Powerball Posted April 8, 2021 Share Posted April 8, 2021 And 1 new SPC outlook later, DFW has gone from being in the enhanced risk area to barely being in the slight risk area, lol.. Link to comment Share on other sites More sharing options...
cstrunk Posted April 8, 2021 Share Posted April 8, 2021 I guess they decided that the Euro wasn't the model to follow after all (or maybe the Euro caved)? This update lines up with what the NAM and HRRR are showing. Link to comment Share on other sites More sharing options...
Powerball Posted April 8, 2021 Share Posted April 8, 2021 15 minutes ago, cstrunk said: I guess they decided that the Euro wasn't the model to follow after all (or maybe the Euro caved)? This update lines up with what the NAM and HRRR are showing. The EURO was already an outlier when they issued the outlook this morning. Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 Pretty insane sounding at 22z over the eastern half of DFW. Cap is virtually gone too. Link to comment Share on other sites More sharing options...
WhirlingWx Posted April 9, 2021 Share Posted April 9, 2021 16 minutes ago, Powerball said: Cap is virtually gone too. Still doesn't really convect here in the metro though (not that I want a supercell with baseball-sized hail roaring through DFW), so I'm just wondering what's up with that. Upper 80s surface temps, >4000 CAPE, and little CINH, is there something I'm missing? Of course, have to see what other CAMs say, but HRRR has been the most notorious at bombing areas with convection, so I feel like there's at least some significance in it not really showing much here for multiple runs. Edit: flow is pretty bleh, but I'm not knowledgeable enough to know if it's typical for that to just suppress convention entirely. Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 15 minutes ago, TexMexWx said: Still doesn't really convect here in the metro though (not that I want a supercell with baseball-sized hail roaring through DFW), so I'm just wondering what's up with that. Upper 80s surface temps, >4000 CAPE, and little CINH, is there something I'm missing? Of course, have to see what other CAMs say, but HRRR has been the most notorious at bombing areas with convection, so I feel like there's at least some significance in it not really showing much here for multiple runs. Well technically, it still shows the tiniest bit of mixed level CINH, but I've seen storms break through that easily. So it's understandable why FWD has been so ominous in their discussion, especially with the strong surface convergence from the dry line. The 3km NAM does make a valiant attempt at breaking the cap though. I just took a look at the HRRR's forecasted sounding where this evening's supercell in Central TX originated, and it had similar CINN values to what the HRRR's advertising for tomorrow afternoon/evening. 1 Link to comment Share on other sites More sharing options...
cheese007 Posted April 9, 2021 Author Share Posted April 9, 2021 Meanwhile Bryan is under a tornado warning... Link to comment Share on other sites More sharing options...
WhirlingWx Posted April 9, 2021 Share Posted April 9, 2021 5 minutes ago, Powerball said: Well technically, it still shows the tiniest bit of mixed level CINH, but I've seen storms break through that easily. So it's understandable why FWD has been so ominous in their discussion, especially with the strong surface convergence from the dry line. The 3km NAM does make a valiant attempt at breaking the cap though. I just took a look at the HRRR's forecasted sounding where this evening's supercell in Central TX originated, and it had similar CINN values to what the HRRR's advertising for tomorrow afternoon/evening. Well, yeah, I do agree. It wouldn't surprise me if we have a Wylie 2016 repeat or a cap bust at this point. Both seem well within the realm of possibility lol. Definitely is a nasty supercell pounding College Station right now, and many HRRR runs earlier showed like nothing firing up there until the storm had formed pretty much, iirc Link to comment Share on other sites More sharing options...
WhirlingWx Posted April 9, 2021 Share Posted April 9, 2021 3 minutes ago, cheese007 said: Meanwhile Bryan is under a tornado warning... Lots of reports of golf ball sized hail there Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 6 minutes ago, cheese007 said: Meanwhile Bryan is under a tornado warning... 2 minutes ago, TexMexWx said: Lots of reports of golf ball sized hail there Between the tragic incident earlier and now this, it's just not their day. 1 Link to comment Share on other sites More sharing options...
