hm8 Posted April 14, 2012 Share Posted April 14, 2012 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT SAT APR 14 2012 VALID 141200Z - 151200Z ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS MUCH OF CENTRAL AND EASTERN NEBRASKA AND PARTS OF ADJACENT NORTH CENTRAL KANSAS/WESTERN IA... ...THERE IS A HIGH RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING ACROSS PARTS OF SOUTH CENTRAL KANSAS INTO NORTH CENTRAL OKLAHOMA... ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK AREA ACROSS THE REMAINDER OF CENTRAL AND EASTERN NEBRASKA...WESTERN IOWA...NORTHWEST MISSOURI...CENTRAL AND EASTERN KANSAS...AND PARTS OF NORTHERN AND CENTRAL OKLAHOMA... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK AREA ACROSS A LARGE PORTION OF THE CENTRAL AND SOUTHERN PLAINS... ..SYNOPSIS MODELS ALL INDICATE THAT A STRONG MID/UPPER JET STREAK...NOW DIGGING INTO THE BASE OF A LARGE-SCALE UPPER TROUGH OVER THE WESTERN U.S...WILL CONTINUE EASTWARD ACROSS THE SOUTHERN PLATEAU TODAY...BEFORE NOSING NORTHEASTWARD ACROSS THE SOUTHERN ROCKIES INTO THE CENTRAL PLAINS BY LATE TONIGHT. THIS IS EXPECTED TO INCLUDE A 90-100+ KT 500 MB JET CORE...WHICH MAY BE PRECEDED BY ANOTHER SIGNIFICANT SPEED MAXIMUM ACROSS THE SOUTHERN ROCKIES/ CENTRAL PLAINS REGION DURING THE DAY. GUIDANCE SUGGESTS THAT ASSOCIATED FORCING WILL CONTRIBUTE TO RAPID INTENSIFICATION OF A SURFACE CYCLONE TO THE LEE OF THE CENTRAL ROCKIES...WITH A 1000 MB LOW CENTER DEEPENING BELOW 990 MB ACROSS EASTERN COLORADO INTO SOUTHWEST NEBRASKA BETWEEN 14/12Z AND 15/00Z. WITHIN ITS WARM SECTOR...A SOUTHERLY LOW-LEVEL JET WILL STRENGTHEN ACROSS THE SOUTHERN INTO CENTRAL PLAINS /50+ KT AT 850 MB BY LATE AFTERNOON...INCREASING UP TO 70 KT DURING THE EVENING/. THIS WILL CONTRIBUTE TO THE CONTINUING NORTHWARD ADVECTION OF INCREASINGLY RICH MOISTURE RETURNING OFF THE WESTERN GULF OF MEXICO...BENEATH AT LEAST MODESTLY STEEP LAPSE RATES. MIXED LAYER CAPE IS EXPECTED TO EXCEED 2000 J/KG WITHIN A CORRIDOR ACROSS CENTRAL TEXAS THROUGH MUCH OF OKLAHOMA AND CENTRAL/EASTERN KANSAS...INTO THE VICINITY OF A WARM FRONTAL ZONE EXTENDING EAST OF THE LOW ACROSS NEBRASKA INTO THE MISSOURI VALLEY. THIS ENVIRONMENT IS EXPECTED TO BE CONDUCIVE FOR A SIGNIFICANT OUTBREAK OF SEVERE STORMS...THAT MAY IMPACT PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS THROUGH MUCH OF THE PERIOD. THIS MAY INCLUDE SEVERAL TORNADIC SUPERCELLS...AND PERHAPS...BY TONIGHT... THE EVOLUTION OF A SUBSTANTIAL SQUALL LINE. ..NEBRASKA NORTH AND EAST OF THE DRY LINE WRAPPING INTO THE DEEPENING SURFACE CYCLONE...INTO THE VICINITY OF THE WARM FRONT...CONDITIONS APPEAR LIKELY TO BECOME VERY CONDUCIVE TO THE FORMATION OF DISCRETE TORNADIC SUPERCELLS...AS THE EXIT REGION OF THE CYCLONIC MID/UPPER JET OVERSPREADS THE REGION. THIS COULD OCCUR AS EARLY AS 18-21Z...IF NOT BEFORE...ACROSS PARTS OF SOUTHWEST INTO CENTRAL NEBRASKA...BEFORE DEVELOPING EASTWARD AND INCREASING IN COVERAGE ACROSS CENTRAL INTO EASTERN NEBRASKA THROUGH THE REMAINDER OF THE AFTERNOON. THIS IS WHERE LOW-LEVEL HODOGRAPHS ARE EXPECTED TO BECOME LARGE AND CLOCKWISE CURVED...AND SUPPORTIVE OF LONG-LIVED SUPERCELLS CAPABLE OF PRODUCING STRONG TORNADOES. ..KANSAS AND OKLAHOMA INTO NORTH CENTRAL/NORTHWEST TEXAS BARRING COMPLICATIONS FROM RESIDUAL EARLY DAY CONVECTIVE DEVELOPMENT...THE WARM SECTOR ENVIRONMENT AHEAD OF THE DRY LINE ACROSS MUCH OF CENTRAL/EASTERN KANSAS AND OKLAHOMA PROBABLY WILL STILL BE CAPABLE OF SUPPORTING LONG-LIVED SUPERCELLS CAPABLE OF PRODUCING STRONG TORNADOES. HOWEVER...CONCERN EXISTS THAT THE POTENTIAL COVERAGE OF DISCRETE SUPERCELL STORMS MAY REMAIN SOMEWHAT SPARSE...PRIOR TO SQUALL LINE EVOLUTION THIS EVENING AS A COLD FRONT OVERTAKES THE DRY LINE AND SURGES EASTWARD ACROSS THE PLAINS. ONCE THIS OCCURS...DAMAGING WIND AND LARGE HAIL MAY BECOME THE PRIMARY SEVERE THREAT. ..KERR/LEITMAN.. 04/14/2012 Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 14, 2012 Share Posted April 14, 2012 45% Link to comment Share on other sites More sharing options...
