andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 Deamplifies the initial shortwave for Friday/Saturday, although Saturday is fixing to be nasty from what is showing up at 12z in the morning on it. I mean just wow at that LLJ... Link to comment Share on other sites More sharing options...
tornadotony Posted April 11, 2012 Share Posted April 11, 2012 00z NAM really isn't that impressive for Thursday or Friday, maybe somewhere near a high-end slight risk for both days FWIW. Using the 72h NAM ftl. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 11, 2012 Share Posted April 11, 2012 Not sure what you're looking at. 00z NAM valid at 00Fri in Hays, KS Looks significantly different than what I was watching flow in. Might have been a cache issue. Whatever, it's the NAM 3 days out. Link to comment Share on other sites More sharing options...
brettjrob Posted April 11, 2012 Share Posted April 11, 2012 00z NAM really isn't that impressive for Thursday or Friday, maybe somewhere near a high-end slight risk for both days FWIW. I'd consider what it's showing near the warm front and triple point Thursday to be pretty impressive. Moderate instability, LCLs <= 1000 m, strong LLJ, and large looping hodographs with convective initiation between 21-00z. Highest threat looks near or just north of the I-70 corridor in NW KS. On both days, moisture seems like something of an issue along the dryline. However, it's possible the WRF is being too aggressive in mixing out moisture. The ECMWF looks much more optimistic in that regard for both days. We'll have to watch the trends carefully, because the kinematics for Friday are borderline-classic. Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 Wish we had the old C/W thread, considering it is looking increasingly possible we could see some impressive warm frontal action on one or more days in the GL/OV sub-forum's coverage area. Very strong wind profiles in this area as well, with adequate moisture/instability for supercells. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 11, 2012 Share Posted April 11, 2012 Cached run. Haven't had that in a while. As mentioned, only big issue seems to be the marginal moisture return. That should be worked out as we get closer. Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 Here's the GL/OV thread for those interested and who haven't seen it: Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 11, 2012 Share Posted April 11, 2012 I'd consider what it's showing near the warm front and triple point Thursday to be pretty impressive. Moderate instability, LCLs <= 1000 m, strong LLJ, and large looping hodographs with convective initiation between 21-00z. Highest threat looks near or just north of the I-70 corridor in NW KS. On both days, moisture seems like something of an issue along the dryline. However, it's possible the WRF is being too aggressive in mixing out moisture. The ECMWF looks much more optimistic in that regard for both days. We'll have to watch the trends carefully, because the kinematics for Friday are borderline-classic. Yeah around HLC looked pretty darn impressive, really nice moisture/instability pool in that area with a gorgeous hodo at 0z. Link to comment Share on other sites More sharing options...
Indystorm Posted April 11, 2012 Share Posted April 11, 2012 Wish we had the old C/W thread, considering it is looking increasingly possible we could see some impressive warm frontal action on one or more days in the GL/OV sub-forum's coverage area. Very strong wind profiles in this area as well, with adequate moisture/instability for supercells. Maybe if things develop into a significant event as we get closer the mods might merge the thread into one on the main forum page. This has happened before. Simultaneous warm and cold front action in a larger geograhic area that overlaps subregions in this forum looks quite probable. And with the trough hanging back west of the Mississippi until Tuesday we definitely could be looking at multi day concerns. Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 GFS keeps it strong further east as well, perhaps into the OH Valley/SE later. This combined with the things that Indy just mentioned and the high to the east being in a very conducive position for prolonged moisture return out of the Gulf and Caribbean definitely suggests this may not just be done at all once this initial vort max ejects on Saturday/Sunday. Link to comment Share on other sites More sharing options...
Jim Martin Posted April 11, 2012 Share Posted April 11, 2012 Here is the Hill City, KS 0z NAM sounding valid at 7pm cdt Thursday evening. Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 For lack of a better word, wow...I'll be damned if that isn't a classic looking hodograph for significant tornadic action. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 11, 2012 Share Posted April 11, 2012 now that's kinda nice Here is the Hill City, KS 0z NAM sounding valid at 7pm cdt Thursday evening. Link to comment Share on other sites More sharing options...
brettjrob Posted April 11, 2012 Share Posted April 11, 2012 For lack of a better word, wow...I'll be damned if that isn't a classic looking hodograph for significant tornadic action. If you could add another 10-20 kts of storm-relative flow at H3-H2 for ventilation, I'd say that's simply textbook for supercells producing strong to violent tornadoes. Doubt that weakness will be a dealbreaker if it verifies verbatim, though. Guessing we'll probably see a 30% hatched along the WF on the new SWODY2. (Though, another caveat is that the GFS, and to a lesser extent EC, do show a narrower warm sector and more southward-sloping WF). Link to comment Share on other sites More sharing options...
David Reimer Posted April 11, 2012 Share Posted April 11, 2012 I have a feeling all the hotel rooms in Hays, KS are about to be booked solid. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 11, 2012 Share Posted April 11, 2012 I have a feeling all the hotel rooms in Hays, KS are about to be booked solid. agreed lol Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 If you could add another 10-20 kts of storm-relative flow at H3-H2 for ventilation, I'd say that's simply textbook for supercells producing strong to violent tornadoes. Doubt that weakness will be a dealbreaker if it verifies verbatim, though. Guessing we'll probably see a 30% hatched along the WF on the new SWODY2. (Though, another caveat is that the GFS, and to a lesser extent EC, do show a narrower warm sector and more southward-sloping WF). Scary part is we could see stuff like that over much, much larger areas on Friday and Saturday. Link to comment Share on other sites More sharing options...
