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cheese007

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  1. Monday got part of the risk area bumped to 30% in the D4, primary threat being hail but tornadoes and strong winds also likely
  2. Another early week system with a big D5 15% and a D6 15% for outside this subforum. ZCZC SPCSWOD48 ALL ACUS48 KWNS 280900 SPC AC 280900 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Mar 28 2024 Valid 311200Z - 051200Z ...DISCUSSION... ...Day 4/Sunday: Mid Mississippi Valley into the Central/Southern Plains... The upper trough/low over the western states should slowly advance eastward towards the Southwest and southern/central High Plains on Sunday. Upper ridging is forecast to remain over the central/ southern Plains through Sunday night, which in tandem with a low-level temperature inversion should tend to suppress most convection. One possible exception may be along a sharpening warm front across MO/IL, where some guidance suggests elevated convection may form either Sunday morning, and/or Sunday night with strong low-level warm advection/lift occurring. Steepening mid-level lapse rates are forecast to overspread the mid MS Valley from the southwest through the period. These lapse rates, along with increasing moisture/instability in the presence of strong deep-layer shear, may support a risk for isolated supercells with associated threat for large hail. Regardless, confidence remains too low in this mainly elevated convection occurring, given upper ridging persisting, to add a 15% severe area for Sunday along/near the warm front in MO/IL at this time. ...Day 5/Monday: Southern/Central Plains into the Mid Mississippi and Ohio Valleys... Even though some differences remain in medium-range guidance regarding the ejection of an upper trough over the central CONUS on Monday, confidence has increased in the general location of relevant surface features, including the primary low, position of a southward-extending dryline, and northward extent of the warm front into the OH Valley. Even though the overall upper trough orientation may remain somewhat positively tilted, most deterministic guidance shows that a mid-level speed max and associated shortwave trough will eject northeastward over the southern/central Plains through Monday evening. Low-level mass response should encourage the eastward development of a surface low to the OK/KS vicinity in a similar time frame. Favorable low-level trajectories emanating from the Gulf will act to increase low-level moisture in tandem with steepening mid-level lapse rates and daytime heating across a broad warm sector extending from the southern/central Plains into the lower/mid MS Valley and OH Valley. A favorable thermodynamic and kinematic environment for organized severe convection will exist across much of these regions, with supercells capable of producing large hail and tornadoes possible initially. With time Monday evening/night, some upscale growth seems probable across the mid MS and OH Valleys, as mid-level flow should become increasingly parallel to a surface cold front. Therefore, a 15% severe area has been introduced for Monday where confidence is greatest that robust convection will develop in a parameter space characterized by weak/moderate instability and strong deep-layer shear. A nocturnal minimum in severe convective potential may be realized Monday night into early Tuesday morning across parts of the lower MS Valley into Mid-South, given the positively tilted nature of the upper trough. ...Day 6/Tuesday: Ohio/Tennessee Valleys into the Appalachians... Some severe threat should continue Tuesday over parts of the OH/TN Valleys into the Appalachians as the upper trough continues eastward. Even though there is still some uncertainty with the exact placement of the primary surface low and evolution of the upper trough, enough confidence exists in a fairly narrow corridor across these regions to add a 15% severe area for Tuesday. Rich low-level moisture should be in place ahead of an eastward-moving cold front. Redevelopment and/or re-intensification of convection seems probable by Tuesday afternoon. Strong deep-layer shear and weak instability should be sufficient for organized severe convection posing some threat for damaging winds, and perhaps tornadoes given the forecast strength of a low-level jet focused over parts of the OH/TN Valleys. The northward extent of the severe risk across OH and vicinity remains uncertain, as the placement of the warm front varies in model guidance. Similarly, convection should eventually encounter a less unstable airmass across the Appalachians. But, an isolated severe risk may continue Tuesday evening into early Wednesday morning across the southern/central Appalachians into portions of the Southeast. ...Day 7/Wednesday and Day 8/Thursday... Predictability remains too low to include a 15% severe delineation for Wednesday across the Mid-Atlantic/Southeast along/ahead of a cold front. By this extended time frame, there are significant differences in model guidance regarding the evolution of the upper trough, including its possible interaction/merging with a northern-stream trough, and placement of relevant surface features. Still, at least an isolated severe risk may persist Wednesday along/ahead of the eastward-sweeping cold front. Once this front clears the East Coast, severe potential appears minimal across the CONUS next Thursday. ..Gleason.. 03/28/2024 CLICK TO GET WUUS48 PTSD48 PRODUCT