Memphis Weather Posted April 14, 2012 Share Posted April 14, 2012 45% tor risk in the north Nailed it! LOL Still sounds like SPC very leery of the KS/OK risk. Wondering still if it weren't for the initial Day 2 that it wouldn't be MDT right now... Link to comment Share on other sites More sharing options...
Stebo Posted April 14, 2012 Share Posted April 14, 2012 I wonder if we will see a rare 60% later today, I think that has only been used once. I think if everything holds suit and any sort of uncertainties are ironed out we will see a 60%. Link to comment Share on other sites More sharing options...
andyhb Posted April 14, 2012 Share Posted April 14, 2012 Earliest greater than 30% tor probs ever issued now too. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 14, 2012 Share Posted April 14, 2012 I don't think there's room for a 60% lol Pretty compact as of now. Link to comment Share on other sites More sharing options...
andyhb Posted April 14, 2012 Share Posted April 14, 2012 That 45% area is larger in areal coverage than 4/27 or 5/24 of last year. Link to comment Share on other sites More sharing options...
hm8 Posted April 14, 2012 Share Posted April 14, 2012 IIRC the last 60% tor prob was issued when tornadoes were already in progress. To have an actual 60% before initiation would be remarkable. Think about it like this, if you live in an area in a 60% prob area, that means chances are literally better than not that your area (within 25 miles) will be hit by a tornado. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 14, 2012 Author Share Posted April 14, 2012 I doubt there will be a 60% for tomorrow, but then again I am usually wrong. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 14, 2012 Share Posted April 14, 2012 Yeah I doubt we will see a 60% tomorrow, but then again i didn't think we would see a 45% with the first day 1. Link to comment Share on other sites More sharing options...
andyhb Posted April 14, 2012 Share Posted April 14, 2012 The convection ongoing over the southern part of the risk area doesn't appear to be very restrictive looking (I.E. there's no giant MCS ongoing that could otherwise hamper destabilization later in the day). Link to comment Share on other sites More sharing options...
Minnesota Meso Posted April 14, 2012 Share Posted April 14, 2012 I think with the next update you will see the northern extent of the tornado risk move slightly to the north. At this time they only have a 2% chance for SW MN, but I think that will increased with the next update to a 15% chance or better. Time will tell. Link to comment Share on other sites More sharing options...
Buckeye05 Posted April 14, 2012 Share Posted April 14, 2012 The convection ongoing over the southern part of the risk area doesn't appear to be very restrictive looking (I.E. there's no giant MCS ongoing that could otherwise hamper destabilization later in the day). Could produce boundaries though. Link to comment Share on other sites More sharing options...
andyhb Posted April 14, 2012 Share Posted April 14, 2012 Could produce boundaries though. I'm fairly sure it will. Link to comment Share on other sites More sharing options...
tmagan Posted April 14, 2012 Share Posted April 14, 2012 00Z RGEM at tau=24 Helicity Lifted Index Dew Point Wind Shear Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 14, 2012 Share Posted April 14, 2012 The 4km WRF which is usually a few hours too fast, agrees with the NE play. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 14, 2012 Author Share Posted April 14, 2012 Pretty stark differerences in the numerical models w.r.t. DMC initiation along I35. I will say one thing though...GGEM and RGEM have absolutely led the way with this event w.r.t. the general upper level config and cyclogenesis. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 14, 2012 Author Share Posted April 14, 2012 NAM 4 km simulated IR. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 14, 2012 Share Posted April 14, 2012 NAM 4 km simulated IR. def a few monsters in the southern risk area. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 14, 2012 Author Share Posted April 14, 2012 def a few monsters in the southern risk area. Yeah definitely some big boys in there. Going to be an interesting day tomorrow watching all this evolve. Link to comment Share on other sites More sharing options...
andyhb Posted April 14, 2012 Share Posted April 14, 2012 def a few monsters in the southern risk area. And some ridiculous looking action in NE and Northern KS. Link to comment Share on other sites More sharing options...
