tornadotony Posted November 20, 2011 Share Posted November 20, 2011 TWC is much more popular than SPC and Forbes makes what's perceived as an aggressive forecast, so it's a ploy for attention? That's quite a jump in logic. I thought you had something else since you presented it like it was factual. My apologies for making it sound so factual. Link to comment Share on other sites More sharing options...
andyhb Posted November 20, 2011 Share Posted November 20, 2011 Day 3 is even larger in area than the Day 2. Fred Gossage has certainly drawn his attention to this over on Talkwx, if any of you are interested. Good discussions from him over there. http://www.talkweath...ek/page__st__25 06z NAM shows impressive 0-1 km and 0-3 km SRH across Northern Texas/Southern Oklahoma from 18z Monday to 03z Tuesday. Link to comment Share on other sites More sharing options...
janetjanet998 Posted November 20, 2011 Share Posted November 20, 2011 thread in main forum that will cover sveral subforums http://www.americanwx.com/bb/index.php/topic/29923-nov-21-22-severe-weather-event/ Link to comment Share on other sites More sharing options...
Srain Posted November 20, 2011 Share Posted November 20, 2011 thread in main forum that will cover sveral subforums http://www.americanw...-weather-event/ Good idea. We can certainly give it a try and see how it goes. I know many have complained about the 'lack of activity' on the main page. Link to comment Share on other sites More sharing options...
brettjrob Posted November 20, 2011 Share Posted November 20, 2011 This cold air means business... I don't see the front making it any farther N than DFW by tomorrow evening, at this point. The WRF-NNM has it closer to AUS at mid-afternoon . I think the reality of the calendar just set in. This is no March/April-style setup with 55/53 and rain N of the warm front... it's a bona fide cold airmass bleeding down the Plains like a density current and outpacing all but the highest-resolution models, as we see so often in the cold season. Still some risk for surface-based supercells across central to northeast TX, but I'm throwing in the towel on more than a marginal tornado threat. Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 20, 2011 Share Posted November 20, 2011 82ºF at CRS. That front does mean business. If the GFS is right, DFW is open to all modes, if the NAM is right, maybe just hail. Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 20, 2011 Share Posted November 20, 2011 Svr watch for NC Texas. RUC TT are 55 for DFW, but mainly speed shear, ~30 knots, in the meatier CAPE region. South of the Metroplex plenty warm, but looks like showers have to cross the front before they really break the cap. Link to comment Share on other sites More sharing options...
ICEHOCEY77 Posted November 20, 2011 Share Posted November 20, 2011 Link to comment Share on other sites More sharing options...
thewxmann Posted November 20, 2011 Share Posted November 20, 2011 I have a tough time believing the WF will make it past I-20 tomorrow, especially considering all the convection in the cold sector that is progged to be ongoing. Link to comment Share on other sites More sharing options...
brettjrob Posted November 20, 2011 Share Posted November 20, 2011 lolz... stick a fork in this one. SREF SigTor up to 30% for the Hill Country now, but I strongly suspect even it is too generous with the expanse of the warm sector by 00z Tue. How many days 'til March? Link to comment Share on other sites More sharing options...
tornadotony Posted November 20, 2011 Share Posted November 20, 2011 I think the story for this system is going to be written on Tuesday... Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 20, 2011 Share Posted November 20, 2011 I'm not giving up all hope for the Metroplex yet. Pressures aren't rising around DFW anymore, the front is between Hillsborough and Corsicana and appears nearly stationary. I won't give up hope on the warm sector at least getting near I-20 tomorrow. Link to comment Share on other sites More sharing options...
ksstormhunter Posted November 21, 2011 Share Posted November 21, 2011 Just updated my 23Z Smartcast run showing strong storms across the Tyler/Texarkana area for the next 6 hours. Potential for hail up to 3/4" and wind gusts 55-60mph possible in these areas. Link to comment Share on other sites More sharing options...
Jim Martin Posted November 21, 2011 Share Posted November 21, 2011 The 0z NAM sounding for Fort Worth is very telling @ 6pm tomorrow... It appears there will not be much of a severe threat for Fort Worth tomorrow... Link to comment Share on other sites More sharing options...
