jaxjagman

We probably need a thread

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0757 AM CDT Sat Apr 13 2019 Valid 131300Z - 141200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF EAST TEXAS...CENTRAL/NORTHERN LOUISIANA...SOUTHEASTERN ARKANSAS...AND WESTERN/CENTRAL MISSISSIPPI... ...SUMMARY... Tornadoes -- some potentially strong to violent (EF2+) -- are possible today from east Texas to central Mississippi. Otherwise, numerous severe thunderstorms will pose a risk of large hail, damaging wind and tornadoes from central Texas this morning to the Tennessee Valley region overnight. ...Synopsis... In mid/upper levels, a leading/northern-stream perturbation will eject northeastward across from its present position over Lake Superior and northern Ontario, across Quebec. To the southwest, a deep, high-amplitude trough is evident in moisture channel imagery over NM, far west TX, and northern MX. This trough will pivot east-northeastward today, developing a closed 500-mb low by 00Z near the DFW Metroplex, and extending southwestward across Coahuila. By 12Z, that low should reach eastern MO, with trough southwestward over the Arklatex to deep south TX. At the surface, the 11Z analysis showed the primary surface low along a band of convection south of SJT. A double structure was apparent to baroclinic zones to its east: the first a quasistationary front across central TX to near a SHV-CBM-CHA axis. The southern front was quasistationary just south of UVA and SAT, becoming a warm front over southeast TX and south-central LA, then quasistationary again over coastal AL and coastal western FL Panhandle. The primary surface low should deepen and cross the Arklatex region late this afternoon into early evening, reaching the lower Ohio Valley around EVV by 12Z. The southern is expected to accelerate northward from mid/late morning, to and perhaps past the I-20 corridor in northeast TX and LA, then over Mississippi, likely merging with the northern one. By that time, a cold front should extend from the low south-southwestward across the MS Coast area, likely preceded by an organized quasi-linear MCS over the Deep South. ...TX to Lower Mississippi Valley, Mid-South and TN Valley... A regional outbreak of severe thunderstorms, with the main concern being damaging tornadoes, still appears possible today in and near the categorical moderate-risk area. Only peripheral adjustments were needed for this outlook package, based on convective trends this morning and (on the eastern edge) continuity of overnight severe potential into the early day-2 period. Strong-severe thunderstorms are ongoing across portions of the Hill Country southward toward the Rio Grande. This convection will pose a severe threat into central TX through the rest of the morning. Refer to SPC watches 48-49 and associated mesoscale discussions for near-term details. East of the ongoing activity, the parameter space will become very supportive of supercell/tornado potential through the day in the warm sector, with the main uncertainties being longevity and discreteness of favorable storm mode. As the southern front moves farther inland, a deeply moist boundary layer will spread across the region, with surface dew points commonly in the mid/upper 60s F and locally near 70, PW 1.5-1.75 inches, and mean mixing ratios increasing to 15-16 g/kg, with forecast soundings showing favorably low LCL. Gradual diabatic heating in pockets will weaken already meager MLCINH from midmorning onward, enabling storm formation on pre-MCS sources for weak lift such as confluence/convergence lines, and perhaps persistent/relatively deep horizontal convective rolls. Lapse rates will strengthen with westward extent, supporting preconvective MLCAPE ranging from 2000-3000 J/kg over parts of east TX to 1000-2000 J/kg over portions of LA and MS. Such buoyancy will be more than favorable for all forms of severe, amidst strengthening deep shear related to the approach of the mid/upper trough. Furthermore, low-level shear vectors and hodograph sizes will be quite large along and south of the warm front, with forecast soundings yielding 250-600 J/kg effective SRH. Any sustained supercells in this environment will be capable of significant tornadoes. With time this evening and overnight, convection should organize into a roughly north/south-aligned band over the lower Mississippi Valley region, as deep convergence becomes better-focused in the mass response ahead of the synoptic wave. As this occurs, the main threat in a bulk sense may become damaging wind tonight. However, given the strong inflow-layer SRH, tornadoes still will be probable from both embedded supercells and QLCS mesovortices. ...Central/eastern NC and vicinity... Widely scattered to scattered thunderstorms are expected to develop through this afternoon, offering the potential for damaging gusts -- perhaps reaching severe limits on an isolated basis -- and isolated severe hail. Mid/upper-level support will be lacking, beneath a belt of southwesterlies aloft. However, diabatic surface heating amidst weak ambient MLCINH should enable only weak lift necessary to initiate convection. The area will straddle a low-level moist axis characterized by surface dew points generally in the mid/upper 60s F, supporting peak preconvective MLCAPE in the 1500-2000 J/kg range. Though low-level flow will be weak, limiting boundary-layer shear and hodograph size, the height gradient will remain sufficiently tight aloft to support strong storm-relative/ventilating winds in upper levels, and effective-shear magnitudes around 40-50 kt. As such, a few organized multicells and sporadic supercell structures will be possible. Convective potential will be strongly tied to the diurnal cycle, and should wane precipitously after 00Z. ..Edwards/Wendt.. 04/13/2019

