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Bob's Blog on Central Texas Weather

Matthew Becomes a Hurricane. Quiet, Autumn Weather will Persist into Next Week.
Thursday, September 29, 2016 4:47 PM

Tropical storm Matthew strengthened into a hurricane early Thursday afternoon.  Despite being in an environment with 15-20 mph shear, Matthew's cloud pattern became better organized today and its winds increased to hurricane force.  As of late Thursday afternoon, hurricane Matthew was centered near the central Caribbean Sea, roughly 150 miles north-northeast of the Island of Curacao.  Matthew is moving quickly toward the west at near 17 mph.  A westward to west-southwestward motion with some decrease in forward speed is expected during the next couple of days as the hurricane rounds the western extent of a ridge of high pressure.  Maximum sustained winds are near 75 mph with higher gusts.  Gradual strengthening is expected during the next 48 hours as Matthew moves into a region of less wind shear.  By the way, the unusually far south track of Matthew has necessitated the National Hurricane Center to issue a tropical storm watch for a portion of the coast of Columbia.

 

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                                                                                                NOAA-NASA GOES Project

Matthew is still forecast to make a sharp turn to the north beginning Friday night.  The official forecast from the National Hurricane Center calls for Matthew to continue moving to the north-northeast this weekend, with a turn more to the north early next week.  On this path, Matthew is forecast to move somewhere between Jamaica and Haiti Monday, crossing eastern Cuba on Tuesday. 

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There is considerable uncertainty in the path of Matthew beyond next Tuesday.  However, it appears now there is little chance Matthew will turn west into the Gulf of Mexico.  Most of Thursday's computer forecast solution called for Matthew to continue to moving north through the Bahamas and stay just offshore of the East Coast.  But again, there remains much uncertainty in these solutions and track further to the west or east will be possible.  The uncertainty in Matthew's long-term path should decrease over the next few days.

The rest of tropical Atlantic is quiet and there are no systems in place that pose a threat for development over the next 5 days.

Back across Central Texas, a reinforcing surge of cool air spread south across the region on Thursday.  With a stable atmosphere in place, weather conditions were sunny, breezy and very pleasant.

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With a dry air mass in place, readings Thursday night will cool very nicely.  Lows Friday morning will include the upper 40s to low 50s across the Hill Country, the mid 50s across Central Texas and the upper 50s towards the coast.

Thursday's forecast data indicates the sunny and pleasant weather pattern will continue Friday through early next week.  The temperature is expected to slowly warm over the next 4 days.  Highs Friday and Saturday will be around 80-82 degrees, rising to the mid 80s Sunday through Tuesday.  Low temperatures Saturday morning will range from the low and mid 50s across the Hill Country to around 60 degrees near the coast.  Lows will warm to the low 60s Monday night and into the mid 60s Tuesday night.

A cold front is forecast sweep southeast across Texas Wednesday.  The front is forecast to slowly move across Central Wednesday night and push off the middle Texas coast Thursday afternoon.  With only a limited amount of moisture in place, just a few scattered rain showers and isolated thunderstorms are forecast with the front.  Rain amounts should be low; generally around a quarter inch or less.  The front will bring only minor cooling for late next week with highs in the low to mid 80s and lows in the 60s.

Long-range forecasts suggest the first half of October will offer only limited amounts of rain.  The temperature should average near to slightly above normal.

Bob

Previous Blog Entries

Dry and Fall-Like Weather Expected through Monday.
Wednesday, September 28, 2016 6:38 PM

There has been a taste of autumn in the air for the past couple of days thanks to a cold front which moved passed through the area Monday and is now located in the Gulf of Mexico. This was indeed the first significant cold front of the autumn season.  The front pushed away the warm and very humid conditions that have been in place for weeks.  Drier and slightly cooler air have followed the front.  Readings early Wednesday morning were the coolest our region has seen since May.  According to LCRA's Hydromet, http://hydromet.lcra.org low temperatures included the mid and upper 50s across the Hill Country, the upper 50s to mid 60s across Central Texas and the mid to upper 60s across the coastal plains.  This fall-like weather pattern is forecast to persist for the next several days, and in the wake of a very warm September, these cooler readings will be very refreshing.

Wednesday afternoon's analysis showed a bubble of Canadian high pressure covering Texas and the south central US.  The atmosphere was very stable, causing a clear sky. Dewpoint temperatures ranged from the mid 40s across the northern Hill Country to the mid 60s near the coast, producing low relative humidity levels.  With dry air in place, the temperature is expected to cool down nicely again overnight.  Low temperatures Thursday morning will range from the mid and upper 50s across the Hill Country to the mid 60s towards the coast.

