andyhb Posted March 22, 2012 Author Share Posted March 22, 2012 Andy, do you think the threat for elevated convection would at least extend into southern MB? Looks like a rather impressive warm air advection regime. Would be a classic elevated scenario for sure in North Dakota. Not sure how far north, though.. I honestly wouldn't be surprised to see some surface based storms into ND considering LCL heights are fairly favorable, I'm not so sure for your area, but I'd keep an eye on this, looking at the Euro more closely, I'm pretty sure, like Brett said, that it looks like a rather impressive setup for the Northern/Central Plains on Monday. Link to comment Share on other sites More sharing options...
chase_stormz Posted March 22, 2012 Share Posted March 22, 2012 Monday looks pretty nice on the 12z EC. It's quite a bit faster, with the shortwave trough axis already into CO by 00z Tue, resulting in a 988 mb SLP on the NE/SD border. Nice triple point setup for parts of SD and northern NE, with further dryline activity possible down through KS and the Panhandles. GFS is less enthusiastic due to less-favorable timing (for Monday). Well, quite a bit of CIN but wow! Souix Falls, SD, 00z Tues. 12z GFS. Link to comment Share on other sites More sharing options...
andyhb Posted March 22, 2012 Author Share Posted March 22, 2012 That is a damn impressive wind profile. With that said, on the GFS, the 700 mb temperatures for Monday (Not Tuesday) are looking pretty unfavorable for development. Link to comment Share on other sites More sharing options...
SquatchinNY Posted March 22, 2012 Share Posted March 22, 2012 Are we looking at your regular 'classic severe storms' here, or more low topped, or cold core? Link to comment Share on other sites More sharing options...
chase_stormz Posted March 22, 2012 Share Posted March 22, 2012 That is a damn impressive wind profile. Sure is lol. I looked at a few more in that general vicinity and such as Omaha and Sioux City, IA and they are very impressive as well. Link to comment Share on other sites More sharing options...
andyhb Posted March 22, 2012 Author Share Posted March 22, 2012 On Tuesday, temperatures in the mid levels look much less problematic, and I would think that the 12z GFS is underdoing instability values given surface temps in the 60s and 70s (likely underdone), dewpoints in the upper 50s and 60s, 700 mb temperatures <5 degrees and 500 mb -10 degrees or lower. The GFS also shows a tongue of 850 mb dewpoints in excess of 10 degrees reaching the area by 18z. Just wanted to take a look into the thermodynamics on Tuesday because there are some very impressive dynamics aloft by 18z. The LLJ jet on Tuesday also looks to be on a much more favorable trajectory to get GoM moisture into the warm sector. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted March 22, 2012 Share Posted March 22, 2012 Are we looking at your regular 'classic severe storms' here, or more low topped, or cold core? Definitely not cold core. Link to comment Share on other sites More sharing options...
chase_stormz Posted March 22, 2012 Share Posted March 22, 2012 On Tuesday, temperatures in the mid levels look much less problematic, and I would think that the 12z GFS is underdoing instability values given surface temps in the 60s and 70s (likely underdone), dewpoints in the upper 50s and 60s, 700 mb temperatures <5 degrees and 500 mb -10 degrees or lower. The GFS also shows a tongue of 850 mb dewpoints in excess of 10 degrees reaching the area by 18z. Just wanted to take a look into the thermodynamics on Tuesday because there are some very impressive dynamics aloft by 18z. The LLJ jet on Tuesday also looks to be on a much more favorable trajectory to get GoM moisture into the warm sector. While I agree with you, and there are a number of days for this to change, I'm not all that impressed with the tornado threat on Tuesday due to a much more unidirectional wind field. Of course, we know how things change across the models as days near, but I just wanted to point that out. It looks to be a more substantial wind threat than anything else at THIS time. Link to comment Share on other sites More sharing options...
andyhb Posted March 22, 2012 Author Share Posted March 22, 2012 While I agree with you, and there are a number of days for this to change, I'm not all that impressed with the tornado threat on Tuesday due to a much more unidirectional wind field. Of course, we know how things change across the models as days near, but I just wanted to point that out. It looks to be a more substantial wind threat than anything else at THIS time. It is not unidirectional, look at the soundings around La Crosse, Waterloo, Davenport and Minneapolis from around 15z on (and then eastward further into WI and IL by 00z). The Euro is even more impressive, btw. Link to comment Share on other sites More sharing options...
