Tallis Rockwell Posted December 20, 2018 Share Posted December 20, 2018 Some decent instability and modest shear are going to meet in Southeast Texas and Louisiana next week. ZCZC SPCSWOD48 ALL ACUS48 KWNS 200818 SPC AC 200818 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Thu Dec 20 2018 Valid 231200Z - 281200Z ...DISCUSSION... High-PW air mass will be shunted off the Atlantic coast during the day2 period. Current medium-range model guidance suggest numerous fast-moving short waves will traverse the CONUS such that moisture/instability will struggle to return north until Christmas day when a significant moisture surge is expected across the western Gulf basin into TX. This moisture surge will be induced by a significant trough that will progress across the southwestern US/southern Rockies region. While models agree broadly that destabilization should occur across the southern Plains, timing of the ejecting trough may greatly influence potential severe threat with this feature. Will not introduce severe probs at this time but organized convection may ultimately evolve during the day7/8 time frame. ..Darrow.. 12/20/2018 Could this be a significant event? Link to comment Share on other sites More sharing options...
Tallis Rockwell Posted December 24, 2018 Author Share Posted December 24, 2018 NAM is starting to put in a much more interesting mode over Houston and Central TX Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0212 AM CST Mon Dec 24 2018 Valid 261200Z - 271200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF CENTRAL TEXAS IN THE EVENING AND INTO SOUTHEAST TEXAS OVERNIGHT WEDNESDAY... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday over portions of central Texas during the evening and moving into southeast Texas overnight. ...Synopsis... A lower-latitude, mid-level shortwave trough will eject east into the central-southern High Plains from the southern Rockies with a closed mid-level circulation evolving Wednesday night over southwest KS. A broad belt of strong, cyclonic mid-level flow will overspread a destabilizing moist sector located over TX/OK. In the low levels, a surface cyclone will develop northeastward from the TX/NM border across the TX/OK Panhandles and into north-central KS by early Thursday morning. A north-south dryline is forecast from the eastern TX Panhandle into southwest TX and a Pacific cold front will overtake the aforementioned boundary and accelerate east across much of central TX late. ...TX Panhandle/far western OK into northwest TX... A seemingly conditional risk for severe thunderstorms will probably unfold beginning by the early-mid afternoon through the evening over this region. Strong low-level moisture transport will occur to the southeast of a deepening surface low, in a warm sector with an increasingly narrow moist/unstable airmass with northwest extent, from western north-central TX northwestward into the eastern TX Panhandle. Despite boundary-layer dewpoints only in the mid to upper 50s, very cool 500mb temperatures (-17 to -18 degrees C) may yield SBCAPE in the 250-750 J/kg range. However, strong DCVA (and 120m/12hr 500mb height falls over the South Plains between 12z-00z) may promote an early convective initiation (CI) during the morning over West TX. The early CI scenario is possible and would have deleterious effects on the development of buoyancy. As it stands currently, a marginal risk for severe gusts and perhaps a tornado seem to be a sufficient highlight. But...if the early CI scenario does not occur and a brief window (1-2 hour) of cloud breaks and heating can occur, a greater risk for supercells with an attendant tornado/wind risk would develop. ...Central into eastern TX... A moist airmass, characterized by lower to middle 60s degree F dewpoints, will gradually destabilize during the day as stronger deep-layer forcing for ascent remains to the west and northwest of the region. Strong south-southeasterly low-level winds veering to the southwest in the mid levels will result in a wind profile supporting thunderstorm organization. By the late afternoon/early evening, thunderstorms are forecast to develop over the Concho Valley with thunderstorm coverage expected to increase as this activity moves into richer low-level moisture near I-35. Severe gusts and the possibility for a few tornadoes may accompany a band of thunderstorms as it grows upscale and moves east reaching the Upper Coast of TX during the midnight-6am CST period. Farther north over northeast TX, weaker instability may result in a lower risk for wind damage as thunderstorms move through the area overnight. Link to comment Share on other sites More sharing options...
Sydney Claridge Posted December 26, 2018 Share Posted December 26, 2018 And we now have an enhanced risk (with 10% tornado risk/30% severe wind risk) including Austin and the NW suburbs of Houston, with the slight risk extending northwards to DFW. I'm a little skeptical of severe in DFW given that most of the models tend to keep them in the lower-to-mid-60s for temperatures (with dew points a few degrees lower) along with what appears to be multiple rounds of convective precipitation, though the shear seems good, and the models have at least trended a little bit upwards on moisture return. The presence of isolated thunderstorms in a high-shear environment on the HRRR and NAM 3k does have me a bit intrigued, though much of this appears to be elevated convection ahead of the main line. With such a slow year for severe thunderstorms it has been at least it is something. Hopefully 2019 will have some more interesting setups to look forward to. Link to comment Share on other sites More sharing options...
Tallis Rockwell Posted December 26, 2018 Author Share Posted December 26, 2018 This looks to be an interesting hit or miss scenario... any cells that become surface-based could turn into super cell. Link to comment Share on other sites More sharing options...
Sydney Claridge Posted December 26, 2018 Share Posted December 26, 2018 Winds are picking up here in Fort Worth. Also, SPC has expanded the Enhanced risk zone further west and northwards, now including Abilene and reaching just south of DFW. Slight risk now goes up to the Red River and even includes a little bit of southern OK. Definitely seems that the SPC is hinting towards stronger moisture return further north, as the tornado risk has also shifted northwards too. Link to comment Share on other sites More sharing options...
