andyhb Posted May 16, 2015 Author Share Posted May 16, 2015 Analog wise, 4/5 top matching events for CIPS from the 00z run had F3+ tornadoes in the S Plains (5/8/1986, 5/7/1995, 4/25/1994 and 5/3/1999). Also growing increasingly concerned about nocturnal potential too, not only because of recent events, but also because all signs point to a BL that will be slow to decouple, with rich low level moisture, a lack of any significant capping source and a strong low level jet. If storms don't become predominantly linear by that time, I don't like the prospects for the I-35 corridor in particular. Link to comment Share on other sites More sharing options...
andyhb Posted May 16, 2015 Author Share Posted May 16, 2015 06z HRRR absolutely ignites the dryline/warm sector with numerous supercells by 21z. Link to comment Share on other sites More sharing options...
UKStormFan Posted May 16, 2015 Share Posted May 16, 2015 06z HRRR absolutely ignites the dryline/warm sector with numerous supercells by 21z. Just to clarify something here Andy, as I've been wondering. Is that 21z US time, or 21z Euro time? Presuming it's US time, but hoping not as that's 3am over here... Link to comment Share on other sites More sharing options...
JasonOH Posted May 16, 2015 Share Posted May 16, 2015 Just to clarify something here Andy, as I've been wondering. Is that 21z US time, or 21z Euro time? Presuming it's US time, but hoping not as that's 3am over here...ZULU time so yes, your time. On the plains that is 4:00 PM.Edit: can't do math Link to comment Share on other sites More sharing options...
rolltide_130 Posted May 16, 2015 Share Posted May 16, 2015 Convection across Oklahoma/Texas is pretty widely scattered this morning, with more significant convection across Kansas. However the biggest blob across Kansas is already starting to push towards the eastern edge of the risk area and could clear out by 9 A.M. Link to comment Share on other sites More sharing options...
Quincy Posted May 16, 2015 Share Posted May 16, 2015 Have to think we'd be looking at a very high end/possibly historic event, IF it wasn't for the current state of morning convection from the TX PH into KS. Although the coverage of significant severe seems questionable on the large scale in my mind, at least north of the KS/OK border, at least a few sig/long-lived tornado events appear likely. Western OK is where I'd tend to think the greatest magnitude threat is. Mesoscale details over the next few hours could change that a bit. Link to comment Share on other sites More sharing options...
Msalgado Posted May 16, 2015 Share Posted May 16, 2015 Really not happy to see the stuff in the TX panhandle growing around Lubbock. Will grab breakfast here in OKC and head out to Sayre and wait to see where the dryline actually gets setup. Link to comment Share on other sites More sharing options...
andyhb Posted May 16, 2015 Author Share Posted May 16, 2015 Really not happy to see the stuff in the TX panhandle growing around Lubbock. Will grab breakfast here in OKC and head out to Sayre and wait to see where the dryline actually gets setup. There's nothing really too organized about this convection at this time. Link to comment Share on other sites More sharing options...
Quincy Posted May 16, 2015 Share Posted May 16, 2015 There's nothing really too organized about this convection at this time.The back edge is just about to a Amarillo to Wichita Falls line too. Assuming it doesn't back build, that's some gradual clearing happening rather soon. Link to comment Share on other sites More sharing options...
Ian Posted May 16, 2015 Share Posted May 16, 2015 Definitely more convection than shown in HRRR runs last night. Link to comment Share on other sites More sharing options...
andyhb Posted May 16, 2015 Author Share Posted May 16, 2015 The back edge is just about to a Amarillo to Wichita Falls line too. Assuming it doesn't back build, that's some gradual clearing happening rather soon. If you told me two days ago this is the look that we would see at 8:30 AM today, I would say that would be pretty favorable. Link to comment Share on other sites More sharing options...
andyhb Posted May 16, 2015 Author Share Posted May 16, 2015 Definitely more convection than shown in HRRR runs last night. At least going back to the 04z run, the HRRR did have this second round of convection. It's right on time too. Link to comment Share on other sites More sharing options...
jojo762 Posted May 16, 2015 Share Posted May 16, 2015 I still like today overall, and still think we will probably sig-severe at least across Oklahoma later, but the northern half of the MDT risk is a bit uncertain attm. Looking at SFC observations across SW/C KS you find lots of observations that read with temps in the upper 50's/low 60's, DP's in the mid/upper 50's, and tons of cloud cover over head and incoming caused by loosely organized crapvection and showers.. Theta-E advection also looks to not really recover imo into that area regardless of what the models show, it's only 8:38 right now, but we will see how it looks at about 11:30 or noon. Link to comment Share on other sites More sharing options...
