Texas/Oklahoma 2023 Obs and Discussion

[Stx_Thunder]

 

Looks like another decent mid-level shortwave moving through the state in the NW mid-upper flow aloft this afternoon with storms increasing over the hill country region now, north of SAT.

Looks like convective chances continue through early next week for TX coast. CAMs today also showing a 500mb Low meandering around here or just east over the Northwestern Gulf the next few days.

 

On 9/27/2023 at 6:40 AM, Ed, snow and hurricane fan said:

Monday was wind and thunder and power out, Tuesday looked to be dry with big storms to the E, but they made it here around 7 pm.  Severe warned, but just a nice rain with a little thunder.  Maybe turning the corner on the drought.  Warmer than normal doesn't look to change.

Saw a few nice anvil crawlers on the backside of the developing MCS going southwest into the Coastal Bend region on Houston's uptown EarthCam after sunset Monday evening.

Missed the show when it was coming into Houston during day. But saw more of the lightning from the parent cells as it got more organized on a live streaming nest cam around Victoria area after dark. Didn't see much or hear any thunder around me later that evening/after midnight. Stayed mostly west before fully decaying.

----------

CFS showing somewhat below normal temps for much of state in Mid-October. So looks like a bigger and more active pattern shift to actual TX Fall still in the cards for next month. And subtropical High continues to be on weakening trend out west with 500mb heights no more than about 590 forecast around the core going into next week.

Definitely nowhere near as strong or dominant as it was during the past months (thankfully). Which is all good news. Also have to keep ongoing and strengthening EN in mind here too. Which generally means more cooler/active Fall-Spring due to more southerly storm tracks.

[Ed, snow and hurricane fan]

Autumn is finally coming.

[Stx_Thunder]

Saw a nice little thunder cell develop right over me around sunrise yesterday after seeing some decent lightning strikes going on an hour before, off to the southeast before it started getting daylight.

Looks like the 2023 horrible domination season of the furnace 500mb High for TX is officially coming to a close next week. Expecting good rain chances, Every day now through next week for TX Coast with a persistent gulf moisture influx aloft. Much more normal for September down here.

---------

Statewide, things look like they will be getting quite convectively active next week around Thursday, with the first significant incoming Pacific trough of the season that could be pretty deep moving into TX.

Recent - latest GFS & Euro runs generally been showing up to 50 kts bulk shear over the central/northern part. So supercells are definitely not out of question next week. Which there could be a more organized severe (MCS) threat for the eastern half. Especially with EN finally back and evidently in play here early in the season.

I suspect SPC will input a 15% risk area in the Day 4 - 8 outlook tomorrow or Sunday, as they've already discussed the potential today. Even though it may be a narrowly organized threat.

[Stx_Thunder]

Well WPC already jumped the excessive rainfall outlook slight risk bandwagon. Which is plausible given there's still more than enough time for Gulf moisture to build further north ahead of the incoming trough/surface front. Main question now will be how deep the trough is coming into the state mid-week.

[Ed, snow and hurricane fan]

Extra zero in 15000, and my house is only marginal, but the front Thursday looks to be a wet one as well

 

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
429 AM EDT Tue Oct 03 2023
 
Day 1
Valid 12Z Tue Oct 03 2023 - 12Z Wed Oct 04 2023 

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF 
THE TEXAS COAST...


...Texas Coast...

Southeasterly flow from the Gulf of Mexico will interact with a 
coastal trough to produce showers and thunderstorms this afternoon 
and early evening. Heavy rainfall is possible within the Slight 
Risk area, between Houston and Corpus Christi this afternoon, when 
instability will be at its peak (1000-15000J/Kg). There will be 
plenty of moisture present, despite the lack of dynamic support, 
with PWATs between 2-2.5" along the Texas coast. HREF neighborhood 
exceedance probabilities of 2-5" are reasonably high at this time 
so those were used as a proxy for this day 1 Slight Risk area.

[Stx_Thunder]

After a long while of not having one down here, had a good thunder day, all day during the daytime yesterday down here with training cells coming onshore, with what appeared to be an old frontal boundary that came down the coast to right around me (before moving back northeast toward Houston today).

Some of the lightning strikes were pretty bright inside as it wasn't really dark at all outside underneath the cells. Radar showed about 4 - 5 in. storm totals from yesterday alone. On top of the heavier rainfall that started last week around TX coast.

----------

Just as I suspected they would (even though they didn't sooner in the day 4 - 8 last weekend), SPC finally going with a slight risk area over much the northern half of TX into OK for tomorrow ahead of the incoming trough.

