1900hurricane Posted April 25, 2015 Share Posted April 25, 2015 Looks like yet another disturbance in what has turned out to be a fairly active southern stream lately will have some potential to spark severe thunderstorms across the Southern Plains beginning Sunday and continuing into Monday. Guidance is indicating that the disturbance currently over British Colombia will drop south into the SW U.S. with an attendant jet streak ejecting out from the base beginning the latter half of Sunday. Lee side cyclogenesis resulting in a sub-1000 mb surface low in the Texas Panhandle will establish return flow in the wake of the last system, advecting rich boundary layer moisture back into Texas beneath a renewed Elevated Mixed Layer. Models are progging favorable parameters for severe weather across much of Central Texas east of a dryline extending south of the aforementioned surface low, and as of now, all types of severe weather remain on the table. As with the days before any severe weather event though, questions exist about the potential. Perhaps the biggest this go around is moisture return. Guidance shows good boundary layer moisture to work with, but with their solutions so quickly returning moisture in the wake of the last system, questions arise as to whether this is overdone. The SPC has much of the Southern Plains under a Slight Risk for Sunday and has included a hatched area for significant severe in Central Texas. A severe threat may also exist on Monday, but this threat will depend heavily upon how the parent disturbance ejects eastwards and on how convection evolves Sunday going into Monday. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
andyhb Posted April 25, 2015 Share Posted April 25, 2015 That D2 that came out from SPC left me scratching my head to say the least. Very nice discussion from FWD on the other hand... ON SUNDAY...A VERY IMPRESSIVE UPPER TROUGH /CHARACTERIZEDBY NEARLY 80 METER HEIGHT FALLS/ IS FORECAST TO AMPLIFY ACROSS THEGREAT BASIN. THE RESULTANT SOUTHWEST FLOW ACROSS THE LEE OF THENEW MEXICO ROCKIES SHOULD INDUCE LOW LEVEL CYCLOGENESIS. AS THEUPPER LOW CLOSES OFF SOMEWHERE OVER NEW MEXICO...THE SURFACECYCLONE SHOULD DEEPEN QUICKLY. IN RESPONSE...MOISTURE TRANSPORTACROSS AREA SHOULD INCREASE. WITH AROUND 50 KNOTS OF MID LEVELFLOW...THE VERY DIFFLUENT REGIME ALOFT AND WITH THE BOUNDARY LAYERMOISTENING...THE STAGE WILL BE SET FOR ANOTHER ROUND OF SEVEREWEATHER. TAKING A CLOSER LOOK AT THE AREAL EXTENT OF THE BEST LOWLEVEL MOISTURE...IT APPEARS THAT MOST OF THE COARSER MODELS AREFAIRLY CONSISTENT WITH BRINGING 65+ DEGREE DEWPOINTS INTO OURSOUTHERN ZONES. THIS APPEARS PLAUSIBLE AS THERE HAVE NOT BEEN ANYRECENT INTRUSIONS OF CONTINENTAL AIR DOWN INTO THE WESTERN GULF OFMEXICO RECENTLY. WHILE A STOUT CAP WILL BE IN PLACE...30 TO 40METER HEIGHT FALLS /INDICATIVE OF LARGE SCALE ASCENT/ WILLOVERSPREAD WESTERN ZONES ON SUNDAY EVENING. A DRYLINE IS EXPECTEDTO SHARPEN SOMEWHERE ACROSS THE BIG COUNTRY DURING THE AFTERNOONHOURS ON SUNDAY. LOW LEVEL CONVERGENCE COUPLED WITH THE FAVORABLEDYNAMICS SHOULD PROVE SUFFICIENT TO OVERCOME THE CAP. STEEP MIDLEVEL LAPSE RATES SHOULD YIELD A VERY HEALTHY INSTABILITY PROFILE/3000+ J/KG OF CAPE/ AND 0-6 KM BULK SHEAR VALUES OF AROUND 50KNOTS SHOULD FOSTER SUPERCELLULAR STORM STRUCTURES. WITH THE STEEPMID LEVEL LAPSE RATES AND A VERY "FAT" CAPE PROFILE...LARGE HAILAPPEARS PROBABLE. IN ADDITION...THE STRENGTHENING OF THE LOW LEVELJET /WINDS OF AROUND 30-35 KTS/ AROUND THE 00-03 UTC TIME FRAME ONMONDAY WILL SUPPORT A RATHER SUBSTANTIAL TORNADOTHREAT...PRIMARILY ACROSS OUR WESTERN AND SOUTHWESTERN ZONES. FORNOW...IT APPEARS THAT THE BEST CHANCES FOR PRECIPITATION WILLREMAIN CONFINED TO AREAS WEST OF THE INTERSTATE 35 CORRIDOR ONSUNDAY AFTERNOON AND SUNDAY EVENING...WITH PRECIPITATION LIKELYOVERSPREADING THE REST OF NORTH/CENTRAL TEXAS SUNDAY NIGHT INTOMONDAY MORNING. Link to comment Share on other sites More sharing options...