A second Canadian cold front was located Wednesday afternoon across southern Oklahoma, moving to the south.  This front is forecast to sweep south across North Texas Wednesday night, reaching the Austin area around sunrise Thursday.  The front is forecast to push off the middle Texas coast late Wednesday afternoon.  With the atmosphere so dry and stable, no rain is forecast with the front.  Expect northerly winds to increase to around 10-15 mph behind the front, bringing cooler air.  Thursday's weather is forecast to be sunny and mild.  High temperatures will include the upper 70s across the northern Hill Country, the low 80s across Central Texas and the mid to upper 80s across the coastal plains.  Low temperatures Friday morning will be around 50-52 degrees across the Hill Country, in the mid 50s across Central Texas and in the upper 50s across the coastal plains.

Forecast data indicates this dry, fall-like weather pattern will continue in place Friday, this weekend and Monday as the dome of Canadian high pressure holds in place over the region.  High temperatures look to be near 80-82 degrees Friday through Sunday, and in the mid 80s on Monday.  Low temperatures Saturday and Sunday mornings will range from the mid 50s across the Hill Country to the low 60s across the coastal plains.  Lows Monday morning will be low 60s.

Southerly winds are forecast to return to the region early next week, bringing warmer and a bit more humid weather.  Weather conditions should continue mostly sunny Tuesday.  But a trough of low pressure pushing east across the Plains states is expected to push a weak cold front across the state sometime late Wednesday into Thursday.  The front is expected to cause a few scattered rain showers and thunderstorms, but rain amounts are forecast to average less than a quarter inch.  Dry and just slightly cooler weather is forecast behind the cold front late next week.  Today's long-range solutions indicate a dry pattern will likely persist well into the second week of October.

More info on our fall weather and tropical storm Matthew in Thursday's report.

Bob

Tropical Storm Matthew Develops in the Eastern Caribbean Sea
Wednesday, September 28, 2016 2:27 PM

Reports from an Air Force Reconnaissance aircraft earlier this morning indicated that strong tropical wave which had been tracking across the tropical Atlantic for the past several days developed a closed surface circulation and strong winds near to 60 mph.  As a result, the National Hurricane Center upgraded the system to tropical storm Matthew, the 13th named storm of the hurricane season.  As of early Wednesday afternoon, Matthew was centered over the Windward Islands of the eastern Caribbean Sea, about 25 miles southeast of the island of St. Lucia.  Matthew is moving toward the west at near 20 mph.  A westward motion with some decrease in forward speed is expected the next couple of days.  On the forecast track, the center of Matthew will move away from the Windward Islands this evening and be over the eastern and central Caribbean Sea Thursday and Friday.  Gradual strengthening is forecast during the next couple of days, and Matthew could become a hurricane by Friday.

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                                                                                                NOAA-NASA GOES

Matthew is currently being steered to the west by a large ridge of high pressure located over the western Atlantic.  The storm is forecast to reach the western edge of the ridge Friday night or Saturday morning and at that time, a sharp turn to the northwestward is forecast.  The exact timing of this turn will have huge implications for where the storm will eventually end up.  The National Hurricane center is calling for Matthew to approach Jamaica and eastern Cuba Monday into Tuesday.  Matthew is expected to have favorable conditions for intensification this weekend as it heads north, with low wind shear, very warm ocean waters, and a very moist atmosphere. Today's model solutions are quite bullish on this storm becoming a hurricane over the weekend.

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Beyond Monday, the forecast becomes much more uncertain.  This morning's most reliable computer-forecast solutions call for Mathew to continue moving north, reaching a position somewhere just off the southeastern coast of Florida late next week.  This forecast is based on the idea that a trough of low pressure will move across the Plains states the middle of next week and help pull the storm to the north-northeast.  In the off-chance the trough is not as strong or it doesn't move as far south as is currently forecast, there is some chance Matthew could bend west into the Gulf of Mexico.  This track doesn't appear likely, but it cannot be ruled out at this time.

This morning's suite of computer-forecast solutions generally call Matthew to track north-northeast to a position just off the southeastern coast of the US mid to late next week.  But I will caution not to put much faith or confidence into these solutions just yet.  A lot of changes can take place in the atmosphere over the next few days.  The Hurricane Center will be flying a plane to the Caribbean later today to sample the atmosphere around Matthew.  This data will help tonight's computer-forecast solutions and hopefully provide a clearer long-range forecast track over the next couple of days.

