jaxjagman

Probably watch the models tonight and even in the morning.Some of the cams show some discrete cells after the cap breaks in the afternoon,We could possibly hit 85 tomorrow which would break our record.Nashville sure sounds concerned National Weather Service Nashville TN 234 PM CDT Fri Mar 27 2020 .DISCUSSION... As a citizen of Middle TN, I hate writing these AFDs. However, as a met and a scientist, they`re the ones you wait for. Now look, tomorrow isn`t going to be an April 2011 kind of day, nor do I expect for us to have a repeat of March 3rd. However, tomorrow evening, despite the differences in the models warrants everyone in Middle TN, especially those along and west of I-65 (this includes but is not limited to the Metro area) to be very weather aware tomorrow evening. Let`s start with what`s going on now: A mix of sun of clouds and a warm breeze is making for a great day across Middle TN. Temperatures are running about 20 degrees above average which is a welcomed increase in temperatures for spring. The southerly winds will continue to blow overnight. Not gusty, but the warmth and persistent increase of low-level moisture will continue. I have 67 for a morning low tomorrow and while I don`t expect us to remain above 70, the record max low temperature for March 28th is 70 degrees set in 1907. Unexpected cloud cover in the morning would likely help us break that record, but as I said, unexpected. As we get into the afternoon hours tomorrow and the boundary layer continues to warm and low-level moisture increases, temperatures should be as warm or warmer than today. That means tomorrow`s high temperature will also be under assault. I have 83 in there and the record is only 85 set in 2012. If you`re a regular reader of the AFD, you see where we`re headed here... Throughout the day tomorrow, an intensifying low pressure system will continue to develop over the Plains. In the afternoon, those well north of us will be dealing with problems of their own, but as the front nears Middle TN tomorrow evening, we very well could have issues, too. I alluded to it earlier, forecast soundings aren`t in great agreement, but the only thing they aren`t in great agreement about is how bad it`ll be. As is normal, the NAM is the outlier in this situation. It`s a little slower, it has winds out of the south (which would increase the low-level helicity and in turn, the discrete supercell potential) as well as instability that is considerably higher than other models. Fingers crossed that the GFS and Euro are closer to the actual solution. That wouldn`t absolve us from a severe weather threat, just the overall severity of it. GFS soundings show surface winds that are veered compared to the NAM. This means more of a QLCS and a straight-line wind threat (but still NOT a zero tornado threat). All of that said, I`m leaning towards the GFS solution. The main surface low is well north of us and the overall system is very wrapped up, becoming occluded at the point when the the front starts to near Middle TN. We don`t TYPICALLY get discrete cell development in this scenario. A NAM solution would require the development of a secondary surface low closer to the mid- state and right now, the likelihood of that is low. So the main thing we`re going to want to monitor tomorrow afternoon and early evening: what are the surface winds doing? The more southerly they are, the better chance of discrete development (and a better tornado threat). More of a southwesterly component, we should be looking at the development of a line, less low-level helicity and a reduced chance of things getting out of hand -- but still a severe wind threat. Here`s the next problem: models continue to show this as another nocturnal event. That means it`s going to be after dark before the cap can break and develop occurs (no matter what kind). I`m looking at a 6 pm to midnight event, and 6 pm might be a touch early. This means today is the day to make sure you have multiple ways to get warnings. A properly programmed NOAA Weather Radio, your cell phone (make sure it`s turned on and up) and preferably one other way -- all something that will wake you up if you go under a warning and you`re sleeping. Storms/rain should be off the Plateau before sunrise and we`ll return to these fantastic dry conditions we`ve been experiencing the last couple of days. Our next shot at rain won`t be until Tuesday. Current trajectories keep Tuesday`s system from being severe for us, but will need to be monitored over the coming days. &&

