brettjrob Posted March 23, 2015 Share Posted March 23, 2015 In a quick respite from the most depressing, locked-in synoptic pattern imaginable, two low-amplitude shortwaves will quickly traverse the region early this week. The first significant severe of the year (or really, severe at all) looks likely for the Ozarks Tuesday, and then parts of the southern Plains into the Ozarks again on Wednesday.Monday, March 23A subtle lead shortwave may affect the dryline across the TX PH, W OK, and SW KS late in the afternoon into the evening, but height falls will be weak and low-level moisture meager. There's an outside shot at an isolated, high-based supercell (likely becoming elevated quickly around 00z) somewhere in this area, but it's looking less promising than it had a few runs ago. Plenty of elevated storms should get going after dark across N KS into MO, with MUCAPE and shear supporting large hail.Tuesday, March 24The primary shortwave will zip across the width of KS during the afternoon hours, with impressive shear and moderate instability in the warm sector over the Ozarks and Ouachitas. Tonight's NAM has an impressive signal for apparent discrete convection along the dryline/Pacific front between 21z-00z from near MLC to JLN and on into MO. Low-level veering looks like an issue with time, depending on the spatiotemporal evolution of cells, but otherwise all modes of severe appear possible. Even absent any tornadoes, intense supercells would be likely, starting severe weather season with a bang. In my opinion, right now, the ceiling for the event does feature several tornadoes between 21z-03z, but we'll see how things evolve tomorrow.Wednesday, March 25As the +PNA ridge from hell begins to reamplify, another shortwave should drop into the southern Plains in WNW flow late Wednesday into Thursday morning. Because of the timing, large-scale forcing looks somewhat weaker than Tuesday; on the other hand, the cold front will begin to surge south by evening, which should forcibly initiate convection if nothing else has happened by then. The ECMWF has been painting a seasonably (and by 2015 standards thus far, obviously) impressive picture over much of central and southern OK, possibly into far N TX, Wednesday afternoon and evening. NCEP guidance has trended in that direction with each run today, although the GFS is still decidedly less enthused. Tonight's (23/00z) NAM suggests another round of dryline supercells initiating late in the afternoon across W OK, then racing ENE across the state and being undercut from N to S. Similarly, all modes of severe are possible, with seasonably impressive CAPE+SRH combinations and nice directional shear over the I-35 corridor.Taking model guidance at face value, Wednesday would seem to have the highest ceiling and the highest probability for a handful of tornado reports to break our March drought. Of course, climo favors the Ozarks and a setup like Tuesday's as being more successful at this time of year; plus, I can't recall many sig severe episodes in March around here associated with a shortwave diving in from the WNW. The takeaway: the first large hail reports of the year should come in for much of the region Tue-Wed, and some formidable supercells should be there for the chasing. Tornadically, I'd lean slightly more than 50/50 in favor of this episode spoiling the CONUS's tornadoless March, but take a conservative approach to each individual day for now.Thoughts? Link to comment Share on other sites More sharing options...
Stebo Posted March 23, 2015 Share Posted March 23, 2015 I think between Tuesday and Wednesday the drought for March ends. There will be at least a tornado, though I wouldn't be shocked if between the 2 days we get 5-10. Link to comment Share on other sites More sharing options...
David Reimer Posted March 23, 2015 Share Posted March 23, 2015 Excellent discussion and roundup of each day's threats Brett. I don't have any meteorological input to add but plan to be out chasing all three days. Link to comment Share on other sites More sharing options...