WPC backed off on the expansive excessive rainfall Slight risk area for Wednesday - Thursday period they originally had last weekend for most of TX. But still have a large marginal risk covering the eastern and southern half. So wouldn't be surprised if they reintroduce a slight risk further south for Thursday - Friday period.

 

 

 

[Stx_Thunder]

Latest CAMs showing 50 - 60 kts bulk shear by this evening (Wednesday) over North TX as the main convective show gets going and starts pushing south through the state into Thursday.

 

[Stx_Thunder]

 

- SPC finally getting their act together. Wouldn't be surprised if they expand that enhanced risk into or near the DFW area this afternoon due to more significant damaging wind gusts or hail events (given the upward of 60 kt shear CAMs are showing in that region by this evening).

Probably a good mid-level shortwave coming into the mix too given how deep that incoming upper level trough probably is also. Can't really underestimate these EN Fall systems. Especially being early in the season.

[Powerball]

21 minutes ago, Stx_Thunder said:

 

- SPC finally getting their act together. Wouldn't be surprised if they expand that enhanced risk into or near the DFW area this afternoon due to more significant damaging wind gusts or hail events (given the upward of 60 kt shear CAMs are showing in that region by this evening).

Probably a good mid-level shortwave coming into the mix too given how deep that incoming upper level trough probably is also. Can't really underestimate these EN Fall systems. Especially being still pretty early in the season.

Not going to happen due to less than ideal timing (late evening hours) and already somewhat marginal instability with an unimpressive dewpoint/temp spread, likely preventing much of that shear from mixing down to the surface.

The enhanced risk is mainly for very large hail (2-3"+) with the initial activity.

[Stx_Thunder]

Despite the lower CAPE on this morning's sounding, I wouldn't say that's marginal instability up there in DFW given the already fairly weak inhibition, 700mb - 500mb lapse rates already up at 7 C, a 70 F + surface dew point (which I would think is pretty high for this time of year up there in October), and already almost 35 kts Effective shear, and nearing 100 kts cloud layer shear now.

And, the forecast of no real MLCINH on CAMs around there through the evening.

Craven/Brooks SigSevere already at 20,000 also. Which will likely increase through the day just like the shear values with the upper trough obviously getting closer. BRN low, but will probably go up later today with lower-level flow veering and increasing from the south-southeast.

Plus, 12Z CAM runs like the ARWs this morning are pushing back on the main and pretty sharp convective line further into the evening compared to yesterday evening runs. This could be an indication of the upper trough deepening/slowing down.

--- 
At this point, it looks like a close call looking at the latest data and parameters this morning as more would seem to favor it later today than not (despite it being a nocturnal convective event).

Especially if there's a potent incoming mid-level shortwave involved (like SPC is talking about today). If there isn't or timing is off with the stronger dynamics coming in this evening, then severe would be less likely around there.

[Powerball]

9 minutes ago, Stx_Thunder said:

Despite the lower CAPE on this morning's sounding, I wouldn't say that's marginal instability up there in DFW given the already fairly weak inhibition, 700mb - 500mb lapse rates already up at 7 C, a 70 F + surface dew point (which I would think is pretty high for this time of year up there in October), and already almost 35 kts Effective shear, and nearing 100 kts cloud shear now.

And, the forecast of no real MLCINH on CAMs around there through the evening.

Craven/Brooks SigSevere already at 20,000 also. Which will likely increase through the day just like the shear values with the upper trough obviously getting closer. BRN low, but will probably go up later today with lower-level flow veering and increasing from the south-southeast.

Plus, 12Z CAM runs like the ARWs this morning are pushing back on the main and pretty sharp convective line further into the evening compared to yesterday evening runs. This could be an indication of the upper trough deepening/slowing down.

--- 
At this point, it looks like a close call looking at the latest data and parameters this morning as more would seem to favor it later today than not (despite it being a nocturnal event).

Especially if there's a potent incoming mid-level shortwave involved (like SPC is talking about today). If there isn't or timing is off with the stronger dynamics coming in this evening, then severe would be less likely around there.

To clarify, the reason I say somewhat marginal instability for severe weather is because much of that instability on the sounding you presented is elevated. Even the CAMs indicate a stable layer forming near the surface by the time the storms arrive into DFW (temps only in the low 80s and dewpoints in the low/mid 70s), which will significantly temper downburst potential.