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At this time Matthew doesn't appear to be a threat to the western Gulf of Mexico, but it's way too early to let our guard down.  I urge everyone to keep an eye out for later updates and forecasts from the National Hurricane Center.

Bob

Rain Diminishing Monday Night. Dry and Pleasant Weather Expected Tuesday through Friday.
Monday, September 26, 2016 2:42 PM



An area of low pressure dropping south across West Texas over the weekend produced widespread rain showers and thunderstorms across Central and South Texas.  The highest totals of rain occurred across the Hill Country, generally between Rocksprings, Mason and Llano where amounts of 4.5-5.5 inches were observed.  Parts of Concho and Edwards Counties received between 6 and 8 inches.  The rain was considerably lighter along the middle Texas coast where totals were less than a quarter inch across most of Colorado and Wharton Counties.  Across Central Texas, totals were generally between 1 and 2 inches, although the western half of Fayette County received between 3 and 5 inches.

 

National Weather Serivce rainfall estimate for the period 9 am Friday through 9 am Monday:

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Late this morning, a large area of light to moderate rain is falling across the Hill Country and along the Interstate corridor, between Austin and San Antonio.  This rain is being generated by a disturbance in the upper atmosphere that is slowly moving northwest across the Hill Country.  Light to moderate rain showers are forecast to continue across the Hill Country this afternoon, with much of the activity diminishing by late afternoon.  Just a slight (30 percent) chance for rain showers is forecast this evening.  Additional totals to near 1 inch will be possible.   Across the Central Texas and coastal regions, there will be a 50 percent chance for rain showers and isolated thunderstorms this afternoon as a cold front pushes southeast across the area.  Just a slight (30 percent) chance for rain showers is forecast this evening and overnight.  Additional totals should average less than a half inch.

A cold front is currently pushing southeast into Central Texas out of the Hill Country.  As noon, the front stretched from near Corsicana to Austin, to just northwest of San Antonio to Del Rio.   Behind the front, the temperature across the Hill Country was generally in the low and mid 60s.  Ahead of the front, readings were in the 70s across Central Texas and in the 80s across the coastal plains.  The front will move across the Central Texas region this afternoon, and the coastal plains region overnight.  Cooler air behind the front along with a cloudy sky will keep today's temperature unusually cool.  High temperatures are forecast to be in the upper 60s across the Hill Country, in the low to mid 70s across Central Texas and in the mid 80s across the coastal plains. Low temperatures Tuesday morning will include the upper 50s across the Hill Country, the low 60s across Central Texas and around 70 degrees across the coastal plains.  Expect a north winds at 10-15 mph for areas behind the front this afternoon and tonight.

The sky is forecast to remain mostly cloudy Tuesday as a weak overrunning pattern continues.  A few spotty showers will still be possible across the coastal plains region but most other locations should stay dry.  High temperatures Tuesday look to be in the upper 70s across the Hill Country and Central Texas regions and in the mid 80s across the coastal plains.  Lows Wednesday morning will range from the mid 50s across the Hill Country to the low 60s across Central Texas to the upper 60s near the coast.

Sunny conditions are forecast to develop Wednesday and continue through late week as the atmosphere dries out and a stable ridge of high pressure develops over the south central US.  A second surge of cooler air is expected to push south across the region Thursday, reinforcing the dry and pleasant conditions.  High temperatures Wednesday through Friday will generally be in the mid 80s.  Low temperature will be in the mid 50s across the Hill Country and the low to mid 60s at most other locations.

Mostly sunny, mild and dry weather conditions will continue this weekend and early next week as a ridge of high pressure holds in place across the region.  Daily high temperatures will be in the mid to upper 80s.  Low temperatures will generally in the low and mid 60s this weekend, and in the upper 60s early next week.

A trough of low pressure tracking east across the Plains states is forecast to push a cold front across our region next Tuesday night into Wednesday morning.  An area of rain showers and isolated thunderstorms is forecast to develop along the cold front, but should quickly clear out behind the front.  As of now, rain amounts are not expected to be very heavy; totaling around a half inch or less.  Dry and slightly cooler weather is forecast next Thursday and Friday.  High temperatures will be in the low and mid 80s with lows in the 50s and 60s.

Tropical Weather Update
National Hurricane Center forecasters are closely monitoring an area of showers and thunderstorms associated with a strong tropical wave and an area of low pressure.  As of early this afternoon, the system was located in the central tropical Atlantic, about 950 miles east-southeast of the Windward Islands.  The system is showing signs of organization and environmental conditions are expected to remain conducive for development.  According to the Hurricane Center, a tropical depression is likely to form in the next day or two around mid-week while the low moves westward to west-northwestward at 15 to 20 mph.  Heavy rains and strong gusty winds will likely spread over the Windward Islands and portions of the southern Lesser Antilles beginning late Tuesday or Wednesday.  An Air Force Hurricane Hunter aircraft is scheduled to investigate this disturbance on Tuesday afternoon.

