Stebo Posted March 7, 2011 Share Posted March 7, 2011 A decent sized slight risk for both day 2/3, wouldn't shock me to see a small moderate region get put up when it comes to day 1 range but we will see... Decent synoptic set-up, just going to depend on those dew points getting high enough. Agree, although if the trends of the models bumping cape up continues through 12z runs today, I could see a 1630Z day 2 moderate risk. Link to comment Share on other sites More sharing options...
David Reimer Posted March 7, 2011 Share Posted March 7, 2011 12Z NAM isn't as bullish on CAPE and really veers out the low level jet in N/NE TX. Link to comment Share on other sites More sharing options...
tornadotony Posted March 7, 2011 Author Share Posted March 7, 2011 From SHV... OUR PRIMARY FOCUS THOUGH WILL TURN TO OUR WNW TUESDAY EVENING...AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED AS IT LIFTS NE ACROSS CNTRL OK/KS INTO NW AR/SW MO. THE DRY LINE WILL MIX E TOWARDS THE I-35 CORRIDOR BY LATE AFTERNOON...BEFORE BEING OVERTAKEN DURING THE EVENING BY THE ATTENDANT COLD FRONT...AS BOTH FEATURES BEGIN TO APPROACH SE OK/NE TX. WITH THE WARM FRONT EXPECTED TO LIFT N TO NEAR THE RED RIVER BY EARLY EVENING...DIABATIC HEATING WILL CONTRIBUTE TO MODERATE LOW LEVEL INSTABILITY...WITH SFC BASED CAPES OF 1500+ J/KG POSSIBLE ACROSS ECNTRL TX BY EARLY EVENING NEAR THE ADVANCING COLD FRONT/DRYLINE. BOTH THE NAM/GFS INDICATE STRONG CONVERGENCE ALONG THIS BNDRY AS IT APPROACHES SE OK/NE TX DURING THE EVENING...WITH VERY STEEP 850-700MB LAPSE RATES OF 7.5-8 C/KM ADVECTING NE ALONG THE I-30 CORRIDOR BENEATH THE PRIMARY TROUGH AS IT BEGINS TO EJECT NE. COUPLED WITH STRONG 0-1KM SPEED AND DIRECTIONAL SHEAR...WITH AMPLE BUOYANCY /0-3KM HELICITY OF 400-450 M2/S2/ AND EHI/S OF 2-3 M2/S2/...SCATTERED SUPERCELLS MAY DEVELOP ALONG THE SFC BNDRY AND RAPIDLY SPREAD NE ALONG AND N OF THE I-30 CORRIDOR TUESDAY EVENING. HAVE INSERTED MENTION OF SVR IN THE FORECAST FOR THIS CORRIDOR OF NE TX/SW AR/SE OK...WITH DAMAGING WINDS...LARGE HAIL...AND AN ISOLATED TORNADO ALL POSSIBLE. Link to comment Share on other sites More sharing options...
tornadotony Posted March 7, 2011 Author Share Posted March 7, 2011 Link to comment Share on other sites More sharing options...
Reed Stough Posted March 7, 2011 Share Posted March 7, 2011 I think we are going to have to wait to see how the day goes and how muddy the warm sector is. The last event had a very muddy warm sector. Most of the severe weather occuried along the warm front. Which I think is going to happen again with this event. In looking at the 250mb loop -- right now -- the greatest venting of potential thunderstorms occurs from a line from SGF to PAH, during 3/8 12Z to 3/9 12Z. What looks overlooked is the potential Eastern GA/SC severe event. Late in the model runs 3/10 18z to 3/11 00z a secondary piece of energy deepens the trough and Eastern GA and SC look like they might be setting for a nice severe weather event. Link to comment Share on other sites More sharing options...