Chinook Posted April 9, 2021 Share Posted April 9, 2021 for those interested: DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT FRI APR 09 2021 VALID 091200Z - 101200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR PARTS OF EXTREME SOUTHEAST ARKANSAS INTO FAR NORTHEAST LOUISIANA INTO CENTRAL MISSISSIPPI... ..SUMMARY A COMPLEX SEVERE-WEATHER SCENARIO IS EXPECTED TO UNFOLD ACROSS THE MID-SOUTH INTO THE SOUTHEAST LATE THIS MORNING THROUGH THE AFTERNOON AND OVERNIGHT HOURS. SIGNIFICANT SEVERE STORMS, INCLUDING WIDESPREAD DAMAGING WINDS, AND AT LEAST A FEW TORNADOES ARE EXPECTED ACROSS PORTIONS OF NORTHEAST LOUISIANA INTO MISSISSIPPI, ESPECIALLY OVERNIGHT. LARGE HAIL IS ALSO EXPECTED TO BE A CONCERN, MAINLY DURING THE DAY ACROSS PARTS OF EASTERN OKLAHOMA INTO THE ARKLATEX REGION. Link to comment Share on other sites More sharing options...
cheese007 Posted April 9, 2021 Author Share Posted April 9, 2021 Forecast for this one has been all over the place. Curious to see what actually pans out+ 1 Link to comment Share on other sites More sharing options...
janetjanet998 Posted April 9, 2021 Share Posted April 9, 2021 New day 1 ACUS01 KWNS 091252 SWODY1 SPC AC 091251 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0751 AM CDT FRI APR 09 2021 VALID 091300Z - 101200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN ARKANSAS...NORTHERN LOUISIANA...CENTRAL MISSISSIPPI...AND WESTERN ALABAMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEPARATELY OVER PARTS OF SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA... ..SUMMARY MULTIPLE EPISODES OF SEVERE THUNDERSTORMS ARE EXPECTED TODAY FROM PARTS OF EASTERN OKLAHOMA AND NORTH-CENTRAL/NORTHEAST TEXAS, ACROSS THE MID-SOUTH AND MISSISSIPPI DELTA REGIONS, TO PARTS OF ALABAMA AND GEORGIA. THIS INCLUDES A THREAT FOR A SWATH OF SEVERE WIND FROM ARKANSAS ACROSS THE LOWER MISSISSIPPI VALLEY. LARGE, DAMAGING HAIL AND TORNADOES ALSO ARE POSSIBLE. ..SYNOPSIS IN MID/UPPER LEVELS, A SPLIT-FLOW PATTERN WILL BE MAINTAINED OVER THE CENTRAL CONUS, AS ONE CYCLONE EJECTS OUT OF A BROADER-SCALE TROUGH CAUSING THE SPLIT, AND ANOTHER TAKES ITS PLACE. THE LEADING CYCLONE -- INITIALLY CENTERED NEAR LSE -- IS FORECAST TO WEAKEN GRADUALLY TO AN OPEN-WAVE TROUGH AND HEAD NORTHEASTWARD OVER UPPER MI AND LAKE SUPERIOR OVERNIGHT. UPSTREAM, A STRONG SHORTWAVE TROUGH WAS APPARENT IN MOISTURE-CHANNEL IMAGERY FROM EASTERN MT SOUTHWARD TO CENTRAL CO. THIS FEATURE WILL DIG SOUTHEASTWARD ACROSS THE CENTRAL PLAINS TODAY AND THIS EVENING, BEFORE PIVOTING EASTWARD TONIGHT AS A CLOSED CYCLONE, ACROSS PARTS OF THE LOWER MISSOURI VALLEY. BY 12Z, THE ASSOCIATED 500-MB LOW SHOULD BE LOCATED NEAR THE KS/MO LINE SOUTH OF MKC. FARTHER SOUTH, A BROAD AREA OF STRONG CYCLONIC FLOW ALOFT WILL SPREAD EASTWARD ACROSS THE OUTLOOK AREA, WITH EMBEDDED, CLOSELY SPACED PERTURBATIONS NOW EVIDENT OVER SOUTHWESTERN/CENTRAL