CPCOutlk.png                                                                                          NOAA-NASA GOES Project

This system has a good chance of becoming a tropical depression or tropical storm somewhere in the Caribbean Sea by late week.  Forecast model guidance indicates this system will track west across the Caribbean Sea this week, reaching a position somewhere over the western Caribbean early next week.  As of now, it's not clear where the system will go from here.  Some of the long-range forecast models call for the system to bend northwest toward Florida or the Bahamas beyond 5 days, but this is far from certain.  There is a chance the tropical cyclone could move into the Gulf of Mexico early next week.  I urge everyone to keep up with the latest developments with this system as we go through the week.

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NHC forecasters are also watching an area of clouds and thunderstorms located over the southwestern Gulf of Mexico, associated with a trough of low pressure.  The clouds and showers and drifting to the west.  Upper-level winds are not unfavorable for significant development before the system moves inland over northeastern Mexico on Tuesday.  NHC forecasters are only giving this system a 10 percent chance for development over the next 48 hours. 

Elsewhere across the tropical Atlantic, the Caribbean Sea and the Gulf of Mexico, there are no systems which pose a threat for tropical development over the next five days.

Bob

Wet and Soggy Weather Expected Sunday through Monday. Fall-Like Temperatures Next Week.
Friday, September 23, 2016 4:11 PM

 

Ingredients are coming together that will likely produce widespread rain showers and thunderstorms across the region Sunday through Monday.  I will point out there's still some uncertainty on the exact timing of the rain and the cooler temperatures, but confidence is high that the current summertime pattern is on its way out.

Friday morning's analysis showed a large trough of low pressure in the upper atmosphere stretching from the Pacific Northwest to the Four Corners region, moving to the east.  In the lower atmosphere, southerly winds have developed across Texas in advance of the trough.  These winds are beginning to pull a deep layer of moisture north from the Gulf of Mexico. The increasing moisture has resulted in the development of some spotty rain showers along the Interstate 35 corridor as well as the coastal plains region.  Additional spotty rain showers are expected across the area this afternoon, with the activity expected to diminish around sunset.  The probability for rain will be near 30 percent at any given location and rain amounts should generally total less than a quarter inch.  Today's temperature will warm to the low 90s.

Today's forecast solutions indicate the trough across the western US will move east  tonight and Saturday.  The trough is forecast to separate into two pieces late Saturday, with the northern half taking off to the northern Plains/Great Lakes region.  Meanwhile, the southern portion of the trough is forecast to sink south across New Mexico Sunday, reaching a position over northern Mexico on Monday.  This portion of the trough will the main driver causing the development of rain showers and thunderstorms across Central Texas Sunday into Monday.

A large plume of very moist air will be drawn north off the Gulf of Mexico Saturday in advance of the approaching trough.  This is expected to result in the development of scattered to numerous rain showers and isolated thunderstorms Saturday afternoon and Saturday night.  The probability for rain will be near 30-40 percent.  Expect a mostly cloudy sky and a high temperature near 90 degrees.  Rain totals are forecast to average mostly between 0.25 and 0.5 inch.

A fairly widespread coverage of rain showers and thunderstorms is forecast to develop across the region Sunday into Monday as the upper trough slowly sinks south into northern Mexico.  With a very moist atmosphere in place, moderate to occasionally heavy rain is forecast.  Some of the heaviest rain is expected to occur late Sunday night into Monday when a Canadian cold front slowly pushes south through the area.  The front looks to push across the Hill Country late Sunday night, reaching the Interstate 35 corridor Monday morning.  The front should push off the middle Texas coast Monday evening.  The probability for rain will near 70 percent Sunday into Monday.  A 40 percent chance for mainly light rain is forecast Monday night.  This will be followed by a 30 percent chance for light rain showers Tuesday.  The chance for rain should taper off Tuesday night into Wednesday morning as the upper low shifts to the west.  Partly cloudy and dry weather is forecast Wednesday through Friday.

This morning's forecast data indicates the highest totals of rain this weekend should occur across the Concho Valley and the western Hill Country.  For the period from 7 am Friday through 7 am next Wednesday morning, the National Weather Service is calling for totals of 5-6 inches across this region.  Totals of 2-4 inches are forecast across the rest of the Hill Country while totals of 1.5-3 inches are forecast from the Austin area southeast to the coast.