chase_stormz Posted March 22, 2012 Share Posted March 22, 2012 It is not unidirectional, look at the soundings around La Crosse, Waterloo, Davenport and Minneapolis from around 15z on (and then eastward further into WI and IL by 00z). You're right, i wasn't looking out that far across the warm sector. My bad lol. Link to comment Share on other sites More sharing options...
tornadotony Posted March 22, 2012 Share Posted March 22, 2012 In the broad, general synoptic sense, the confluent flow in the warm sector, the deep low, and intense yet compact shortwave are hallmarks of a Midwestern tornado outbreak. A lot needs to be realized, however, to make that a reality. If we see the general moisture/instability fields that the GFS has be realized, then we've got a good shot at a tornado event of substance next week for the upper 1/3 of the Mississippi valley. Link to comment Share on other sites More sharing options...
Hoosier Posted March 22, 2012 Share Posted March 22, 2012 In the broad, general synoptic sense, the confluent flow in the warm sector, the deep low, and intense yet compact shortwave are hallmarks of a Midwestern tornado outbreak. A lot needs to be realized, however, to make that a reality. If we see the general moisture/instability fields that the GFS has be realized, then we've got a good shot at a tornado event of substance next week for the upper 1/3 of the Mississippi valley. My biggest concern at this point is probably the moisture return. Link to comment Share on other sites More sharing options...
MnWeatherman Posted March 22, 2012 Share Posted March 22, 2012 Monday looks downright nasty. Hodos are off the hook, dewpoints in the 60s with temps in upper 70s/ low 80s in central south dakota. It appears the ECMWF did lead the way and now 18z GFS is similar in track and timing. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted March 22, 2012 Share Posted March 22, 2012 My biggest concern at this point is probably the moisture return. Yeah I agree with that. The rapid ejection with a relatively short period of leeside troughing combined with the weak front that pushes through the GOM as that cutoff slowly progresses eastward won't be conducive to rich moisture return. Dewpoints will struggle to reach 60 since vegetation is still sparse. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted March 22, 2012 Share Posted March 22, 2012 Monday looks downright nasty. Hodos are off the hook, dewpoints in the 60s with temps in upper 70s/ low 80s in central south dakota. It appears the ECMWF did lead the way and now 18z GFS is similar in track and timing. I didn't see any 60F dewpoints in the ECMWF or GFS. Link to comment Share on other sites More sharing options...
MnWeatherman Posted March 23, 2012 Share Posted March 23, 2012 I didn't see any 60F dewpoints in the ECMWF or GFS. Yeah, your right. Around 60 is plausible, but as of the 00z GFS run i'm a bit worried of the moisture return myself. Also, the GFS has warm 700mb temps to induce a cap. It's lagging in bringing in the cooler temps from the west, but given the amplification of this system, I wouldn't doubt if storms fire up before dark. Link to comment Share on other sites More sharing options...
brettjrob Posted March 23, 2012 Share Posted March 23, 2012 The best chance for convective initiation on Monday might be in the southern High Plains along the dryline, where higher theta-e air in the BL will be resident under H7 temps that are similar to those farther north. Weaker flow and high LCLs will likely mitigate the sig svr threat, though. The most potent environment kinematically will be over NE and SD, but I'm not sure moisture will recover in time. Link to comment Share on other sites More sharing options...
cyclone77 Posted March 23, 2012 Share Posted March 23, 2012 Based on the new GFS I like south-central into central SD on Monday. Deep moisture is a bit questionable, but everything else looks great IMO. Love the kinematics, and the nice funneling of theta-e into that area. Link to comment Share on other sites More sharing options...
cyclone77 Posted March 23, 2012 Share Posted March 23, 2012 As for Tue the GFS still forecasts very nice soundings/hodos from central/eastern Iowa up into southern Minnesota. The forecast instability is very marginal, but given the tendency for the GFS to low ball temps in these types of setups I'm not taking that too seriously. A little more instability in the presence of this highly sheared environment and we'll have a fantastic setup for tornadic supercells IMO. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted March 23, 2012 Share Posted March 23, 2012 Some of the hodographs across SD are off the charts near/along the warm front. Obviously surface based initiation will be challenging if not possible...but much is dependent upon timing as well as the quality of ejection (i.e., how strong of a shortwave we are dealing with). Link to comment Share on other sites More sharing options...