SmokeEater Posted March 7, 2011 Share Posted March 7, 2011 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 AM CST MON MAR 07 2011 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR ERN PARTS OF THE SRN PLAINS TO THE LOWER/MID MS VALLEY... ...SYNOPSIS... PROGRESSIVE UPPER-LEVEL SHORTWAVE TROUGH DIGGING SEWD OVER THE SWRN CONUS MONDAY MORNING WILL MOVE DOWNSTREAM ACROSS THE SRN PLAINS DURING TUE AFTERNOON...ACCOMPANIED BY STRONG 70 KT MIDLEVEL JET...AND THEN EJECT NEWD INTO THE MID MS VALLEY BY 09/12Z. AS THIS OCCURS...SURFACE LOW IS FORECAST TO PROGRESS ACROSS OK THROUGH TUE AFTERNOON...AND THEN MOVE NEWD ACROSS MO DURING THE OVERNIGHT HRS. A MODIFIED CP AIRMASS WILL BE DRAWN NWD IN RESPONSE TO THE SURFACE CYCLONE...BOUNDED BY A DRYLINE TRAILING SWD ACROSS TX...AND A RETREATING WARM FRONT...WHICH IS FORECAST TO RAPIDLY LIFT NWD INTO SRN AR BY 09/00Z. ...AR DURING THE MORNING AND AFTERNOON... AS THE LOW-LEVEL CYCLONE ATTENDANT TO THE UPPER TROUGH EMERGES OVER THE SRN PLAINS...40-50 KT SLY 850 MB JET WILL DEVELOP OVER THE LWR MS VALLEY BY LATE MORNING. THIS WILL RESULT IN ROBUST LOW-LEVEL WAA/MOISTURE ADVECTION ABOVE A STABLE BOUNDARY LAYER AIRMASS...AIDING IN DESTABILIZATION AND MUCAPE VALUES NEAR 500 J/KG ACROSS AR AS MIDLEVEL LAPSE RATES STEEPEN TO 7.0-7.5 C/KM. GIVEN SWLY 500 MB FLOW INCREASING TO 60 KT COMBINED WITH DEEPENING FREE CONVECTIVE LAYER...EFFECTIVE BULK SHEAR VALUES NEAR 40 KT APPEAR PROBABLE...WHICH MAY SUPPORT MARGINALLY SVR HAIL ACROSS AR THROUGH MID AFTERNOON. ...ERN OK/NERN TX EWD TO OZARKS/MID SOUTH... FARTHER W...NARROW WEDGE OF MID TO UPR 50S DEWPOINTS ARE FORECAST TO ADVECT NWD BENEATH A PLUME OF STEEP MIDLEVEL LAPSE RATES OVER CNTRL/ERN OK BY MID TO LATE AFTERNOON. MEANWHILE...A ZONE OF STEEP LOW-LEVEL LAPSE RATES WILL DEVELOP NEWD ACROSS SWRN OK BEHIND THE DRYLINE AND AHEAD OF A COLD FRONT OVER W-CNTRL AND N-CNTRL OK. THIS SHOULD PROVE SUFFICIENT FOR THE DEVELOPMENT OF A CORRIDOR OF MLCAPE VALUES FROM 500-1000 J/KG. STRONGEST LOW-LEVEL CONVERGENCE IS EXPECTED FROM THE TRIPLE POINT N-NEWD ALONG THE COLD FRONT OVER N-CNTRL/NERN OK...WHICH WILL AID IN THUNDERSTORM INITIATION DURING THE AFTERNOON. DUE TO AN INCREASINGLY NARROW ZONE OF INSTABILITY WITH NWD EXTENT...STORMS MAY STRUGGLE TO PERSIST N OF I-40. HOWEVER...A STRONGLY SHEARED ENVIRONMENT JUXTAPOSED WITH STEEP MIDLEVEL LAPSE RATES MAY FAVOR A FEW SVR STORMS PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS. FARTHER S ALONG THE DRYLINE OVER SERN OK/NERN TX...FORCING FOR ASCENT WILL BE WEAKER...WHICH MAY DELAY INITIATION UNTIL LATE AFTERNOON. THE POTENTIAL FOR AN INITIALLY DISCRETE CONVECTIVE MODE...COMBINED WITH INCREASING DOWNSTREAM DESTABILIZATION...WILL FAVOR LONGER-LIVED STORMS...LIKELY SUPERCELLS GIVEN STRONG DEEP LAYER SHEAR /0-6 KM BULK SHEAR AOA 60 KT/ SPREADING ACROSS THE DRYLINE. THIS ACTIVITY SHOULD MOVE QUICKLY E-NEWD INTO AN EXPANDING WARM SECTOR OVER NRN LA AND SRN AR...AND WILL POSE A THREAT FOR LARGE HAIL/DAMAGING WINDS AND TORNADOES. THE FORECAST POSITION OF THE WARM FRONT IS NOT