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Severe storms are not expected.  However, several locations may experience minor flooding with flood waters capable of causing small streams, creeks, and ditches to become swollen and possibly overflow.

Noticeably cooler air will spread in behind Monday's cold front.  Monday's high temperature is forecast to range from the low 70s across the northern Hill Country to the low 80s near the coast.  High temperatures Tuesday will generally be near 78-80 degrees.  High temperatures Wednesday through Friday are forecast to be in the low to mid 80s.  Low temperatures next week are forecast to be in the 50s across the Hill Country and in the low to mid 60s at most other locations.

Tropical Weather Update

The National Hurricane Center is monitoring a strong tropical wave in the far eastern Atlantic Ocean, located southeast of the Cabo Verde Islands.  This system is moving rapidly westward at about 20-25 mph across the tropical Atlantic Ocean.  This fast motion is expected to continue for the next several days with the system possibly reaching the Lesser Antilles next Tuesday or Wednesday.  Environmental conditions are marginally conducive for some gradual development of this system over the next few days.  NHC forecasters are giving this system a 20 percent chance for tropical development over the next 5 days.

Tropical storm Karl is currently located about in the west central Atlantic, about 230 miles south of Bermuda.  Karl is forecast to pass near or just east of Bermuda Friday night or early Saturday.  Karl is forecast to strengthen into a hurricane Saturday as it accelerates northeast into the open Atlantic.

Tropical depression Lisa is located in the eastern open Atlantic, about 930 miles west-northwest of the Cabo Verde Islands.  Lisa is encountering strong wind shear and is forecast to weaken to a remnant low pressure system Saturday as is continues moving northwest over open waters.

 

WO.png                                                                                         NOAA-NASA GOES Project

 

Weather conditions across the rest of the tropical Atlantic are quiet.  There are no systems which pose a threat for tropical development over the next 5 days.

Have a good weekend.

Bob

Widspread Rain Developing Sunday into Monday. Cooler Temperatures Arriving Monday.
Thursday, September 22, 2016 4:21 PM


Big changes in the weather are expected this weekend and early next week as the first strong cold front of fall slowly moves through our area.  Small changes in the pattern are forecast to take place as early as Friday when tropical moisture is drawn inland by a broad trough of low pressure moving east from the West Coast.  Some scattered, spotty rain showers will be possible around the region, but rain amounts should average less than a quarter inch.  The probability for rain will be 20 percent across the Hill Country and Central Texas regions and near 40 percent towards the coast.  High temperatures will be in the low 90s.

A more widespread coverage of rain showers and isolated thunderstorms is forecast Saturday into Saturday night as the atmosphere becomes increasingly moist and unstable.  The sky is forecast to be  mostly cloudy and the probability for rain will be near 40-50 percent.  Rain amounts are forecast to generally average between 0.25 and 0.5 inch.  Saturday's temperature is still expected to be warm; reaching the lower 90s.

The highest probability for rain and thunderstorms is forecast to occur Sunday into Monday when a piece of the West Coast trough breaks off and sinks south from New Mexico and Far West Texas into northern Mexico.  With a very moist air mass in place, increasing atmospheric lift associated with the advancing trough is forecast to cause the development of widespread rain showers and thunderstorms across the region.  Severe weather is not expected but a few of the storms may cause strong and gusty winds.  The biggest concern over the two-day period will likely be moderate to heavy rain as rain showers develop and slowly track north out ahead of the slow-moving trough of low pressure.  Another factor promoting the moderate to heavy rain will be a Canadian cold front.  The front is forecast to push southeast out of West Texas late Sunday into Monday.  The front is expected to track across the Hill Country late Sunday night, reaching a position just east of the Interstate 35 corridor around sunrise Monday morning.  The  front should continue moving southeast, pushing off the middle Texas coast Monday night.  The threat for moderate to heavy rain is expected to end from west to east Monday afternoon into Monday evening as the cold front pushes into the Gulf.

Rain totals between Sunday morning and Tuesday morning have the potential to be quite high.  Most model solutions are calling for 2-day totals in the range of 3-5 inches.  Do note that some solutions are calling for isolated higher totals, especially across the western and northern Hill Country.

National Weather Service rainfall forecast, for the period from 7 pm Thursday through 7 pm next Thursday:      
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Forecast data indicates occasional light rain showers will continue across the region Tuesday and Wednesday as a weak overrunning pattern sets up.  Rain amounts through the period are forecast to remain under a half inch.  The sky will be mostly cloudy Tuesday and Wednesday but should turn mostly sunny Thursday and Friday.