National Weather Service Nashville TN 641 AM CDT Sat Apr 13 2019 .UPDATE... FOR 12Z AVIATION DISCUSSION. && .DISCUSSION... Early this Saturday morning, scattered light showers were occurring over the southeast half of Middle Tn. These showers were located along a stalled frontal zone. The front will begin to lift northward today, spreading scattered showers across the area. Isolated thunder will develop late morning through the afternoon, but no severe wx or heavy rainfall is expected today. In fact, forecast rainfall amounts are less than one quarter inch. Back to our southwest, a few powerful thunderstorms were raging in East Tx and La early this morning. These had developed in response to a strong trough moving out of the southwest states into Tx. Over the next 36 hours, the big trough will move to the Ms Valley as a surface low deepens and moves northeast to the Ohio Valley. The result will be an outbreak of severe thunderstorms across the Lower Ms Valley Region today, with these storms shifting northeastward to the Tn Valley Region late tonight into Sunday morning. On Sunday the focus for storms will spread from the Tn Valley across a large part of the Appalachian Region. There continue to be uncertainties about the exact timing and evolution of the thunderstorms across Middle Tennessee. We do feel confident there will be a wave of storms coming in from the southwest late tonight and crossing the area very late night through Sunday morning. Then, there will be some additional thunderstorm development along a cold front midday into Sunday afternoon. For simplicity- severe thunderstorms will be possible from midnight tonight until 6 PM Sunday. The late night and early morning threat will be area wide, while the Sunday afternoon focus will be east of I-65. Most of the area is under a slight risk, with the eastern third under an enhanced risk. These risk areas will likely be adjusted a bit through the next 24 hours. I would not focus on these nuances- the main story is that all of Mid Tn could have severe thunderstorms with damaging winds, large hail, and a few tornadoes. Prepare now for what you will do if a tornado warning is issued - or a severe thunderstorm warning for powerful winds - and make sure you have ways to receive warnings. Forecast parameters showing 300-500 J/kg CAPE late tonight, increasing to around 1000 by mid morning Sunday as dew points climb into the low to mid 60s. 0-6km layer shear is well over 50KT with 850MB winds reaching over 50KT around 12Z. Like any severe storm forecast, this is no slam dunk, but this deepening, very dynamic system certainly has the potential to create damage from all modes of severe wx. Strong winds outside thunderstorms will also be a concern with some gradient wind gusts over 40 mph at times. Some heavy downpours are possible, mainly with the late night storms, but we think fast storm motion with help limit the flood threat. Generally, 1 to 2 inches of rainfall is expected with some locally greater amounts. All the action will decrease and/or move east of our area by Sunday evening. Monday looks dry and cooler, then a warmup with return flow Tuesday. Rain chances will return starting late Wednesday with strong thunderstorms possible by Thursday as another big low pressure system crosses the region. &&

The NAM is slower than the GFS.This pattern we are stuck in seems to be we see systems come in faster than being shown,but we'll see.GFS shows the LLJ strenghten into Mid Tn to around 60-70kts with low capes and high helicities we should have the potential to see more mesocyclones.Not really sure but i think the enhanced could be shifted further west next update,if the NAM is right we'd see more capes,but the bias SLOWER NAM outside 24 hrs..,believe the GFS might be right.

You might want to start and look at habyhints.Lots of tools here.

Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Apr 12 2019 Valid 141200Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN OHIO AND WEST VIRGINIA SOUTHWARD INTO THE SOUTHEAST... ...SUMMARY... Strong/severe thunderstorms are anticipated Sunday -- centered over the mid and upper Ohio Valley, and central and southern Appalachians. ...Synopsis... A strong mid- and upper-level trough exiting the Plains early in the period is expected to advance steadily east across the Mississippi/Tennessee/Ohio Valleys and central Gulf Coast states, reaching a position from the lower Great Lakes to the southern Appalachians/Southeast late in the period. At the surface, a deepening low is forecast to shift east-northeast across the Ohio Valley through the day, and then across the central Appalachians to the Hudson Valley vicinity by the end of the period. Widespread thunderstorms -- and a broad severe risk -- will accompany this system. ...The Ohio Valley and central Appalachians south to the Southeast... Showers and thunderstorms are forecast to be ongoing in a north-south band from Indiana to Alabama early in the period, ahead of the advancing cold front. As modest heating of a moistening pre-frontal warm sector commences, 500 to 1000 J/kg mixed-layer CAPE is expected to evolve ahead of the ongoing band of convection, from the Ohio Valley to the Gulf Coast. This should result in a gradual intensification of storms through the afternoon, aided by a very strong deep-layer wind field accompanying this storm system -- including 80 to 100 kt south-southwest flow at mid levels. Primary storm mode is progged to be banded/loosely linear, with embedded/complex bows and rotating updrafts. Damaging winds will likely be the primary threat, though tornadoes will also be possible across much of the area -- particularly near and west of the mountains. Risk should diminish gradually through the evening, though local wind risk may persist through the end of the period.

Didn't get to watch the game because of my sons Regional Gymnastics Meet in Alachua,FL.The reception was just plain horrid.That was good anyways,it's easier to digest the loss and move on. But i was more happier with my sons meet results.My son competed with 90 gymnast through out the Southeast.He came in 4th place. We're going to Reno baby !!Junior Olympic National Championship https://www.jonationals.com/men/

Just saying if the MJO gets into the Pacific you could see once again the jet get excited by Enso.This pattern seems to be on going with this ENSO bringing LP's through the Valley

It should be easy to spot the MJO.Other than some desructive interference ENSO signs around the IDL the MJO is looking stronger as it gets into the IO.No telling beyond that though,

Certainly a chance of hail and wind Sunday.NAM is being shown as the outlier in which it should be MJO ,seems possible it gets into the IO wk2.but after that? Chance for a decent system in the long range as the PNA goes negative but at the same time there finally could be a more negative NAO that everyone was waiting on this winter,this would be more or less a suppressed storm track like the Euro shows but at the same time say "Hello" to April showers with potential some serious rain for any part of the Valley especially with any convection

I'll be in Alachua,Fl Saturday for my sons regional gymnastics meet.Of course his meet would be Saturday starting at 5PM

CanSIPS shows Nino lasting until March 2020(end of the run) and maybe beyond.Last ETA shows the waters are warm almost 100m down into the thermocline practically basin wide,with some cooler waters which was probably from the last KW upwelling,mainly around east of the IDL. The BOM update shows a Moderate Nino will peak around May/June then fall off

US National Weather Service Nashville Tennessee 3 hrs · (ALL INFO IS PRELIMINARY & SUBJECT TO CHANGE!) After surveying the wind damage from the storms on Saturday March 30th, a NWS storm survey team has determined that an 8 mile long by 1 mile wide downburst (straight-line winds) caused the damage in and around Orlinda (Robertson County). Several barns in the area were damaged, a few homes lost shingles, and scattered trees were snapped and uprooted. Winds were estimated from 65 to 75 mph. Further south, it was determined that a small but severe microburst around 1 mile long by 300 yards wide caused the damage along John Lunn Road just south of Saturn Parkway in Spring Hill (Maury County). These damaging winds were associated with the RFD (rear flank downdraft) of the supercell thunderstorm that moved over the Spring Hill area. One barn was destroyed, several others were damaged, and numerous trees were snapped and uprooted. Winds were estimated up to 80 mph.

Be fun to watch the MJO upcoming.CFS looks like the MJO could get stronger about at the same time it would also seem to look like a DWKW towards the mid of Apill,but this could also be destructive interference from the ENSO along the IDL.Right now the MJO looks to come off Africa into wk.2 of April.

So weird looking.With the jet extension you see westerlies to the west with which looks to be HP into Bermuda/Florida and shortwaves rotating along a negative tilted trough.Try and figure this one out what the Euro shows..lol

Believe who was monitoring this site retired?I can't remember his name but i'd use caution using this site.