Instability and moisture levels are definitely good enough for prolific rain producers and frequent lightning though, which is already pretty well covered in the current outlooks/forecasts.

[Stx_Thunder]

14 hours ago, Powerball said:

To clarify, the reason I say somewhat marginal instability for severe weather is because much of that instability on the sounding you presented is elevated. Even the CAMs indicate a stable layer forming near the surface by the time the storms arrive into DFW (temps only in the low 80s and dewpoints in the low/mid 70s), which will significantly temper downburst potential.

MUCAPE this morning is at 990mb. Which is literally just above the surface layer...

I would in no way, consider that elevated.

Even with a stable near surface layer, if you have enough deep-layer or effective shear and support for lift going on aloft with a relatively unstable boundary layer, it can still promote stronger cells and higher wind gusts. Especially in a very linearly forced MCS or segment.

Since you replied toward me, the only other thing I'm going to add is SPC, especially on updated Day 1 outlooks, would not be highlighting your area in a large Slight risk if they knew the severe potential wasn't actually there. And, they've pretty much explained their reasoning with just about everything I wrote about the ongoing convective parameters in here. It's not just about what the conditions are at or near the surface (or how unstable/stable it is in that layer alone in your case). Elevated supercells also do actually exist.

On the contrary, from all my convective analysis experience over the years, it has a lot more to do with the boundary layer when it comes to instability. And even with limited or very conditional instability overall, it still does not mean severe can't happen at all (and has before in high sheared environments). Even SPC talks a lot about all of these things too, reading their discussions frequently over the years.

Also, they've expanded the enhanced risk area much closer to you now in the late morning update.

 

[Powerball]

30 minutes ago, Stx_Thunder said:

MUCAPE this morning is at 990mb. Which is literally just above the surface layer...

I would in no way, consider that elevated.

Even with a stable near surface layer, if you have enough deep-layer or effective shear and support for lift going on aloft with a relatively unstable boundary layer, it can still promote stronger cells and higher wind gusts. Especially in a very linearly forced MCS or segment.

Since you replied toward me, the only other thing I'm going to add is SPC, especially on updated Day 1 outlooks, would not be highlighting your area in a large Slight risk if they knew the severe potential wasn't actually there. And, they've pretty much explained their reasoning with just about everything I wrote about the ongoing convective parameters in here. It's not just about what the conditions are at or near the surface (or how unstable/stable it is in that layer alone in your case). Elevated supercells also do actually exist.

On the contrary, from all my convective analysis experience over the years, it has a lot more to do with the boundary layer when it comes to instability. And even with limited instability overall, it still does not mean severe can't happen at all (and has before). Even SPC talks a lot about all of these things too, reading their discussions frequently over the years.

Also, they've expanded the enhanced risk area much closer to you now in the late morning update.

 

The severe threat is definitely there. I just disagree that it's great enough for an upgrade to an enhanced risk (as you seem to) for DFW.

The better potential will be NW of here, where the activity will occur during or just after peak heating.

[cheese007]

Tornado Warning
TXC113-139-050330-
/O.NEW.KFWD.TO.W.0066.231005T0242Z-231005T0330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Fort Worth TX
942 PM CDT Wed Oct 4 2023

The National Weather Service in Fort Worth has issued a

* Tornado Warning for...
  Northwestern Ellis County in north central Texas...
  Southern Dallas County in north central Texas...

* Until 1030 PM CDT.

* At 942 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Midlothian, moving east at 30 mph.

  HAZARD...Tornado and half dollar size hail.

  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...
  Cedar Hill and Midlothian around 950 PM CDT.
  Waxahachie, Ovilla and Oak Leaf around 955 PM CDT.
  Glenn Heights and Red Oak around 1000 PM CDT.
  Ennis around 1015 PM CDT.
  Palmer around 1020 PM CDT.

Other locations impacted by this tornadic thunderstorm include Ike,
Garrett, Trumbull, Pecan Hill, Boyce, Rockett, India and Joe Pool
Lake.

This includes the following highways...
 Interstate 35E between mile markers 399 and 414.
 Interstate 45 between mile markers 251 and 270.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to an interior room on the lowest floor of a
sturdy building. Avoid windows. If you are outdoors, in a mobile
home, or in a vehicle, move to the closest substantial shelter and
protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 3232 9661 3242 9709 3243 9709 3251 9708
      3255 9704 3258 9704 3261 9656
TIME...MOT...LOC 0242Z 283DEG 25KT 3250 9704

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.25 IN

$$

Bonnette

[Chinook]

Wow! That might be a TDS confirmed tornado at Britton Texas, near Midlothian. I thought this severe event might be over.