1900hurricane Posted April 25, 2015 Author Share Posted April 25, 2015 You know, I was kinda thinking the same thing when I was posting this last night. I know the current system is pushing a front through this area, but moisture isn't going to exactly be scoured far away. Heck, the front may not even clear the Texas coast. I can understand the SPC not fully buying into mid 70*F dewpoints all up and down I-35, but 55-60 seems really low, especially considering how well the NAM, GFS, and SREFs were in agreement in that regard. Still though, they are the experts and I did give their forecast a nod in the original post. Maybe I'm missing something. Perhaps vertical mixing? Return may be a little on the shallow side. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
1900hurricane Posted April 25, 2015 Author Share Posted April 25, 2015 Just looked at the SPC's Day Three, which wasn't yet available when I started this thread last night. Wording seems curiously strong and weighted towards tornadoes for a straight 15% risk. DAY 3 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0209 AM CDT SAT APR 25 2015 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EAST TX TO THE CNTRL GULF COAST... ...THERE IS A MRGL RISK OF SVR TSTMS IMMEDIATELY SURROUNDING THE SLGT RISK... CORRECTED FOR MRGL DESCRIPTION ...SUMMARY... THUNDERSTORMS...A FEW SEVERE...WILL DEVELOP ACROSS EAST TEXAS TO THE CENTRAL GULF COAST DURING THE DAY3 PERIOD. ...TX TO CENTRAL GULF COAST... LATEST SHORT-RANGE MODEL GUIDANCE SUGGESTS UPPER LOW WILL EJECT SLOWLY ACROSS THE SRN PLAINS DURING THE DAY2-3 TIME FRAME. AS UPPER LOW SHIFTS INTO SRN OK IT APPEARS THE STRONGEST MID-LEVEL FLOW WILL TRANSLATE ACROSS SOUTH TX TOWARD THE LOWER SABINE RIVER VALLEY. WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP WITHIN WARM ADVECTION ZONE AND WITHIN EXIT REGION OF AFOREMENTIONED MID-LEVEL JET. THE PROSPECT FOR STRONG BOUNDARY LAYER HEATING SHOULD BE LIMITED TO POST DRY LINE REGION OF TX BUT SUFFICIENT BUOYANCY IS EXPECTED ACROSS EAST TX TO THE CNTRL GULF COAST FOR ROBUST ORGANIZED STORMS. THE MOST LIKELY REGION FOR CONCENTRATED ORGANIZED TSTMS WILL BE ACROSS EAST TX THROUGH THE AFTERNOON HOURS WHERE LLJ SHOULD BE FOCUSED IN RESPONSE TO MID-LEVEL JET. FORECAST SOUNDINGS ACROSS THE UPPER TX COAST EXHIBIT SUBSTANTIAL VEERING WITH HEIGHT AND PROFILES STRONGLY SUPPORTIVE OF SUPERCELLS. SOUTH OF SYNOPTIC FRONT/EFFECTIVE BOUNDARY A CORRIDOR OF VERY MOIST AND SUFFICIENTLY BUOYANT AIR COULD SUPPORT TORNADOES GIVEN THE STRONGLY SHEARED ENVIRONMENT. THIS ACTIVITY WILL SPREAD/DEVELOP EWD ALONG CNTRL GULF COAST DURING THE LATTER HALF OF THE PERIOD. ..DARROW.. 04/25/2015 Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Quincy Posted April 25, 2015 Share Posted April 25, 2015 I'd be more intrigued by the zone closest to the surface low/triple point in the eastern TX panhandle, IF there was more instability and higher dew-points progged there. The environment along the dryline in central TX looks most appealing from a chase standpoint at this time. Moisture should be quite abundant here and with partial to plenty of clearing, expect some good destabilization. The convection-allowing models all show storms firing in both areas and then spreading into the Red River Valley before swinging north. Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 26, 2015 Share Posted April 26, 2015 Not really impressed with this period either, and won't be chase worthy for me. Tomorrow probably has a slightly better potential than Monday, but once again there are many issues. Link to comment Share on other sites More sharing options...
Msalgado Posted April 26, 2015 Share Posted April 26, 2015 As long as moisture return is good tomorrow, I am planning on heading out. Will wait to see next 00z and 12z set of models before heading out. The fact that it is only 3-4 hours driving time makes it very hard to turn down. Link to comment Share on other sites More sharing options...