  3. D2 ENH with Sigtor hatch SPC AC 241723 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sun Mar 24 2024 Valid 251200Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms with a threat for a few tornadoes and damaging winds are possible Monday through Monday night from parts of east Texas through the Lower Mississippi Valley. ...Synopsis... Deep upper troughing is forecast to be in place across the central CONUS early Monday morning. Several shortwave troughs will be embedded within this large parent upper troughing, including one over the Mid MO Valley and another over the southern High Plains. The northern shortwave is forecast to continue northward through the Upper MS Valley while the southern shortwave moves quickly northeastward across eastern OK/northeast TX and into the Mid MS Valley. Evolution of these shortwaves, in particularly the southern High Plains shortwave, will induce a more negative tilt to the parent upper trough as the entire system gradually shifts eastward. The surface pattern early Monday morning will be complicated by an ongoing convective line across TX, but the general expectation is for a low to be over central KS with the primary cold front extending southwest from this low across the TX Panhandle into northeast NM. A secondary cold front/dry line will also extend southward from this low across central OK and north TX into the TX Hill Country. Showers and thunderstorms will likely be ongoing along an outflow boundary preceding this secondary cold front/dry line from southwest MO through western AR and northeast TX. The cold fronts and convective line are all forecast to progress eastward throughout the day, with some intensification of the convective line possible as it interacts with the greater low-level moisture over the Lower MS Valley. Thunderstorm development is also expected farther north across western IA as the primary surface low moves through during the afternoon. ...Mid-South into the Lower MS Valley... Favorable low-level moisture will exist ahead on the convective line expected to be ongoing early Monday from southwest MO through northeast TX, contributing to modest buoyancy despite widespread cloud cover and relatively cool surface temperatures. Generally modest convection will likely be ongoing within this line early Monday, but the expectation is for the line to reintensify during the early afternoon as large-scale forcing increases, the cold front catches up to the line, and buoyancy reaches its diurnal max. This reintensification will likely begin near the TX/LA border, with storms reaching their maximum intensity across far southeast AR, eastern LA, and western MS. Very impressive wind fields are anticipated across the region, with southeasterly surface winds ahead of the line contributing to large, looping low-level hodographs. Additionally, very strong southwesterly mid-level flow will support a southwesterly deep-layer shear vector with a notable line-perpendicular orientation. Consequently, there is likely a risk for a robust, forward propagating line capable of both strong gusts and embedded QLCS tornadoes. Also, given that the line is expected to be fairly weak at the beginning of the period, there is some chance for more discrete updrafts as the reintensification of the line begins, particularly with southern extent. The airmass will become less unstable with eastward extent into AL, and the expectation is for the overall intensity of the line to weaken as it moves into AL overnight. ...Western Iowa/Far Northwest MO and Vicinity... Within the larger-scale upper trough over the central states, an embedded, cold-core mid-level shortwave trough will move quickly northeastward across the Upper Midwest Monday. Most guidance still shows low 50s surface dewpoints present near a deep surface low across western IA and vicinity Monday afternoon. Given the cold mid-level temperatures, only modest daytime heating is needed for airmass destabilization. Deep-layer shear appears strong enough for a few organized thunderstorms and isolated/marginally severe hail and strong/gusty winds may occur with any sustained low-topped convection. ..Mosier.. 03/24/2024
  4. D5 15% contour added covering much of AR/LA/MS as well as the MO bootheel, far western TN, and a smidge of east TX
  5. SPC has put out a D5 15% contour with hints at more unsettled weather in the following days ZCZC SPCSWOD48 ALL ACUS48 KWNS 200900 SPC AC 200900 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Wed Mar 20 2024 Valid 231200Z - 281200Z ...DISCUSSION... Medium-range models suggest that blocking centered over the northeastern Pacific will break down this weekend, as a more progressive regime shifts across the central into eastern mid-latitude Pacific, and gradually inland through much of the U.S. by the middle to latter portion of next week. Initially, flow downstream of the weakening blocking may undergo amplification, including mid-level troughing offshore of the southern Atlantic Seaboard, and larger-scale mid-level troughing progressing inland of the U.S. Pacific coast through the Great Plains and Mississippi Valley through early next week. Within the inland advancing troughing, there appears reasonable agreement between the ECENS/ECMWF, GEFS and GFS model output that a significant lead short wave perturbation will accelerate northeastward out of the Southwest across the southern Rockies late Sunday into Sunday night. As this occurs, a rather deep cyclone is forecast to continue to form to the lee of the Front Range during the day, before migrating southeastward then eastward into the adjacent high plains. Although it still appears that low-level moisture return