Jim Martin Posted October 3, 2016 Share Posted October 3, 2016 The chance is on the table that a few discrete supercell thunderstorms could develop late Tuesday afternoon/evening across parts of S Central KS and Western Oklahoma. The sounding here is near Kingfisher, Oklahoma in Kingfisher County Tuesday Evening. Link to comment Share on other sites More sharing options...
JasonOH Posted October 3, 2016 Share Posted October 3, 2016 It's weirdly quiet in here. Moisture concerns are less of a factor now in my opinion since model consensus gets mid 60s dews. Wind fields look excellent in western OK. The lapse rates are junk, leading to lower cape values than we should have. Minor improvements in this department could yield major gains in instability. Overall we have a decent setup that is definitely chaseable. With what the models show now, I'll be chasing on Tuesday. I focused on OK since I won't be going any further to chase. Link to comment Share on other sites More sharing options...
Jim Martin Posted October 3, 2016 Author Share Posted October 3, 2016 12z 4k NAM sounding for Moore, Oklahoma at 7:00 PM CDT Tuesday. While not the most impressive sounding, it is not the worst either. Link to comment Share on other sites More sharing options...
David Reimer Posted October 3, 2016 Share Posted October 3, 2016 I know most local folks in the Southern Plains will be chasing tomorrow. Not every October you get a decent southern Plains setup. Overnight and morning model data has continued to trend the Kansas target downward in terms of chaseable tornadic potential. It appears probable a cool pool will develop with early afternoon convection. That cool pool/OFB will move east and shrink the warm sector through early evening. It'll also tend to undercut convection and diminish tornado potential. There will likely be a few brief tornadoes along with plenty of large hail and damaging wind gusts. I wouldn't be too surprised to see a small MDT in KS for hail/wind potential if everything were to come together. My focus on a chaseable target will be in West-Central to Northwest Oklahoma. My preferred model of choice is the 0Z/06Z TTU WRF. This typically conservative model shows the Kansas play well along with a few discrete cells south into Central Oklahoma. 12Z 4KM & 12KM NAM indicate any dominant supercells would have the potential to become tornadic. Storm motions will be a tad more favorable and with more discrete storm mode compared to Kansas. Potential caveats that could diminish potential tomorrow would be convection tonight that results in more cloud cover tomorrow. Another factor would be if moisture return is less impressive or more shallow than models show. If some of this morning's model runs do come to pass I wouldn't be surprised if one or two supercells produced a couple tornadoes tomorrow in Oklahoma - possibly infringing on the OKC metro by 7 PM. We'll see how trends evolve tonight. Link to comment Share on other sites More sharing options...
Jim Martin Posted October 3, 2016 Author Share Posted October 3, 2016 A snippet from the afternoon Day 2 Outlook from the Storm Prediction Center... ...ERN KS...N CNTRL OK...SERN NEB AND SWRN IA... EARLY THUNDERSTORMS ARE EXPECTED FROM NERN KS INTO ERN NEB/WRN IA TUE MORNING RELATED TO LIFT FROM WARM ADVECTION. SMALL HAIL MAY OCCUR WITH THIS ACTIVITY. IN ITS WAKE...HEATING AND MOISTURE ADVECTION WILL COMMENCE AND LEAD TO MODERATE INSTABILITY BY LATE AFTERNOON AHEAD OF THE SFC TROUGH OVER ERN KS INTO NRN OK. SFC CONVERGENCE WILL BE WEAK...BUT STRONG COOLING ALOFT WITH THE SHORTWAVE TROUGH AND A PLUME OF STEEP LOW-LEVEL LAPSE RATES ACROSS S CNTRL KS/NW OK WILL SUPPORT SCATTERED STORMS BY LATE AFTERNOON ROUGHLY FROM OMAHA TO WICHITA TO ENID. HODOGRAPHS WILL STRONGLY FAVOR SUPERCELLS...EVEN IF ACTIVITY FORMS ALONG A LINE. LARGE HAIL...SOME OVER 2 INCHES DIAMETER IS EXPECTED ALONG WITH A FEW TORNADOES AS STORMS INTERACT WITH A 40-50 KT SLY LOW-LEVEL JET NEAR 00Z. Link to comment Share on other sites More sharing options...
Jim Martin Posted October 3, 2016 Author Share Posted October 3, 2016 Well, the 18z GFS, NAM, and 4km NAM are still suggesting that Central Oklahoma looks still to be in play for supercell thunderstorm development late tomorrow afternoon and evening. Link to comment Share on other sites More sharing options...
brettjrob Posted October 4, 2016 Share Posted October 4, 2016 Been a bit too busy to follow this setup with my usual full attention, but have to note that the RGEM and GFS both still suggest CI along the OK portion of the dryline tonight. The hi-res models have been largely discouraging, though, including last night's NCAR ensemble. Right now sustained convection before 01-02z (i.e., decoupling) in the most favorable environment -- roughly 40 mi either side of END-LAW -- seems like about a 50/50 prospect. For the KS threat, we'll see how mode evolves, but I like the threat for a few brief tubes up that way even if mode is on the messy side. Link to comment Share on other sites More sharing options...