cyclone77 Posted March 23, 2012 Share Posted March 23, 2012 Some of the hodographs across SD are off the charts near/along the warm front. Obviously surface based initiation will be challenging if not possible...but much is dependent upon timing as well as the quality of ejection (i.e., how strong of a shortwave we are dealing with). If we can get some surface based storms in that environment it should do quite well. Whenever we see a funneling effect of the low-level moisture/theta-e like what's being forecast by tonight's GFS into a region just ahead of the surface cyclone I always feel pretty good about chances of convection rooting into the BL. I guess we'll see how it goes. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted March 23, 2012 Share Posted March 23, 2012 The best chance for convective initiation on Monday might be in the southern High Plains along the dryline, where higher theta-e air in the BL will be resident under H7 temps that are similar to those farther north. Weaker flow and high LCLs will likely mitigate the sig svr threat, though. The most potent environment kinematically will be over NE and SD, but I'm not sure moisture will recover in time. The high amplitude shortwave ridge is going to cause major capping problems across the SD where the best kinematic environment exists. There may be a narrow opportunity near the surface low/cold front, but it seems much of the best environment will be strongly capped. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted March 23, 2012 Share Posted March 23, 2012 The 00Z GEM has major capping issues...no surprise. High amplitude shortwave ridge with extreme height falls owing to a deamplifying bowling ball low in SW flow doesn't incite confidence. Link to comment Share on other sites More sharing options...
andyhb Posted March 23, 2012 Author Share Posted March 23, 2012 As for Tue the GFS still forecasts very nice soundings/hodos from central/eastern Iowa up into southern Minnesota. The forecast instability is very marginal, but given the tendency for the GFS to low ball temps in these types of setups I'm not taking that too seriously. A little more instability in the presence of this highly sheared environment and we'll have a fantastic setup for tornadic supercells IMO. This, it does get 60s dews into E IA and IL for Tuesday (although I can still see issues with moisture quality/depth), and with that said, I can already see there is a big difference in the sfc temps between the NAM and GFS at 72 hrs. Given the likely capping problems on Monday, I tended to think Tuesday held the greater potential here, but of course that could change being 4-5 days out still. Link to comment Share on other sites More sharing options...
andyhb Posted March 23, 2012 Author Share Posted March 23, 2012 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0345 AM CDT FRI MAR 23 2012 VALID 261200Z - 311200Z ...DISCUSSION... THE ECMWF AND GFS MODELS ARE IN EXCELLENT AGREEMENT IN DEPICTING A POTENT SHORTWAVE TROUGH...NOW OVER THE ERN PACIFIC...EJECTING NEWD ACROSS WY AND INTO THE NRN HIGH PLAINS ON MON/D4. BOTH MODELS ALSO DEPICT A DEEP SURFACE LOW...WITH 1-2 MB/HR PRESSURE FALLS PERSISTING ALL DAY OVER SD AND WRN NEB NEAR THE SURFACE LOW. WITH THE COMPACT NATURE OF THIS SYSTEM...A TIGHT PRESSURE FALL/RISE COUPLET IS EXPECTED...WHICH WILL INTERACT WITH STEEP LAPSE RATES AND SUFFICIENT INSTABILITY TO PRODUCE A DAMAGING WIND THREAT FROM WRN SD INTO N CNTRL NEB. THE UPPER SHORTWAVE TROUGH WILL TAKE MORE OF AN EWD DIRECTION ON TUE/D5 AS IT MOVES ACROSS THE UPPER MS VALLEY. WITH STRONG VORTICITY ALOFT...BANDS OF STORMS ARE LIKELY ALONG THE LEADING EDGE OF THE VORTICITY MAX. HOWEVER...IT APPEARS THAT THE SURFACE MOIST AXIS WILL BECOME NARROW...AND STRONG MIXING MAY OCCUR AS WELL. THE RESULT COULD BE A SMALL WINDOW OF OPPORTUNITY FOR SEVERE STORMS. AT THIS TIME...IT IS TOO UNCERTAIN TO INTRODUCE SUCH A SMALL AREA. AS THIS TROUGH CONTINUES EWD ACROSS THE GREAT LAKES...A COLD FRONT WILL TRAIL SWWD ACROSS THE OH VALLEY INTO THE MID MS VALLEY...WITH A CONTINUED THREAT OF THUNDERSTORMS. ALTHOUGH SOME LOCALIZED SEVERE MAY OCCUR IN THE FORM OF WIND AND HAIL...NO LARGE SCALE AREAS APPEAR WARRANTED AT THIS TIME. ..JEWELL.. 03/23/2012 Link to comment Share on other sites More sharing options...
trapperman Posted March 23, 2012 Share Posted March 23, 2012 At least for up here, someone wake me up in late April. Next. Link to comment Share on other sites More sharing options...