NM AND THE TX PANHANDLE. THESE PERTURBATIONS WILL MOVE ACROSS OK AND SOUTH TX TODAY. TONIGHT, THEY SHOULD REACH PARTS OF TN/MS/LA, LIKELY BLENDING INTO CONVECTIVELY GENERATED VORTICITY FIELDS. THE BROAD LEFT-EXIT REGION OF A CYCLONICALLY CURVED, 250-MB SUBTROPICAL JET, ALSO EXHIBITING PRONOUNCED DIFLUENCE, ALSO WILL SHIFT EASTWARD OVER MUCH OF CENTRAL/NORTH TX AND LA TODAY AND TONIGHT TOWARD THE DELTA REGION. AT THE SURFACE, 11Z ANALYSIS SHOWED AN OCCLUDED, ELONGATED AREA OF LOW PRESSURE ACROSS NORTHWESTERN WI TO NORTHERN IA. AN OCCLUDED FRONT WAS DRAWN FROM THE NORTHERN PART ACROSS LAKE SUPERIOR AND LOWER MI, WITH WEAKENING/QUASISTATIONARY FRONT ACROSS WESTERN OH, EASTERN PORTIONS OF TN/KY, AND NORTHERN AL. A WARM FRONT EXTENDED ACROSS LAKE ERIE, EASTERN WV, AND SOUTHWESTERN/SOUTHERN VA NEAR THE NC LINE. THIS BOUNDARY WILL MOVE SLOWLY NORTHWARD OVER SOUTHERN/ CENTRAL VA TODAY. A COLD FRONT EXTENDED ACROSS SOUTHERN IA, NORTHWESTERN MO, CENTRAL/WESTERN KS, AND SOUTHEASTERN CO. A MARINE/WARM FRONT EXTENDED FROM A LOW OVER NORTHWEST TX ACROSS NORTH-CENTRAL TX, CENTRAL LA, AND SOUTHERN PORTIONS OF MS/AL. THIS BOUNDARY WILL MOVE NORTHWARD ACROSS SOUTHERN /EASTERN OK, AR, AND CENTRAL MS/AL THROUGH THE DAY. THE NORTHERN LOW SHOULD CONSOLIDATE IN FORM BUT CONTINUE TO FILL, AND MOVE NORTHEASTWARD OVER ON. MEANWHILE, A SECOND LOW IS EXPECTED TO DEVELOP ALONG THE FRONT TODAY NEAR THE DRYLINE INTERSECTION, PERHAPS EVOLVING OUT OF THE INITIAL/PREFRONTAL LOW OVER NORTHWEST TX. THE RESULTING LOW SHOULD DEEPEN AS THE NEXT MID/UPPER CYCLONE APPROACHES, AND MOVE NORTHEASTWARD TO NEAR STL BY 12Z TOMORROW. BY THAT TIME, THE COLD FRONT SHOULD EXTEND FROM THE LOW SOUTHWARD DOWN THE MISSISSIPPI VALLEY TO NEAR BTR, THEN SOUTHWESTWARD ACROSS MID/UPPER TX COASTAL WATERS TO DEEP SOUTH TX. ..SOUTHERN PLAINS TO ARKLATEX/MID-SOUTH/DELTA REGIONS EPISODES OF SEVERE THUNDERSTORMS ARE EXPECTED TODAY INTO THIS EVENING BETWEEN EASTERN OK, NORTH TX AND MISSISSIPPI, RESULTING IN LARGE (LOCALLY VERY LARGE) HAIL, SEVERE GUSTS AND SEVERAL TORNADOES. THIS IS A COMPLEX SCENARIO WITH AN ASSORTMENT OF MESOSCALE POSSIBILITIES MORE DIVERSE THAN THE NUMBER OF MODELS AND ENSEMBLE MEMBERS AVAILABLE. PROGS SOMEWHAT INCONSISTENTLY DEPICT EARLY INITIATION AND EVOLUTION OF THE CONVECTION ACROSS THIS REGION, WHETHER NEAR THE FRONT IN OK (A VERY PLAUSIBLE CONSENSUS THEME), ON THE DRYLINE (MORE ISOLATED/CONDITIONAL DUE TO STRONG CAPPING), AND IN THE WARM SECTOR (HIGHLY VARIABLE). MULTIPLE EPISODES OF STRONG-SEVERE THUNDERSTORMS MAY MOVE OVER ANY GIVEN SPOT THROUGH TONIGHT. THIS OUTLOOK REPRESENTS BOTH: 1. THE POTENTIAL FOR OVERLAPPING AREAS OF SEVERE AT DIFFERENT TIMES THROUGH THE DAY AND EVENING AS DIFFERENT AREAS OF CONVECTION EVOLVE, BUT ALSO: 2. A SCENARIO THAT MOST PROGS REASONABLY DO CONVERGE UPON DESPITE EARLY DIFFERENCES: A DOMINANT QLCS/MCS EVOLVING OUT OF