brettjrob Posted May 9, 2014 Author Share Posted May 9, 2014 And again, that's my concern for the northern target. But I do not think the southern target is any more of a sure bet at this stage and I've seen and chased a number of these types of setups that end up working out very nicely. And if it is about a 1 and 10 chance... then we're due. But you and I both know outside of this year thus far, northern setups work out more than that. I generally agree. Maybe it's just a matter of perspective, but I can't count how many times those of us based in OUN have chased a solid-looking dryline setup, only to curse when we see multiple tornado-warned sups along the WF hundreds of miles farther NE by mid-afternoon. You're less likely to get a gorgeous storm, but perhaps more likely to see a tornado in an absolute sense in many situations where both the DL and WF are in play. Link to comment Share on other sites More sharing options...
ZackH Posted May 9, 2014 Share Posted May 9, 2014 The 18z NAM looks downright dangerous in southern Iowa Sunday. For what its worth and if things can pop and stay discrete. Link to comment Share on other sites More sharing options...
andyhb Posted May 9, 2014 Share Posted May 9, 2014 The 18z NAM looks downright dangerous in southern Iowa Sunday. For what its worth and if things can pop and stay discrete. Parameters are maxed out up there, thanks to crazy low level backing south of the WF. Link to comment Share on other sites More sharing options...
Chicago Storm Posted May 9, 2014 Share Posted May 9, 2014 DMX all in... AFTER A BRIEF LULL INTO THE NIGHT ATTENTION TURNS UPSTREAM WITH INCREASING INFLUENCE BY MATURING ROCKIES LONG WAVE TROUGH. STRONG THETA-E ADVECTION AND ADVANCING ELEVATED INSTABILITY ALOFT WILL LIKELY RESULT IN MO VALLEY MCS ENTERING SWRN IA PLUS/MINUS 12Z. THIS THERMODYNAMIC FORCING CONTINUES INTO THE DAY ALONG WITH INCREASING KINEMATIC FORCING AND DIFFLUENCE ALOFT AS AS WARM FRONT MATURES INTO IA. NAM/GFS MLCAPES BOTH DEPICT MLCAPES OVER 3000 J/KG DURING THIS PERIOD WITH LITTLE CINH SO THERE SHOULD BE NO PROBLEM INITIATING CONVECTION AND HAVE BOOSTED POPS THROUGH THE LIKELIES TO CATEGORICAL IN SPOTS. LOW LEVEL AND DEEP SHEAR ARE IMPRESSIVE...AS WELL AS HODOGRAPHS WITH SRH WELL INTO THE HUNDREDS...SO TORNADIC POTENTIAL IS CERTAINLY DISCONCERTING. GFS/NAM SOUNDINGS BOTH DEPICT VERY FAVORABLE TORNADO PARAMETERS WITH ELEVATED SIG TOR VALUES AND SUFFICIENTLY LOW LCLS. WOULD NOT BE AT ALL SURPRISED TO SEE CURRENT DAY 3 SLIGHT RISK ELEVATED TO MODERATE OR HIGH ALONG AND SOUTH OF WHERE EVER THE FRONT EVENTUALLY LAYS OUT. PRECIPITABLE WATER VALUES EXCEED 2SDS IN THE WARM SECTOR AS WELL SO LOCALLY HEAVY RAINS ARE ALSO QUITE POSSIBLE. ALTHOUGH CONDITIONS ARE NOT AS IDEALISTIC...ANOTHER ROUND OF SEVERE PEAK HEATING CONVECTION MAY BRIEFLY OCCUR IN ERN SECTIONS MON BEFORE ADVANCING EWD WITH THE FRONT. Link to comment Share on other sites More sharing options...
ZackH Posted May 9, 2014 Share Posted May 9, 2014 I think Iowa looks good Sunday... but was extremely surprised to hear how bullish Des Moines was in the latest AFD. Link to comment Share on other sites More sharing options...