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Tue Mar 24 2020 Valid 241300Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-SOUTH/TENNESSEE VALLEY... ...SUMMARY... Scattered severe storms, including the potential for hail/wind damage along with a few tornadoes, are expected over the Mid-South, Tennessee Valley, and southern Appalachians vicinity. ...Mid-South/Tennessee Valley to southern Appalachians... Bands of elevated showers/thunderstorms are ongoing early this morning across the Ozarks into much of Tennessee and northern portions of Mississippi and Alabama. A low-amplitude shortwave trough/mid-level speed max over the south-central Plains and Ozarks early today will steadily progress eastward, reaching the Tennessee Valley by early evening. In response to this feature, a weak surface low will shift into Arkansas by early afternoon as the frontal zone that is currently draped across the central Gulf States lifts north toward the Tennessee border. This surface low will then track along the wind shift into middle Tennessee by early evening. Diurnal heating will be maximized ahead of the surface low across Arkansas where low-level flow should veer and surface temperatures should reach convective temperatures by mid-afternoon. Surface-based supercells are expected to initially develop across eastern Arkansas into western Tennessee/northern Mississippi within the warm sector and near the warm front. This activity will develop within strong deep-layer shear, but low-level shear is not forecast to be particularly strong initially given the southwesterly surface winds. The surface-based nature of these storms suggests all hazards are possible, including a few tornadoes. Hail will be the primary risk north of the warm front. While exact later-day positioning of the warm front is a bit uncertain, there is concern that a somewhat more focused/heightened supercell and tornado potential could materialize across portions of Middle Tennessee and northern Alabama in vicinity of the surface triple point. Near the modestly deepening surface low/warm front, low-level shear/SRH will be maximized with an enlargement of hodographs expected toward sunset. Portions of Middle Tennessee and northern Alabama will be reevaluated later today for the possibility of a higher risk category (Enhanced).

Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Mar 23 2020 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE TENNESSEE VALLEY... ...SUMMARY... Thunderstorms associated with wind damage, a tornado or two and hail will be possible in the mid Mississippi, Ohio and Tennessee Valleys on Tuesday. ...Mid Mississippi Valley/Ohio and Tennessee Valleys... A fast-moving shortwave trough will move eastward into the mid Mississippi Valley on Tuesday. At the surface, a low will move eastward into the Ozarks with a warm front extending eastward from the low into the Tennessee Valley. Thunderstorms associated with a marginal severe threat will be likely to the northeast of the surface low across southern Missouri during the morning. As the low moves eastward, low-level flow will strengthen across the Tennessee Valley. In response, low-level moisture will increase with surface dewpoints reaching the lower to mid 60s F from northern Mississippi into western Tennessee. Surface heating should enable MLCAPE to peak in the 500 to 1000 J/kg range by afternoon. Surface-based thunderstorms appear likely to develop across just ahead of the approaching shortwave trough. This convection is forecast to move eastward across the Tennessee Valley during the afternoon reaching the southern Appalachians by early evening. Forecast soundings across the Tennessee Valley Tuesday afternoon show strong deep-layer shear profiles and steep low-level lapse rates. 0-6 km shear is forecast to be 65 to 75 kt range which should be favorable for supercells and short bowing line segments. A tornado threat, along with a potential for wind damage and hail will be possible with supercells. Short line segments should also be capable of producing wind damage. The severe threat is expected to become isolated as scattered thunderstorms move eastward into the southern Appalachians and southeastward into the central Gulf Coast States during the evening. ..Broyles.. 03/23/2020

Yes and should wait and see if/where any triple point sets up Tues afternoon,think the question will be how far the warm front lifts north

