Late Notes on Thursday’s Severe Weather Risk
- Thursday, 12 June 2014 01:30
The new severe weather outlook for Thursday has a few changes compared to the outlook we shared on Wednesday. Again I should emphasis that we could still see changes to the outlook areas depending on any residual outflow boundaries and cloud cover today. With that in mind here is the new outlook from the Storm Prediction Center. An enhanced threat of severe weather is expected from the mid afternoon hours (say from 3 to 4 PM) into the mid-evening hours across portions of the Hill Country, North Texas, Central Texas, Northeast Texas, and East TExas. Brownwood, Killeen, Waco, all of the D/FW Metroplex, Paris, Longview, Texarkana, Shreveport, and Lufkin are in the enhanced risk zone highlighted in red on the outlook graphic. Those locations are where confidence is currently highest in the possibility of severe weather occuring later today. Initial storm development will likely be discrete and supercellular. The strongest storms could produce destructive hail up to the size of baseballs, localized damaging wind gusts over 70 MPH, and even a few tornadoes as they move east/southeast. Not all locations in the enhanced risk zone will be impacted by severe weather today but the zone does highlight where there will likely be more high-impact severe storms today. Surrounding the enhanced risk zone is an area of possible severe weather which includes Wichita Falls, Abilene, San Angelo, Sonora, Kerrville, Austin, and College Station. The orange zone on the graphic will likely have a few strong and severe thunderstorms but confidence and the overall threat is not as high as the enhanced risk zone. The strongest storms definitely could produce large hail and damaging wind gusts. Otherwise there is a small possibility of a couple strong storms and maybe an isolated severe storm in the yellow shaded regions.
We continue to anticipate a volatile atmosphere across North Texas by the afternoon hours as rich moisture combines with surface heating and a storm system aloft to produce an extremely unstable atmosphere. While wind shear values will not be as impressive compared to April or May the extreme instability values will likely compensate for the weaker winds aloft and create the threat for significant severe weather. Luckily the weaker wind shear will help keep the tornado threat at bay (mostly) with the threat of very large, destructive hail being a big player in today’s strongest storms. Should the storms form into a cluster by the evening hours there is the potential for an enhanced damaging wind threat tonight.
The tornado threat today is secondary compared to the damaging hail and gusty wind threats but because of the extremely high instability values and residual outflow boundaries from storms on Wednesday there could definitely be a couple tornadoes with any dominant supercell that interacts with an outflow boundary today. The tornado threat will be of most concern in the enhanced risk zone highlighted on the graphic. Jenny is on vacation and camping down in Fairfield which just so happens to be in the enhanced risk zone today. While she won’t be chasing I wouldn’t be surprised if she ended up ‘driving’ around a bit and just so happen to come upon a storm. I’ll be in the weather center covering today’s threats online. I’ll also be watching for any impressive live streams from storm chasers. If some manage to pop up today I’ll be sure to share their links for your viewing pleasure.
Weather Roundup – Wednesday June 11th
- Wednesday, 11 June 2014 14:26
Jenny will be offline for the next few days as she enjoys a camping trip with her family. Meanwhile our state is headed back into an active weather pattern with increasing moisture and instability in the atmosphere. The result will be the risk for severe weather over the next two days especially as we get into Thursday across North and Northeast Texas. We’ll focus on today’s storm potential in this article.
The Storm Prediction Center has placed portions of the Texas Panhandle, Northwest Texas, and West-Central Texas in a risk for a few severe storms later this afternoon and into the overnight hours. This risk runs east of a Amarillo, Lubbock, and Midland line to Vernon, Abilene, Ballinger, and Sonora. We could see a couple strong to marginally severe storms surrounding the possible risk zone into North Texas later tonight. Based on the latest high resolution weather model data I wouldn’t be totally shocked to see the low and possible risk zones extended east towards Interstate 35 in the next severe weather outlook due out around 3 PM. High cloud bases and weak low level wind shear will keep the threat for tornadoes minimal today with the strongest storms likely capable of producing damaging straight-line winds up to 70 MPH and half dollar to golf ball size hail this afternoon in the ‘possible’ risk zone. While not shown on the risk graphic the storms may form into one or two complexes by mid-evening and push east towards Interstate 35 in North and Central Texas. By the time these storms reach I-35 they should be in a weaker state but may remain strong with gusty winds.
By late afternoon we expect at least a couple of thunderstorms to develop on the western axis of higher moisture values in the Texas Panhandle into West and Southwest Texas. As discussed above these storms will be high based but could be strong to severe with strong winds up to 70 MPH and large hail. As these storms begin to move east they could congeal into at least one cluster of thunderstorms. These clusters would likely continue to produce gusty winds on their leading edges and maybe some small hail as they move east. There is some uncertainty on how far east these storms will go tonight but the latest weather model guidance does suggest they will make it to Interstate 35 in North Texas by the late evening hours (11 PM – 1 AM). They shouldn’t be as strong as they were earlier in the evening across West Texas by the time they reach I-35 but could still contain stronger cores of gusty winds and lightning. Should a cluster of storms move into North Texas tonight it will likely play a role in thunderstorm chances on Thursday as residual outflow boundaries and any post-storm impacts (clouds, etc) could either enhance or decrease the severe weather threat. We’ll have more about Thursday’s storm threat in a separate blog post later this evening as we continue to look over data and keep an eye on trends. Tomorrow’s threat does look to be more significant than today across parts of North, Central, and East Texas so please stay tuned.