Ian Posted May 16, 2015 Share Posted May 16, 2015 At least going back to the 04z run, the HRRR did have this second round of convection. It's right on time too. I feel like these threads are for cheerleading only sometimes. Think my last run was 3z. To be clear, I don't think it matters a huge ton compared to what expectations are. Seemingly not part of a perfect plan ('historic') scenario though. I kinda doubt we see a high .. more likely a refining of the 15% later.. could be wrong. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted May 16, 2015 Share Posted May 16, 2015 Victor might have to update his scale...but it still plots the max.. HRRR showing a max sig tor of 23 southeast of a discrete supercell at 23z later in southwest OK. We're driving through most of KS but initial target is Elk City, with sights possibly further south. Link to comment Share on other sites More sharing options...
tornadotony Posted May 16, 2015 Share Posted May 16, 2015 What's important is that there's no significant cold pool with this morning convection. It's 8:47 AM, and this stuff is showing signs of clearing to the NE, at least across the TX PH, which should be clean by 17z. I think all systems are go for a significant/major tornado event for at least south-central KS and western/central OK. Link to comment Share on other sites More sharing options...
Quincy Posted May 16, 2015 Share Posted May 16, 2015 I know we shouldn't rely too heavily on the 4km NAM at this juncture, but FWIW, it appears to be intensifying some of the current convection over northwestern Oklahoma around midday, followed by the "main show" from southwestern Kansas into the panhandles and eventually western Oklahoma with numerous semi-discrete to discrete storms. Link to comment Share on other sites More sharing options...
brettjrob Posted May 16, 2015 Share Posted May 16, 2015 There are enough pitfalls that I wouldn't be upgrading the outlook either, if it were my call. Ongoing convection is more substantial than forecast last night even by the HRRR, for one thing. Even ignoring the potential thermodynamic effects from that, I think it's becoming likely that this will be a 5/5/07 or 4/26/09 style day with almost continuous initiation off the dryline from lunchtime on, rather than a distinct "main show" initiating at an optimal time in the afternoon (21z-00z) following a long lull. Also similar to 4/26/09 is the questionable H5-H85 crossover and some VBV issues, leading to the potential for mixed storm mode or at least "strung out" supercells (which HRRR composite reflectivity hints at in some cases). None of this is to say I'm downplaying today as a bust; I just think a HIGH risk setup would be more flawless than this. In reality, I can see a pretty wide range of outcomes, all the way from what would be widely perceived as a bust to something verifying a HIGH. When VBV and meridional flow are major issues, it seems like often you just don't know until the storms form and you can observe their characteristics. There are pretty decent analogs like 4/26/09 and 5/7/95 which featured HIGH risk busts on the dryline due to mixed/messy storm mode, but this has the advantage of being a few weeks later into the season and having a truly negative-tilt trough, at least. Perhaps today will be something more like 5/5/07 shifted 50-100 mi. S. Link to comment Share on other sites More sharing options...
andyhb Posted May 16, 2015 Author Share Posted May 16, 2015 That outflow boundary in N OK might serve as another focus for initiation/tornado potential later on. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted May 16, 2015 Share Posted May 16, 2015 There are enough pitfalls that I wouldn't be upgrading the outlook either, if it were my call. Ongoing convection is more substantial than forecast last night even by the HRRR, for one thing. Even ignoring the potential thermodynamic effects from that, I think it's becoming likely that this will be a 5/5/07 or 4/26/09 style day with almost continuous initiation off the dryline from lunchtime on, rather than a distinct "main show" initiating at an optimal time in the afternoon (21z-00z) following a long lull. Also similar to 4/26/09 is the questionable H5-H85 crossover and some VBV issues, leading to the potential for mixed storm mode or at least "strung out" supercells (which HRRR composite reflectivity hints at in some cases). None of this is to say I'm downplaying today as a bust; I just think a HIGH risk setup would be more flawless than this. In reality, I can see a pretty wide range of outcomes, all the way from what would be widely perceived as a bust to something verifying a HIGH. When VBV and meridional flow are major issues, it seems like often you just don't know until the storms form and you can observe their characteristics. There are pretty decent analogs like 4/26/09 and 5/7/95 which featured HIGH risk busts on the dryline due to mixed/messy storm mode, but this has the advantage of being a few weeks later into the season and having a truly negative-tilt trough, at least. Perhaps today will be something more like 5/5/07 shifted 50-100 mi. S. I think 4/26/09 is a good little analog and I was also out that day. The radar to me actually has that look. Weaker cap should allow for what you're saying but I also wouldn't rule out a "main show" later on type solution in southwest OK up to the metro. Link to comment Share on other sites More sharing options...
