Stx_Thunder

New MD out for maturing MCS in East TX: https://www.spc.noaa.gov/products/md/md2118.html --------- SPC Day 1 outlook TX Marginal Risk area for today larger now than on Day 2 outlook yesterday.

- Saw this evening's 0Z Fort Worth upper-air SPC sounding a short while ago and it's very interesting to note how little CAPE & not much atmospheric moisture there is (especially for the time of year) being acted on by this apparently vigorous incoming mid-level shortwave up there in North TX as new clusters are starting to fire up east/southeast of DFW now. Though the frequent cloud lightning I'm seeing on webcams in Dallas and Fort Worth right now, is being attributed to those steep mid-level lapse rates near 8 C. ---------- This evening's 0Z CAM runs seem to be doing a poor job handling this mesoscale convective event, but do show the current activity making a run down into Houston overnight. Would not be surprised if it makes it given that it's a pretty vigorous incoming second shortwave the CAMs were showing yesterday. Tomorrow could be interesting further down into Southern TX region.

Looks like a decent thunder event for DFW shortly. Looking at one of the live streaming EarthCams there right now, the lightning is fairly frequent off to the northwest (EarthCam.com). Though I don't see many CG strikes at all on current lightning map data.

SPC has MD out for the developing cluster in DFW region: https://www.spc.noaa.gov/products/md/md2116.html It's also looking a lot better now with organization into an MCC for the most part now on TX centered radar/lightning data map: Finally nice to see a convective event that's non-tropical and linearly organized like that going on in the state again especially after this summer..

A LOT of that can be thanks to the typical compressional heating effects of the cool front in DFW vicinity near the Red river (not really the heat dome High as 500 MB heights are < 595 on this morning's 12Z upper-air soundings so not lots of subsidence/warming aloft anymore). As there's a cluster of Thunder cells firing now in Wichita Falls area ahead of that 2nd incoming shortwave impulse in OK moving southeast in the established mid-upper level northerly flow aloft. https://www.spc.noaa.gov/obswx/maps/500_230908_12.gif

- Well-defined, thunder active outflow inching closer to Houston with that lead shortwave approaching TX/LA coast.

Should be a different story up there around Eastern TX region tomorrow afternoon - Saturday. CAMs also starting to show stuff reaching into Southern TX by Saturday now instead of Sunday. ARWs holding on, and now 0Z HRRR run tonight latching onto those 2 defined mid-level impulses diving south through DFW - HOU regions with some decent sized convective clusters around Houston area later Friday afternoon and Dallas area from the second main impulse Friday night tomorrow.

- Can you also see the bigger signs outside, ongoing just off to your East in Louisiana?

SPC has now really expanded the Slight risk area over basically all of Northeastern - Southeastern TX and Western LA in the midday Day 2 outlook update.

Thunder initiation and intensity wise, it personally wouldn't surprise me if those series of mid or upper level shortwave troughs starting to come into Texas today and especially this weekend in the already established northerly mid-upper level flow up there in Eastern TX, are more stout than forecast. Combine that with a cooling column and all this Texas heat/humidity still around. Given El Niño is definitely in play here, the northerly flow is also connected to the southern jet stream not far off to the northwest. https://www.spc.noaa.gov/obswx/maps/500_230907_12.gif ---------- HRW - ARWv2, CAM this morning is also showing one fairly well-defined 500 MB shortwave moving through Eastern TX all the way through Houston, intact later tomorrow (Friday): Moisture aloft should not be a problem in that region tomorrow also. ----------- Also showing another fairly stout shortwave impulse diving south from DFW - HOU regions early Saturday: https://mag.ncep.noaa.gov/model-guidance-model-area.php

SPC now has decent sized areas of Marginal and Slight Risks over DFW and HOU regions in Day 2 & 3 outlooks today, also. https://www.spc.noaa.gov/products/outlook/day2otlk.html https://www.spc.noaa.gov/products/outlook/day3otlk.html