Euro starts to kick in the LL/Shear into the morning and afternoon Tuesday,more into the western and possibly the Middle Valley.,could get some supercells develop.NAM shows the TT'S 52-54 mid afternoon into Mid Valley but like always it could be over doing it but it did do well IMO when Nashville had its Tornado recently even at this range,still wouldnt trust it.Like BNA stated it should go into a QLCS Tuesday as it progress eastward with mesocyclones possibly embedded. Much as i like severe weather,i'm hoping this won't happen this time,anywhere ational Weather Service Nashville TN 216 PM CDT Sun Mar 22 2020 .DISCUSSION... Showers are showing up on radar just off to the west of the TN River currently, and moving eastward. Rain will continue eastward through the afternoon and evening, and still expecting the heaviest rainfall after midnight for areas south of I-40. Around an inch to an inch and a half will be possible closer to the AL border as the upper trough moves through the OH River Valley tonight. Left in mention of thunderstorms in the southern zones where some instability will work its way into the area overnight. Showers should come to an end from west to east during the day, with some lingering showers holding on in the afternoon on the Plateau. Monday night early on looks to be dry as we will be between troughs, but the next stronger Plains trough will be moving eastward and start impacting the area Tuesday morning. Warm air will already be in place from the previous trough, but the next trough will bring a warm front through the area Tuesday morning after sunrise, allowing more warm moist air to spread over the region. Model soundings show a shallow low level inversion that should limit convection early on, but once the warm front passes through, the mid state will be uncapped in the warm sector for the rest of the morning and afternoon. The GFS/NAM have heavier showers and thunderstorms mainly along the I-40 corridor and northward Tuesday before noon, and enough instability is around for some strong to severe storms during that time. After the warm front passes, there may be a brief break before additional storms develop ahead of the cold front in the warm sector during the afternoon, and spread eastward. As the trough and its axis approach the mid state, both instability and shear increase, along with low level helicity. MLCAPE values around 500 to 1000 J/kg look likely across the area during the afternoon, with the NAM not surprisingly showing slightly higher values. Deep layer shear is consistent between the models, however, showing 60 to 70 knots from 0-6km. Low level shear and helicity increase mid afternoon through the early evening, with 0-3km helicity values around 300 m2/s2 during that time. Model soundings also showing some decent dry air aloft, with mainly moist adiabatic lapse rates later in the afternoon. Better mid level lapse rates exist in the morning before earlier convection works it over a bit. All of this would suggest that damaging winds will be the primary threat, and could occur from late morning through the mid evening. Hail looks more likely in the late morning through mid afternoon, and will also be more likely with any isolated stronger convection that develops ahead of the squall line/QLCS. A few tornadoes can also not be ruled out, but as of right now, look more likely from mid afternoon to the early evening when convective mode looks more linear/QLCS-like. 00Z models tonight and even 12Z runs tomorrow morning will hopefully paint a better picture and help narrow down timeframes a bit more for Tuesday.

NWS Storm Prediction Center Norman OK 0146 AM CDT Sun Mar 22 2020 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI...OHIO AND TENNESSEE VALLEYS... ...SUMMARY... Thunderstorms associated with wind damage, a tornado or two and hail will be possible in the mid Mississippi, Ohio and Tennessee Valleys on Tuesday. ...Mid Mississippi/Ohio and Tennessee Valleys... A shortwave trough is forecast to move quickly eastward into the Mid Mississippi Valley on Tuesday. A large cluster of thunderstorms, associated with a marginal severe threat, should be ongoing Tuesday morning just ahead of the shortwave trough in central and southeastern Missouri. This convection, located on the northern edge of the moist sector near a surface low, is expected to move eastward across southern Illinois and into parts of western Kentucky around midday. Surface dewpoints should reach the lower to mid 60s F by afternoon across much of southern Kentucky, Tennessee and northern Mississippi. In response, MLCAPE may increase into the 800 to 1000 J/kg range from just south of the Ohio River southward into northern Mississippi. Surface-based thunderstorms that develop in this area Tuesday afternoon could obtain a severe threat due to the strong deep-layer shear in place. O-6 km shear is forecast to be in the 70 to 80 kt which would be favorable for supercells and bowing line segments. Although wind damage would be the primary threat, hail would also be possible with the stronger updrafts. Low-level shear is also forecast to be sufficient for an isolated tornado threat. Large-scale ascent and deep-layer shear is forecast to be strong ahead of the short-wave trough. This may be enough for squall-line development during the late afternoon across the Ohio and Tennessee Valleys. If this occurs, the wind damage threat could be maintained into early evening. A chance for QLCS tornadoes would be possible, associated with rotating cells embedded in the line. Due to the potential for a severe convective line, the slight risk has been expanded eastward across much of middle Tennessee and central Kentucky.