CONVECTION INITIATING IN OK AND/OR NORTHEAST TX, THEN MOVING EAST-SOUTHEASTWARD TO SOUTHEASTWARD OVER THE ARKLATEX TO DELTA REGIONS, ORGANIZING A WELL-DEVELOPED COLD POOL, AND PRODUCING A SWATH OF SEVERE WIND. WHETHER OR NOT THIS EVENT WILL QUALIFY AS A DERECHO IS A SEMANTIC EXERCISE, AND LIKELY REGULATED BY MESOSCALE CONVECTIVE/BOUNDARY PROCESSES YET TO BECOME APPARENT. REGARDLESS, HURRICANE-FORCE CONVECTIVE GUSTS ARE A THREAT WITH ANY SUCH COMPLEX, IN THE ENHANCED AND MODERATE AREAS. ALSO, BECAUSE BOTH THE PROBABLE QLCS AND ANY PRECEDING SUPERCELL(S) WILL ENCOUNTER AN ENVIRONMENT OF MODERATE- STRONG BUOYANCY, STEEP MIDLEVEL LAPSE RATES AROUND THE EASTERN RIM OF AN EML, ENLARGED LOW-LEVEL HODOGRAPHS, AND FAVORABLE VERTICAL SHEAR, TORNADOES ALSO ARE EXPECTED. PEAK PRECONVECTIVE MLCAPE ACROSS THE WARM SECTOR COMMONLY SHOULD BE IN THE 2000-3000 J/KG RANGE, AMIDST 40-55-KT EFFECTIVE-SHEAR MAGNITUDES. AS ONE OR MORE MCSS PLOW COLD POOLS INTO THIS ENVIRONMENT, THEY SHOULD BE MAINTAINED SOUTHEASTWARD TOWARD SOUTHERN MS/AL TONIGHT, CONTINUING A WIND-DAMAGE AND SPORADIC TORNADO THREAT. ..CENTRAL GULF COAST TO AL/GA THIS MORNING/AFTERNOON WIDELY SCATTERED TO SCATTERED THUNDERSTORMS SHOULD DEVELOP FROM MID/LATE MORNING THROUGH THIS AFTERNOON, WITH A THREAT FOR SPORADIC LARGE HAIL AND DAMAGING GUSTS. A CONDITIONAL, LOCALIZED TORNADO THREAT ALSO MAY DEVELOP. FOR NEAR-TERM COVERAGE, PLEASE SEE SPC MESOSCALE DISCUSSION 338. MIDLEVEL LAPSE RATES WILL BE LESS THAN IN THE MORE EML-INFLUENCED AIR MASS OF THE PLAINS/DELTA AREA. STILL, RICH LOW-LEVEL MOISTURE SPREADING INLAND, COMBINED WITH AREAS OF DIURNAL HEATING (TEMPERED IN PACE BY MID/UPPER CLOUD COVER FROM UPSTREAM CONVECTION), WILL WEAKEN MLCINH AND YIELD FAVORABLE SURFACE-BASED BUOYANCY. MEANWHILE, LOW-LEVEL SHEAR WILL BE MAXIMIZED NEAR THE MARINE FRONTAL ZONE, THOUGH WEAK ABSOLUTE SPEEDS WILL LIMIT HODOGRAPH SIZE SOMEWHAT. MODIFIED 12Z RAOBS AND FORECAST SOUNDINGS FROM MIDDAY THROUGH AFTERNOON INDICATE AROUND 1500-2000 J/KG MLCAPE IS POSSIBLE, WITH 35-45 KT EFFECTIVE-SHEAR MAGNITUDES. EFFECTIVE SRH WILL RANGE FROM AROUND 200-250 J/KG ON THE FRONT TO AROUND 100-1-50 J/KG COASTWARD IN THE WARM SECTOR. WITH UPPER SUPPORT MEAGER IN THIS AREA, BUT ALSO MODEST MLCINH, CONVECTIVE COVERAGE ALONG AND SOUTH OF THE FRONT IS UNCERTAIN. Link to comment Share on other sites More sharing options...
mob1 Posted April 9, 2021 Share Posted April 9, 2021 I wonder if that large area of convection offshore will put a bit of a lid on things later. Either way, most mesoscale models show a decent nocturnal tornado threat, though they're likely to be embedded in a line. Link to comment Share on other sites More sharing options...
cheese007 Posted April 9, 2021 Author Share Posted April 9, 2021 Morning cloudyness probably keeps storms at bay in DFW Link to comment Share on other sites More sharing options...