andyhb Posted March 23, 2015 Share Posted March 23, 2015 I'm fairly impressed with what recent model guidance seems to be settling on for Wednesday. Seems to be a decided look towards a stronger secondary vort dropping SE after the first trough's passage on Tuesday (which may leave behind some subsidence to ward off morning convection I might add). The cold frontal push with this isn't overwhelmingly strong either, which should leave a decent window for storms to remain surface based on the northern/northwestern edge of a pretty favorable parameter space along the surface pressure trough. For Tuesday, the window will likely be shorter, but that kind of strong, fast moving shortwave trough can do a lot in a hurry. Based on the 00z guidance that is already in, I think that 3 hour window between 21z and 00z should present the best opportunity for storms to go tornadic. The 4 km NAM (fwiw) is putting out a string of pearls along the dryline/boundary at that time in E KS, then quickly moving them into Central MO. Based on the environment they look to move into, there would be a decent shot to break the tornado drought right then and there, and still have Wednesday to work with. Both of these days will have instability strongly driven by cold air aloft, with 500 mb temps of -15˚C or colder. I've pulled some soundings with impressive mid level lapse rates of 8-9 C/km (and these were on the GFS I might add). With any appreciable low level moisture, those could yield 1500-2000+ J/kg CAPE in a hurry (obviously more skeptical of some of the larger amounts the NAM is putting out, but on the other hand that isn't too much of a surprise given what I just mentioned). I do think one or both of these days has a decent shot at going at least to enhanced risk, with Wednesday having the higher ceiling of the two for a more widespread event (as you've said). Edit: On a related note, I haven't really been keeping track on how well the upgraded GFS has been doing as far as thermodynamics go, perhaps someone could offer some input on what they've seen so far. That said, there hasn't been much to look at in that sense anyways. Link to comment Share on other sites More sharing options...
andyhb Posted March 23, 2015 Share Posted March 23, 2015 By the way, I generated this sounding off the 18z GFS for SGF at 18z Wed using the new SHARPpy program, I look forward to using this a lot now that I've gotten it set up. Link to comment Share on other sites More sharing options...
mappy Posted March 23, 2015 Share Posted March 23, 2015 Nice right up, Brett. Your dates are little messed up though, Monday March 23rd and so on Link to comment Share on other sites More sharing options...
Quincy Posted March 23, 2015 Share Posted March 23, 2015 4/22/11 comes up as the top overall and best SLP analog for Tuesday via NAM. At the very least, the top three overall analogs are from the latter half of April with #5 being 5/4/03. (In terms of SLP, 4/22 and 5/4 come in at #1 and #2) It looks like the region will have at least an elevated risk at an early spring severe outbreak. After this bout, there probably won't be much to talk about in the area until sometime in April. Link to comment Share on other sites More sharing options...
JoMo Posted March 24, 2015 Share Posted March 24, 2015 Crickets on this thread...... Looks like Reed Timmer will be visiting my neck of the woods tomorrow. Local mets don't seem too concerned about tornadoes, neither does the NWS who thinks the main threat will be hail. Link to comment Share on other sites More sharing options...
Indystorm Posted March 24, 2015 Share Posted March 24, 2015 Crickets on this thread...... Looks like Reed Timmer will be visiting my neck of the woods tomorrow. Local mets don't seem too concerned about tornadoes, neither does the NWS who thinks the main threat will be hail. That's what I've been reading on local NWS AFD's in your area. Hopefully they are correct for the opening salvo of this spring season. I see some elevated convection starting to fire this Monday evening in ne KS. Link to comment Share on other sites More sharing options...
andyhb Posted March 24, 2015 Share Posted March 24, 2015 Crickets on this thread...... Looks like Reed Timmer will be visiting my neck of the woods tomorrow. Local mets don't seem too concerned about tornadoes, neither does the NWS who thinks the main threat will be hail. Dewpoints near the Texas coast are only in the upper 50s and low 60s currently, going to need some bolstering to reach model forecast moisture, at least for Tuesday. Link to comment Share on other sites More sharing options...
OKwx2K4 Posted March 24, 2015 Share Posted March 24, 2015 Dewpoints near the Texas coast are only in the upper 50s and low 60s currently, going to need some bolstering to reach model forecast moisture, at least for Tuesday. Yeah. Writing off Tuesday for the most part on the really heavy stuff. Wednesday is lookin pretty good though. Link to comment Share on other sites More sharing options...
brettjrob Posted March 24, 2015 Author Share Posted March 24, 2015 Yeah, unsurprisingly, neither day is looking as impressive now. New SWODY1 has gone with 2% tornado probs for the Ozarks, and with sfc flow as veered as it looks to be (even earlier in the afternoon), I'm inclined to agree. The last 24 h have seen most of the models cave toward the more progressive GFS solution Wednesday, which even in my infinite pessimism I didn't quite expect. The ECMWF has held its ground up to now; we'll see what tonight's run has to say. Regardless, I'd expect low-level veering to be an issue again and (related) capping concerns abound anywhere that isn't along the surging front late in the day. Still should see some legitimate sups immediately ahead of that front in OK, and if the Red River Valley can convect before dark, perhaps something a bit more impressive there. It wouldn't shock me to get no tornado reports out of either day, though obviously one or two are still possible. Link to comment Share on other sites More sharing options...