Looking at latest model runs/trends, things are actually getting interesting both Convective & temperature (change) wise for most of TX, this weekend and next week. An actual cool front looks to move through the state next week as the ultra stubborn furnace subtropical High shrinks more and becomes displaced further west-southwest in Mexico, with potentially slightly below normal heights < 585 dipping into the state. Along with some pretty deep incoming troughing into the mid-south that could also be influenced by the northerly flow on the western outer circulation of Hurricane Lee in the Atlantic. Which would drive the front even further south like Idalia did. Looking into latter September also, this finally looks to be the official end of the relentless 2023 summer EN induced intense heat and dryness that's plagued the state all season. Still looks to be quite warm (nowhere as hot as it's been this summer), for highs though, through the rest of the month. But continued, much more normal 500 MB heights for a change thankfully (to start the coming EN Fall 2023). On both GFS/Euro ensembles. ----------Latest multi-global model consensus output is showing clustered, higher thunder probabilities (some severe possible with the deepening/strengthening and cooling northerly mid-upper level flow and all this remnant summer heating/humidity) probability moving south/east at times starting this weekend in Eastern TX. But particularly Monday - Thursday timeframe (potential MCS or MCCs): ---------- WPC already showing front well south through the state and pretty widespread higher 24-hr POPs going into Wednesday (13th): https://www.wpc.ncep.noaa.gov/medr/nav_conus_pmsl.php?fday=6&fcolor=wbg

All things considered this summer in TX, these temps, and No heat index, must definitely feel like Fall around DFW today behind that well-advertised late summer frontal passage:

A coming El Niño Fall looks to start taking the edge off the relentless summer heat of 2023, next week over TX (to end August)..: *** Local AFD today had talks of the front actually moving through South TX also around mid-week..

60+ mph wind gusts being reported around Corpus Christi and near 70 mph further south around Kingsville, TX in Kleberg county closer to the center of Harold moving inland (after making landfall south of Baffin Bay), within the past 2 hours. ---------- Got noisy inside here in those heavier squalls in the past hour and have a small tree limb down on the yard.

https://www.wpc.ncep.noaa.gov/metwatch/metwatch_mpd_multi.php?md=0960&yr=2023 ------------- Decent impacts from TS Harold here this morning on the TX coastal bend (around Corpus Christi area) since the outer bands started coming onshore around 4 a.m. CDT with a decent amount of lightning discharges in those. Getting some estimated 50 - 55 mph wind gusts at times now. Harold is just moving too fast now to even have much of a flooding impact at this point. The southeast quadrant offshore is also pretty dry on radar right now as well. But at least the tail moisture inflow on the southeastern periphery could provide one last decent convective round tonight before Harold completely pulls away from the region Wednesday.

WPC Excessive Rainfall risk upgraded for Day 3 outlook over Lower TX coast today: https://www.wpc.ncep.noaa.gov/qpf/excessive_rainfall_outlook_ero.php * WPC currently going 3 - 5 in. (isolated 7 in. totals) in slight risk area if Invest 91L becomes a TC before landfall, in ERO discussion.

WPC Excessive Rainfall risk upgraded for Day 3 outlook over lower TX coast today: https://www.wpc.ncep.noaa.gov/qpf/excessive_rainfall_outlook_ero.php * WPC currently going 3 - 5 in. (isolated 7 in. totals) in slight risk area if the now Invest 91L becomes a TC before landfall, in ERO discussion.