Not sure you should use sig severe outbreak.Outbreak is a outbreak but i know what you mean.Nothing anywhere would compare to 2011

Would think we could see a slight risk the next upcoming update.GFS and Euro aren't far off but still some timing this afternoon with synoptics on the 12z run today Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Fri Mar 20 2020 Valid 231200Z - 281200Z ...DISCUSSION... ...Monday/Day 4 and Tuesday/Day 5... On Monday, the medium-range models move a shortwave trough across the southern Plains. A moist airmass is forecast to advect northward into the Red River Valley with a dryline setting up across western Oklahoma and northwest Texas. Scattered thunderstorm development will be possible to the east of the dryline Monday afternoon. Strong deep-layer shear associated with a 75 to 90 kt mid-level jet is forecast to create conditions favorable for severe storms. Supercells and bowing line segments will be possible with a potential for tornadoes, wind damage and large hail. The magnitude of the threats will likely depend upon how much moisture can return northward and how much instability can develop on Monday. At this time, the potential for a severe weather event appears great enough to warrant adding a 15 percent area. On Tuesday, the shortwave trough is forecast to move eastward across the Mississippi Valley. A moist airmass is forecast to be in place in most of the southeastern states. Scattered thunderstorms will be possible across parts of the Ohio and Tennessee Valleys where enough instability and deep-layer shear should be in place for a severe threat. A tornado threat along with potential for wind damage will be possible Tuesday afternoon and evening. A threat area could be added as confidence increases concerning where the greatest severe threat will be.

When we had the big outbreak in 2011 this was basically from a resurgent Nina into 2011.This is where the NA SST tripole was negative but started to transition to +ve.The Enso is going to be a big player with out a doubt into next winter.Not sure i'd proclaim next winter as gloom or doom right yet.It seems possible next winter might be colder than you think it will be and warmer the next

By the looks this would be a good call with a early terminating Nino into spring

This is the right map of Jamstec,as i said above i wasn't sure that map was correct

Just looking at the GWO we are headed into a favorable stronger tornado threat upcoming in March,doesn't mean it will be into the Valley.Could just be anywhere east of the Rockies.But if the GWO stays out of phase 5 and circulates back we could very well be seeing the transition to a more Nina pattern upcoming.Not sure that will happen,some signs of it could happen tho.Have to wait and see

Yes,you can just as well follow the GWO just as well. https://journals.ametsoc.org/doi/10.1175/MWR-D-15-0289.1?mobileUi=0

Subsurface has cooled recently.Surface temps have rose recently which seemingly is by Kelvin and MJO.The Euro shows the MJO going into the IO then gradually lose the signal,we'll see if this is right because there seems to be signals the MJO will get into the Maritime stronger than the Euro shows today

Looking like lots of volatility in the upcoming pattern trying to figure out the mid range into the long range,The trough is coming off East Asia today which already looks like a cluster mess, so it looks like we'll see all kinda of changes upcoming

See what happens,the GFS has already shifted the Upper level ridge further east tonight and shows a stronger system,just timing

Like Jeff mentioned in his post on the 5th.The Upper level Ridge is fixing to get kicked out to the east around the middle of next week.Right now the Euro and GFS both has a system coming off the Lee.Like always at this range in time we'll have to keep watching, but right now seemingly we should be looking at some possible strong storms towards the end of the work week into the weekend time frame.