Monday's cold front is expected to bring a noticeable change in the temperature.  High temperatures Monday are forecast to only be in the mid 70s.  Highs Tuesday and Wednesday are forecast to be in the upper 70s.  Highs are forecast to reach the low 80s Thursday and Friday.  Low temperatures next week will be in the low and mid 60s, with widespread 50s expected across the Hill Country.

I'll pass along another update Friday regarding this significant change in the weather.

Bob

Summer Heat Will Continue through Thursday. Rain Increasing this Weekend.
Tuesday, September 20, 2016 6:00 PM

 

 

Summer heat continues to dominate Central Texas weather thanks to an unusually strong ridge of high pressure.  Tuesday's analysis showed the ridge was centered over central Oklahoma, a shift northeast from when it was near El Paso Monday.  The ridge is causing unusually hot and stable weather conditions across most of Texas.

Today's forecast data indicates we may have seen the peak of the hot temperatures.  The center of the ridge of high pressure is forecast to shift east toward Arkansas Wednesday and the Middle Mississippi Valley Thursday.  While the ridge will still be in place across Central Texas, it is expected to be somewhat weaker and this should translate into slightly lower readings.  High temperatures Wednesday and Thursday are forecast to be in the mid 90s.   

More changes are forecast Friday and this weekend when a large trough of low pressure drops southeast out of the Pacific Northwest.  The trough is forecast to reach a position over the Rockies over the weekend.  One piece of the trough is forecast to lift northeast toward the New Mexico and the Texas Panhandle region.  The advancing trough will help pull moisture north from the Gulf of Mexico beginning Friday.  This will result in a slight chance for rain showers across the Hill Country and Central Texas regions and a 30-40 percent chance for rain across the coastal plains.  High temperatures Friday are forecast to be in the low 90s.

A wet and unsettled pattern is forecast Saturday through Tuesday as waves of low pressure track across the state out of Mexico.  There will be periods of rain and thunderstorms each day.  Some of the rain could even be moderate to heavy in intensity.  The latest National Weather Service 7-day rainfall forecast indicates totals may be in the range of 1-2 inches.

NWS rainfall forecast for the period from 7 pm Tuesday through 7 pm next Tuesday:
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With clouds and rain in the area, high temperatures should be around 88-90 degrees.

Forecast solutions call dry and a little cooler weather next Wednesday through Friday as a weak area of Canadian high pressure settles south across the state.  High temperatures are forecast to be in the upper 80s with low temperatures in the low and mid 60s.  A noticeable change.

Bob

Summer-Like Temperatures Expected through Thursday. A Chance for Rain this Weekend.
Monday, September 19, 2016 3:49 PM

A very summer-like weather pattern developed across Texas over the weekend and this pattern looks to persist through late week.  Today's analysis showed a large dome of high pressure in the upper atmosphere covering the southwestern and south central US along with northern Mexico.  The ridge was centered just west of El Paso.  Interestingly, this ridge is of roughly the same strength we typically find during July and August, so it's no surprise that temperatures over the next couple of days will be unusually hot and at near record levels.  The ridge is forecast to weaken significantly late this week and long-range solutions indicate we shouldn't see a return of this kind of hot pattern anytime in the near future.


 

Analysis of upper air pattern at approximately 30,000 feet
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With the ridge in place, mostly sunny, dry and hot weather conditions are forecast today through Thursday.  There may be just enough moisture in place each afternoon to cause a few isolated rain showers across the coastal plains region.  However, the rain will be spotty in nature and totals should average less than a quarter inch.   High temperatures today and Tuesday are forecast to be in the upper 90s.  High temperature Wednesday and Thursday are forecast to be in the middle 90s.  Keep in mind the normal high temperature for late September is around 88 degrees, so this week's readings will be well above normal.

A change in the pattern is forecast to take place late week into this coming weekend when the ridge of high pressure over the south central US shifts to the Lower Mississippi Valley and the southeastern US.   At the same time, a large, broad trough of low pressure is forecast to develop across the western US.  The northern half of the trough is forecast to take off northeast to the northern Plains states late Sunday into Monday.  Meanwhile, the southern half of the trough is forecast to break away from the main trough and set up over the Desert Southwest this weekend, continuing into early next week.  With the ridge weakening and a trough setting up over the southwestern US, we should begin to see a change in our weather.  Gulf moisture will begin returning northwest into Texas Friday in advance of the southwestern trough, resulting in the development of scattered rain showers and isolated thunderstorms.  The probability for rain Friday will be near 30 percent.  A 30-40 percent for rain showers and thunderstorms will continue over the weekend and early next week as disturbances rotate around the southwestern trough and move across Texas.  Periods of rain and thunderstorms are forecast.  As of now, rain amounts through the upcoming period are not expected to be very heavy, with most totals around and an inch.  However, this could change, depending on how the southwestern trough evolves.  High temperatures are forecast to lower to around 90 degrees Friday and be near 88-90 degrees this weekend and early next week.

