MTW Discussion

The 2009 Atlantic Hurricane Season does not begin for another few days, but there is plenty to watch in the Gulf of Mexico right now. Just east of New Orleans there is a very well organized tropical disturbance packing tropical storm force winds to the northern Gulf coast. The National Hurricane Center rates the probabilities of tropical cyclone formation as high. The mitigating factor inhibiting development prior to landfall is the proximity to land. As of 1:30AM CDT, the center of circulation is approximately 50 miles from land. With the storm moving essentially due north, it may not have enough time over water to fully develop a closed circulation and reach Tropical Storm status. However, if the circulation does close, I suspect the National Hurricane Center will name the storm Ana immediately as maximum sustained winds are well over Tropical Storm force.

Should “Ana” be declared, MyTexasWeather will keep you updated. Check out our Tropics page for the latest information.  I don’t think that this storm will have much of an effect here on South-Central Texas as the upper level jet should push most of the energy out east.

Meanwhile back out here, we are tracking a weakening ridge and numerous storms that develop with the help of daytime heating.   The capping inversion I briefly discussed last time eroded much quicker than anticipated, which is why many of you reported rain yesterday and why we say so much lightning overnight.  The same general setup should persist through the weekend with scattered hit and miss thunderstorms.  I do think these storms will be slightly more numerous this weekend than they were Friday.  Due to the lack of upper level winds, these storms will move very slowly if at all.  However, the good news is that the lack of sufficient wind shear will prevent these storms from reaching severe limits. But, I would not be surprised if a couple of these storms get strong enough to drop small hail here and there.

By Monday and Tuesday the winds will shift to the South and Southwest.  This will help reduce the humidity but also increase the temperatures drastically. You may want to limit the amount of heat you add to the barbecues on Memorial Day as the outdoor air temperature should suffice.  Highs on Monday should hover in the mid 90s under partly cloudy skies.  Tuesday, however, may top out near 100 degrees.

Beyond Tuesday, a series of shortwave troughs will move through the region allowing for storms to develop on a nearly daily basis beginning Wednesday.  As the event(s) near, I will be able to get more specific on what to expect out of these storms.  However at this time, a severe weather outbreak is not anticipated.

Stay tuned.

Another spectacular afternoon across South-Central Texas on Wednesday.  High temperatures topping in the mid 80s with clear skies and low relative humidity.  It is impossible to ask for anything better towards the end of May, no?

Unfortunately, yesterday was probably the last nice and cool day we will experience for quite a while… possibly even until the fall.  Atmospheric heights aloft are going to progressively weaken, which will in effect weaken the strong cap we have on top of us.  At the same time, computer models are bringing in a surface low across the state.  Both factors combined leave the possibility for some showers and thunderstorms to develop across the region mainly on Saturday, however some of the storms may linger through the overnight hours  Saturday night and into early Sunday morning.   Due to the lack of upper level dynamics, severe weather is not likely.  However we will have enough instability in place that some small hail cannot be ruled out in some of the storms that do develop.

Late Sunday and into the early portions of next week, the atmospheric heights rebuild and the winds will shift towards the west at the surface.  This will dry out the atmosphere both aloft and at the surface and add a compressional heating component.  Computer models are trending warmer for Monday and Tuesday, and our current 8-day reflects these changes.   Triple digit heat is certainly not out of the question.   The main mitigating factor will be how much rain we recieve this weekend as to how hot it will get early next week.  The wetter the soil, the more insulated our temperatures will remain.

As we move into the longer range, models show absolutely no agreement.  Some runs bring in deep troughs into the region and other runs promote ridging aloft.  Keep checking the latest blog updates for up-to-the minute weather information.

Stay tuned.

Yes, yes… I know its been a while since the last update.  You will have to forgive me for the laziness. :)  That said, there are quite a few things to discuss in this entry with respect to the weather across South-Central Texas.

First and foremost, the current drought situation. According to the Drought Monitor (viewable on our website here), all of South-Central Texas remains in an Extreme or worse drought, while from points from San Antonio southward still face a chart-topping Exceptional drought. While we have seen beneficial rainfalls across the region recently, much more is needed to reverse the effects of this long-term drought.

Unfortunately, relief may come too late to do us much good.  As of May 12, 2009, the J-17 Well in Bexar County, where the official Edwards Aquifer readings are recorded, stands at 652.1 feet above sea level.  That is 2.1 feet above the trigger for Stage 2 watering restrictions for the city of San Antonio and SAWS customers.  For more information regarding Stage 2 watering restrictions, visit the SAWS website.

