Reed Stough Posted April 13, 2011 Share Posted April 13, 2011 To me this is one of the better setups of the whole year for a tornado outbreak. All the other systems have seemed too progressive and the upper support seemed to lag behind the surface low. THIS on the other hand seems to be a much better setup. Question will be to watch the moisture return over the next 24 hours. If the dewpoints come up and there is not the super-cap that they have been having recently, this could get very nasty. Link to comment Share on other sites More sharing options...
JoMo Posted April 13, 2011 Share Posted April 13, 2011 Both the 12z NAM/GFS break out convection, so it looks like no capping issues, however..... GFS breaks out convection a lot earlier in the day and has been over the past few days of model runs. Springfield actually preferred the GFS moisture return over the NAM due to how rapidly moisture should transport north once this thing starts wrapping up. I did notice the GFS did back off a bit on moisture return while the NAM increased a bit, so maybe they are coming to a consensus. Link to comment Share on other sites More sharing options...
JoMo Posted April 13, 2011 Share Posted April 13, 2011 SPC's WRF has updated. http://www.emc.ncep.noaa.gov/mmb/mpyle/cent4km/conus/12/ Link to comment Share on other sites More sharing options...
JoMo Posted April 13, 2011 Share Posted April 13, 2011 Updated my blog with a nice sounding from Paducah on Friday - keep in mind this blog is for layman - not mets http://weatherobserv...y.blogspot.com/ Excellent blog and explanations. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 13, 2011 Share Posted April 13, 2011 uh oh... Link to comment Share on other sites More sharing options...
huronicane Posted April 13, 2011 Share Posted April 13, 2011 uh oh... That is a bit concerning. Link to comment Share on other sites More sharing options...
brettjrob Posted April 13, 2011 Share Posted April 13, 2011 While there's certainly a significant threat over much of eastern OK, I almost feel like the most sure-fire bet for tornadoes may be the bent-back area in central KS where even purely meridional H5 flow will have a significant component normal to the dryline. Right now, directional shear in the richer moisture over OK and N TX looks sufficient for tornadic supercells, but dProg/dT makes that aspect of the setup a question in my mind. Link to comment Share on other sites More sharing options...
JoMo Posted April 13, 2011 Share Posted April 13, 2011 New SPC Day 2 is out: ...A SIGNIFICANT SEVERE WEATHER EPISODE IS POSSIBLE THURSDAY AFTERNOON/EVENING ACROSS SERN KS/ERN OK AND EXTREME NWRN AR/SWRN MO--THIS THREAT WILL INCLUDE VERY LARGE HAIL AND A FEW DAMAGING TORNADOES... http://www.spc.noaa.gov/products/outlook/day2otlk.html Link to comment Share on other sites More sharing options...
tornadotony Posted April 13, 2011 Share Posted April 13, 2011 While there's certainly a significant threat over much of eastern OK, I almost feel like the most sure-fire bet for tornadoes may be the bent-back area in central KS where even purely meridional H5 flow will have a significant component normal to the dryline. Right now, directional shear in the richer moisture over OK and N TX looks sufficient for tornadic supercells, but dProg/dT makes that aspect of the setup a question in my mind. I tend to agree with you on this. Link to comment Share on other sites More sharing options...
BrentO Posted April 13, 2011 Share Posted April 13, 2011 http://www.rap.ucar.edu/weather/model/displayMod.php?var=eta_sfc_dewp&hours=hr60 .......12z NAM puts 55td's into central IN and IL and 60td's down here in southern IN, was reading what the SPC said about moisture and tornadoes for this area on friday. Will 55-60Td do it? Oh and nice PAH sounding Beau. Link to comment Share on other sites More sharing options...
janetjanet998 Posted April 13, 2011 Author Share Posted April 13, 2011 seperate thread for Friday http://www.americanwx.com/bb/index.php/topic/17065-april-15th-severe-weather-thread-tornado-outbreak-possible/ Link to comment Share on other sites More sharing options...
JoMo Posted April 13, 2011 Share Posted April 13, 2011 Both SPC and NWS Springfield sound like they both believe storms will move off the dryline. 15z SREF Link to comment Share on other sites More sharing options...
Indystorm Posted April 13, 2011 Share Posted April 13, 2011 From 18z NAM for Thursday night... Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 13, 2011 Share Posted April 13, 2011 Just my two cents... With the NAM/SREF showing more impressive parameters father into AR than previous runs, I think it would be feasible to suggest that a greater tornado risk could occur farther east into AR than the current Day 2 suggests and the MDT risk should be expanded a bit east. This could be a rather dangerous situation since the most significant threat appears to be after dark... NAM Surface LCL: EHI: Link to comment Share on other sites More sharing options...
