekend.

Bob
 

A Wet Pattern Expected to Persist through the Weekend and into Next Week
Wednesday, September 5, 2018 6:00 PM

A moist and unstable pattern looks to remain in place across Central and South Texas through the upcoming weekend.  There will be a 40-50 percent chance for scattered rain showers and thunderstorms Thursday and Friday.  However, forecast solutions are indicating the chance for more widespread and significant rain will occur Saturday into Sunday when a weak cold front sags south out of North Texas and stalls over the region.  The chance for rain both days is predicted to be near 50-60 percent.  Weekend totals are forecast to be around 1-2 inches.

Forecasts for next week call for a continued chance for scattered rain showers and thunderstorms throughout most of the week as a moist and somewhat unsettled pattern continues.  High temperatures will be mostly in the mid-90s.

The National Weather Service's rainfall forecast for the next 7 days calls for totals of 2-4 inches for areas to the west of Interstate 35.  To the east of the Interstate, totals are forecast to generally total between 1 and 2.5 inches.

NWS rainfall forecast for the period 7 pm Wednesday through 7 pm next Wednesday:
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Hurricane Florence Strengthens into a Category 4 Hurricane

Hurricane Florence has steadily strengthened since late Tuesday, and has now reached category 4 hurricane status. At 4 pm CDT, the eye of Hurricane Florence was located over the central tropical Atlantic, roughly 1295 miles east-southeast of Bermuda.  Florence is moving toward the northwest near 13 mph, and this general motion is expected to continue through Thursday.  A turn toward the west-northwest with a decrease in forward speed is forecast to begin Thursday night, followed by a turn back toward the northwest early next week.
 
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RAMMB-CIRA 09/05/18 1:30 pm CDT

Maximum sustained winds have increased to near 130 mph with higher gusts.  Florence is now a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Some weakening is forecast during the next couple of days, but Florence is expected to remain a powerful hurricane through early next week.

National Hurricane Center forecasters stated there is considerable model ensemble spread and run-to-run variability for Florence's track beyond day 5.  Given the large uncertainty at these time ranges, it is far too soon to speculate what, if any, impacts Florence may have on the U.S. East Coast next week. Regardless of Florence's eventual track, large swells emanating from the hurricane will reach Bermuda beginning on Friday, resulting in life-threatening surf and rip currents on the island. Swells from Florence could also reach the U.S. East Coast by early next week.    

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Bob



A Daily Chance for Rain Expected All Week and this Weekend.
Tuesday, September 4, 2018 4:27 PM



A rainy pattern developed across the region over the holiday weekend as the persistent ridge of high pressure moved away from Texas and abundant tropical moisture spread north from the Gulf of Mexico.  The heaviest and most widespread rain over the past 3 days has occurred over the Hill Country, where most totals have averaged between 1 and 2 inches.  Totals were generally less and more spotty across Central Texas where amounts ranged from a quarter inch, to around an inch.  A few spots across Bastrop, Lee and Washington Counties received zero rain.  Meanwhile, an LCRA gauge located in central Hays County, Dripping Springs 5 SSW, recorded 5.01 inches.  Towards the coast, totals generally averaged around a half inch across Colorado and Wharton Counties.  Matagorda County saw widespread totals of 2-4 inches.

NWS Estimated Rain Falling between 3 pm Saturday and 3 pm Tuesday:
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Tuesday's weather maps showed a broad trough of low pressure over the Desert Southwest and the southern Rockies.  The ridge of high pressure which had been over Texas last week is now situated over the eastern and northeastern US.  Circulation around the western trough and the eastern ridge has pulled abundant moisture into Texas out of the Gulf of Mexico, resulting in a very moist atmosphere.  Weak disturbances moving through the western trough and pushing inland off the Gulf of Mexico have been responsible for the recent rain and thunderstorm activity.  One other feature of note is tropical storm Gordon, which was centered Tuesday morning over the north central Gulf of Mexico.  Gordon is forecast to push inland tonight across the central Gulf coast, just to the east of New Orleans.  The remnants of Gordon are forecast to spread northwest across Louisiana and Mississippi Wednesday, moving into Arkansas on Thursday.  From here, Gordon's remnants are forecast to turn north to the Plains states late week into the weekend, having no impact on Central Texas.