CERTAIN ATTM DUE TO THE POTENTIAL FOR PERSISTENT CONVECTION AND SUBSEQUENT COLD POOL REINFORCEMENT. HOWEVER...ADDITIONAL STORM DEVELOPMENT WILL BE POSSIBLE ALONG THE BOUNDARY OVER AR GIVEN A FAVORABLE ORIENTATION OF THE LLJ ACROSS THE FRONT...AIDING IN MESOSCALE ASCENT. LOW-LEVEL VERTICAL WIND SHEAR WILL BE QUITE STRONG /EFFECTIVE SRH VALUES IN EXCESS OF 300 M2 S-2/ OVER SRN AR/NRN LA...AND WILL FAVOR A FEW TORNADIC STORMS /POSSIBLY PRODUCING STRONG TORNADOES/ ASSOCIATED WITH EITHER THE ACTIVITY MOVING OUT OF SERN OK/NERN TX...OR NEW DEVELOPMENT INVOF THE WARM FRONT. OVERNIGHT...THE UPPER TROUGH AND SURFACE COLD FRONT WILL PROGRESS ACROSS AR AND SRN MO. INCREASING LINEAR FORCING FOR ASCENT WILL FAVOR A TRANSITION TO A QUASI-LINEAR CONVECTIVE MODE...POSING A CONTINUED THREAT FOR DAMAGING WINDS AND TORNADOES. ...E TX AND LOWER MS VALLEY... FARTHER S OVER ERN TX...THUNDERSTORM INITIATION IS SOMEWHAT IN QUESTION GIVEN A PERSISTENT CAP NOTED IN MODEL FORECAST SOUNDINGS. HOWEVER...IF A FEW STORMS MANAGE TO DEVELOP...THE POTENTIAL WILL EXIST FOR DAMAGING WINDS AND LARGE HAIL. OVER LA/MS...STRONG UPPER DIVERGENCE/LARGE-SCALE ASCENT IS FORECAST TO DEVELOP FROM SRN LA ACROSS SWRN MS. THUNDERSTORMS ARE EXPECTED TO FORM WITHIN THIS REGIME BY LATE AFTERNOON THROUGH THE NIGHT...FOCUSED ALONG AND AHEAD OF A SW-NE ORIENTED LOW-LEVEL CONVERGENCE ZONE...AS WELL AS ALONG THE SRN EXTENSION OF THE WARM FRONT. A VERY MOIST BOUNDARY LAYER /SURFACE DEWPOINTS IN THE MID 60S/ AND MODERATELY STEEP MIDLEVEL LAPSE RATES WILL SUPPORT MLCAPE VALUES AROUND 1000 J/KG. IN ADDITION...STRONG VERTICAL WIND SHEAR PROFILES WILL BE IN PLACE...WITH EFFECTIVE SRH NEAR 400 M2 S-2 /PARTICULARLY NEAR THE WARM FRONT/. THE STRONGLY SHEARED AND MOIST ENVIRONMENT WILL FAVOR SUPERCELLS POSING A THREAT FOR TORNADOES /POSSIBLY SIGNIFICANT/ AND DAMAGING WINDS. ..GARNER/EDWARDS.. 03/07/2011 Link to comment Share on other sites More sharing options...
kwt Posted March 7, 2011 Share Posted March 7, 2011 Certainly sounds to me like they may well be tempted to up the threat to a moderate...though for now I think a slight will do till day 1 as I said before then review it. I've gotta admit to being a little excited about this, whilst it may not be as good as some of the events deeper into the season, the first few events of a year always are neat to me, esp as I seem to take a little bit of time getting back into the swing of things! Link to comment Share on other sites More sharing options...
tornadotony Posted March 7, 2011 Author Share Posted March 7, 2011 Heh I just realized tomorrow is Fat Tuesday...this could set up to be a major disaster if Louisiana is in the cross-hairs of a tornado outbreak on one of its biggest days of the year... Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 7, 2011 Share Posted March 7, 2011 sounds like tomorrow will be a MDT risk if I had to bet. scariest words from that outlook are "through the night" coupled with possibly significant tornadoes. Link to comment Share on other sites More sharing options...