David Reimer Posted April 14, 2012 Share Posted April 14, 2012 Here I am sitting at the hotel getting ready to hit the sack and I happen to pull up the radar. Notice my SpotterNetwork position on this graphic relative to a well-defined hook echo and a weak, but obvious low level circulation. This was around 1:30 AM CDT. I went outside and observed a decent wall cloud with rapid rising motion then was assaulted by the wet RFD that had fairly good winds. Mind you this is all out my hotel door in my pajamas. Considering the look the El Reno supercell is displaying right now, I think I'm going to wait up and make sure I don't need to take protective action for it. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 14, 2012 Share Posted April 14, 2012 Yeah definitely some big boys in there. Going to be an interesting day tomorrow watching all this evolve. We are leaning to the NE play but it just takes one to go down south. Link to comment Share on other sites More sharing options...
Jim Marusak Posted April 14, 2012 Share Posted April 14, 2012 to those chasing tomorrow, be safe. Link to comment Share on other sites More sharing options...
OHweather Posted April 14, 2012 Share Posted April 14, 2012 After looking at models I'm in agreement with the northern high risk area...there will be morning convection to deal with but the warm sector should be capped and convection free south of the warm front, so moderately unstable air should make it into NE although the northern edge of the high risk might be borderline depending on how quickly the ongoing convection and subsequently the warm front can lift north. Left exit portion of 120kt H25 jet steak will move over head by 21z along with nose of 100kt H5 jet streak near dark. Hodos are shown to be very curved with near 90 degrees of turning from the surface through 500mb near the warm front...should see several discrete cells fire capable of long trackers in that environment with 21z-3z likely being the best window given timing of jet streak and likely development of low level inversion after dark. Storms will likely initiate over central NE along dry line and warm front near the triple point and rapidly surge ENE through the warm sector...potentially posing some tornadic threat in southern MN and IA overnight. Given strong LLJ transporting moisture and high theta-e air northward, tornado threat will likely exist as far west as the surface low late afternoon into this evening. As for farther south, they will be in the right-exit quadrant of the jet streak which will probably limit storm coverage until after midnight when the rest of the jet streak swings overhead and the cold front pushes east. However, capping will erode by mid afternoon and moderate to strong instability will be in place. Modeled negative vertical velocities indicate convection should begin to initiate along the dryline between 18-21z in KS/OK. 50kt low lvl jet which should increase near dark combined with a backed low level flow supporting curved hodos will support supercellls capable of producing tornadoes through the evening. Likely isolated coverage combined with shear vectors running more perpendicular to the dry line should prevent things from quickly going linear until the cold front starts surging eastward. Storm coverage will likely be isolated but a couple-few storms will probably put down decently long tracked tors in northern-central OK into central KS...the high might be borderline there based on lack of coverage but a particularly strong tornado or two may evolve in the southern high risk. The presence of -VV's should indicate convection firing near dark (if not sooner based on the cooling mid level temps and erosion of the cap several hours prior to dark) 700mb temps... And this is really impressive turning, especially up in NE: Link to comment Share on other sites More sharing options...
tmagan Posted April 14, 2012 Share Posted April 14, 2012 KOMA RUC BUFKIT forecast sounding for 23Z April 14th. Link to comment Share on other sites More sharing options...
nwburbschaser Posted April 14, 2012 Share Posted April 14, 2012 Just got to Des Moines, and I think Nebraska is my play. I think the Southern target will be a zoo, but I am waiting till about 8 this morning before I commit. Link to comment Share on other sites More sharing options...
David Reimer Posted April 14, 2012 Share Posted April 14, 2012 BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE NORMAN OK 224 AM CDT SAT APR 14 2012 THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A * TORNADO WARNING FOR... EXTREME NORTHWESTERN OKLAHOMA COUNTY IN CENTRAL OKLAHOMA... EXTREME NORTHEASTERN CANADIAN COUNTY IN CENTRAL OKLAHOMA... EXTREME SOUTHWESTERN LOGAN COUNTY IN CENTRAL OKLAHOMA... * UNTIL 300 AM CDT * AT 222 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED 1 MILES NORTHEAST OF PIEDMONT...MOVING NORTHEAST AT 20 MPH. * THIS TORNADIC THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF EXTREME NORTHWESTERN OKLAHOMA...EXTREME NORTHEASTERN CANADIAN AND EXTREME SOUTHWESTERN LOGAN COUNTIES Link to comment Share on other sites More sharing options...
andyhb Posted April 14, 2012 Share Posted April 14, 2012 Impressive meso and reflectivity signature on that cell near Piedmont. Link to comment Share on other sites More sharing options...
Stebo Posted April 14, 2012 Share Posted April 14, 2012 These 2 cells Near Edmond and NE of Guthrie really getting their act together again, both tornado warned. The one NE of Guthrie has a 80kt GTG at 4000' Link to comment Share on other sites More sharing options...
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