in the wake of prior low-level drying and cooling across the northern Gulf Basin may still be on the margins for vigorous thunderstorms, the development of steep lower/mid-tropospheric lapse rates may compensate. Coupled with potentially intense wind fields and strong forcing for ascent, organized severe thunderstorm development seems probable late Sunday afternoon into Sunday night. This may include supercells initially, then an evolving narrow squall line. Into the early through middle portion of next week, uncertainties concerning a subsequent short wave emerging from the Southwest increase. However, it appears probable that there will be at least narrow corridors of strong to severe thunderstorm development on following days across the southeastern Great Plains into lower Mississippi Valley and perhaps parts of the Southeast. ..Kerr.. 03/20/2024 CLICK TO GET WUUS48 PTSD48 PRODUCT
  6. This storm ended up dropping a brief EF-0 over the UNT Frisco parking lot
  7. 50/30 tor probs URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 42 NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 14 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central/eastern Oklahoma North-central Texas * Effective this Thursday morning and evening from 1110 AM until 600 PM CDT. * Primary threats include... A few tornadoes and a couple intense tornadoes possible Widespread large hail and scattered very large hail events to 3 inches in diameter likely Scattered damaging wind gusts to 70 mph possible SUMMARY...Supercell thunderstorms will continue to increase in coverage and intensity through the afternoon, while posing a threat for very large hail, severe/damaging winds, and a few tornadoes. The tornado watch area is approximately along and 65 statute miles east and west of a line from 45 miles east northeast of Tulsa OK to 65 miles southwest of Sherman TX. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... 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. && OTHER WATCH INFORMATION...CONTINUE...WW 40...WW 41... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 24035. ...Gleason/Goss
  8. 10% tor added for D1 and a slight risk added for Austin/San Antonio area for D2
  9. Vince Waelti on YouTube seems to have a good angle
  10. ENH added for D1 around KC but no sig-tor hatching as of 8AM
  11. Slight risk added for the 13th as of today, with a large expansion of the risk area + hatching added for the 14th. Below is the discussion for the latter SPC AC 120731 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Tue Mar 12 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MIDDLE MISSISSIPPI VALLEY INTO EASTERN OKLAHOMA...EAST TEXAS...AND THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Strong to severe thunderstorms are possible across a large area from the Middle Mississippi Valley into eastern Oklahoma, East Texas, and the Lower Mississippi Valley on Thursday. ...Synopsis... A surface low is forecast to be over the NE/IA/MO border vicinity early Thursday morning, with a cold front extending southwestward from this low across eastern KS and central OK into the TX Hill Country. An expansive warm sector is expected to be in place east of this cold front, from the Mid MS Valley into the southern Plains and Lower MS Valley early Thursday morning, supported by the previous days' return flow. Showers and thunderstorms may be ongoing in the vicinity of a warm front extending north-northeastward from the surface low, but much of the warm sector is currently expected to be free from any early period storms. This broad warm sector is expected to destabilize throughout the day with two primary corridors of severe thunderstorms potential, one near the surface low from southern IA/northern MO into west-central IL and another farther south from eastern OK and east TX into LA and AR. ...Southern IA/Northern MO/West-Central IL... Upper 50s dewpoints are expected south of the warm front throughout the period. Despite this somewhat modest low-level moisture, moderate to strong buoyancy is still anticipated early in the afternoon as surface temperatures climb into the low 70s, supported by cold mid-level temperatures and resulting steep mid-level lapse rates. Low-level convergence near the surface low and warm front will likely result in convective initiation amid vertical wind profiles that support supercells. There may be a tendency for storms to move north of the warm front over time, but enough residence in the warm sector is anticipated for some storms to reach maturity. Any mature supercells would be capable of all severe hazards, including tornadoes, strong gusts, and very large hail. ...Eastern OK and East TX into LA and AR... Weak surface troughing will likely interact with an increasingly unstable airmass across the region during the afternoon, with convective initiation anticipated around 18Z across southeast OK and northeast TX. Given robust buoyancy and moderate vertical shear, initial development will likely be supercellular and capable of all severe hazards, including very large hail. How the convection evolves after the initial more discrete storms remains uncertain, with some potential for development into more linear structures given the front-parallel deep-layer vertical shear. If upscale growth is realized, the resulting convective line would then push eastward into AR and LA, with some potential for damaging gusts. ..Mosier.. 03/12/2024
  12. Got another advace-forecast with a D6 15% including DFW and part of the Austin metro. Something to watch
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