500mb High on the move, away... Today (19th): --- Gulf now full of atmospheric moisture:

In a Good nutshell. Usually is most of the time

Saw a few nice thunder heads and one with an overshooting top not too far offshore to the east later in the afternoon yesterday and a few very skinny (ultra-tropical) sea breeze cells off to the west inland. Obviously, none of those are associated with the incoming tropical entity, yet. But just nice to see more signs of a coming pattern change around TX coast. It doesn't actually look like there'll be flooding rains down here as the first major tropical entity of the year for the region is projected to keep moving at a steady pace. Even when it comes onshore, due to the stronger steering flow around the High not being too far away to the north. But just glad to see a significant change and especially relief coming this week from the very relentless summer heat this year. Which will thankfully give the A/C a major break with all the cloud cover and rain too. It thankfully also doesn't look like it'll completely dry out after it moves away later in the week as both the GFS and Euro are showing some more waves of deeper atmospheric moisture coming in at times from the Gulf and from another Low in the southwestern Gulf around the end of the week. So this should be the start of the usual September rains around TX coastal region. Albeit, could still end up being quite wet despite a very dry summer, with a (slowly) strengthening El Niño at this point. All grasses are brown down here too as it hasn't rained around the coastal bend since early July also. Which only amounted to about a quarter inch on average. I'd say a half inch or even a little more around Houston is not out of question, as the system (especially if it develops a closed circulation like a depression) could still end up tracking a bit further north as they tend to. Unless, the High ends up further south than currently projected. But with more organized convection from even just a mid-level Low can send a number of outflow boundaries further north. As that would help fire off more cells mixed with daytime heating up there, and with some of the deeper tropical moisture (can produce downpours even in low-topped cells or showers), being drawn further north from the eastern region of the circulation. And possible sea breeze assistance as well. From all convective scenarios I've seen around Houston over the years, it usually doesn't take much to get some cells going up there even if there is some subsidence aloft like from the dominant subtropical High this time of year, in this case. But yes, it's likely San Antonio gets more rain than Houston with this first major tropical entity of the year for TX coast given current projections of the 500mb high not too far off to the north.

WPC now also indicating a marginal excessive rainfall risk on the day 5 outlook for most of TX coast region on Tuesday. If it develops a 500mb circulation (regardless of any TC development), the risk would likely be upgraded as a Mid-level Low does create better support for lift and deeper (tropical) moisture advection aloft for more organized deep convection on the northern region. It should keep a steady track through the Gulf (mid-upper level high not too far off to the north providing stronger steering flow) that some shower/storms could start coming onto the southern TX coast by this Sunday.

Most Euro members on latest 0z run still holding onto good size generally southeast - northwest oriented swath of 2 - 5 in. average rainfall next week around middle TX coast and closer to a San Antonio - Del Rio line. If the system stays an open circulation aloft and especially given that this is a tropical entity, deeper atmospheric moisture from the southern Gulf and Carribean would get drawn further northwest in the onshore flow pattern around the northern side. Which would also be aided by the southwestern periphery flow around the 500mb high off to the northeast. WPC now spreading higher rainfall probabilities over San Antonio and Del Rio areas now as the 500mb high looks to stay more northeast, around the Arkansas/Tennessee region at least early next week. NBM precip output also spreading further inland to the northwest.

NBM and multi-global model outputs continue holding Strong with an S on TX Coast rainfall next week starting around 22nd (Tuesday). The real question now (regardless of any tropical development in Western Gulf if at all), is...: - How much rain? Euro op also coming back on track with rain over TX coast (instead of further east the past days). Though many of the members this week were already showing 2 - 4 in. swath on average, generally over middle TX coast region next week. Even more of them now on today's 12z run. NBM showing about 2 in. right along most of TX coast through 28th. - Latest 12z Multi-global model output today: *Some higher probabilities spreading over San Antonio later on 22nd now, also. Personally now, even just additional cloud cover would make a difference like the anvil shield from yesterday's thunder cluster around here did for me (and on A/Cs). --------- Also, good amount of deep dry air aloft over the state today seen on water vapor...:

Radar lighting up around South TX later this afternoon with that old front hanging down here: Was pretty dark off to the north on the southeast edge of the convective shield of that pretty strong easternmost cluster. Not surprising with all this crazy and quite persistent TX heat/humidity with very little dynamics aloft this time of year.