Quincy Posted April 26, 2015 Share Posted April 26, 2015 The convective evolution today/tonight is quite complex, with multiple rounds of storms possible in central to north Texas. It will be interesting to see if there's too much overturning, as that might mitigate the severe threat. If storms can manage to stay discrete and persist into (or fire in) late afternoon to early evening, there would be an enhanced tornado threat. Watch around midday to see if any junk gets in the way as a weak impulse swings through. As it stands now, the signs are mixed. There certainly is support aloft with the timing and alignment of a shortwave tonight. If everything comes together, with is far from set in stone, there could be some significant severe weather. Link to comment Share on other sites More sharing options...
jhamps10 Posted April 26, 2015 Share Posted April 26, 2015 8AM day one update has placed a large enhanced risk across Texas, including DFW, Waco, San Antonio, Austin... 10%tor placed for the I-35 corridor from DFW down to just north of Austin Link to comment Share on other sites More sharing options...
1900hurricane Posted April 26, 2015 Author Share Posted April 26, 2015 1300Z outlook also mentions a possible upgrade to Moderate depending on how things play out. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
SmokeEater Posted April 26, 2015 Share Posted April 26, 2015 Moderate out for the Metroplex now. Link to comment Share on other sites More sharing options...
rolltide_130 Posted April 26, 2015 Share Posted April 26, 2015 Quite a bit of scattered showers out across the MOD area, especially on the northern end. Link to comment Share on other sites More sharing options...
Quincy Posted April 26, 2015 Share Posted April 26, 2015 Should be game on just ahead of the dryline, south of I-20 by mid to late afternoon. Moderate instability already sampled with increasing kinematic support advecting northeast as we approach sunset. Link to comment Share on other sites More sharing options...
jhamps10 Posted April 26, 2015 Share Posted April 26, 2015 Should be game on just ahead of the dryline, south of I-20 by mid to late afternoon. Moderate instability already sampled with increasing kinematic support advecting northeast as we approach sunset. Let me ask you about the metroplex, will the clouds and showers just sw of ft worth hurt our chances even tho it's already 85 with south winds at the moment? Link to comment Share on other sites More sharing options...
Santa Clause Posted April 26, 2015 Share Posted April 26, 2015 I'd say metroplex is primed. Just time to watch the development. Link to comment Share on other sites More sharing options...
andyhb Posted April 26, 2015 Share Posted April 26, 2015 I'd say metroplex is primed. Just time to watch the development. These morning/early afternoon showers will help keep moisture in place as opposed to mixing out. Link to comment Share on other sites More sharing options...
rolltide_130 Posted April 26, 2015 Share Posted April 26, 2015 That cell headed towards Anson looks like trouble. Link to comment Share on other sites More sharing options...
cstrunk Posted April 26, 2015 Share Posted April 26, 2015 This could be a very long afternoon/evening. Multiple supercells forming ahead of the dryline that already have "the look". Link to comment Share on other sites More sharing options...
KSWx Posted April 26, 2015 Share Posted April 26, 2015 So is the general consensus that we'll be seeing another watch issued with the DFW metro included later? Link to comment Share on other sites More sharing options...
jhamps10 Posted April 26, 2015 Share Posted April 26, 2015 I think this one surprised everyone, including chasers... nobody around there that streams... hopefully there's eyes on these suckers Link to comment Share on other sites More sharing options...
andyhb Posted April 26, 2015 Share Posted April 26, 2015 So is the general consensus that we'll be seeing another watch issued with the DFW metro included later? Yes, in all likelihood. Link to comment Share on other sites More sharing options...
bubba hotep Posted April 26, 2015 Share Posted April 26, 2015 Things are getting started for sure Link to comment Share on other sites More sharing options...
Jim Marusak Posted April 26, 2015 Share Posted April 26, 2015 So is the general consensus that we'll be seeing another watch issued with the DFW metro included later? metroplex to ft hood for sure. how much further south for the tornado watch and where the t-storm watches take over is the question. Link to comment Share on other sites More sharing options...
jhamps10 Posted April 26, 2015 Share Posted April 26, 2015 From watching a streamer in NW Tarrant county, it appears the sun is still mixing in around Lake Worth.. down here near Hulen and I-20 it's pretty cloudy and I don't think the sun is mixing in at all down here attm... Link to comment Share on other sites More sharing options...
andyhb Posted April 26, 2015 Share Posted April 26, 2015 Big wall cloud from the Minuteman stream here on the Novice cell. https://tvnweather.com/live Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 26, 2015 Share Posted April 26, 2015 Parameters are in place, lets see how long these cells can remain discrete Link to comment Share on other sites More sharing options...
andyhb Posted April 26, 2015 Share Posted April 26, 2015 Rotation increasing markedly on the Anson and Novice cells. Link to comment Share on other sites More sharing options...
jhamps10 Posted April 26, 2015 Share Posted April 26, 2015 Big wall cloud from the Minuteman stream here on the Novice cell. https://tvnweather.com/live that cell NEEDS a tornado warning on it Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 26, 2015 Share Posted April 26, 2015 Getting meaner Link to comment Share on other sites More sharing options...
Disc Posted April 26, 2015 Share Posted April 26, 2015 Cross Plains storm becoming better organized. Tornado warned now and has started to turn right in the last couple of frames. Edit: Looks like Quincy is on that one. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.