andyhb Posted May 9, 2014 Share Posted May 9, 2014 I think Iowa looks good Sunday... but was extremely surprised to hear how bullish Des Moines was in the latest AFD. DMX tends to be more on the conservative side (IIRC with previous events) so they must be looking also towards the list of bigger WF events that have played out in IA (and there is a good number of them). OAX discussion: MAIN ISSUE OF INTEREST COMES THIS WEEKEND. ON SUNDAY...INTENSEBAROCLINIC ZONE DROPPING INTO THE CNTRL PLAINS WILL BE THE FOCUS FOR SCT SHOWER/THUNDERSTORM ACTIVITY DURING THE AFTN EVENING HOURS. STOUT BNDRY LYR THETA-E ADV THRU THE DAY WILL PROVIDE AMPLE ENVIRONMENTAL MOISTURE TO TAP INTO. THIS COUPLED WITH DAYTIME HEAT WILL RESULT IN SBCAPES RANGING ANYWHERE FROM 3500-4000J/KG. IN THE MEANTIME...PARAMETERS FAVORING SUPERCELL DEVELOPMENT...MUCAPES/EFF SRH/EBWD...ALONG WITH WHERE CAP WILL BE WEAKEST...WILL PRETTY MUCH BE FOCUSED SOUTH OF THE I-80 CORRIDOR THUS...A DISTINCT POSSIBILITY A FEW STORMS COULD BECOME SVR BY LATE AFTN/EARLY EVENING. IN ADDITION...GIVEN AMPLE ENVIRONMENTAL MOISTURE CONTENT...WOULD EXPECT RAINFALL TOTALS FOR SOME LOCATIONS DOWN SOUTH WILL BE QUITE GENEROUS. Link to comment Share on other sites More sharing options...
David Reimer Posted May 9, 2014 Share Posted May 9, 2014 DMX all in... AFTER A BRIEF LULL INTO THE NIGHT ATTENTION TURNS UPSTREAM WITH INCREASING INFLUENCE BY MATURING ROCKIES LONG WAVE TROUGH. STRONG THETA-E ADVECTION AND ADVANCING ELEVATED INSTABILITY ALOFT WILL LIKELY RESULT IN MO VALLEY MCS ENTERING SWRN IA PLUS/MINUS 12Z. THIS THERMODYNAMIC FORCING CONTINUES INTO THE DAY ALONG WITH INCREASING KINEMATIC FORCING AND DIFFLUENCE ALOFT AS AS WARM FRONT MATURES INTO IA. NAM/GFS MLCAPES BOTH DEPICT MLCAPES OVER 3000 J/KG DURING THIS PERIOD WITH LITTLE CINH SO THERE SHOULD BE NO PROBLEM INITIATING CONVECTION AND HAVE BOOSTED POPS THROUGH THE LIKELIES TO CATEGORICAL IN SPOTS. LOW LEVEL AND DEEP SHEAR ARE IMPRESSIVE...AS WELL AS HODOGRAPHS WITH SRH WELL INTO THE HUNDREDS...SO TORNADIC POTENTIAL IS CERTAINLY DISCONCERTING. GFS/NAM SOUNDINGS BOTH DEPICT VERY FAVORABLE TORNADO PARAMETERS WITH ELEVATED SIG TOR VALUES AND SUFFICIENTLY LOW LCLS. WOULD NOT BE AT ALL SURPRISED TO SEE CURRENT DAY 3 SLIGHT RISK ELEVATED TO MODERATE OR HIGH ALONG AND SOUTH OF WHERE EVER THE FRONT EVENTUALLY LAYS OUT. PRECIPITABLE WATER VALUES EXCEED 2SDS IN THE WARM SECTOR AS WELL SO LOCALLY HEAVY RAINS ARE ALSO QUITE POSSIBLE. ALTHOUGH CONDITIONS ARE NOT AS IDEALISTIC...ANOTHER ROUND OF SEVERE PEAK HEATING CONVECTION MAY BRIEFLY OCCUR IN ERN SECTIONS MON BEFORE ADVANCING EWD WITH THE FRONT. Someone needs to lay off the sugar... Link to comment Share on other sites More sharing options...
Stebo Posted May 9, 2014 Share Posted May 9, 2014 Someone needs to lay off the sugar... I don't know about a high but a moderate risk isn't unbelievable projection for that area, especially if the models continue to show what they have been for the area from Topeka to Omaha to Des Moines. Link to comment Share on other sites More sharing options...
Ground Scouring Posted May 10, 2014 Share Posted May 10, 2014 Someone needs to lay off the sugar... Who wrote that AFD? A newbie? Considering how conservative DMX is, I'm wondering about the authorship. Link to comment Share on other sites More sharing options...
ZackH Posted May 10, 2014 Share Posted May 10, 2014 Who wrote that AFD? A newbie? Considering how conservative DMX is, I'm wondering about the authorship. There aren't any newbies in the weather service yet. Lol Sent from my LG-LS980 using Tapatalk Link to comment Share on other sites More sharing options...
andyhb Posted May 10, 2014 Share Posted May 10, 2014 Who wrote that AFD? A newbie? Considering how conservative DMX is, I'm wondering about the authorship. Brad Small is a senior forecaster, so that isn't it. Link to comment Share on other sites More sharing options...
ZackH Posted May 10, 2014 Share Posted May 10, 2014 The high risk statement may be a bit over the top but the analysis of the potential environment is spot on based on today's trends Sent from my LG-LS980 using Tapatalk Link to comment Share on other sites More sharing options...