David Reimer Posted November 21, 2011 Share Posted November 21, 2011 The 21Z SREF has increased the significant tornado ingredients number to '40' across portions of South Texas tomorrow. Tomorrow's tornado threat will not be widespread, but I can't ignore this algorithm after it's been proven so effective once it gets into the higher range. The threat has shifted south considerably, but may still be noteworthy in a localized area. Link to comment Share on other sites More sharing options...
brettjrob Posted November 21, 2011 Share Posted November 21, 2011 I think the story for this system is going to be written on Tuesday... That's a possibility, though the 00Z NAM sure does look veered out over most of the warm sector. If we can get at least localized backing, that could make it a whole different story. Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 21, 2011 Share Posted November 21, 2011 The 21Z SREF has increased the significant tornado ingredients number to '40' across portions of South Texas tomorrow. Tomorrow's tornado threat will not be widespread, but I can't ignore this algorithm after it's been proven so effective once it gets into the higher range. The threat has shifted south considerably, but may still be noteworthy in a localized area. The operational NAM doesn't seem to have much activity in the warm sector. That said, if places like Temple and Austin got warmer than forecast, and could get warm sector initiation, it would be interesting. But the forecast CINH numbers would suggest a temperature several degrees warmer than forecast would be required. Link to comment Share on other sites More sharing options...
Chicago Storm Posted November 21, 2011 Share Posted November 21, 2011 thread in main forum that will cover sveral subforums http://www.americanw...-weather-event/ Good idea. We can certainly give it a try and see how it goes. I know many have complained about the 'lack of activity' on the main page. This isn't going to work with this thread staying open. This one should be closed and pinned, with a link to the main thread in the general forum. Link to comment Share on other sites More sharing options...
David Reimer Posted November 21, 2011 Share Posted November 21, 2011 This isn't going to work with this thread staying open. This one should be closed and pinned, with a link to the main thread in the general forum. What's the point of the sub-forum if were not going to be discussing specific weather events for the regions? Just limit this one to tomorrow and the threat here in Texas, then put the southeast threat for Tuesday in their forum. I don't want to have to go through a main thread covering half the southern United States when I'm trying to find information specific to my region or post information specific to my region. The main thread is mainly talking about Tuesday, as it does look to be the most significant threat of all three days. Just let them keep their thread and let us keep ours for tomorrow's marginal threat. Link to comment Share on other sites More sharing options...
Chicago Storm Posted November 21, 2011 Share Posted November 21, 2011 What's the point of the sub-forum if were not going to be discussing specific weather events for the regions? There it is... Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 21, 2011 Share Posted November 21, 2011 I'm not all that excited about Tuesday either. Maybe some wind with low topped stormsinto the Ohio Valley. Further South, I don't think there is enough helicity/too much veering. Both GFS and NAM seem to suggest that. Link to comment Share on other sites More sharing options...
andyhb Posted November 21, 2011 Share Posted November 21, 2011 I'm not all that excited about Tuesday either. Maybe some wind with low topped stormsinto the Ohio Valley. Further South, I don't think there is enough helicity/too much veering. Both GFS and NAM seem to suggest that. Except the fact that the GFS/NAM have been overestimating veering and underestimating shear recently... Link to comment Share on other sites More sharing options...
Hoosier Posted November 21, 2011 Share Posted November 21, 2011 What's the point of the sub-forum if were not going to be discussing specific weather events for the regions? Just limit this one to tomorrow and the threat here in Texas, then put the southeast threat for Tuesday in their forum. I don't want to have to go through a main thread covering half the southern United States when I'm trying to find information specific to my region or post information specific to my region. The main thread is mainly talking about Tuesday, as it does look to be the most significant threat of all three days. Just let them keep their thread and let us keep ours for tomorrow's marginal threat. I'm not entirely opposed to having severe threads in the main forum but the question to me is when is it worthy of being in the main forum? That could become a little messy/confusing. Anyway, the current thread over there has been green lighted but IMBY posts are to be kept to a minimum. Link to comment Share on other sites More sharing options...