However, despite the news about the drought situation worsening, we do have some glimmers of hope for rain falling across our region.  The upper level ridge which has been sitting on top of us for at least the last week and a half providing plenty of heat and smog is showing signs of weakening.  That means that the air is not sinking as rapidly, allowing for the air and subsequent moisture in the air to rise more freely.  The more the ridge weakens, the better the lifting motion and the easier it becomes to fire off thunderstorms during the peak hours of daytime heating.  If you check our new 8-day we have increasing rain chances now through the weekend across South-Central Texas.

The weakening of the ridge will also allow for disturbances to sneak through the area. Saturday night into Sunday the flow aloft will switch from the Southeast to the North.  Usually when this occurs, conditions are favorable for the development of an organized complex of thunderstorms, otherwise known as a Mesoscale Convective System (MCS).  These are excellent sources for heavy beneficial rains in a short period of time.  Should this occur, we will keep a very close eye on what develops over the Panhandle and North Texas to see what heads our direction.

Behind the possible MCS will be a surge of “cooler” and drier air. Instead of flirting with 100, our highs will flirt with 90 Monday and Tuesday.  Overnight lows will bottom out in the 60s, much cooler than the middle to upper 70s we have been contending lately.   Winds will shift back to the southeast late Tuesday into Wednesday bringing in more humidity across our region.

Looking into the long-term I see an interesting, yet unconvincing pattern.  For some reason long-range computer models want to bring in a more Spring-like weather pattern than the summer one we have been dealing with as of late.  That is, it wants to bring the storm track further south and inhibit the development of a powerful subtropical ridge.  I don’t quite buy into yet since such a pattern is becoming increasingly unseasonable and seems quite backward to what we have experienced thusfar.  Stay tuned.

After a record-breaking high of 99� in San Antonio Thursday, we will enjoy a cooler afternoon today. Expect highs to stay in the low-to-mid 80s across South-Central Texas as a cold front heads south around the Rio Grande Valley. Tomorow, the front will retreat northward passing though here as a warm front bringing in a warm, humid, tropical air mass into the region.

We’re setting up for a nasty outbreak for severe thunderstorms across South-Central Texas Easter weekend. A powerful upper level low that will be moving in from California will bring in the proper dynamics, instability, and moisture to generate widespread severe thunderstorms beginning as early as Saturday afternoon across West-Central Texas shifting eastward into the rest of the state overnight Saturday and all day Easter Sunday.

Expect storms to fire up across West-Central Texas first on Saturday Afternoon in the form of scattered supercells. The main threat on Saturday will be large hail, and isolated reports of damaging winds. I really do not expect a high tornado threat, though one or two cannot be ruled out. These storms will continually progress eastward throughout the evening and overnight hours as they organize and form a Mesocale Convective Complex (MCS), or squall line. The main threats out of any MCS that forms will be damaging winds, hail, an isolated brief tornado, and much needed heavy rain.

As we head into Sunday morning and afternoon, more storms should fire up in the incredibly unstable airmass we have in South-Central Texas. During this period will be our greatest risk for severe storms in the San Antonio-Austin metropolitan areas with the main threats being very large hail, damaging winds and tornadoes. It is possible for a secondary line of storms to form along the dryline that will pass through later in the afternoon on Easter ending our threat for severe weather.

Later on in the evening on Sunday, we are expecting more supercell thunderstorms to develop across North and East Texas. The largest limiting factor will be instability, but if we have enough, then the scope of the outbreak will be huge with long-lived tornadic supercells before a final line moves through.

We will bring you the latest updates on MyTexasWeather via the forum, Twitter, front page, and Justin.tv. Stay tuned!

Another perfect day across South-Central Texas today.  The San Antonio International Airport reached a maximum afternoon temperature of 79º under partly cloudy skies.

The next such day may take a while to return. Humidity is on the increase with a steady southeast wind at the surface.  Moisture is also on the increase in the mid to upper levels from the Pacific due to an offshore trough.  A series of storm systems approaching the West coast now will move through the central plains this weekend and early next week.   These systems will be generally weaker than the powerful system that brought severe weather to the region earlier this week.  Therefore, we will be hard-pressed to recieve soaking, beneficial rainfall.   Any rain that falls Friday through Tuesday should be light in nature.  A final cold front will move through the region on Tuesday, leaving the possibility of a thunderstorm.

Beyond Tuesday, the skies will clear and the humidity will drop.  However, temperatures will remain pleasant in the 70s in the daytime and lower 50s to upper 40s at night. Another system may approach the region by late Friday or early Saturday of next week.