Indystorm Posted April 13, 2011 Share Posted April 13, 2011 Was wondering the same thing about AR myself. Not good given their history of overnight tors. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 13, 2011 Share Posted April 13, 2011 18z NAM Rather impressive given its resolution: Link to comment Share on other sites More sharing options...
Stebo Posted April 13, 2011 Share Posted April 13, 2011 Yeah I was just going to remark normally the NAM doesn't go over 45DBZ on the simulated reflectivity maybe something to monitor in of itself. Link to comment Share on other sites More sharing options...
Chinook Posted April 13, 2011 Share Posted April 13, 2011 18z NAM Rather impressive given its resolution: Wow, what is that? GRLevel2AE (??) displaying model and terrain information? Link to comment Share on other sites More sharing options...
JoMo Posted April 13, 2011 Share Posted April 13, 2011 Wow, what is that? GRLevel2AE (??) displaying model and terrain information? think it's probably GREarth http://www.stormreports.org/grearth.htm Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 13, 2011 Share Posted April 13, 2011 Wow, what is that? GRLevel2AE (??) displaying model and terrain information? GREarth. Amazing product. Works for pretty much every element of extreme weather. Link to comment Share on other sites More sharing options...
Srain Posted April 13, 2011 Share Posted April 13, 2011 E OK into AR looks prime. Stacked low should produce. Good Luck! Link to comment Share on other sites More sharing options...
k*** Posted April 14, 2011 Share Posted April 14, 2011 i wish i had more time to chase...tomorrow would be a good day to take the short trip down to the mod risk zone, but i am tied up all day. i wonder what kind of weirdness i'll get as i sit the NE of the low...i get the squall line on the NAM, so i guess that would be better than nothing. Link to comment Share on other sites More sharing options...
JoMo Posted April 14, 2011 Share Posted April 14, 2011 i wish i had more time to chase...tomorrow would be a good day to take the short trip down to the mod risk zone, but i am tied up all day. i wonder what kind of weirdness i'll get as i sit the NE of the low...i get the squall line on the NAM, so i guess that would be better than nothing. You may get some nados/landspouts embedded in that or something. I'm curious to see tonight and of course tomorrows model runs. Link to comment Share on other sites More sharing options...
k*** Posted April 14, 2011 Share Posted April 14, 2011 You may get some nados/landspouts embedded in that or something. I'm curious to see tonight and of course tomorrows model runs. I'm not really all that familiar with these types of setups...this will be a first for me Link to comment Share on other sites More sharing options...
Stebo Posted April 14, 2011 Share Posted April 14, 2011 I'm not really all that familiar with these types of setups...this will be a first for me Yeah I could see a potential like JoMo stated playing out, which is somewhat common in Kansas. Link to comment Share on other sites More sharing options...
k*** Posted April 14, 2011 Share Posted April 14, 2011 Yeah I could see a potential like JoMo stated playing out, which is somewhat common in Kansas. this afternoon's AFD is mildly intriguing...the mention of NNW moving supercells gives me a little hope for some local action THURSDAY AND THURSDAY NIGHT...THE SURFACE LOW PRESSURE WILL CONTINUETO DEEPEN OVER SOUTHWEST AND SOUTH CENTRAL KANSAS ON THURSDAY. WHILEMOISTURE WILL BE STREAMING NORTH...THE TRUE WARM SECTOR WILL ONLYSEE SURFACE DEWPOINTS IN THE UPPER 50S OVER PARTS OF THE FORECASTAREA. IN ADDITION...THE WARM SECTOR IS EXPECTED TO BE QUITENARROW...ON THE ORDER OF 75 TO 150 MILES. VERY COLD MID LEVEL TEMPSWITH STEEP LAPSE RATES WILL OVERTAKE THE AREA BY LATE AFTERNOON WITHFAVORABLE CONDITIONS FOR SEVERE WEATHER. IN TERMS OF MODELPREFERENCE...PREFER THE HIGHER RESOLUTION OF FEATURES GIVEN BY THENAM...ALTHOUGH DEWPOINTS MAY BE OVERDONE JUST A TAD.HOWEVER...PREFER THE TRACK OF THE LOW TO BE CLOSER TO THAT OF THEECMWF AND GFS...POTENTIALLY BRINGING THE WARM SECTOR JUST A BITFARTHER NORTH.THAT SAID...EXPECT AN INITIAL ROUND OF THUNDERSTORMS TO DEVELOP OVERCENTRAL