jojo762 Posted April 9, 2021 Share Posted April 9, 2021 1 hour ago, cheese007 said: Morning cloudyness probably keeps storms at bay in DFW I'm not going to pull the trigger on saying there will for sure be N TX dryline storms today... But SFC temps sure seem to be running at-forecast or even a smidge above 12z HREF mean temps for 15z. The cloud cover doesn't seem to be having much of an impact -- and it looks like the LLVL clouds could clear out a bit more. Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 1 hour ago, cheese007 said: Morning cloudyness probably keeps storms at bay in DFW A cluster of storms (which will likely become severe for the Arklatex region later) did blow up just to the NE, on the nose of the LLJ. Link to comment Share on other sites More sharing options...
cheese007 Posted April 9, 2021 Author Share Posted April 9, 2021 Most of DFW back under the sign hail hatch Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 11 minutes ago, cheese007 said: Most of DFW back under the sign hail hatch The cloud deck has finally moved to the east, so now it's just waiting to see what happens as temps surge. Link to comment Share on other sites More sharing options...
Santa Clause Posted April 9, 2021 Share Posted April 9, 2021 Looks like active severe evening ahead, not big tornado threat but hail and wind threats look high end. Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 Dry line is already entering the western half of DFW. We'll see if it does slows down, or if it moves through and sets up shop just east of the Metroplex like the GFS has been showing. Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 18z 3km NAM does pop one lone cell over parts of Dallas County later today. Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 18z sounding from FWD. They're going to do another sounding at 21z Link to comment Share on other sites More sharing options...
cheese007 Posted April 9, 2021 Author Share Posted April 9, 2021 What does the sounding indicate re: capping? Link to comment Share on other sites More sharing options...
WhirlingWx Posted April 9, 2021 Share Posted April 9, 2021 Also a 10% hatched TOR added for parts of MS/AL in the updated SPC outlook Link to comment Share on other sites More sharing options...
cheese007 Posted April 9, 2021 Author Share Posted April 9, 2021 Mesoscale Discussion 0345 NWS Storm Prediction Center Norman OK 0314 PM CDT Fri Apr 09 2021 Areas affected...central and eastern Oklahoma/western Arkansas/North Texas Concerning...Severe potential...Watch likely Valid 092014Z - 092115Z Probability of Watch Issuance...80 percent SUMMARY...Eventual storm development expected across this region will likely require WW issuance late this afternoon. DISCUSSION...Midday RAOB from KOKC revealed stout capping just above 850 mb, supporting persistent low cloud cover across central Oklahoma. While the low clouds persist, a slight change in character toward more cumuliform elements is occurring -- particularly over portions of western/southwestern Oklahoma. As a cold front continues to advance southeastward across this area, ahead of a mid-level vort max shifting southeastward out of the High Plains, ascent will continue to allow the cap to weaken -- resulting in eventual storm development. Intensity of the initial cells over far western Oklahoma will likely remain limited, but with 2000 J/kg mixed-layer CAPE now indicated within the very steep lapse rates within the elevated mixed layer above the cap, robust storms will likely evolve. Storm intensity will be aided by a belt of stronger mid-level flow expected to spread across the region south/southeast of the upper system. Along with potential for locally damaging wind gusts, very large hail will also be possible with the strongest/rotating storms. ..Goss/Thompson.. 04/09/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SGF...SHV...TSA...ICT...FWD...OUN... LAT...LON 35389873 36389838 37019704 37019488 36089383 34429374 33199511 33479796 34439850 35389873 Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 33 minutes ago, cheese007 said: What does the sounding indicate re: capping? Yes. A very strong one at that. Link to comment Share on other sites More sharing options...
WhirlingWx Posted April 9, 2021 Share Posted April 9, 2021 NOW the HRRR wants to fire storms off in/near the Metroplex, so I guess we should watch for that. I remember hearing yesterday that the monster supercell that ended up going through Bryan/College Station didn't really start getting picked up by the models until only a couple hours before, so I'm wondering if the same thing happens again. Link to comment Share on other sites More sharing options...
Powerball Posted April 9, 2021 Share Posted April 9, 2021 The area circled below (the line of agitated CU ) is going to be the place to watch for any storms that first initiate along the dry line... Link to comment Share on other sites More sharing options...
cheese007 Posted April 9, 2021 Author Share Posted April 9, 2021 4 minutes ago, TexMexWx said: NOW the HRRR wants to fire storms off in/near the Metroplex, so I guess we should watch for that. I remember hearing yesterday that the monster supercell that ended up going through Bryan/College Station didn't really start getting picked up by the models until only a couple hours before, so I'm wondering if the same thing happens again. What timeframe would this be? Link to comment Share on other sites More sharing options...
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