A mostly cloudy, wet and unsettled weather pattern is forecast to remain in place across Central and South Texas this week as the current moist and tropical air mass holds in place across the region.  The high pressure ridge along the East Coast is not expected to move back across Texas.  Weak disturbances pushing inland off the Gulf, combined with weak disturbances moving northwest out of northern Mexico will cause a daily chance for rain across the entire region today through Friday.  The probability for rain will generally be 40-50 percent.  The most favorable period for rain looks to be from late morning through late evening.  Daily rain amounts are forecast to generally average between 0.25 and 0.5 inches, with isolated totals of 1-2 inches possible.  The sky is forecast to remain mostly cloudy throughout the week, keeping high temperatures mostly in the low 90s.

The chance for rain and thunderstorms is forecast to increase across the northern Hill Country late Friday and across the rest of the region Friday night into Saturday when a weak cold front sags south out of Oklahoma.  The front is forecast to slow down and stall across Central Texas Saturday afternoon into Saturday night.  A widespread shield of rain is forecast along and behind the cold front Saturday.  This area of widespread rain is predicted to weaken and push south of the region Sunday, with a slight chance for rain lingering Sunday afternoon.  High temperatures this weekend are forecast to continue in the low 90s.

Rain totals over the next 7 days are forecast to be significant.  The National Weather Service is calling for totals of 2-4 inches across the Hill Country, extending east to the Interstate 35 corridor.  Totals of 1-2 inches are forecast for areas to the east of Interstate 35.  Keep in mind that due to the tropical nature of the atmosphere, some higher totals will be will possible at a few locations.

NWS rainfall forecast for the period 7 am Tuesday through 7 am next Tuesday:
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The outlook for next week calls for a somewhat drier pattern as the tropical air mass weakens.  A slight chance for mainly afternoon and evening rain showers and thunderstorms is forecast throughout the week.  With a weak ridge of high pressure spreading over the area, high temperatures are predicted to be in the middle 90s.   

Tropical Weather Update

The tropical Atlantic has come alive, with two named systems and the potential for a third system soon.

Tropical Storm Gordon

… A Hurricane Warning is in effect from the Mouth of the Pearl River to the Alabama-Florida Border…

At 4 PM CDT, the center of Tropical Storm Gordon was located by NOAA Doppler weather radars over the north central Gulf of Mexico, about 95 miles south of Biloxi, Mississippi.   Gordon is moving toward the northwest near 15 mph and this general motion is expected to continue until landfall occurs tonight along the north-central Gulf coast.  A northwestward motion with some decrease in forward speed is expected after landfall, with a gradual turn toward the north-northwest and north forecast to occur on Friday.  On the forecast track, the center of Gordon will make landfall along the north-central Gulf Coast within the hurricane warning area this evening or tonight, and then move inland over the lower Mississippi Valley through Wednesday.

Data from NOAA Doppler weather radars indicate that maximum sustained winds have increased to near 70 mph with higher gusts.  Some additional strengthening is still possible, and Gordon could become a hurricane before landfall occurs along the north-central Gulf Coast this evening.  Rapid weakening is forecast after Gordon moves inland.

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Hurricane Florence

…Florence becomes the third hurricane of the Atlantic season and poses no threat to land through the upcoming weekend…

At 4 pm CDT , the center of Hurricane Florence was located over the central tropical Atlantic, roughly 1305 miles east of the northern Leeward Islands.  Florence is moving toward the west-northwest near 12 mph, and this motion is expected to continue through Wednesday night.  A northwestward motion is expected to begin by Thursday with Florence's forward speed decreasing by the weekend.  Maximum sustained winds have increased to near 85 mph with higher gusts.  Some additional strengthening is possible through tonight, but Florence is expected to weaken beginning on Wednesday and continuing through Friday.

A New Tropical Disturbance

National Hurricane Center forecasters are closely monitoring a broad low pressure system located a few hundred miles south of the Cabo Verde Islands.  This system is forecast to move slowly westward to

west-northwestward across the eastern tropical Atlantic for the next several days.  Environmental conditions are expected to gradually become more conducive for development, and a tropical depression is

likely to form by late this week or this weekend.  NHC forecasters are giving this disturbance an 80 percent chance for development over the next 5 days.

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RAMMB-CIRA 09/04/18  11:15 am CDT 

Bob

Weather Trending Wetter and Less Hot Next Week as Summer Pattern Begins to Fade.
Friday, August 31, 2018 4:27 PM

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.

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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.
 
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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.

Bob

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