andyhb Posted October 4, 2016 Share Posted October 4, 2016 00z 4 km NAM and the most recent NCAR ensemble do seem to be suggesting at least attempts at initiation on the dryline in W OK. Dewpoints appear to be progressing nicely on the SREF with mid to even upper 60s dews reaching even into KS (impressive given the poor return flow pattern with that cut-off recently), which seems reasonably inline with the 00z soundings further south in TX. There won't be a heck of a lot of forcing to the south in OK, but I think given the relatively weak cap, I'd still lean towards isolated initiation further south. Would like to see at least an attempt at backing winds SSEly along the dryline to enhance convergence though. Question of how long will storms have to try to produce tornadoes given the relatively cool BL this time of year is a valid one (outrunning the effective warm sector seems unlikely given relatively moderate storm motions), along with some question of the degree of low level shear (especially if that surface backing doesn't manifest) and some concern about rather paltry mid level lapse rates. The hodograph shape itself has been and continues to be excellent. Link to comment Share on other sites More sharing options...
jojo762 Posted October 4, 2016 Share Posted October 4, 2016 51 minutes ago, andyhb said: 00z 4 km NAM and the most recent NCAR ensemble do seem to be suggesting at least attempts at initiation on the dryline in W OK. Dewpoints appear to be progressing nicely on the SREF with mid to even upper 60s dews reaching even into KS (impressive given the poor return flow pattern with that cut-off recently), which seems reasonably inline with the 00z soundings further south in TX. There won't be a heck of a lot of forcing to the south in OK, but I think given the height falls and relatively weak cap, I'd still lean towards isolated initiation further south. Would like to see at least an attempt at backing winds SSEly along the dryline to enhance convergence though. Question of how long will storms have to try to produce tornadoes given the relatively cool BL this time of year is a valid one (outrunning the effective warm sector seems unlikely given relatively moderate storm motions), along with some question of the degree of low level shear (especially if that surface backing doesn't manifest) and some concern about rather paltry mid level lapse rates. The hodograph shape itself has been and continues to be excellent. Interested to see if any differential heating boundaries/OFB get left over from morning convection. While an MCS (that would obviously produce an OFB) isn't expected, still think it could happen. Generally I'd favor somewhere near the KS/OK border between 22-02Z, after 02Z either the BL should decouple or storms might be more linear/clustered. As long as low-level winds and BL moisture end up as modeled, I see no reason why we wouldn't get a few nice supercells, with at least a couple tornadoes. Link to comment Share on other sites More sharing options...
jojo762 Posted October 4, 2016 Share Posted October 4, 2016 SPC added the dreaded 10% TOR prob for SC KS/NC OK. On the plus side, it isn't hatched, so maybe it won't bust like all the others. Link to comment Share on other sites More sharing options...
rockchalk83 Posted October 4, 2016 Share Posted October 4, 2016 Concerned about the moisture not making it far enough north quickly. Both the HRRR & 4KM NAM have S KS in mid-60 dewpoints by mid-afternoon, prior to convective initialization in this area. Right now, KICT's dew is at 60, with KEND at 66. If the moisture can get up here in time, it looks like it could be game on for some big supercells. Link to comment Share on other sites More sharing options...
David Reimer Posted October 4, 2016 Share Posted October 4, 2016 Morning model runs have been extremely consistent with a supercell developing around the Wichita Mountains in SW OK around 5 PM CT. Storm would than move northeast along I-44 towards or just south of OKC. During conditional events in the past those mountains have been the trigger point for many storm initiation. Leaning toward chasing that possibility this afternoon. If it looks like the SW OK play will bust it doesn't take long to get up to the KS/OK border. Link to comment Share on other sites More sharing options...
brettjrob Posted October 4, 2016 Share Posted October 4, 2016 The OK threat is definitely looking more serious than I thought last night as the mesoscale details begin to emerge. Moisture is verifying on the high end of guidance, and a DL bulge looks to develop between the Red River and I-40 over the next few hours. CI is supported by most hi-res guidance, and as long as we warm a few more degrees by peak heating, should be very attainable on the N side of that bulge. The environment advertised by the HRRR is quite concerning for the metro if CI occurs early enough, e.g. by 5-5:30pm with storm maturity by 6:30pm. If CI is on the late side, the window of opportunity will be fairly narrow temporally. But this seems like a classic "5% hatched" scenario to me right now. Link to comment Share on other sites More sharing options...
David Reimer Posted October 4, 2016 Share Posted October 4, 2016 1 minute ago, brettjrob said: The OK threat is definitely looking more serious than I thought last night as the mesoscale details begin to emerge. Moisture is verifying on the high end of guidance, and a DL bulge looks to develop between the Red River and I-40 over the next few hours. CI is supported by most hi-res guidance, and as long as we warm a few more degrees by peak heating, should be very attainable on the N side of that bulge. The environment advertised by the HRRR is quite concerning for the metro if CI occurs early enough, e.g. by 5-5:30pm with storm maturity by 6:30pm. If CI is on the late side, the window of opportunity will be fairly narrow temporally. But this seems like a classic "5% hatched" scenario to me right now. Hope to see you out in the field! I'm going to leave OUN around 230PM for I-44 between Chickasha to Elgin. Link to comment Share on other sites More sharing options...