Hoosier Posted March 7, 2011 Share Posted March 7, 2011 The low level shear is just crazy in the OV tomorrow night into Wednesday (note 0-3km helicity over 1000 and 0-1km in excess of 700 in some areas) with hodographs resembling the St. Louis Arch but there's little instability to speak of. Link to comment Share on other sites More sharing options...
thewxmann Posted March 7, 2011 Share Posted March 7, 2011 The reason why the LLJ is all veered out is due to the influence of the junk convection to the east. This doesn't improve overnight. IMO this the reason why models fail to initiate precip along the DL before 0Z despite the strong vorticity advection invof the sfc low. Link to comment Share on other sites More sharing options...
tornadotony Posted March 7, 2011 Author Share Posted March 7, 2011 The 12z GFS and 18z NAM are both getting quite aggressive with moisture return, bringing 65F Td solidly through Shreveport by 21z tomorrow. Link to comment Share on other sites More sharing options...
Chicago Storm Posted March 7, 2011 Share Posted March 7, 2011 Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 7, 2011 Share Posted March 7, 2011 for most of the times that have had a 50 they have ended up verifying.. Link to comment Share on other sites More sharing options...
David Reimer Posted March 7, 2011 Share Posted March 7, 2011 for most of the times that have had a 50 they have ended up verifying.. You won't see them either unless it crosses a major interstate. That area is IMPOSSIBLE to chase in. Its a sit yourself down and hope you see something as it goes past you. Visibility is always an issue due to the trees. I'd say Lousianaa is the worst area to chase in. Out in Arkansas you have hills, but its flatter in LA so you don't have any view. If they do get significant tornadoes out there and it hits a town, you can bet it will end up producing a substantial fatality count. Link to comment Share on other sites More sharing options...
tornadotony Posted March 7, 2011 Author Share Posted March 7, 2011 Just about any questions about moisture return are about to go out the window...this is what is waiting about 200mi offshore... Full-screenStation 42001 NDBC Location: 25.888N 89.658W Conditions as of: Mon, 07 Mar 2011 20:50:00 UTC Winds: ESE (120°) at 13.6 kt gusting to 15.5 kt Significant Wave Height: 3.0 ft Dominant Wave Period: 4 sec Atmospheric Pressure: 29.91 in and falling Air Temperature: 73.4 F Dew Point: 72.9 F Water Temperature: 74.7 F View Details - View History Link to comment Share on other sites More sharing options...
L.B. LaForce Posted March 7, 2011 Share Posted March 7, 2011 Yep, moisture seems to be there..lol Link to comment Share on other sites More sharing options...
blackjack123 Posted March 7, 2011 Share Posted March 7, 2011 OMG!! That seems pretty scary. Major Interstates with EF3+ tornadoes!!!!! Link to comment Share on other sites More sharing options...
David Reimer Posted March 7, 2011 Share Posted March 7, 2011 OMG!! That seems pretty scary. Major Interstates with EF3+ tornadoes!!!!! If you're not going to contribute anything productive, stop posting. There's no shame in reading. Link to comment Share on other sites More sharing options...
kwt Posted March 7, 2011 Share Posted March 7, 2011 Thats a neat profile there Tony, good levels of moisture will pretty much ensure the need for a moderate tomorrow, that was really my only doubt given the wind profiles look decent enough. Link to comment Share on other sites More sharing options...
tornadotony Posted March 7, 2011 Author Share Posted March 7, 2011 Thats a neat profile there Tony, good levels of moisture will pretty much ensure the need for a moderate tomorrow, that was really my only doubt given the wind profiles look decent enough. Haha L.B. posted that, but yeah moisture looks to be there. Link to comment Share on other sites More sharing options...
tornadotony Posted March 8, 2011 Author Share Posted March 8, 2011 I had to post this...I can't remember the last time I saw two of the variables come up 35% or higher... Link to comment Share on other sites More sharing options...
David Reimer Posted March 8, 2011 Share Posted March 8, 2011 I had to post this...I can't remember the last time I saw two of the variables come up 35% or higher... Something is not lining up here. I think the models are gonna come in rather surprising at some point. Needless to say, I'm watching the later ranges of the HRRR/RUC very carefully at this point. Link to comment Share on other sites More sharing options...
Indystorm Posted March 8, 2011 Share Posted March 8, 2011 In their latest AFD's both Lake Charles and Shreveport are concerned about instability issues, although Shreveport allows that if temps reach the 70's across the area they could have a very active afternoon and evening. As TT mentioned earlier with it being Mardi Gras time many people will not be paying attention to changes in weather in the region. Link to comment Share on other sites More sharing options...