 

[nwohweather]

7 minutes ago, Chinook said:

Wow! That might be a TDS confirmed tornado at Britton Texas, near Midlothian. I thought this severe event might be over.

 

Exactly my thoughts! The spin and inflow are pretty legit on this thing. We have a large plant in Midlothian so definitely watching with curiosity 

[Chinook]

The northeast side of Dallas may have gotten 2.5"-3" at this point in time. I have not seen a report of a tornado.

[Stx_Thunder]

12 hours ago, Powerball said:

The severe threat is definitely there. I just disagree that it's great enough for an upgrade to an enhanced risk (as you seem to) for DFW.

The better potential will be NW of here, where the activity will occur during or just after peak heating.

 

- Bulk shear was nearing 50 kts (like the 12Z CAMs were showing by evening), effective shear nearing 60 kts, and Significant Severe value was passing 50 K at the time of the 0Z FWD sounding launch tonight, with virtually nil CIN of any kind.

Moisture was lacking a little with 60% RH in both lower and mid levels. So the boundary layer wasn't quite unstable as the lower to mid-level lapse rates dropped some during the day.

Outflow or frontal boundary also outran the storms as I saw on radar going through DFW which cut off some of the boundary layer or southerly lower level inflow into the cells. Had they not been undercut by the boundary, things would've likely been a bit more interesting severe-wise all around there.

Overall, it was a sufficient enough potential to justify the enhanced severe risk around DFW area with all the severe instances and warnings issued around there a while after dark, also taken into account.

Especially, the convective segment with 75+ mph measured gusts that literally came right next to Fort Worth metro as I also saw on base velocity next to 9:00 PM from the west.

 

[Stx_Thunder]

16 hours ago, Powerball said:

The enhanced risk is mainly for very large hail (2-3"+) with the initial activity.

Should also mention that the morning enhanced risk area upgrade update wasn't just for significant severe hail that promoted it, but for significant damaging wind gusts also.

[Powerball]

1 hour ago, Stx_Thunder said:

 

- Bulk shear was nearing 50 kts (like the 12Z CAMs were showing by evening), effective shear nearing 60 kts, and Significant Severe value was passing 50 K at the time of the 0Z FWD sounding launch tonight, with virtually nil CIN of any kind.

Moisture was lacking a little with 60% RH in both lower and mid levels. So the boundary layer wasn't quite unstable as the lower to mid-level lapse rates dropped some during the day.

Outflow or frontal boundary also outran the storms as I saw on radar going through DFW which cut off some of the boundary layer or southerly lower level inflow into the cells. Had they not been undercut by the boundary, things would've likely been a bit more interesting severe-wise all around there.

Overall, it was a sufficient enough potential to justify the enhanced severe risk around DFW area with all the severe instances and warnings issued around there a while after dark, also taken into account.

Especially, the convective segment with 75+ mph measured gusts that literally came right next to Fort Worth metro as I also saw on base velocity next to 9:00 PM from the west.

 

Only 3 confirmed reports so far in DFW.

Granted, there may be more forthcoming, but in all likelihood still not enough to be enhanced risk worthy IMO.

Aside from that overachieving mini-bow echo that moved into FW proper (and actually weakened shorty thereafter), it's been largely "more bark than bite" severe-wise, with impressive shear on paper that didn't translate into a more impressive event. And that's pretty typical for these nighttime events in the Fall, which is why I didn't really buy into the hype.

That being said, it's certainly been a solid event rain-wise for the Metroplex and has been a prolific lightning producer.

[Powerball]

Also, I will say, I did see widespread observations of wind gusts in the 35-45 MPH range, which (although sub-severe) is something.

And that was likely in part due to the somewhat lower than expected RH levels mentioned, as that helped to enhance the downdrafts a bit (though still not enough to overcome the cooling boundary layer).

[Ed, snow and hurricane fan]

Nothing severe, but decent MCS an hour from Houston, morning commute will be interesting.

[cstrunk]

2.7" storm event total since yesterday morning.

[Stx_Thunder]

Had a sudden downpour from an inflow streamer cell come over me around 4 am and another (not as heavy where I am) going on a short while ago. Picking up again with the fanning MCS coming down here and hearing more thunder now. Looks like activity is going to stick around in the southern half all day seeing radar trends further north toward San Antonio.