Jon Posted May 16, 2015 Share Posted May 16, 2015 Victor might have to update his scale...but it still plots the max.. HRRR showing a max sig tor of 23 southeast of a discrete supercell at 23z later in southwest OK. We're driving through most of KS but initial target is Elk City, with sights possibly further south. hrrr sig tor.gif Same run (12z) and frame, if you zoom in to OKC sector, sig tor is really 28. *enhance* Link to comment Share on other sites More sharing options...
nwburbschaser Posted May 16, 2015 Share Posted May 16, 2015 Is that the COD crew I'm behind on 283? Link to comment Share on other sites More sharing options...
Thundersnow12 Posted May 16, 2015 Share Posted May 16, 2015 Is that the COD crew I'm behind on 283? Yes it is Link to comment Share on other sites More sharing options...
nrgjeff Posted May 16, 2015 Share Posted May 16, 2015 In infer from the SPC 13Z that they actually considered down to ENH but I am glad they kept MDT. Tornadoes will verify today, but perhaps not all up and down the DL. Hodos are not great. However where OFBs can enhance local low level shear, total hodos will indeed promote tornadoes - some maybe strong only along OFBs. I infer SPC are concerned about uncertainty, thinking about ENH, but the synoptic pattern requires MDT. Any English majors in the house? I don't have a dog in the hunt. Reluctantly elected to sit out this one. My optimism along OFBs is not wish-casting, but based on my understanding of the meteorology. Good luck to everyone; and, with the messy mode and crowds, please chase extra carefully today. UNCERTAINTY IN THE SUBSEQUENT EVOLUTION OF THIS EARLY CONVECTION AND DEGREE OF AIR MASS RECOVERY IN ITS WAKE DURING THE LATE MORNING/AFTERNOON...AND HOW THIS EVOLVES WILL IMPACT LOCATIONS AND LIKELIHOOD OF SEVERE STORMS THIS AFTERNOON AND EVENING. GIVEN THE FAVORABLE SYNOPTIC PATTERN...HAVE OPTED TO MAKE LIMITED ADJUSTMENTS TO THE OUTLOOK AREAS WITH THE EXPECTATION THAT THE MESOSCALE SCENARIO WILL BECOME MORE EVIDENT AS THE DAY PROGRESSES. Link to comment Share on other sites More sharing options...
UKStormFan Posted May 16, 2015 Share Posted May 16, 2015 This morning we are talking a major outbreak, this afternoon it's Moderate down to Enhanced... something about Saturdays recently. These setups are almost becoming the 'cry wolf' scenario. What is it with morning convection ruining the atmosphere at the moment? Link to comment Share on other sites More sharing options...
andyhb Posted May 16, 2015 Author Share Posted May 16, 2015 This morning we are talking a major outbreak, this afternoon it's Moderate down to Enhanced... something about Saturdays recently. These setups are almost becoming the 'cry wolf' scenario. What is it with morning convection ruining the atmosphere at the moment? There is no reason I'm seeing right now to downgrade from the moderate aside from perhaps in KS. Link to comment Share on other sites More sharing options...
Natester Posted May 16, 2015 Share Posted May 16, 2015 This morning we are talking a major outbreak, this afternoon it's Moderate down to Enhanced... something about Saturdays recently. These setups are almost becoming the 'cry wolf' scenario. What is it with morning convection ruining the atmosphere at the moment? I highly doubt there will be a downgrade to Enhanced. There isn't any backbuilding of the MCS in western Oklahoma. Just have to wait and see. Link to comment Share on other sites More sharing options...
Indystorm Posted May 16, 2015 Share Posted May 16, 2015 I'm trying to recall May 3, 1999, a mentioned analog for today's situation. I remember that SPC outlooks increased from slight to moderate to high as the day progressed. But I don't remember if morning convection was a concern. Link to comment Share on other sites More sharing options...
huronicane Posted May 16, 2015 Share Posted May 16, 2015 MD in production for OK and KS from @NWSSPC twitter: Link to comment Share on other sites More sharing options...
tornadotony Posted May 16, 2015 Share Posted May 16, 2015 Whoa whoa whoa, let's slow down for just one collar-pickin minute here. SPC doesn't explicitly mention a downgrade. It mentions an adjustment, one that I could easily see coming at 1630 UTC. That adjustment would likely be to drop western KS from the moderate risk, but I doubt we see anything more than that. As has been mentioned, convection is not backbuilding in TX, we don't have a giant MCS, and cold pool areal extent is small. Several runs of the HRRR, which all have had a good handle of ongoing convection, each have developed numerous discrete cells in a prime parameter space in a classic synoptic setup. Though I can understand not going High Risk with some VBV questions and exact location of mesoscale features still in question, any talk of a total downgrade is really not appropriate. Link to comment Share on other sites More sharing options...
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