Tallis Rockwell Posted December 26, 2018 Author Share Posted December 26, 2018 Do you think that there will be any significant convection? To me this setup seems to be coverage and duration over intensity, Link to comment Share on other sites More sharing options...
Sydney Claridge Posted December 26, 2018 Share Posted December 26, 2018 Not severe at the moment but there appears to be strengthening cell on radar near San Saba, TX. There is good overlap between helicity and instability there per the SPC mesoscale analysis page. SPC also just issued a "tornado watch likely" mesoscale discussion for this area as well. Link to comment Share on other sites More sharing options...
Tallis Rockwell Posted December 26, 2018 Author Share Posted December 26, 2018 Do know a place where i can get velocity radar? I don't how it will go since there seems to be clutter. Link to comment Share on other sites More sharing options...
Tallis Rockwell Posted December 26, 2018 Author Share Posted December 26, 2018 First watch for the squall line. Link to comment Share on other sites More sharing options...
cheese007 Posted December 26, 2018 Share Posted December 26, 2018 Tor watch out for big swath of the state until 10. Wonder if it will be expanded later Link to comment Share on other sites More sharing options...
CheeselandSkies Posted December 26, 2018 Share Posted December 26, 2018 Several cells in the Waco vicinity have the "look" on reflectivity, but no warnings as of yet.Sent from my SM-G955U using Tapatalk Link to comment Share on other sites More sharing options...
Jebman Posted December 26, 2018 Share Posted December 26, 2018 11 hours ago, BrandonC_TX said: And we now have an enhanced risk (with 10% tornado risk/30% severe wind risk) including Austin and the NW suburbs of Houston, with the slight risk extending northwards to DFW. I'm a little skeptical of severe in DFW given that most of the models tend to keep them in the lower-to-mid-60s for temperatures (with dew points a few degrees lower) along with what appears to be multiple rounds of convective precipitation, though the shear seems good, and the models have at least trended a little bit upwards on moisture return. The presence of isolated thunderstorms in a high-shear environment on the HRRR and NAM 3k does have me a bit intrigued, though much of this appears to be elevated convection ahead of the main line. With such a slow year for severe thunderstorms it has been at least it is something. Hopefully 2019 will have some more interesting setups to look forward to. I sure hope not. I really do NOT want a tornado in North Buda near the county line where I now reside. It only takes one tornado to ruin your day. Link to comment Share on other sites More sharing options...
Tallis Rockwell Posted December 26, 2018 Author Share Posted December 26, 2018 First warning BULLETIN - EAS ACTIVATION REQUESTED Tornado Warning National Weather Service San Angelo TX 445 PM CST WED DEC 26 2018 The National Weather Service in San Angelo has issued a * Tornado Warning for... Northern Callahan County in west central Texas... * Until 530 PM CST. * At 445 PM CST, a severe thunderstorm capable of producing a tornado was located over Eula, or near Clyde, moving east at 35 mph. HAZARD...Tornado. SOURCE...Radar indicated rotation. IMPACT...Flying debris will be dangerous to those caught without shelter. Mobile homes will be damaged or destroyed. Damage to roofs, windows, and vehicles will occur. Tree damage is likely. * This dangerous storm will be near... Baird around 500 PM CST. Putnam around 520 PM CST. Other locations impacted by this tornadic thunderstorm include Admiral and I-20 Near The Callahan-Eastland County Line. This includes Interstate 20 between Mile Markers 295 and 323. Link to comment Share on other sites More sharing options...
cheese007 Posted December 26, 2018 Share Posted December 26, 2018 New tor watch issued including Austin and San Antonio Link to comment Share on other sites More sharing options...
CheeselandSkies Posted December 27, 2018 Share Posted December 27, 2018 The safest area was bang in the middle of the "enhanced" risk. Calendar still says 2018, for 4 1/2 more days. Link to comment Share on other sites More sharing options...
Tallis Rockwell Posted December 27, 2018 Author Share Posted December 27, 2018 My first bust. Link to comment Share on other sites More sharing options...
mayjawintastawm Posted December 28, 2018 Share Posted December 28, 2018 And they canceled the Cotton Bowl!?! BC was in for the first time since Doug Flutie (remember him?) was QB and my sister was a freshman way back in 1985. I was looking for a zillion LSRs today and found basically none in the Metroplex area near the time of the game. Guessing too much CIN and cloud debris to get things going. Of course, lightning alone can ruin your day, but still. What happened? Link to comment Share on other sites More sharing options...
CheeselandSkies Posted December 28, 2018 Share Posted December 28, 2018 Not the Cotton Bowl itself - that's tomorrow. The delayed/cancelled game was the Heart of Dallas/First Responder Bowl, which was being held at Cotton Bowl Stadium. Link to comment Share on other sites More sharing options...
cheese007 Posted December 29, 2018 Share Posted December 29, 2018 On 12/27/2018 at 8:09 AM, CheeselandSkies said: The safest area was bang in the middle of the "enhanced" risk. Calendar still says 2018, for 4 1/2 more days. That is peak 2018 right there Link to comment Share on other sites More sharing options...
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