David Reimer Posted March 8, 2011 Share Posted March 8, 2011 The 0Z NAM is not too good looking for TX tomorrow, but it has one hell of a tornado outbreak in LA by midnight tomorrow night. That is looking very dangerous. Link to comment Share on other sites More sharing options...
Indystorm Posted March 8, 2011 Share Posted March 8, 2011 The 0Z NAM is not too good looking for TX tomorrow, but it has one hell of a tornado outbreak in LA by midnight tomorrow night. That is looking very dangerous. Yes, that would certainly imply a serious situation at a very bad overnight time for LA. What a way to end Mardi Gras if this verifies per NAM. http://wxcaster4.com/nam/CENTRAL_ETA212_ATMOS_STP_27HR.gif Link to comment Share on other sites More sharing options...
tornadotony Posted March 8, 2011 Author Share Posted March 8, 2011 From SHV... 000 FXUS64 KSHV 080343 AFDSHV AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 943 PM CST MON MAR 7 2011 .DISCUSSION... FOR THE UPDATE TONIGHT...RAISED TEMPERATURES JUST A DEGREE OR TWO ACROSS OUR W AND SW ZONES. WINDS BECOMING A LITTLE MORE SOUTHERLY ACROSS THESE REGION WHICH WILL HELP TO HOLD TEMPS NEAR STEADY OVERNIGHT. ELSEWHERE...A 1-3 DEGREE TEMPERATURE DROP IS STILL POSSIBLE AS WE GO THROUGH THE NIGHT BUT NOT EXPECTING MUCH OF A DROP WITH WIDESPREAD CLOUD COVER OVERHEAD. FOR TUESDAY INTO TUESDAY NIGHT...GETTING MORE AND MORE CONCERNED WITH THE THREAT FOR SEVERE WEATHER...ESPECIALLY LATE TOMORROW AFTERNOON THROUGH THE OVERNIGHT HOURS. THE THINKING IS THAT TOWARDS THE PREDAWN HOURS IN THE MORNING THROUGH MID TO LATE MORNING...WE WILL SEE LIGHT RAIN/SHOWERS WITH ISOLATED THUNDERSTORMS DEVELOPING ACROSS THE REGION WITH INCREASING ISENTROPIC LIFT. WARM FRONT WILL BEGIN LIFTING NORTHWARD DURING THE DAY TUESDAY AND SHOULD BE SOMEWHERE ACROSS S AR/SE OK BY LATE AFTERNOON INTO THE EARLY EVENING HOURS. SHOWERY TYPE WEATHER MAY SHUTOFF ACROSS NE TX TUESDAY AFTERNOON AS THIS REGION WILL BE SOUTH OF THE WARM FRONT BY THAT TIME. AS WE TRANSITION INTO THE LATE AFTERNOON/EVENING HOURS...WE BEGIN TO LOOK OUT WEST FOR CONVECTIVE INITIATION ALONG THE DRYLINE WHICH SHOULD BE JUST WEST OF OUR CWA BY 00Z WED. WITH LIFT AIDED BY THE UPPER LEVEL TROUGH...THE 00Z NAM NOW SUPPORTS RAPID CONVECTIVE INITIATION JUST BEYOND 00Z WED ALONG AND NORTH OF THE I-30 CORRIDOR. THIS WILL BE A FAVORED AREA FOR STRONG TO SEVERE THUNDERSTORMS...AND ALONG ANY KIND OF PREFRONTAL TROUGH OR TRAILING WARM FRONTAL BOUNDARY ACROSS OUR EXTREME EASTERN ZONES LATE TUESDAY NIGHT. ALL THIS TO SAY...HAVE BEEFED UP POPS FOR TUESDAY NIGHT ACROSS OUR NW ZONES...MORE IN LINE WITH A SLOWER COLD FRONT/DRYLINE MERGER AND EVENTUAL PUSH INTO OUR REGION. THANKS FOR THE COORDINATION SPC...PRELIMS TO FOLLOW...13. && Link to comment Share on other sites More sharing options...
Chicago Storm Posted March 8, 2011 Share Posted March 8, 2011 Link to comment Share on other sites More sharing options...
tornadotony Posted March 8, 2011 Author Share Posted March 8, 2011 Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 8, 2011 Share Posted March 8, 2011 wow that is hilarious lol you guys post those at the same time as I just saved the images and was going to post them just now. Link to comment Share on other sites More sharing options...
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