Coreyback Posted May 10, 2014 Share Posted May 10, 2014 Brad Small. Only about 20 years of experience at DMX. So, not a small-time guy (pun clearly intended). I can't speak to whether he often writes reactionary AFDs, but he has model support at least. Though it is a bit silly to speculate on future categorical outlooks in an AFD three days out. Link to comment Share on other sites More sharing options...
Stebo Posted May 10, 2014 Share Posted May 10, 2014 The high risk statement may be a bit over the top but the analysis of the potential environment is spot on based on today's trends Sent from my LG-LS980 Exactly and as it stands with the potential at this point I do think a possible upgrade to a mdt is looking more and more likely for at least part of their area. So it isn't a huge leap of faith. Link to comment Share on other sites More sharing options...
Ground Scouring Posted May 10, 2014 Share Posted May 10, 2014 The high risk statement may be a bit over the top but the analysis of the potential environment is spot on based on today's trends Sent from my LG-LS980 Compared to previous runs, the 18Z NAM shows more backed H7 flow over nrn MO / srn IA Sunday evening, so capping could be a close call. The successive previous runs have trended toward warmer H7 temperatures up there as well. Given the situation with possible low-level flow paralleling the front (the NAM being somewhat alone with its backed surface winds in the area) and the possibility of capping, I can only see a MDT Risk for hail, not tornadoes. Correct me if I'm wrong, but I'm really not convinced that the warm front will pop in time over srn IA. Link to comment Share on other sites More sharing options...
Stebo Posted May 10, 2014 Share Posted May 10, 2014 Compared to previous runs, the 18Z NAM shows more backed H7 flow over nrn MO / srn IA Sunday evening, so capping could be a close call. The successive previous runs have trended toward warmer H7 temperatures up there as well. Given the situation with possible low-level flow paralleling the front (the NAM being somewhat alone with its backed surface winds in the area) and the possibility of capping, I can only see a MDT Risk for hail, not tornadoes. Correct me if I'm wrong. The NAM is not alone in the backing of the surface winds, the Euro also shows it and has shown it for a while... Link to comment Share on other sites More sharing options...
Wx 24/7 Posted May 10, 2014 Share Posted May 10, 2014 I know a lot of focus has been on Sunday, but I am curious about tomorrow. I just don't see any large scale lift to really crank things up. Thoughts? Link to comment Share on other sites More sharing options...
Stebo Posted May 10, 2014 Share Posted May 10, 2014 I know a lot of focus has been on Sunday, but I am curious about tomorrow. I just don't see any large scale lift to really crank things up. Thoughts? There is a shortwave that lifts northeast tomorrow along with the warm front, I wouldn't be surprised if there are some hailers in northeast KS and northern MO tomorrow into tomorrow night. Those storms would probably congeal into a MCS after dark and move toward east central MO. Link to comment Share on other sites More sharing options...
ZackH Posted May 10, 2014 Share Posted May 10, 2014 Compared to previous runs, the 18Z NAM shows more backed H7 flow over nrn MO / srn IA Sunday evening, so capping could be a close call. The successive previous runs have trended toward warmer H7 temperatures up there as well. Given the situation with possible low-level flow paralleling the front (the NAM being somewhat alone with its backed surface winds in the area) and the possibility of capping, I can only see a MDT Risk for hail, not tornadoes. Correct me if I'm wrong, but I'm really not convinced that the warm front will pop in time over srn IA. Disagree a bit with your assessment. Almost all of models have shown backed surface winds in IA... the GFS has been the weakest in this solution but it still shows backed surface winds along the triple point and WF: Further, the ECMWF has been consistent with backed winds along this boundary as well. At this point, with the NAM trending towards the GFS and ECMWF timing wise, I tend to start paying attention to it since we are starting to get into its best forecast range. Also not really seeing the backed H7 flow you're referring to along the boundary. Maybe further east but not in the area I'm most excited about... at 21z there is an EML present but it is not very strong and I imagine it will erode fairly quickly once the mid-level jet streak starts to nose into eastern NE and western IA in the afternoon... this is southwest IA at 00z near the triple point: Link to comment Share on other sites More sharing options...
KSWx Posted May 10, 2014 Share Posted May 10, 2014 Here's the Topeka wx story. Does everyone agree that Sunday has a relatively low risk for tornadoes? "Low" in this sense is obviously subjective, but I feel like Sunday may warrant at least a medium risk. Link to comment Share on other sites More sharing options...
ZackH Posted May 10, 2014 Share Posted May 10, 2014 If the 00z suite holds steady, I believe we will see a Day 2 moderate with possible strong tornadoes mentioned. They may decide to wait until the 12z data tomorrow, but I believe if it stays true, one way or the other the moderate will be issued. Still way too far out to know if this setup has high risk potential. Link to comment Share on other sites More sharing options...
