jaxjagman Posted April 30, 2017 Author Share Posted April 30, 2017 If the 2nd line does develop though east of the Ms River though,could be some supercells develop west of Nashville with diurnal heating,SREF shows some 45% supercells late in the afternoon as the SPC mentions above ssippi Valley to western slopes of the Appalachians... Taking into account the preceding discussion, uncertainties seem too large to allow for more than an outlook of a categorical slight risk at the present time. But given the strength of the synoptic system and associated wind fields, and at least a corridor of pre-frontal boundary layer moisture characterized by surface dew points in the mid 60s to near 70F, it may not be out of the question that a window of opportunity for considerable severe weather potential could develop this afternoon and evening. This seems mostly likely to be focused near or just east of the Mississippi Valley, and mostly in the wake of an initial north/south oriented band or two of thunderstorms spreading east of the Mississippi Valley, where guidance appears suggestive that breaks in the overcast could allow insolation to contribute to at least pockets of mixed layer CAPE on the order of 1000-2000 J/kg. Of particular concern is that the environment could become conducive to at least isolated to widely scattered long lived discrete supercell development, initially anywhere from portions of eastern Missouri into Illinois, southward through portions of western Kentucky and Tennessee into northern Mississippi. In the presence of clockwise curved low-level hodographs characterized by strong to extreme shear, some of these could become capable of producing strong tornadoes. Link to comment Share on other sites More sharing options...
samadamsuk Posted April 30, 2017 Share Posted April 30, 2017 On 29/04/2017 at 2:30 AM, jaxjagman said: Welcome to the Tn Valley.Nice to see neighbors across the pond,think you're the first to post here. Hey Jaxjagman, thanks for the welcome - great forum! thanks, Samos Link to comment Share on other sites More sharing options...
jaxjagman Posted April 30, 2017 Author Share Posted April 30, 2017 Should be some strong storms in Mid Tn mid afternoon if the HRRR is anywhere correct Link to comment Share on other sites More sharing options...
jaxjagman Posted April 30, 2017 Author Share Posted April 30, 2017 Mesoscale Discussion 0614 NWS Storm Prediction Center Norman OK 0121 PM CDT Sun Apr 30 2017 Areas affected...northeast Alabama...northwest Georgia...middle Tennessee into extreme southern Kentucky Concerning...Severe potential...Watch likely Valid 301821Z - 301915Z Probability of Watch Issuance...80 percent SUMMARY...Threat for isolated damaging wind and a couple of tornadoes is expected to increase this afternoon over middle Tennessee into southern Kentucky. Also additional storms farther west across north central AL should eventually move into northeast AL and northwest GA. A ww will likely be issued downstream from ww 182 prior to 19Z. DISCUSSION...Early this afternoon a band of convection extends across the western portions of middle TN with more organized activity farther south into northern AL. The downstream atmosphere is only marginally unstable with widespread clouds slowing diabatic warming of the boundary layer. Nevertheless, as temperatures slowly warm through the 80s F MLCAPE from 500-1000 J/kg will become sufficient to support at least a modest threat for organized storms given strengthening deep-layer, unidirectional winds, 30-40 kt effective bulk shear, and around 200 m2/s2 0-1 km storm relative helicity based on current storm motions. The convection is expected to gradually increase or maintain intensity as it develops east next few hours. Storms may organize with embedded meso-vortices and bowing segments posing a risk for isolated damaging wind and a couple of tornadoes. Link to comment Share on other sites More sharing options...
samadamsuk Posted April 30, 2017 Share Posted April 30, 2017 Hey all, Looking juicy out there! ESRH looks to be 200-400+ , with some good cape - what's anyone's thoughts on whether anything discrete will develop? I can see some divergence aloft over KY and a weakening cap there - thanks, Samos Link to comment Share on other sites More sharing options...
nrgjeff Posted May 1, 2017 Share Posted May 1, 2017 Low level shear was excellent on Sunday but deep shear was pretty unidirectional. Friday was a colossal waste of CAPE and lifting boundary, but with the awful cap and rising heights. Warm air aloft rushed in with the same efficiency as in winter, lol! Link to comment Share on other sites More sharing options...
jaxjagman Posted May 1, 2017 Author Share Posted May 1, 2017 3 hours ago, nrgjeff said: Low level shear was excellent on Sunday but deep shear was pretty unidirectional. Friday was a colossal waste of CAPE and lifting boundary, but with the awful cap and rising heights. Warm air aloft rushed in with the same efficiency as in winter, lol! Waste of a storm indeed,could have been worse .Sad news is all the lives lost.:( Link to comment Share on other sites More sharing options...