andyhb Posted March 24, 2012 Author Share Posted March 24, 2012 DAY 3 CONVECTIVE OUTLOOKNWS STORM PREDICTION CENTER NORMAN OK 0120 AM CDT SAT MAR 24 2012 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE BLACK HILLS NEWD INTO NWRN MN... ...SYNOPSIS... A POTENT SHORTWAVE TROUGH WILL MOVE FROM THE GREAT BASIN MON MORNING INTO THE NRN HIGH PLAINS BY LATE AFTERNOON. AT THE SURFACE...LOW PRESSURE WILL RAPIDLY DEEPEN FROM ERN MT INTO WRN SD/NEB. AN INTENSE COLD FRONT WILL MATERIALIZE OVER WY AND CO...AFFECTING SD AND NEB DURING THE EVENING WITH STRONGLY FORCED CONVECTION CAPABLE OF DAMAGING WINDS. ...DAKOTAS INTO WRN MN... ELEVATED THUNDERSTORMS MAY BE ONGOING OVER THE ERN DAKOTAS WITH A CONDITIONAL THREAT OF LARGE HAIL DRIVEN BY WARM ADVECTION WITH THE LOW LEVEL JET. THESE STORMS MAY CONTINUE THROUGH MIDDAY AS THEY GRADUALLY SHIFT NWD ACROSS ND AND PERHAPS NWRN MN. TO THE S...THE PLAINS WILL BE CAPPED MOST OF THE DAY. PRESSURES WILL FALL RAPIDLY OVER NRN HIGH PLAINS AHEAD OF THE TROUGH...WITH CONVERGENCE INTENSIFYING AS A COLD FRONT SURGES ACROSS WY AND CO. SINCE THE FRONT WILL ARRIVE LATE...PEAK HEATING WILL HAVE BEEN ACHIEVED AND VERY STEEP LOW TO MID LEVEL LAPSE RATES WILL BE IN PLACE. DEWPOINTS MAY ONLY BE IN THE 40S TO LOWER 50S F...BUT CAPE WILL BE NONZERO AND SHEAR WILL BE VERY STRONG. HIGH BASED CONVECTION IS EXPECTED ALONG THE FRONT BEGINNING OVER WY...AND SPREADING RAPIDLY NEWD ACROSS THE DAKOTAS. MODELS HAVE BEEN CONSISTENT IN DEPICTING A RAPID AND STRONG WIND SHIFT WITH WLY 850 MB POST FRONTAL FLOW IN EXCESS OF 60 KT. SO WHILE INSTABILITY WILL BE THE LIMITING FACTOR...STRONG FORCING AND STEEP LAPSE RATES SHOULD COMPENSATE AND DAMAGING WINDS ARE EXPECTED. OTHER STORMS WILL PERSIST N OF THE WARM FRONT...FROM THE ERN DAKOTAS INTO MN WITH A LARGE HAIL THREAT. ..JEWELL.. 03/24/2012 Link to comment Share on other sites More sharing options...
Derek30 Posted March 24, 2012 Share Posted March 24, 2012 Latest NAM (even GFS) are more north with the low pressure system on Monday/Tuesday. NAM actually has the low cutting a bit into southern Manitoba. That would give me a great show at elevated convection, especially Monday night and Tuesday morning. Looking forward to this event. Regardless, we should get some much needed precip up here in southern MB. Fires have already been igniting in southeastern portions this past week. Link to comment Share on other sites More sharing options...