Storm fizzled out just east of Eagleville,maybe loss of diurnal heating is starting to factor in

Tornado shown is from the Centerville cell,weak rotation but it still is ongoing towards Murfreesboro

Storm around Olinda had reports of 70mph winds with pole and home damage,certainly could be str8 line winds but we'll see when they survey

Rotation with the tornado headed towards Spring Hill which is being shown

Tornado by Orlinda,really don't see rotation with this

Some rotation showing up into Kentucky and some weaker between Hohenwald and Centerville into Tn,finally seeing some storms though

Don't see nothing rotating,we're partly cloudy now with the sun out,Storm looks more depressive as we lost Okeke with a torn ACL that will need surgery.Such a freak non-contact injury

National Weather Service Nashville TN 250 PM CDT Sat Mar 30 2019 .DISCUSSION... Showers and storms have already fired up to the west along the MS and OH River Valleys, and models have that line of convection continuing across the mid state from mid afternoon through the evening hours. A strong upper level trough will progress eastward today, and drag a strong cold front through the area late this afternoon and evening. Consensus between the models shows decent instability, with MLCAPE values in the 400-1000 J/Kg range, and 0-6km deep layer shear around 50 to 60 knots. 0-1km shear is moderately strong as well, with values around 20 to 30 knots. Sounding analysis shows strong low level curvature in the hodographs, which would not only support rotating updrafts but even support some isolated tornado potential as well. 0-1km and 0-3km helicity values are also strong as expected with great low level curvature in the hodographs. With the approaching cold front providing the lift to keep convection ongoing through the area, and with the instability/shear environment in place, the main threat with any strong to severe thunderstorms would be damaging winds, and isolated tornadoes. Mid level lapse rates do briefly support some hail potential as well, and would be more likely should any isolated cells develop ahead of the main line of convection. After the front passes through the area from west to east during the evening, severe potential will fall off rapidly as cold air settles in near the surface and decreases surface based instability.

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Sat Mar 30 2019 Valid 302000Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-SOUTH/TENNESSEE VALLEY REGION AND VICINITY... ...SUMMARY... Severe thunderstorms are possible through 10 PM CDT across portions of Mississippi, Tennessee, Kentucky, and Alabama. Expected hazards include isolated to scattered damaging winds, large hail, and a couple tornadoes. ...Discussion... Instability has been slow to develop across the risk area, due to widespread cloud cover limiting heating, and dewpoints running a bit lower than most model forecasts. Still, the overall forecast appears reasonable, in terms of risk level and areal extent. Therefore, aside from a few tweaks to the thunder line, no substantial changes to the outlook are needed at this time, with isolated severe risk expected to evolve over the next 1-2 hours. ..Goss.. 03/30/2019 .PREV DISCUSSION... /ISSUED 1125 AM CDT Sat Mar 30 2019/ ...MS/TN/KY/AL... Primary changes are to shift wind probabilities north/east across KY, and increase/expand tornado/hail probabilities. These changes result in a net expansion of the Slight and Marginal Risks. A shortwave trough near Kansas City will move east across the Midwest while amplification of a separate trough occurs upstream over the Upper Great Lakes region through tonight. Surface wave over far southern IL will deepen as it approaches the Lower Great Lakes. An attendant stout cold front will push southeast likely passing a line from Columbus, OH to Lake Charles by 00Z. Upper 50s to lower 60s surface dew points will be common ahead of the front from the Mid-South southward where moderate boundary-layer heating in cloud breaks will drive MLCAPE values to 500-1000 J/kg. An increasingly narrow/more marginal moisture plume will exist farther north and eventually be occluded by the impinging cold front. Forcing for ascent will be focused in a band near the front, stronger north than south, which suggests predominately linear/cluster mode north and a mix of discrete cells/clusters south as storms mature towards late afternoon. Deep-layer vertical shear will be sufficient for splitting supercells with relatively long hodographs, and moderate low-level hodograph curvature. The greatest combined probabilities should exist surrounding the TN/MS/AL border region where all hazards are possible but large hail may be the primary threat given the remnant elevated mixed layer and potential dominance of left-mover supercells as suggested by most HREF members. Isolated to scattered damaging winds will be the primary concern with northern extent. The severe threat will wane after sunset and should cease by late evening.