Chicago Storm Posted March 24, 2015 Share Posted March 24, 2015 Outside of being the first real threat of any kind on the season, I never really found this period to be too interesting or chase-worthy (unless you live close and/or are desperate). Link to comment Share on other sites More sharing options...
Quincy Posted March 24, 2015 Share Posted March 24, 2015 SPC is actually going with an enhanced risk now for portions of the southern Plains on Wednesday: Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 24, 2015 Share Posted March 24, 2015 Don't really like either day but if I had to chase tomorrow I'd be near the LAW-SPS area during the late afternoon evening hoping to get enough p-falls to back the sfc winds a little but fear mixing/SW'ly 850's mix down some drier air and also keep the winds more due south. That area looks to have the best threat of anything noteworthy. Link to comment Share on other sites More sharing options...
brettjrob Posted March 24, 2015 Author Share Posted March 24, 2015 Well, model trends for tomorrow are looking up in terms of frontal placement/speed, but not so much kinematically in the low-levels. Guidance is now converging on a solution closer to the Euro's steadfast idea from the past several days, so all is right in the NWP world. Expecting discrete supercells for at least 2-3 hours in the afternoon along, and perhaps just NW, of the I-44 corridor from SPS to OKC. A little more low-level backing than progged would go a long way, but I wouldn't hold my breath, given the positive-tilt nature of this wave. And if this wasn't already broken-record enough to say every single setup last year: thanks in large part to our awesome JFM of dry NW flow and occasional 0.05" QPF "winter storms," I'd fully expect mixing to yield T/Td spreads of 3-6 F larger than the model consensus by 22z. All that said -- should be some fairly beastly sups by March standards, and a nice start to the chase season if the pattern weren't tanking again in short order. Link to comment Share on other sites More sharing options...
Indystorm Posted March 24, 2015 Share Posted March 24, 2015 Mesoscale Discussion out now for sw MO for this Tuesday with some possible tornadic action expected along the warm front. Dews are still rather low, however Link to comment Share on other sites More sharing options...
Superstorm93 Posted March 24, 2015 Share Posted March 24, 2015 Watch being drawn up at the SPC Finally going to break that drought \ Link to comment Share on other sites More sharing options...
Chinook Posted March 24, 2015 Share Posted March 24, 2015 Severe thunderstorm watch #5 has been issued! The previous FOUR watches this year were tornado watches. We probably should be on #50 or better by now for total watches (tornado/svr thunderstorm). Link to comment Share on other sites More sharing options...
huronicane Posted March 24, 2015 Share Posted March 24, 2015 Lightning really increasing on both Kansas storms. Mainly cloud lightning so far, but CG on the increase in the northern storm. Link to comment Share on other sites More sharing options...
andyhb Posted March 24, 2015 Share Posted March 24, 2015 And if this wasn't already broken-record enough to say every single setup last year: thanks in large part to our awesome JFM of dry NW flow and occasional 0.05" QPF "winter storms," I'd fully expect mixing to yield T/Td spreads of 3-6 F larger than the model consensus by 22z. I think this has more to do with the poor trajectories out of the Gulf for most of the lead up time to this event, considering it's still March especially. Link to comment Share on other sites More sharing options...
brettjrob Posted March 24, 2015 Author Share Posted March 24, 2015 I think this has more to do with the poor trajectories out of the Gulf for most of the lead up time to this event, considering it's still March especially. No doubt that will be a factor. I will say though that I think land surface effects have often been a bigger cause of moisture underperforming relative to model guidance out here in recent years, as opposed to simply not being very good. Greenness and related land surface properties are parameterized in our NWP, of course, but near-surface dew point forecasts in the southern Plains warm sector still seem to be chronically high-biased during springs with substantial drought. Barton Co. MO sup not looking too shabby right now... could get the first sig hail report of the day here shortly. Minor spike on KSGF 0.5°. Link to comment Share on other sites More sharing options...