andyhb Posted March 26, 2012 Author Share Posted March 26, 2012 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT MON MAR 26 2012 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE DAKOTAS INTO NWRN MN... ...SYNOPSIS... COMPACT SHORTWAVE TROUGH...CURRENTLY MOVING THROUGH SRN CA PER WATER VAPOR IMAGERY...WILL REMAIN PROGRESSIVE THIS FORECAST PERIOD TRACKING FROM THE GREAT BASIN TO ND BY 12Z TUESDAY. THIS TROUGH IS EXPECTED TO EVOLVE INTO A RATHER POTENT SYSTEM AS IT REMAINS NEGATIVELY-TITLED AND UNDERGOES DEEPENING MONDAY NIGHT INTO A CLOSED LOW OVER ND. AT THE SURFACE...A LEE CYCLONE WILL DEEPEN OVER ERN MT INTO THIS AFTERNOON AND THEN TRACK ENEWD ACROSS ND THIS EVENING/OVERNIGHT. A COLD FRONT TRAILING SWD FROM THIS PRIMARY SYNOPTIC LOW IS EXPECTED TO EMERGE INTO THE NRN HIGH PLAINS LATE THIS AFTERNOON OR BY 27/00Z. THIS BOUNDARY WILL THEN ADVANCE QUICKLY ENEWD ACROSS THE DAKOTAS AND NEB THROUGH 27/12Z. MEANWHILE...A WARM FRONT WILL MOVE NWD ACROSS MUCH OF SD TODAY...AND SHOULD EXTEND SEWD FROM ERN MT INTO SOUTH CENTRAL ND TO ERN SD AND WRN IA BY LATE THIS AFTERNOON. ...NRN PLAINS TO NWRN MN... A VERY STRONG EML/PLUME OF MIDLEVEL LAPSE RATES /7.5-9 C PER KM/ WILL CONTINUE TO SPREAD ENEWD ACROSS THE NRN AND CENTRAL PLAINS TODAY...EFFECTIVELY CAPPING THE WARM SECTOR THROUGH THE AFTERNOON. THE EXCEPTION MAY BE ALONG THE E/NERN EXTENT OF THE CAP...WHERE STRONG LOW LEVEL WAA WITHIN THE NOSE OF STRENGTHENING SLY LLJ EXTENDING INTO THE ERN DAKOTAS/WRN MN SUPPORTS ELEVATED TSTM ACTIVITY THIS MORNING INTO THE AFTERNOON. EFFECTIVE BULK SHEAR TO AROUND 40 KT AND MUCAPE TO AROUND 1000 J/KG SUGGEST THE STRONGER ELEVATED STORMS WILL BE CAPABLE OF PRODUCING SEVERE HAIL. THE FOCUS FOR LATE AFTERNOON/EARLY EVENING STRONG TO SEVERE STORM INITIATION SHIFTS TO WRN SD AS STRONG FORCING FOR ASCENT/90-120 METER HEIGHT FALLS SPREAD INTO THE NRN HIGH PLAINS. THIS FORCING IS EXPECTED TO BE SUFFICIENT FOR WEAKENING THE CAP/INHIBITION FOR THE DEVELOPMENT OF HIGH BASED STORMS. MLCAPE UP TO 1000 J/KG OVER WRN SD AND EFFECTIVE BULK SHEAR OF 35-50 KT WILL SUPPORT STORM ORGANIZATION WITH SEVERE HAIL AND DAMAGING WINDS THE INITIAL PRIMARY THREATS. FORECAST SOUNDINGS SUGGEST PARCELS WILL TEND TO BE ROOTED ABOVE THE SURFACE...OR MORE ELEVATED...WITH ENEWD EXTENT ACROSS CENTRAL/NERN SD INTO SRN/ERN ND EARLY MONDAY EVENING WITH THE APPROACH OF THE SURFACE LOW AND COLD FRONT. HOWEVER...THE STRONG FORCING FOR ASCENT ALONG THE TRACK OF THE DEEPENING TROUGH MAY PROVE SUFFICIENT IN OVERCOMING THE CAP SUCH THAT SURFACE BASED STORMS WILL BE POSSIBLE. FOR THIS REASON...THE THREAT FOR DAMAGING WINDS HAS BEEN EXTENDED FARTHER ENEWD THAN INDICATED BY THE PREVIOUS OUTLOOKS FOR THIS REGION. IN ADDITION...A CONDITIONAL TORNADO THREAT WILL EXIST ACROSS CENTRAL SD INTO SOUTH CENTRAL ND...WHERE THE 12Z ECMWF AND 00Z NAM SUGGEST A SUB-SYNOPTIC SURFACE LOW WILL TRACK FROM SWRN-NORTH CENTRAL SD EARLY THIS EVENING. ENHANCED LOW LEVEL SHEAR WITH THIS LOW AND RELATIVELY HIGHER SURFACE DEWPOINTS SUGGEST AN ISOLATED TORNADO THREAT IS POSSIBLE...WITH SFC-1 KM SHEAR EXCEEDING 30 KT. AN ELEVATED HAIL THREAT MAY PERSIST LATER MONDAY EVENING ACROSS ERN/NERN ND AS STORMS BECOME MORE ELEVATED WITH NERN EXTENT. Link to comment Share on other sites More sharing options...
tornadotony Posted March 26, 2012 Share Posted March 26, 2012 I will be floored if there is a tornado today. Absolutely floored. I don't know what's more inhibitive, the cap or the sky-high cloud bases. Link to comment Share on other sites More sharing options...
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