Stay weather aware Thursday, the last time we had a curved hodograph like this was just this January 24th when the EF-3 went though the Pasadena/Ship channel area.And a few smaller tornadoes occurred that day also.
When you include the several severe weather events that occurred in June this year.It looks like maybe SE Texas is slowly getting back into it's normal pattern of severe weather events every few months or so.That patterns been absent for the past several years.
Yikes... Sounding from the 0Z NAM for Houston Thursday afternoon. There were PDS soundings showing up in the models before the January tornado emergency also. An Enhanced risk is probably likely if the model trends continue.
don wrote: ↑Tue Nov 28, 2023 9:21 pm
Yikes... Sounding from the 0Z NAM for Houston Thursday afternoon. There were PDS soundings showing up in the models before the January tornado emergency also. An Enhanced risk is probably likely if the model trends continue.
That looks bad. Is this looking likely that SETX will get a tornado or tornadoes, hopefully not widespread. I’m trying to understand is this a strong probability this will happen.
Thursday definitely looks intense. I don't chime in much anymore, but this potential event deserves some major recognition. I hope the local weather people are cautioning folks as they plan their commute to and from Houston. It's downright chilly at the time of this posting. From cold to Tornadoes. That's messed up.
Cromagnum wrote: ↑Wed Nov 29, 2023 6:54 am
Enhanced risk update. Right on cue.
Still time for the enhanced area to expand. And even in the slight area, I wouldn’t let your guard down one bit. South of I-10 though it doesn’t look like we’re gonna get much rain outta this but could still see some severe storms.
What a time for our radar to be down. What are good alternatives to KHGX ? It's going to be difficult to track tornado signatures with radars much further away.
Cromagnum wrote: ↑Wed Nov 29, 2023 8:56 am
What a time for our radar to be down. What are good alternatives to KHGX ? It's going to be difficult to track tornado signatures with radars much further away.
Severe thunderstorms will be possible on Thursday over SE TX.
A strong upper level storm system will move across TX on Thursday helping to develop deepening surface low pressure over NW TX early Thursday morning. Warm sector air mass over coastal SE TX early Thursday will spread inland through the morning into the early afternoon hours on a strong low level jet of 40-50kts around 5,000 ft. Warm front will slowly advance northward over the area and likely reach a line from College Station to Liberty by early afternoon. Veering wind profiles with height will support strong low level shear by mid to late morning over much of SE TX. However, while low level shear will be enhanced over the area, there are a few negative factors on Thursday that may keep the severe threat more isolated than widespread. First instability is lacking some, and while it does not take a lot of energy this time of year especially with the strong shear in place, this may keep storms more isolated. Additionally, mid level temperatures begin to warm during the day, and this may act to cap the low level air mass some and prevent deeper convection from developing.
Showers and thunderstorms will begin to develop early Thursday as lift increases over the area and the surface warm front lifts northward. The severe weather threat will increase from the mid morning hours into the mid to late afternoon hours when shear values will be maximized and instability the strongest. Greatest severe threat will likely be along and just north of the warm front and on the northern edge of the increasing mid level temperatures….or roughly along and north of I-10. Given the slightly backed low level winds near the warm front…SPC has included a 10% tornado probability within 25 miles of a given point for areas north of I-10 on Thursday and upgraded this area into the “enhanced” (3 out of 5) risk for severe weather. The rest of SE TX is in a slight (2 out of 5) risk.
While isolated tornadoes will be the main threat on Thursday, damaging winds of 60-70mph will also be possible given strong low level wind fields. In fact it will not take much for scattered showers the bring down some of the stronger winds aloft and even non-severe gusts of 40-50mph will be possible with the fast moving showers. As low pressure deepens over N TX during the day, the local pressure gradient will become increasingly tight with frequent 25-35mph winds across the area Thursday.
I was going to post Jeff’s update it but I still can’t post images, so it’s on S2K. I will continue to post his updates on S2K with any attached images.
Sounds like they are considering backing off of the enhanced TS risk depending how trends go.
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1106 AM CST Wed Nov 29 2023
Valid 301200Z - 011200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
SOUTHEAST TEXAS...
...SUMMARY...
Scattered storms, some severe, will be possible during the day on Thursday, mainly over southeast Texas. A conditional risk for a few tornadoes will be possible during the day. Otherwise, marginal hail will be possible extending northward into parts of Oklahoma.
...Discussion...
A rather conditional severe thunderstorm set up is expected on
Thursday, mainly during the morning and afternoon hours across southeast Texas. A warm advection regime, resulting in widespread cloudiness and ongoing showers/thunderstorms will be underway at the beginning of the period as a shortwave trough tracks across thecentral/southern Plains vicinity. Upper 60s F dewpoints will be focused near the Middle and Upper Texas Coast with low to mid-60s F dewpoints extending northward toward the Red River/ArkLaTex vicinity. A surface low will develop and shift east/northeast across OK/MO as a trailing cold front moves southeast across the southern Plains after 00z.
Forecast vertical shear profiles are impressive with large, curved
low-level hodographs becoming elongated/straight near 3 km. Strong low-level southerly flow, with around 40-50 kt at 850 mb, is expected. Effective SRH values greater than 300 m2/s2 near and north of a warm front across east TX are depicted in forecast guidance as well. This shear space conditionally would support supercell thunderstorms.
However, low-level thermodynamics appear problematic. Surface temperatures and dewpoints may struggle to reach higher than 68-69 F (except perhaps near the immediate coast). Furthermore, cloudiness and morning convection will limit heating, and forecast soundings indicate low-level lapse rates remaining quite poor and nearly moist adiabatic. HREF members also continue to depict stronger negative UH tracks than positive UH tracks, which is an indication that storms may struggle to be rooted near the surface, limiting access to better low-level vertical shear. Additionally, forecast guidance shows modest warming through the day in the 850-500 mb layer, while stronger large-scale ascent remains focused north of the region.
An outlook downgrade was considered. However, if boundary-layer moisture is greater than forecast, or any stronger heating can occur, low-level thermodynamics would improve and allow convection to access better low-level shear, resulting in an increased risk for a few tornadoes. As such, will maintain the Enhanced (level 3 of 5) risk with only minor changes/eastward adjustments compared to the previous outlook based on latest guidance.
Further north across north TX into OK, steeper midlevel lapse rates are forecast closer to the midlevel speed max. Convection will remain elevated, but sufficient elevated instability within a favorable shear environment will support isolated hail in the stronger cells through early evening.
Its important to note that severe weather tomorrow is conditional mainly depending on instability. Could get a mini outbreak, or just a few strong storms. Keep an eye on the mesoscale models today/tonight to get better hints of what may occur.
Regardless there will be thunderstorms tomorrow, its just a question if they will mainly be plain jane thunderstorms or supercells.
SE TX's afternoon high temps today will warm into the mid/upper 60s. Rain chances return to the forecast tonight and peak during the day on Thu. There is some potential for strong/severe storm development Thu, and locally heavy rainfall is possible too. #txwx #houwx #glswx #bcswx