andyhb Posted November 21, 2011 Share Posted November 21, 2011 I'm not exactly sure what is going on regarding the other thread, but here's the Day 1: DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1145 PM CST SUN NOV 20 2011 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS TX/SRN OK EWD INTO CENTRAL AR... ...SYNOPSIS... A SHORTWAVE TROUGH...CURRENTLY LOCATED IN THE CA/NV REGION...IS FORECAST TO SHIFT RAPIDLY EWD INTO NM TODAY...AND THEN ENEWD INTO ERN KS OVERNIGHT. THIS UPPER SYSTEM WILL BECOME NEGATIVELY TILTED DURING THE SECOND HALF OF THE PERIOD AS A 70-80 KT MID LEVEL JET MAX MOVES FROM THE BASE ONTO THE EAST SIDE OF THE TROUGH. ...TX/SRN OK EWD INTO CENTRAL AR... THE SEVERE FORECAST THIS FORECAST WILL BE COMPLICATED BY THE PRESENCE OF AN EXISTING COLD SHALLOW AIR MASS...WITH THE LEADING EDGE CURRENTLY EXTENDING FROM NERN AR SWWD INTO CENTRAL TX. MODELS ARE CONSISTENT IN MAINTAINING SURFACE RIDGE ACROSS MUCH OF OK SWD INTO CENTRAL TX TODAY AND GIVEN CONTINUED SLOW SWD MOTION OF FRONT AND WEAK PRESSURE RISES...EXPECT FRONT IN CENTRAL TX TO REMAIN QUASI-STATIONARY THROUGH MUCH OF THE DAY. HOWEVER...THE PORTION OF THE FRONT IN AR/ERN TX MAY RETREAT SLOWLY WWD... POSSIBLY TO NEAR AN AUS -HRO LINE BY EVENING...AS THE UPPER TROUGH APPROACHES. GIVEN THE ABOVE FRONTAL LOCATION...THE GREATER HEIGHT FALLS/DYNAMICAL FORCING WILL OCCUR NORTH AND WEST OF THE FRONT THROUGH THE DAY. THE FORCING IS EXPECTED TO RESULT IN ELEVATED STORMS FORMING EARLY IN THE DAY IN WRN TX...SPREADING RAPIDLY ENEWD ACROSS NRN TX AND OK. DESPITE THE COLD BOUNDARY LAYER... MUCAPES AROUND 1000 J/KG AND 50 KT DEEP LAYER SHEAR ABOVE THE BOUNDARY LAYER WILL BE SUFFICIENT FOR SOME ROTATING STORMS...WITH HAIL THE PRIMARY THREAT. AS THE STORMS PROGRESS AND APPROACH THE WARMER AND MORE UNSTABLE BOUNDARY LAYER...THE POTENTIAL FOR WIND DAMAGE WILL INCREASE FROM FAR ERN OK SWD INTO ERN TX. AS THE UPPER WAVE BECOMES NEGATIVELY TILTED...A SURFACE WAVE SHOULD DEVELOP ALONG THE FRONT IN AR MONDAY EVENING...AND THEN SHIFT NEWD INTO MO OVERNIGHT. ONCE THIS HAPPENS...THE FRONT WILL BEGIN MOVING EWD WITH THE POTENTIAL FOR MORE LINEAR STORMS TO DEVELOP ALONG IT. INSTABILITY IS NOT FORECAST TO BE PARTICULARLY STRONG...THOUGH THE STRENGTH OF THE WIND FIELDS AND SHEAR WILL BE FAVORABLE FOR WIND DAMAGE AND PERHAPS EVEN A TORNADO OR TWO ...ESPECIALLY IN AR NEAR DEVELOPING SURFACE LOW. ALSO...DURING THE AFTERNOON...THE UPPER FORCING MAY BRUSH THE STATIONARY FRONT IN CENTRAL TX. THE FORECAST SOUNDINGS SHOW A WEAK CAPPING INVERSION AROUND 700 MB...BUT IF SURFACE BASED STORMS CAN DEVELOP NEAR THIS PORTION OF THE FRONT...MLCAPES NEAR 1500 J/KG...DEEP LAYER SHEAR AT 60 KT AND 1 KM SRH AOA 200 M2/S2 WILL BE FAVORABLE FOR SUPERCELLS...INCLUDING TORNADOES. THE SEVERE THREAT WILL DECREASE DURING THE EVENING AS THE FORCING LIFTS NWD OUT OF THE REGION. ..IMY/LEITMAN.. 11/21/2011 Link to comment Share on other sites More sharing options...
tornadotony Posted November 21, 2011 Share Posted November 21, 2011 It's really hard for me to get tingly about any setup with a strong N-S temp. gradient. Those sorts of setups are usually associated with strong isentropic lift, preventing a northward advance of the front. Additionally, any sfc-based storms that might ride along the front or move just N of it immediately become elevated. All-in-all, if there's going to be a story with this system, it's going to be on Tuesday. Link to comment Share on other sites More sharing options...
ICEHOCEY77 Posted November 21, 2011 Share Posted November 21, 2011 Amazingly, the sig tor probs have gotten larger on the last run.... Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 21, 2011 Share Posted November 21, 2011 New NAM still isn't big on warm sector initiation today, which is too bad. AUS area, other than a forecast -70J/Kg inhibition, would look fairly favorable for possible tornado action. But recent check on satellite, the needed Sun to get AUS a couple of degrees warmer than forecast and allow surface based convection isn't looking good now. Link to comment Share on other sites More sharing options...