A weak cold front is forecast to spread south across Texas next Tuesday.  This front is expected to bring slightly cooler weather for the second half of the week.  High temperatures should lower to the mid and upper 80s with low temperatures in the mid and upper 60s.  While not exactly fall weather, this front should produce a noticeable, pleasant change in the temperature.

Tropical Weather Update
Tropical storm Karl is churning over the central tropical Atlantic.  As of early this afternoon, Karl was centered about 895 miles east of the Leeward Islands.   Karl is moving toward the west near 13 mph, and this motion is expected to continue through tonight.  A west-northwestward motion at a similar forward speed is expected on Tuesday.  Maximum sustained winds are near 40 mph with higher gusts. Some slight strengthening is forecast during the next 48 hours.  Karl is forecast to turn north towards Bermuda late this week.

Tom2.png                                                                       NOAA-NASA GOES Project


Showers and thunderstorms associated with a low pressure system are located in the far eastern tropical Atlantic, several hundred miles southwest of the Cabo Verde Islands.  This system continues to show signs of organization and it appears that a tropical depression could be forming.  Occasional heavy rains and gusty winds associated with this system should diminish later today over the Cabo Verde Islands while the low moves westward over the eastern tropical Atlantic.  NHC forecasters are giving this system a 90 percent chance for tropical development over the next 48 hours.  NHC forecasts call for this potential system to bend northwest into the open Atlantic over the next 5 days, with little potential for the disturbance to track west toward the Caribbean Sea.

Elsewhere, conditions are quiet.  There are no other systems in place across the Atlantic, Caribbean Sea and the Gulf of Mexico which pose a threat for development over the next 5 days.

First Day of Autumn
Although our weather certainly won't feel like autumn, the autumnal equinox will occur this Thursday, September 22nd at 9:21 am CDT.  On Thursday, most all locations across the globe will experience roughly 12 hours of daylight and 12 hours of darkness.      

Bob

A Chance for Rain Showers Saturday; Dry and Warm Conditions Expected For Most of Next Week.
Friday, September 16, 2016 12:20 PM

Forecasters continue to monitor an area of disturbed weather located over the northwestern Gulf of Mexico.  Friday morning's analysis indicated this system did not become organized overnight and it now appears unlikely this system will develop into an organized tropical cyclone before moving inland tonight along the upper Texas coast.  NHC forecasters are giving this system only a 10 percent chance for tropical development before moving inland.  High-resolution forecast data calls for most of the moisture from the disturbance to spread northeast across southeast Texas and southern Louisiana this evening and Saturday.  A modest amount of tropical moisture is forecast to spread over the middle Texas coast late tonight and Saturday and this should promote the development of scattered to numerous rain showers and thunderstorms, mainly for areas to the south of Interstate 10.  The probability for rain will be near 40-50 percent.  Wind speeds along the middle Texas coast should stay fairly light.  The disturbance will cause higher than normal tide levels along the middle Texas coast this evening and overnight.  

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A weak ridge of high pressure is in place across Central and South Texas, causing a warm and fairly stable weather pattern.  However, occasional weak disturbances are tracking northeast across West and Northwest Texas, along the western edge of the upper ridge.  These disturbances caused rain and thunderstorms across parts of West Texas and the Concho Valley Thursday afternoon and again early Friday morning.  Some of these storms grazed parts of the northern watershed Thursday afternoon and a similar scenario is forecast this afternoon.  There will be a slight chance for rain and thunderstorms this afternoon across the northern Hill Country while the remainder of the Hill Country and all of Central Texas stays generally dry.  Today's temperature is forecast to reach the low to mid 90s.

A trough of low pressure embedded within the southwesterly wind flow over West Texas is forecast to track a little further to the east on Saturday. This system is expected to cause the development of scattered rain showers and thunderstorms across the Hill Country and Central Texas regions Saturday afternoon and Saturday evening.  However, widespread or soaking rains are not expected.  The probability for rain will be 30 percent.  Rain amounts are forecast to average between 0.25 and 0.5 inch.  Expect a partly to mostly cloudy sky.  High temperatures will again be the low to mid 90s.