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Thu Mar 12 2020 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEASTERN MISSOURI AND NORTHEASTERN ARKANSAS TO PARTS OF THE LOWER OHIO VALLEY...NORTHERN TENNESSEE AND CENTRAL KENTUCKY... ...SUMMARY... The greatest severe-weather threat will be during the day from the eastern Ozarks region to the lower Ohio Valley and central Kentucky, featuring tornadoes, damaging wind and isolated large hail. ...Synopsis... In mid/upper levels, a strong shortwave trough now over the Gulf of Alaska will move southeastward and amplify, approaching the coastal Pacific Northwest by 12Z tomorrow. As this occurs, a persistent/ cut-off cyclone now offshore from southern CA and northern Baja will pivot northeastward across southern CA and the lower Colorado River Valley tonight. In the northern stream, a series of closely associated vorticity maxima and shortwaves will cause an eastward shift of a synoptic trough now extending from north-central Canada to the central Rockies. By 12Z, this should evolve into a strong/closed cyclone over northern ON north or northeast of Lake Superior, with cyclonic flow southward to the Ohio Valley. Surface analysis at 11Z depicted a low near FSD with cold front arching southwestward over northeastern CO, then into southern WY. Another low was located over central KS near GBD, with warm front east-southeastward over the Ozarks western/mid TN, and the Carolinas. The northern low should move northeastward to near Lake Superior and deepen considerably by 00Z in response to mid/upper- level cyclogenesis. Meanwhile, the southern low should become a triple-point feature as the cold front catches up, and is expected to shift east-northeastward across central/southern MO to southeastern IL by 00Z. The warm front then should extend across parts of IN/OH and northern WV. Convective boundaries may exist south of the warm front, with more baroclinicity. The cold front should extend across southeastern MO, southeastern OK and northwest TX. By 12Z, the cold front should reach southern PA, middle TN the Arklatex region, and the southern TX Panhandle, with little or no movement over the southern High Plains. ...Ozarks to central KY/northern TN and north TX... Multiple episodes of severe thunderstorms are possible today, most concentrated in and near the "enhanced risk" area, from mid/late morning through afternoon. Supercells and organized multicells are expected, with the potential for a few supercells to mature/persist long enough for a tornado threat. Significant/EF2+ rated tornadoes may occur. Large hail is possible, especially from supercells, and with modes potentially becoming clustered or messy with time, the wind-damage potential will extend farther eastward. The severe threat will extend down the front across AR to parts of north TX, but in briefer, less-organized fashion with southwestward extent. Activity is expected to develop initially in a zone of strong low-level theta-e advection, south of the warm front and southeast of the cold front, with MUCINH weakening as the warm sector destabilizes from both that effect and weak diabatic surface heating. Sustained surface-based parcels are uncertain with this activity, especially in middle/northern parts, given its position on the northern rim of the warm sector in a low-CAPE, moderate to strong-shear setting. A second round of storms will form along the surface cold front with access to greater CAPE and perhaps stronger shear as well. Buoyancy generally will decrease northward through the warm sector. By contrast, hodograph sizes increase, in concordance with: 1. More-backed surface winds nearer to the warm front, and 2. A LLJ strengthening to 50-60 kt through the day, as part of the mass response to the strong trough passing north of the area. That trough also will tighten height gradients and boost deep shear, rendering 45-50-kt effective-shear magnitudes in forecast soundings in the "enhanced" area, weakening southward as pre-cold-frontal flow becomes weaker and more-veered in the boundary layer. A narrow corridor of theta-e advection ahead of the cold front, combined with diurnal heating and relatively steep midlevel lapse rates, will support a ribbon of 1000-2000 J/kg MLCAPE, transitioning to pockets of 500-1000 J/kg MLCAPE south of the warm front as far east as the southern Appalachians, away from areas of persistent convection. ...West-central/southwest TX late tonight... Isolated, perhaps widely scattered thunderstorms may develop overnight -- especially after 06Z. The main concerns would be large hail and damaging gusts. Large-scale ascent will increase across this area the last several hours of the period in two ways: 1. Early-stage mass response to the approaching Pacific perturbation -- a corridor of elevated low-level warm/moist advection from the Rio Grande Valley. 2. Shots of DCVA related to small-scale perturbations (some convectively induced/enhanced back across northwestern MX) ejecting out of the cyclone within southwest flow. Air-mass recovery above a relatively shallow/stable surface layer may support MUCAPE in the 300-700 J/kg range, amidst 40-55-kt effective-shear magnitudes. Enough residual subcloud drying may persist to support gusts intense enough to penetrate to the surface. Hail is possible, though buoyancy and lapse rates do not appear to support more than marginally severe hail. Concentration of convection in this regime is uncertain, with the potential very conditional. Still, a consistency of synoptic and convection- allowing guidance indicates non-negligible potential for a sustained thunderstorm or two developing in a favorable environment, compelling extension of marginal unconditional probabilities into the region at this cycle. Activity may get as far as north-central TX by the end of the period. ...Portions of AZ/southeastern CA... Widely scattered to scattered thunderstorms should develop from midday through this afternoon and evening, in an arc of strong large-scale lift across northern Baja, southeastern CA and northwestern Sonora. Isolated severe hail/gusts are possible. This activity should move northwestward over parts of southern CA, northward to northeastward over parts of AZ, beneath correspondingly, strongly difluent mid/upper-level flow east of the cyclone. Antecedent moist advection from subtropical latitudes has resulted in anomalously rich low-level moisture, manifest as 50s to 60s F surface dew points across this region. In concert with continued warm advection and muted diabatic heating beneath the cloud cover, this should yield surface-based effective-inflow parcels across much of the region. Peak MLCAPE will be highly variable (300-1000 J/kg, locally higher) amidst favorably strong mid/upper winds and cloud-layer shear. Mostly multicellular mode is expected, though an isolated supercell or two may occur given the presence of marginal effective shear and low-level SRH in a few forecast soundings.

Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Wed Mar 11 2020 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE OZARKS TO THE LOWER OHIO VALLEY/MID-SOUTH VICINITY... ...SUMMARY... Severe thunderstorms are possible across parts of the lower Ohio Valley and Mid South into parts of the southeastern Plains Thursday afternoon and evening. ...ArkLaTex Vicinity to the Ohio/Tennessee Valley Region... A shortwave impulse embedded in larger-scale upper trough over the central U.S. will deepen and eject eastward from the central Plains to the Great Lakes on Thursday. The main surface low associated with this system will track eastward across Ontario with a surface cold front extending south/southwest from the Upper Midwest to western portions of the southern Plains during the morning. A warm front will extend eastward from a weak surface low over northern OK into northern AR/western TN early Thursday, lifting northward toward the Ohio River during the day. Strong warm advection ahead of the east/southeastward progressing cold front will allow low-to-mid 60s F dewpoints to overspread the south-central U.S. from eastern OK/TX into parts of KY/TN. Surface heating likely will be limited by cloud cover and areas of ongoing showers, and strong warm advection between 850-700 mb will result in pockets of stronger capping. However, a 40-50 kt southwesterly low level jet will develop by late afternoon/early evening and pockets of MLCAPE up to 1000 J/kg are forecast along/just ahead of the cold front/triple point near the MO/AR border southwestward into southeast OK, as well as eastward near the warm front across KY/TN. Semi-discrete cells in the warm sector are possible initially, but clusters are expected to grow upscale into during the evening as vertical shear become aligned with the frontal boundary. All severe hazards appear possible, with hail more likely earlier in storm evolution where midlevel lapse rates are expected to range from 7-7.5 C/km across western portions of the Slight risk area. SRH values greater than 250 m2/s2, and enlarged low level hodographs will support tornado potential in both discrete cells and within any bowing line segments. Furthermore, intense low level wind field will support damaging winds through the evening hours as convection spreads eastward into the OH/TN Valley vicinity. ...Central/Southern Appalachians Vicinity... Several forecast models indicate isolated storms may develop across parts of northern GA into Upstate SC/western NC. Dewpoints in the lower 60s will increase across the region, and backed southeasterly surface winds are forecast as a surface trough develops near higher terrain. There is indication that subtle impulses will eject across the region ahead of the main upper trough, leading to weak upper forcing and low level convergence along the surface trough. Stronger heating is likely this far east, and MLCAPE could climb to near 1000 J/kg with marginal low-to-mid level lapse rates forecast withing an adequately sheared environment. While conditional, any cells that develop could pose a risk for marginal hail/gusty winds. ...Lower Colorado Valley Vicinity... An upper low off the coast of southern CA will pivot eastward toward the Lower CO Valley on Thursday. Surface dewpoints near 60F will spread northward along the CA/AZ border beneath steep midlevel lapse rates. Low level shear will be weak, but effective shear will support some organized cells with strong flow expected in mid and upper levels. Instability will be limited, but a couple of strong cells are possible. If trends continue, probability may become warranted in later outlooks, mainly for a marginal hail risk. ..Leitman.. 03/11/2020

Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CDT Wed Mar 11 2020 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY AFTERNOON AND EVENING ACROSS PARTS OF SOUTHEAST MISSOURI AND NORTHEAST ARKANSAS INTO SOUTHERN ILLINOIS...SOUTHERN INDIANA...WESTERN AND CENTRAL KENTUCKY...WESTERN AND MIDDLE TENNESSEE AND PARTS OF ADJACENT NORTHERN MISSISSIPPI... ...SUMMARY... Severe thunderstorms are possible across parts of the lower Ohio Valley and Mid South into parts of the southeastern Plains Thursday afternoon and evening. ...Synopsis... Amplifying mid/upper flow characterized by increasingly prominent blocking appears likely to continue to evolve across the eastern Pacific during this period. To the southeast of a building high, becoming centered near the western Gulf of Alaska, a significant short wave trough is forecast to evolve and dig to the west of the British Columbia coast. As this proceeds, models indicate that a downstream mid-level low, initially to the southwest of the southern California coast, will finally begin to slowly accelerate east-northeastward into parts of the Southwest. In advance of the low, downstream mid-level ridging will attempt to build across the southern Rockies through the southern and central Plains and lower/middle Mississippi Valley. However, this may initially be suppressed by a vigorous short wave trough advancing through a more progressive branch of westerlies, from parts of the northern Plains through the Great Lakes by late Thursday night. This interaction may be one source of considerable spread that has been evident among the various models and their respective ensembles, but this spread appears to be decreasing. While guidance indicates that strongest mid-level jet streak (intensifying in excess of 100 kt at 500 mb) will dig through the mid Missouri Valley before nosing eastward across southern portions of the Great Lakes region, another speed maximum (around 50-70 kt at 500 mb) may develop across the central Plains before propagating eastward into the lower Ohio Valley. Models suggest that the southern jet streak may be accompanied by a developing surface low, near the intersection of a cold front trailing the primary cyclone migrating across Ontario, and an initially stalled remnant frontal zone extending across the southern Mid Atlantic coast through the Ozark Plateau and south central Plains at 12Z Thursday. The latter boundary may advance northeastward into the lower Ohio Valley ahead of the secondary low, accompanied by low-level moistening and destabilization in the presence of strengthening vertical shear and large-scale ascent. ...Lower Ohio Valley into Southeastern Plains... In association with the mid-level perturbation, models indicate that a west-southwesterly 850 mb jet will nose from the Ozark Plateau through Kentucky and Tennessee, while strengthening from 30-50+ kt, Thursday afternoon through Thursday night. This is expected to support the northeastward advection of a fairly moist boundary layer, characterized by surface dew points in the lower 60s, which may become supportive of CAPE in excess of 500 J/kg, despite fairly modest mid-level lapse rates and the possibility of limited surface heating. Discrete storms may initiate near the Missouri/Arkansas border Thursday afternoon before spreading eastward and intensifying in the presence of strong deep-layer and low-level shear. This may include a few supercells which could pose a risk for tornadoes in addition to severe hail and locally damaging wind gusts. Eventually large-scale forcing for ascent may support an upscale growing and organizing convective system across western into central Kentucky, and adjacent portions of southern Illinois and Indiana, as well as western and middle Tennessee by Thursday evening. This probably will be accompanied by increasing potential for damaging wind gusts, and continuing risk for a couple of tornadoes, before activity weakens during the late evening or overnight. While the main cluster of storms spreads through the lower Ohio Valley Thursday evening, at least scattered additional strong to severe thunderstorms may develop southwestward toward the southeastern Great Plains, where boundary-layer CAPE may be larger, but forcing for ascent weaker ahead of the cold front. ..Kerr.. 03/11/2020