KANSAS AND MOVE ALMOST DUE NORTH INTO PARTS OF THE FORECASTAREA. FORECAST SOUNDINGS BY NOON TO 2 PM INDICATE SURFACE BASEDINSTABILITY WITH AMPLE SHEAR IN THE LOW LEVELS AND FAIRLY LOW LFC`S.THAT SAID...INITIAL STORMS IN THIS AREA MAY BE SEVERE WITH SOMETORNADIC THREAT EARLY GIVEN THE QUALITY OF LOW LEVEL SHEAR. THISROUND OF STORMS SHOULD MOVE NORTH OF THE FORECAST AREA AND WEAKEN ABIT BY MID AFTERNOON.A BROKEN LINE OF SUPERCELLS IS THEN EXPECTED TO DEVELOP OVER SOUTHCENTRAL KANSAS AND SLOWLY TREK NORTHEAST WITH THE WARM SECTOR.INDIVIDUAL STORM MOTION SHOULD RANGE FROM NNW TO NE DEPENDING ONLOCATION IN RELATION TO THE SURFACE LOW PRESSURE. SHEAR AND LAPSERATES WILL BE IMPRESSIVE IN AND NEAR THE WARM SECTOR...BUTINSTABILITY WILL QUICKLY DIMINISH FARTHER TO THE NORTHEAST. THOSESTORMS THAT CAN REMAIN IN THE INSTABILITY AXIS FOR THE LONGEST WILLSEE A GOOD CHANCE OF PRODUCING SEVERE WEATHER...INCLUDING VERY LARGEHAIL...DAMAGING WINDS...AND TORNADOES. THE PRIMARY UNCERTAINTY IS INJUST HOW FAR NORTH THE INSTABILITY AXIS EXTENDS INTO THE FORECASTAREA. STORMS WILL TAPER A BIT IN INTENSITY AS THE CONGEAL AND CINHINCREASES AFTER AROUND 10 PM...AND ANY SEVERE WEATHER WILL LIKELY PUSH EAST OF THE AREA AFTER MIDNIGHT. p.s.--lol cut and paste Link to comment Share on other sites More sharing options...
Stebo Posted April 14, 2011 Share Posted April 14, 2011 this afternoon's AFD is mildly intriguing...the mention of NNW moving supercells gives me a little hope for some local action p.s.--lol cut and paste Yeah normally you get a nice shear axis moving Northward in these types of setups, sometimes you can really yield on them. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 14, 2011 Share Posted April 14, 2011 Just diving into the forecast to my west now that I have updated the forecast for a cold rain here back east. Things still looking on track, including the impressive signals for significant hail. Here is an example from the 18z GFS valid at 00z Friday. The image is SBCAPE (generally 1000-2000 J/kg where it is orange), with CAPE in the -10 to -30 C layer (hail growth zone) in blue and freezing level in green. Again almost half the SBCAPE is located in the hail growth zone (about 700-1000 J/kg) with freezing levels between 9 and 11kft. Prime for large and significant hail, and still 50 dBZ cores are only going to need to reach around 29kft to produce severe hail. Link to comment Share on other sites More sharing options...
brettjrob Posted April 14, 2011 Share Posted April 14, 2011 i wish i had more time to chase...tomorrow would be a good day to take the short trip down to the mod risk zone, but i am tied up all day. i wonder what kind of weirdness i'll get as i sit the NE of the low...i get the squall line on the NAM, so i guess that would be better than nothing. Depending on the exact track of the low, I can see your area getting in on some pseudo cold-core type action mid-late afternoon, though the best chances will probably be a bit to your S. I'm fully expecting some tornado reports inside an ICT-RSL-EMP polygon during the 3-6pm window. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 14, 2011 Share Posted April 14, 2011 Another thing I like to look at, especially in regards to regional severe weather as opposed to specific targets, is 0-4km thetae lapse rates and jet level wind speed. Generally speaking 0-4km encompasses the surface to 600 mb layer, and gives you an idea of low/mid level instability. Being able to toggle that with the jet stream gives you an idea of both divergence for lift and speed for shear. Here is an example from the 12z NAM. Values greater than about -4 C/km (red and left on the scale at the top left) are more favorable. You can see the NAM is forecasting some of the best thetae lapse rates I've seen this year, at almost -7 C/km. Over the top of that you have a strong jet streak, approaching 100 knots. We already know about the forecast shear and intense vertical motions that are going to result from this. The GFS forecast for thetae lapse rates is a little closer to -4 C/km, and I'm guessing that is mostly due to the fact that is has ongoing precip at 00z that is cutting down on the values. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.