Tornado Watch Coming Soon for parts of West Texas
- Saturday, 07 June 2014 15:36
The Storm Prediction Center has indicated a Tornado Watch will likely be issued within the next hour or so for parts of West Texas including the South Plains. The first thunderstorm of the day has recently fired up near Tucumcari, NM. Today’s focus point for enhanced severe weather and tornado potential will be an outflow boundary which is sitting from near Muleshoe to Ralls. This outflow boundary is locally enhancing low level wind shear in an environment favorable for supercell development. Cloud bases and other parameters will favor an elevated tornado risk in this area through this evening with dominant right-moving supercells. Besides the tornado risk a risk of very large hail up to the size of baseballs and straight-line winds over 75 MPH will also be possible with the most intense thunderstorms. Today’s tornado risk is elevated compared to Thursday and Friday. Those across West Texas and the South Plains should have a way to receive weather warnings this afternoon and evening. David Drummond will be chasing along with Jenny Brown. I’ll be hanging back today so I can provide timely updates on the weather situation.
MESOSCALE DISCUSSION 0882
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT SAT JUN 07 2014
AREAS AFFECTED…EASTERN NM…TX SOUTH PLAINS/SRN TX PANHANDLE
CONCERNING…SEVERE POTENTIAL…WATCH LIKELY
VALID 072027Z – 072230Z
PROBABILITY OF WATCH ISSUANCE…80 PERCENT
SUMMARY…SUPERCELLS ARE EXPECTED TO DEVELOP ACROSS EASTERN NM AND
THE TX SOUTH PLAINS OVER THE NEXT FEW HOURS. VERY LARGE HAIL WILL
ACCOMPANY THIS ACTIVITY…ALONG WITH A RISK OF TORNADOES.
Evening Update – Flash Flooding Concerns – West Central, Central, South Central & Southeast Texas
- Monday, 26 May 2014 21:32
I don’t think anyone is going to complain too much about any ongoing and anticipated Flash Flooding across parts of west central, central and south central and southeast Texas. This includes the cities of Midland/Odessa, Big Spring, Abilene, Stephenville, Cleburne, Waco, San Angelo, Kerrville, Austin/San Antonio, Bryan/College Station, Huntsville and Houston. Yes, it’s an annoyance, but considering our ongoing severe drought, we’ll take it. Here’s the latest on Flash Flooding Watches expected to last through tomorrow morning. Several inches…most in excess of 2 inches…has already fallen across much of this region over the past several days. Soils in many areas have already become saturated and runoff from rain that has already fallen plus additional heavy rainfall expected this evening and overnight and into tomorrow morning ( 2+ inches for some areas! ) will increase the risk of flash flooding. Here’s a look at the counties currently under Flash Flood Watches through Tuesday morning.
Here’s a look at the latest 3-day rainfall totals across most of the state. This is mighty good, but could lead to major street flooding issues overnight and into tomorrow morning as we head back into the work week.
Last but not least, here’s the latest precipitation forecast from the folks at the Weather Prediction Center. This is out through 7pm tomorrow evening and looks quite healthy! We’ll have numerous other opportunities for rainfall this week as this slow moving low treks across north central Texas, and that’s great news for sure!
Conditional Severe Weather Threat Later Today
- Sunday, 11 May 2014 03:18
There is a conditional risk for a few severe thunderstorms late this afternoon and evening ahead of a dryline. This risk zone includes the eastern counties in the Texas Panhandle along with Northwest Texas into the Concho Valley. Canadian, Childress, Spur, Big Lake, Sonora, San Angelo, Abilene, and Wichita Falls are a few cities included in this conditional risk.
The good news for today is that the storm system responsible for this severe weather risk will be passing north of the region which will result in most upper level energy from this system remaining north of the affected areas on Sunday. As such the main forcing mechanism for thunderstorm development will be localized mesoscale features such as differential heating boundaries, gravity waves, or local dryline features. Without knowing about these features until we get into the afternoon hours there really is no specific way to tell where storms may fire up. Thunderstorm coverage should remain low, but any storms that develop will likely be supercellular with a threat of baseball size hail, damaging winds up to 70 MPH, and even a tornado threat possible after sunset with any dominant right-moving supercells that manage to develop and remain surface based into the evening hours.
Again, this threat is conditional on if storms actually develop today. If it appears like storms will not develop than the severe weather threat level will be dropped. Likewise if it looks like storm coverage will be higher in Texas the severe weather threat level may be increased from ‘Possible’ to ‘Enhanced’ in part of the risk zone.
While there is uncertainty regarding storm development today there does seem to be at least some chance at least one storm will fire off the dryline by early evening. Like a few days ago the forecast could change depending on local mesoscale features that could either increase or decrease coverage of storms. Regardless we are not expecting widespread severe weather today in Texas. The same cannot be said for Kansas or parts of Nebraska, Iowa, or Missouri.
One model we rely on for short to medium range forecasts is the North American Model. Specifically the high resolution 4 kilometer version of the NAM. The high-res version of the NAM is generally one of the more reliable weather models when it comes to forecasting convection with 36 hours. This model does show thunderstorms developing across Northwest Texas by the early evening hours with a threat of large hail and damaging winds as they move east/northeast.
I need to stress that today’s forecast of only a few thunderstorms could change depending on local weather features and any changes in temperatures, moisture, or upper level energy forecasts. As of now we expect the main show to be north out of our state. Any storms that do develop will likely be severe with a threat of hail up to the size of baseballs and localized damaging winds up to 70 MPH. A tornado threat may develop with any dominant right-moving supercells that can remain surface based after sunset. The main tornado issue should be north of Texas today.