Just a slight chance (20 percent) for rain showers is forecast across the region on Sunday.  The sky will be partly cloudy and temperatures should warm to the low and mid 90s.

The southwesterly wind flow across West Texas is forecast to diminish Monday.  Meanwhile, the ridge of high pressure over Texas is forecast to strengthen and hold in place next Monday through Friday.  The ridge is expected to cause a mostly sunny and very warm weather pattern.  Daily high temperatures are forecast to be in the mid 90s. The ridge is forecast to weaken some next weekend when a weak cold front sags south into Texas.  The weaker ridge and cold front are expected to lower afternoon temperatures about 2-3 degrees.

Looking out longer-range, there are indications a somewhat stronger cold front will push into Texas around the middle of the following week (approximately September 27th or 28th).  This front is expected  to bring some slightly cooler temperatures.  However, I'm not convinced yet this will be our first good cold front of autumn.

Tropical Weather Update
The National Hurricane Center continues to closely monitor the progress of tropical storm Julia, located just off the southeastern coast of the US, about 240 miles southeast of Cape Fear, North Carolina.  Maximum sustained winds are near 40 mph.  A slow and erratic motion offshore of the coast of South Carolina is expected during the next couple of days.

Tropical Storm Karl developed Thursday in the far eastern Atlantic.  This morning, Karl was centered about 700 miles west-northwest of the Cabo Verde Islands.  Maximum sustained winds are near 45 mph.  Karl is moving toward the west near 13 mph and this general motion is expected to continue through the weekend.  5-day forecasts call for Karl to track generally west over the central tropical Atlantic.  Karl's path is forecast to bend northwest around the middle of next week, reaching a position northeast of the Lesser Antilles.

A tropical wave moving off of the coast of Africa into the far eastern Atlantic is expected to move west-northwestward for the next few days.  Some development of this system is possible before conditions become less favorable for tropical cyclone formation by the middle of next week. 

Weather conditions across the rest of the Atlantic, Caribbean Sea and the Gulf of Mexico are quiet.  There are no other systems in place which pose a threat for tropical development over the next 5 days.

Harvest Moon
According to folklore, tonight's full Moon will be the Harvest Moon.  The Harvest Moon is defined as the full moon that occurs closest to the autumnal equinox.  The equinox occurs next Thursday , September 22nd at 9:21 am CDT.  The Harvest Moon will very big and bright.  This unusually bright moon will be visible for the next few nights as well.

Bob
Disturbed Weather Continues Across the Western Gulf. System is Drifting to the West.
Thursday, September 15, 2016 4:58 PM

Satellite images and buoy reports this afternoon indicate the area of disturbed weather located over the Gulf of Mexico has become a little better organized.  A weak wind field is currently noted across the Gulf of Mexico, with wind speeds less than 20 knots.  A weak low pressure center at the surface can be seen in this wind field.  While surface pressures have fallen a little since yesterday, they still remain fairly high so nothing is developing very quickly.  The low is currently in an environment that is just marginally favorable for tropical development.  Upper-level winds to the north and to the west of the system are quite hostile, so significant tropical development is not expected.  National Hurricane Center forecasters indicate the probability for development is low, but they have increased the probability for development to 20 percent.  Since this system is so close to the Texas coast, this system will need to be monitored closely over the next 36 hours.

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The system is drifting slowly to the west and is forecast to push inland along the middle and lower Texas coast Friday afternoon or Friday night.  Rain showers and thunderstorms are forecast to increase along the middle and lower Texas coast Friday afternoon with a good chance for rain and thunderstorms expected across the coastal region Saturday and Sunday.  The probability for rain will be near 50 percent  Friday afternoon, Saturday and Sunday.  3-day totals are forecast to average between 1 and 2 inches, with isolated heavier totals.

The area of disurbed weather over the Gulf is forecast to track southwest across South Texas this weekend.  The majority of the clouds and moisture associated with the system is forecast to stay across the coastal plains and South Texas, generally south of a San Antonio to Columbus line.  Across the Hill Country and Central Texas regions, there will be a 20 percent chance for scattered rain showers Friday and a 30 percent chance for mainly afternoon and evening showers and thunderstorms over the weekend.  Rain amounts are forecast to stay below a half inch.  

Warm temperatures look to continue this weekend and all of next week.  High temperatures are forecast to stay mostly in the low 90s.

Looking out longer range, today's forecast solutions indicate we may see a weak cold front move into the area next weekend, followed by a stronger cold front around the 27th or 28th.   I'll pass along more details on this in Friday's report.

Bob

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