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Wed Mar 11 2020 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER MS VALLEY INTO THE CENTRAL GULF COAST STATES... ...SUMMARY... Strong to severe thunderstorms may impact parts of the Ozarks into the Mid-South, lower Mississippi Valley, and central Gulf Coast states today. Isolated damaging winds and large hail may occur, along with a couple tornadoes. ...Ozarks into the Mid-South and Lower Mississippi Valley... A small cluster of thunderstorms will likely be ongoing at the start of the period later this morning across northwestern AR and adjacent southern MO. This convection is expected to continue southeastward across AR and into parts of the Mid-South through the early afternoon in tandem with a 30-40 kt southwesterly low-level jet. These storms will eventually encounter greater low-level moisture across central/southern AR and northern MS as they cross a surface warm front. The potential for strong/gusty winds to reach the surface and produce isolated damage should also gradually increase as diurnal heating occurs ahead of the storms. The southwesterly low-level jet is forecast to gradually weaken through the afternoon as stronger forcing for ascent associated with a large-scale upper trough shifts eastward across the OH/TN Valleys and away from the lower MS Valley. Still, strong northwesterly mid-level flow (50+ kt at 500 mb) will remain over this region, which should support similar values of effective bulk shear. There may be some chance for the bowing cluster to evolve into a broken line of supercells by late morning/early afternoon before the low-level jet weakens substantially. If this occurs, then isolated large hail and perhaps a couple tornadoes would be possible, mainly across parts of eastern AR into northern MS where somewhat greater low-level moisture should be present. Otherwise, mainly an isolated severe hail/wind threat may continue into parts of northern/central AL through the early evening before instability wanes with eastward extent.

Pretty sure this has been updated,i'll double check in a few days,but this should be "JAS"

We shall see.Today, there looks to be a ERW moving along the IDL with Kelvin so this is what the RMM'S show the MJO INTO 5 today and should be the next couple days.There seems to be all kinds of mixed signals afterwards.There still looks as there will be some better blocking into the GOA in the Mid to long range,this should choke off the theta into the Valley during this time unless something changes so more than likely as the theta returns it should be more into the plains as the Mid level heights should rise into the Valley Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Sun Mar 08 2020 Valid 111200Z - 161200Z ...DISCUSSION... Medium-range model output continues to indicate that mid/upper flow over the eastern Pacific may continue to evolve toward a more prominent blocking regime late this coming work week through next weekend. This may include the development of large-scale troughing and an embedded close low, which could eventually encompass much of the West. As this commences, the remnants of a preceding mid-level closed low may finally emerge from the Southwest. After accelerating east-northeast of the southern Rockies on Friday, guidance suggests that the lead perturbation will undergo considerable weakening and deformation within a confluent regime to the north of prominent subtropical ridging centered over the southern Gulf basin. Furthermore, it appears that this may be preceded by a substantive reinforcing cold intrusion across much of the nation to the east of the Rockies. And any subsequent wave development along the front across the southern tier of the U.S. is currently forecast to remain weak. While destabilization along and particularly above/to the cool side of the surface front may contribute to considerable thunderstorm development during the latter half of the period, severe weather potential currently appears best characterized as "low", with probabilities less than 15 percent. However, it is still possible that this could change in later outlooks much closer to this time period. ..Kerr.. 03/08/2020

NMME'S