Stebo Posted May 10, 2014 Share Posted May 10, 2014 Both of those soundings are pretty textbook. Link to comment Share on other sites More sharing options...
soonertrey Posted May 10, 2014 Share Posted May 10, 2014 Here's the Topeka wx story. Does everyone agree that Sunday has a relatively low risk for tornadoes? "Low" in this sense is obviously subjective, but I feel like Sunday may warrant at least a medium risk. It may end up being low, but it could end up being more significant. It's kind of ridiculous that they're telling their viewers that there is a "low" tornado risk 48 hours before the event though. Link to comment Share on other sites More sharing options...
jojo762 Posted May 10, 2014 Share Posted May 10, 2014 It may end up being low, but it could end up being more significant. It's kind of ridiculous that they're telling their viewers that there is a "low" tornado risk 48 hours before the event though. KTOP is seemingly always conservative with tornado potential, general consensus from them seemed to be that TOR potential is low because they're expecting parallel flow to the boundary. Disagree with this idea though, because the surface low(s) should cause SRF winds to back along the entire boundary and DL... Also, was thinking that LCL's might be a bit too high when initiation occurs, given relatively high T/Dp spreads. Should storms be able to remain discrete from about 23Z to 05Z then the TOR threat would be much higher due to a forecasted strong LLJ, as well as srf winds backing a bit more toward 00Z(this seemed to be the general thought from ICT/TOP/EAX.) EDIT: Well, at least those were the thoughts days previous... However, KTOP mentions main tornado limiting factor is front orientation, which could cause detremental downdraft/updrafr interactions... As well as disruptive outflow from other storms, nonetheless still mention if storms stay discrete then TOR potential would be higher, but this scenario seems "unlikely" ALSO... Just to clarify "srf"= Surface Link to comment Share on other sites More sharing options...
andyhb Posted May 10, 2014 Share Posted May 10, 2014 KTOP is seemingly always conservative with tornado potential, general consensus from them seemed to be that TOR potential is low because they're expecting parallel flow to the boundary. Disagree with this idea though, because the surface low(s) should cause SRF winds to back along the entire boundary and DL... Also, was thinking that LCL's might be a bit too high when initiation occurs, given relatively high T/Dp spreads. Should storms be able to remain discrete from about 23Z to 05Z then the TOR threat would be much higher due to a forecasted strong LLJ, as well as srf winds backing a bit more toward 00Z(this seemed to be the general thought from ICT/TOP/EAX.) What are SRF winds? The proper abbreviation for surface is sfc. In addition, the parallel flow concern is more addressed to the wind fields aloft. Link to comment Share on other sites More sharing options...
andyhb Posted May 10, 2014 Share Posted May 10, 2014 Incredible sounding from the 00z NAM near the triple point in southeast NE... Link to comment Share on other sites More sharing options...
Thundersnow12 Posted May 10, 2014 Share Posted May 10, 2014 The environment at 3z Sunday evening in OK is absolutely amazing. Orthogonal shear vectors to the dryline, continued moisture advection, discrete precip signal, hardly any CIN building back in at 3z with still 3000 j/kg of MLCAPE to work with as the LLJ absolutely cranks. Scary. Link to comment Share on other sites More sharing options...
andyhb Posted May 10, 2014 Share Posted May 10, 2014 The environment at 3z Sunday evening in OK is absolutely amazing. Orthogonal shear vectors to the dryline, continued moisture advection, discrete precip signal, hardly any CIN building back in at 3z with still 3000 j/kg of MLCAPE to work with as the LLJ absolutely cranks. Scary. image.jpg Been looking up and down the dryline and across the WF at various points through afternoon/evening Sunday, haven't found a single non-impressive wind profile, especially in terms of low level backing. Link to comment Share on other sites More sharing options...
cyclone77 Posted May 10, 2014 Share Posted May 10, 2014 Euro has been pretty consistent in blowing up, and festering convection over southeast Nebraska Sunday morning into the afternoon just north of the warm front. The tail-end of that ignites a little later in the day on the nose of the best instability, and also juxtaposed with nice shear parameters. I think that will be my play on Sunday. Somewhere in the Concordia KS/Hastings NE/Beatrice NE triangle. If this area looks too messy the dry line down in KS could be sort of a backup plan. Don't think the crashing cold front scenario will be too much of a problem since the GFS has trended toward the Euro, which depicts a less progressive cold front on Sunday. Link to comment Share on other sites More sharing options...
Hoosier Posted May 10, 2014 Share Posted May 10, 2014 Regarding the high risk mention by DMX, maybe someone can chime in on whether this is perception or reality but I'm having trouble recalling SPC going high risk for a warm frontal tornado outbreak. It seems like practically all of the high risks I can recall had the high risk area deeper in the warm sector. Link to comment Share on other sites More sharing options...
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