Indystorm Posted April 11, 2012 Share Posted April 11, 2012 Just continue to follow the strength and positioning of the 300 mb jet as it rounds the base of the trough from the eastern Pacific and enters the good ole U.S.A. Wow! There's your ventilation. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 11, 2012 Share Posted April 11, 2012 The 00z/12z ECMWF really develops that leeside low and associated warm front/dryline intersection much farther N than the NAM...brings it right up into SW NE. It really hits us hard...I am worried because I am on a forecast training shift that day lol. EC 925 hpa at 00Z Friday. Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 00z GFS looks fairly similar to previous runs for Thursday, with perhaps a slight increase in the areal coverage of moisture/instability. And just look at this beast of an UL jet about to make landfall at 48 hrs... Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 I can already tell the UL/mid level jet looks more poised to eject on Saturday than the 12z run. BTW, the GFS precip maps for Friday looks to have a cluster of supercells around the Red River west of DFW Friday evening, Wichita Falls special. Link to comment Share on other sites More sharing options...
wx_chip Posted April 11, 2012 Share Posted April 11, 2012 Focusing on Thursday, only day it looks like we can chase, the NAM and GFS agree on cyclogenisis in SW NE. GFS is a bit farther north, but both hodos near the tp are stout with nice curving and SE surface flow. Both place hints of supercells along the dryline and in prime location to interact with the warm front. In this region the tornado threat will be greatly enhanced. Should be an interesting day in south central NE and north central KS. Chip Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 The GFS is extending this way beyond Saturday as well. Link to comment Share on other sites More sharing options...
tornadotony Posted April 11, 2012 Share Posted April 11, 2012 The GFS is extending this way beyond Saturday as well. Not really. Flow becomes weak/meridional. Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 Monday in AR and vicinity doesn't look too bad, although by this time I do agree that the best upper level support will have deserted this system. Link to comment Share on other sites More sharing options...
Stebo Posted April 11, 2012 Share Posted April 11, 2012 Not really. Flow becomes weak/meridional. For what day Tony? I see there being good wind shear both directional/speed for Monday in the Lower MS Valley and for Tuesday In the Mid MS Valley/Ohio Valley/Great Lakes with good LL moisture as far north as SW MI on Tuesday Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 Not really. Flow becomes weak/meridional. The upper level flow on the GFS ahead of the front on Monday (although I can see it for Sunday) and to an extent Tuesday is not meridional (or very weak for that matter). Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 SPC maintains 15% sig-hatched on Thursday: ELEVATED CONVECTION/TSTMS MAY BE ONGOING AT THE START OF D2 ACROSSPARTS OF THE CENTRAL/SRN PLAINS WITHIN A CORRIDOR OF WAA ALONG A SSWLY LLJ. THIS ACTIVITY COULD PERSIST THROUGH THE DAY AS IT SPREADS ENEWD. THE GREATEST THREAT FOR SEVERE STORMS REMAINS ALONG AND JUST E OF THE GENERALLY N-S ORIENTED DRY LINE...WITH STORM INITIATION EXPECTED BETWEEN 21-00Z. SLY LOW LEVEL FLOW ACROSS WRN PORTIONS OF THE CENTRAL/SRN PLAINS WILL MAINTAIN NWD MOISTURE ADVECTION WITH A NARROW CORRIDOR OF SURFACE DEWPOINTS IN THE LOWER 60S REACHING CENTRAL KS /E OF DRY LINE/. THIS COMBINED WITH STRONG SURFACE HEATING AND STEEP MIDLEVEL LAPSE RATES SHIFTING EWD ATOP THE DRY LINE WILL SUPPORT MODERATE INSTABILITY. STRENGTHENING SWLY MIDLEVEL WINDS /40-50 KT/ THU AFTERNOON COMBINED WITH A 30-40 KT SLY LLJ WILL RESULT IN EFFECTIVE BULK SHEAR OF 35-45 KT WITH VECTORS ORIENTED PERPENDICULAR TO THE SURFACE BOUNDARY. THIS WILL SUPPORT A GREATER POTENTIAL FOR DISCRETE SUPERCELLS CAPABLE OF PRODUCING HAIL...SOME VERY LARGE...AND DAMAGING WINDS. IN ADDITION...EFFECTIVE SRH EXCEEDING 300 M2/S2 WITH LARGE LOW LEVEL HODOGRAPH CURVATURE WILL SUPPORT A TORNADO THREAT...PRIMARILY FROM WRN KS INTO WRN OK/ERN TX PANHANDLE. OVERALL SEVERE WEATHER THREAT SHOULD DIMINISH LATER THU EVENING AS THE INSTABILITY WEAKENS. Link to comment Share on other sites More sharing options...
andyhb Posted April 11, 2012 Author Share Posted April 11, 2012 That doesn't look pretty on the 00z Euro, double barrelled 992 mb SLP with the mid level jet punching right into the warm sector. GGEM going along with this too: Link to comment Share on other sites More sharing options...
brettjrob Posted April 11, 2012 Share Posted April 11, 2012 Indeed... looks like a classic I-35 special on the Euro, provided sufficient instability (doubt this will be an issue). This is the kind of model image I feel compelled to save whether it verifies or not. Link to comment Share on other sites More sharing options...
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