Indystorm Posted March 24, 2015 Share Posted March 24, 2015 That line certainly exploded quickly with numerous hail reports coming in now. Link to comment Share on other sites More sharing options...
jhamps10 Posted March 24, 2015 Share Posted March 24, 2015 That line certainly exploded quickly with numerous hail reports coming in now. looks interesting on radar Link to comment Share on other sites More sharing options...
JoMo Posted March 24, 2015 Share Posted March 24, 2015 The storm near Lamar, MO looks 'interesting'. Had a storm pass just to my north with a severe warning, it had a slight lowering but was pretty high based. Link to comment Share on other sites More sharing options...
jhamps10 Posted March 24, 2015 Share Posted March 24, 2015 Away from the storms, it's interesting how you can see what appears the dryline sitting through Ft worth right now on FWD radar: Link to comment Share on other sites More sharing options...
Indystorm Posted March 24, 2015 Share Posted March 24, 2015 Strong helicity off to the east in MO. If dews were higher I'd really be concerned for tornadic activity. As it is I think it is safe to say that both Springfield and Branson look to be in line for some significant hail in the near future the way these cells keep intensifying. Link to comment Share on other sites More sharing options...
Indystorm Posted March 24, 2015 Share Posted March 24, 2015 ULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 553 PM CDT TUE MAR 24 2015 THE NATIONAL WEATHER SERVICE IN PLEASANT HILL HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN CARROLL COUNTY IN NORTH CENTRAL MISSOURI... NORTHWESTERN SALINE COUNTY IN CENTRAL MISSOURI... * UNTIL 630 PM CDT * AT 551 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR ALMA...AND MOVING NORTHEAST AT 55 MPH. AT 540 PM TRAINED SPOTTER NEAR AULLVILLE REPORTED 2 INCH HAIL. HAZARD...TENNIS BALL SIZE HAIL AND 60 MPH WIND GUSTS. SOURCE...TRAINED WEATHER SPOTTERS. IMPACT...PEOPLE AND ANIMALS OUTDOORS WILL BE INJURED. EXPECT HAIL DAMAGE TO ROOFS...SIDING...WINDOWS AND VEHICLES. EXPECT WIND DAMAGE TO ROOFS...SIDING AND TREES. * LOCATIONS IMPACTED INCLUDE... MALTA BEND...BOSWORTH...GRAND PASS...WAKENDA...MIAMI AND DE WIT Link to comment Share on other sites More sharing options...
oldlogin Posted March 24, 2015 Share Posted March 24, 2015 BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE LITTLE ROCK AR 655 PM CDT TUE MAR 24 2015 THE NATIONAL WEATHER SERVICE IN LITTLE ROCK HAS ISSUED A * TORNADO WARNING FOR... NORTHERN BOONE COUNTY IN NORTH CENTRAL ARKANSAS... NORTHWESTERN MARION COUNTY IN NORTH CENTRAL ARKANSAS... * UNTIL 730 PM CDT * AT 654 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS SEVERE STORM WAS LOCATED 4 MILES NORTH OF SELF...OR 15 MILES NORTH OF HARRISON. DOPPLER RADAR SHOWED THIS SEVERE STORM MOVING EAST AT 55 MPH. IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING LARGE DAMAGING HAIL UP TO GOLF BALL SIZE. * LOCATIONS IN THE PATH OF THIS DANGEROUS STORM INCLUDE... WININGTON... WILLIS... SELF... OZARK ISLE... OMAHA... MYRTLE... LEAD HILL... LAKEWAY... DODD CITY... DIAMOND CITY... SOUTH LEAD HILL... PEEL... MONARCH... BURLINGTON... Link to comment Share on other sites More sharing options...
vwgrrc Posted March 25, 2015 Share Posted March 25, 2015 Away from the storms, it's interesting how you can see what appears the dryline sitting through Ft worth right now on FWD radar: And not to mention the collision of dry line and cold front could punch a hole in the cap Link to comment Share on other sites More sharing options...
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