Paulie21 Posted October 4, 2016 Share Posted October 4, 2016 Quite the cap on the 19Z sounding from OUN. The environment, thermodynamically speaking, is better to the west of OUN closer to the dryline, where the cap is probably not as stout either. The low level wind field is rather impressive, despite the southwesterly 850's along a dryline, which could advect in drier air. 4km NAM and the last 7 HRRR runs are set on CI near the dryline bulge and/or thermal axis in OK. This goes on to become a discrete supercell tracking south of OKC by evening. Should be interesting to see how this plays out.. Link to comment Share on other sites More sharing options...
andyhb Posted October 4, 2016 Share Posted October 4, 2016 Tornado watch up for KS/SE NE, 50/20 probs. ...and an MCD (95% watch issuance) for OK. Parameter space highlighted in the text is concerning for later on. Link to comment Share on other sites More sharing options...
andyhb Posted October 4, 2016 Share Posted October 4, 2016 Nice supercell in progress very close to the 5/25 Bennington/Chapman path. Low level shear environment in that area would fairly readily support tornadogenesis. Link to comment Share on other sites More sharing options...
jojo762 Posted October 4, 2016 Share Posted October 4, 2016 10 minutes ago, andyhb said: Nice supercell in progress very close to the 5/25 Bennington/Chapman path. Low level shear environment in that area would fairly readily support tornadogenesis. Indeed. Interesting part about that storm is that it is well in front of the DL/CF. Main inhibitor up north might be the cap due to lack of appreciable surface heating Link to comment Share on other sites More sharing options...
andyhb Posted October 4, 2016 Share Posted October 4, 2016 Lol of course now that the tornado watch has been issued, the HRRR doesn't initiate in OK at all. Link to comment Share on other sites More sharing options...
jojo762 Posted October 4, 2016 Share Posted October 4, 2016 Initiation in SC KS... Let's see what happens. Link to comment Share on other sites More sharing options...
andyhb Posted October 4, 2016 Share Posted October 4, 2016 Looking like a bust further south. Veered H85 flow (and weaker than forecast) along the dryline, moisture mixing out via the temps overperforming, not enough large scale ascent, etc. etc. Link to comment Share on other sites More sharing options...
jojo762 Posted October 4, 2016 Share Posted October 4, 2016 14 minutes ago, andyhb said: Looking like a bust further south. Veered H85 flow (and weaker than forecast) along the dryline, moisture mixing out via the temps overperforming, not enough large scale ascent, etc. etc. Looking like it might be a bust overall. Stuff north is linear and messy... Stuff west of Wichita is meager right now (struggling with cap, perhaps?) put they could improve... Cell north of Harper KS doesn't look too bad, but it is pretty small. Several hours of potential left, in case any cells mature more. Also some cells trying to develop east of the dryline east and south of ICT. Link to comment Share on other sites More sharing options...
jojo762 Posted October 4, 2016 Share Posted October 4, 2016 Storm west of ICT is quickly attaining supercell characteristics. Currently has an inflow notch/hook. Link to comment Share on other sites More sharing options...
andyhb Posted October 4, 2016 Share Posted October 4, 2016 ...or maybe not... Man these things can be so incredibly fickle sometimes. Link to comment Share on other sites More sharing options...
jojo762 Posted October 4, 2016 Share Posted October 4, 2016 Storm trying to fire near Andarko... Hmm. And yes agree. Just when the CU field starts to decay a storm fires... Sigh Link to comment Share on other sites More sharing options...
StormOne Posted October 4, 2016 Share Posted October 4, 2016 This storm had its warning expired, even though it should still be severe warned IMO. Link to comment Share on other sites More sharing options...
knitwx Posted October 4, 2016 Share Posted October 4, 2016 TOP issued a tor warning for Washington and Riley counties in Kansas at 6 44 p.m.cst. Link to comment Share on other sites More sharing options...
JasonOH Posted October 4, 2016 Share Posted October 4, 2016 Base of the storm west of OKC. Just got a severe warning. Link to comment Share on other sites More sharing options...
andyhb Posted October 5, 2016 Share Posted October 5, 2016 ^ nice view there Big time hook on the storm in the northern Wichita metro right now. VWP is supportive of tornadoes. Link to comment Share on other sites More sharing options...
StormOne Posted October 5, 2016 Share Posted October 5, 2016 3 minutes ago, andyhb said: ^ nice view there Big time hook on the storm in the northern Wichita metro right now. VWP is supportive of tornadoes. Agreed. That cell definitely deserves a Tornado Warning, pretty strong rotation signature on that thing. Link to comment Share on other sites More sharing options...
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