 

On 10/5/2023 at 5:01 AM, Ed, snow and hurricane fan said:

Nothing severe, but decent MCS an hour from Houston, morning commute will be interesting.

Was never forecast to be severe this week over the southern half of TX (including Houston) as the majority of effective shear was going to stay over northern half no matter what this week on models.

But with all the deeper moisture streaming in around the region, WPC still keeping a fairly large Marginal risk area going today. Though I feel they may be underdoing it a little through tonight, at least down here with the several inch rainfall totals I've already seen since last week and the 2"+ PWs already in place.

Could have some training of cells going on around here today (something like what happened Monday). But more interestingly this early in the season with EN back, could have some overrunning type rain and maybe a few thunder cells going on tomorrow behind the initial front with more shortwave energy coming in from the southwest with the southern stream jet (if drier air aloft doesn't filter in too quick).

Real cold front not coming through state till later Friday. Looks like clouds will stick around in the southern half for most of the weekend, with another pattern change later next week when upper level flow veers back southwest.

GFS/Euro showing even cooler temps late next week.

 

On 10/5/2023 at 1:39 AM, Powerball said:

Aside from that overachieving mini-bow echo that moved into FW proper (and actually weakened shorty thereafter), it's been largely "more bark than bite" severe-wise, with impressive shear on paper that didn't translate into a more impressive event. And that's pretty typical for these nighttime events in the Fall, which is why I didn't really buy into the hype.

Oh boy...

I definitely know your type on these places. Not worth anything else here with you at all.

Fort Worth got hurricane force gusts yesterday evening. That's official. You just can't argue with 60 kts effective shear and already nil CIN.

So the risk was 100% there all around DFW regardless of your opinion on what defines an enhanced risk (not SPC's classification/reasoning). 

Which I should add, is below a moderate risk.

[Powerball]

41 minutes ago, Stx_Thunder said:

Oh boy...

I definitely know your type on these places.

 

Respectfully, you can keep your snark to yourself.

So an isolated part of the Metroplex saw 70+ MPH winds. Most areas did not. An isolated high-end report did not make enough justification for an enhanced risk outlook IMO. In fact, my take aligns exactly with the official SPC definitions:

I stand by what I said and you're free to feel whatever type of way about it.

[Chinook]

The Dallas Fort Worth area got some hail/wind reports. I'm sure you guys will be happy to see some of the drought-busting rains and some cooler weather, like 71 for Saturday. I guess in the long run, the drought might go away for the South but remain in the North due to El Nino.

[Ed, snow and hurricane fan]

Expected light show driving N on TX 249.  None.  Full bore thunderstorm, minus the thunder, winds probably gusting near 40 mph moving my car around, blinding rain.  No thunder at all with the heavy rain.  There was thunder with the light rain afterwards.

 

 

[Powerball]

On another note, DFW overachieved temp-wise yesterday as it tied the record high of 96*F from 1898.

This was with quite a bit of cloud cover too.

[Powerball]

1 hour ago, Ed, snow and hurricane fan said:

Expected light show driving N on TX 249.  None.  Full bore thunderstorm, minus the thunder, winds probably gusting near 40 mph moving my car around, blinding rain.  No thunder at all with the heavy rain.  There was thunder with the light rain afterwards.

 

 

There wasn't much thunder here either. I heard maybe one good crack.

[Stx_Thunder]

Rain lasted pretty much all day down here. Thunder ended by around mid-afternoon. Though lots of nice photo-worthy cloudy sky scenes to look at before it got dark.

Still lots of moisture in place aloft with 2" PW still hanging on but lower level flow on 0Z sounding starting to veer all northward now.

Looking to welcome fall with open arms behind tomorrow's first real cold front for the state this season.

 

6 hours ago, Chinook said:

I guess in the long run, the drought might go away for the South but remain in the North due to El Nino.

That's generally how it always goes down here around TX in El Niño with wetter/cooler fall - spring seasons overall. I've already seen close to 10" here on the coast. Just within the last 3 weeks since that subtropical furnace high finally went away, as the grass is really starting to grow fast now between cuts. And we've only entered fall.

A pretty active winter even convective wise being right next to the gulf wouldn't be out of question and especially next spring in '24 (with obviously higher severe probabilities). Spring 2023 was pretty convectively active all things considered in the state when the ENSO transition was going on. It tends to follow a trend into the next year. But even more so around the middle of the decade as I've seen in the past 2.

I can only imagine what spring 2024 & 25 might bring this far out.