Srain Posted November 21, 2011 Share Posted November 21, 2011 MESOSCALE DISCUSSION 2349 NWS STORM PREDICTION CENTER NORMAN OK 0346 PM CST MON NOV 21 2011 AREAS AFFECTED...CNTRL INTO NERN TX CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 212146Z - 212345Z THE THREAT FOR SVR THUNDERSTORMS COULD INCREASE DURING THE NEXT FEW HOURS FROM CNTRL INTO NERN TX...AND THIS AREA WILL BE MONITORED FOR THE POSSIBLE ISSUANCE OF A WW. VISIBLE SATELLITE IMAGERY AND SFC OBS INDICATE A STRONG FRONT SLOWLY RETREATING NWD OVER PORTIONS OF CNTRL/ERN TX...WITH MLCAPE VALUES OF 1000-1500 J/KG SOUTH OF THE BOUNDARY. THIS IS OCCURRING AS INCREASING MID-LEVEL HEIGHT FALLS AHEAD OF A PAIR OF APPROACHING SHORTWAVE TROUGHS INDUCE SFC PRESSURE FALLS OF 3 TO 4 MB PER 2 HRS NORTH OF THE BOUNDARY. LITTLE IN THE WAY OF CONVECTION HAS BEEN NOTED NEAR OR SOUTH OF THE BOUNDARY THUS FAR...OWING TO WEAK VELOCITY CONVERGENCE ALONG THE FRONT...WITH THE STRONGEST DEEP-LAYER ASCENT AND ASSOCIATED CONVECTION FARTHER N ACROSS N-CNTRL TX NWD INTO OK. HOWEVER...AS THE MID-LEVEL TROUGHS MAKE ADDITIONAL EWD PROGRESS...THUNDERSTORMS COULD DEVELOP LATER THIS AFTERNOON. EFFECTIVE BULK SHEAR MAGNITUDES OF 50-55 KT WILL CONDITIONALLY PROMOTE A THREAT FOR SUPERCELLS...WITH SVR HAIL THE PRIMARY CONCERN. HOWEVER...ANY STORMS THAT ARE ABLE TO INTERACT WITH THE FRONT AS IT LIFTS NWD...OR EVOLVE WITHIN THE WARM SECTOR...WILL ALSO BE CAPABLE OF PRODUCING DMGG WIND GUSTS...AND POSSIBLY A TORNADO. HOWEVER...WEAKENING LOW-LEVEL SRH WITH SWD DISPLACEMENT FROM THE BOUNDARY PER VWP DATA SUGGESTS THAT ANY TORNADO THREAT...ALBEIT MINIMAL...WILL BE CONFINED TO A NARROW CORRIDOR ALONG THE SFC FRONT. GIVEN THE UNCERTAINTY IN CONVECTIVE INITIATION/COVERAGE...THE NEED FOR A WW IS UNCERTAIN. HOWEVER...TRENDS WILL CONTINUE TO BE MONITORED FOR POTENTIAL WW ISSUANCE. ..COHEN.. 11/21/2011 ATTN...WFO...SHV...HGX...FWD...EWX... Link to comment Share on other sites More sharing options...
andyhb Posted November 22, 2011 Share Posted November 22, 2011 URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 894 NWS STORM PREDICTION CENTER NORMAN OK 835 PM CST MON NOV 21 2011 THE NWS STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF SOUTHERN AND PORTIONS OF CENTRAL ARKANSAS EXTREME SOUTHEAST OKLAHOMA EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 835 PM UNTIL 200 AM CST. TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES WEST SOUTHWEST OF DE QUEEN ARKANSAS TO 50 MILES EAST NORTHEAST OF PINE BLUFF ARKANSAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4). REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. DISCUSSION...SFC-BASED/NEAR SFC-BASED STORMS HAVE EVOLVED ON SRN FRINGE OF OTHERWISE ELEVATED TSTMS ACROSS SERN OK/NERN TX THIS EVENING. AS LARGE-SCALE ASCENT TIED TO THE MID-LVL WAVE CONTINUES TO MOVE DOWNSTREAM FROM THE SRN PLAINS...MESOLOW VCNTY SERN OK WILL TRACK ALONG BAROCLINIC ZONE ACROSS CNTRL AR THROUGH 08Z. AIR MASS WILL BE CHARACTERIZED BY MLCAPE TO 1000 J/KG AND SUFFICIENT LLVL SHEAR FOR ISOLD TORNADOES. OTHERWISE...SMALL-SCALE BOWS/LEWPS WILL LIKELY GIVE DMGG WIND GUSTS...ESPECIALLY ALONG THE TRACK OF THE MESOLOW. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION VECTOR 25040. ...RACY 2 tornado warnings now. NE of Mena, AR looks pretty nasty on radar. Link to comment Share on other sites More sharing options...
andyhb Posted November 22, 2011 Share Posted November 22, 2011 South of Lockesburg, AR. Rotation intensifying. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.