Blue Ridge Posted May 15, 2017 Share Posted May 15, 2017 Quote ...NWS DAMAGE SURVEY FOR 05/12/17 TORNADO EVENT SHADY VALLEY TN .SHADY VALLEY TORNADO... Rating: EF-0 Estimated Peak Wind: 80 mph Path Length /Statute/: 0.15 miles or 250 yards Path Width /Maximum/: 40 yards Fatalities: 0 Injuries: 0 Start Date: 05/12/2017 Start Time: 02:30 PM EDT Start Location: Unincorporated Town Of Shady Valley TN Start Lat/Lon: 36.5211/-81.9314 End Date: 05/12/2017 End Time: 02:38 PM EDT End Location: Unincorporated Town Of Shady Valley TN End Lat/Lon: 36.5208/-81.9291 Survey Summary: This was a very small and brief tornado that remained on the ground for less than 8 minutes and 250 yards while causing widespread roof damage to two homes, as well as completely destroying two sheds and a carport structure. Everyone interviewed stated that the system was rain shielded thereby not allowing anyone an opportunity to witness it. Storm moved almost due east dropping out of the Holston Mountains and into the valley floor below where the brief EF-0 spun up before falling apart into a straight line wind event with estimated winds of 50-70 mph for another 1/4 mile. The straight line winds also caused some minor roof damage as well as completely destroying an aging barn. Talk about unexpected. Link to comment Share on other sites More sharing options...
Carvers Gap Posted May 17, 2017 Share Posted May 17, 2017 On 5/15/2017 at 9:35 AM, Blue Ridge said: Talk about unexpected. Out of the blue! Link to comment Share on other sites More sharing options...
nrgjeff Posted May 20, 2017 Share Posted May 20, 2017 Decent tornado if 250 yards wide for 8 minutes. Remember average time OTG is only 10 minutes. Their language downplays it I suppose because it's only EF-0. Seems unchasable given witnesses all say hidden in rain. Glad nobody hurt! Link to comment Share on other sites More sharing options...
Blue Ridge Posted May 22, 2017 Share Posted May 22, 2017 On 5/20/2017 at 9:35 AM, nrgjeff said: Decent tornado if 250 yards wide for 8 minutes. Remember average time OTG is only 10 minutes. Their language downplays it I suppose because it's only EF-0. Seems unchasable given witnesses all say hidden in rain. Glad nobody hurt! Was out of town but monitoring radar when the warning was issued. Velocity showed a definitive couplet for 5-6 scans prior to warning issuance. Looks like touchdown occurred roughly 10 min after the warning. Per reflectivity, it was certainly wrapped in rain. Side note: I have clients in the Mountain City community. After the 2011 EF2, they're terrified of strong storms. Ominous clouds all scream "tornado" to them. Hate that another tornado struck there. Link to comment Share on other sites More sharing options...
jaxjagman Posted May 24, 2017 Author Share Posted May 24, 2017 Mesoscale Discussion 0824 NWS Storm Prediction Center Norman OK 0641 AM CDT Wed May 24 2017 Areas affected...Northeast Alabama...eastern Tennessee...northwest Georgia...eastern Kentucky Concerning...Severe potential...Watch possible Valid 241141Z - 241415Z Probability of Watch Issuance...40 percent SUMMARY...Storms should continue to gradually develop through the morning and early afternoon, with an isolated tornado, strong wind gusts and marginal hail possible. DISCUSSION...Storms are beginning to intensify ahead of a strong vort max aloft. Although instability is weak, it may be sufficient for at least isolated severe storms given cooling aloft and strong lift with deepening surface low. Visible satellite imagery shows extensive cloudiness is present downstream of these storms, which may temper their severity somewhat. However, as storms lift northeastward out of Alabama and across Tennessee and into Kentucky, some diurnal intensification is expected. Trends will continue to be monitored for a possible watch. Link to comment Share on other sites More sharing options...
nrgjeff Posted May 24, 2017 Share Posted May 24, 2017 Check of the 12Z Nam shows the LLJ pushing east to Chattanooga and Nashville by midday. It might still be present in the eastern Valley, TYS to MRX and TRI, later today. Upper pattern has a little VBV, but a decent LLJ would create more than adequate turning with height. East Kentucky could be interesting right east of the surface low, but oh that terrain LOL. ATMO is getting overturned and the main show is to our southeast. Well, they said that in Kansas Saturday and a mesocyclone lasted two hours behind the CF with multiple brief tornado touchdowns. We're not in Kansas, but it is still late May... Link to comment Share on other sites More sharing options...
yoda Posted May 24, 2017 Share Posted May 24, 2017 Tornado Watch coming shortly for TN/KY -- http://www.spc.noaa.gov/products/md/md0828.html Link to comment Share on other sites More sharing options...
yoda Posted May 24, 2017 Share Posted May 24, 2017 URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 264 NWS Storm Prediction Center Norman OK 115 PM EDT Wed May 24 2017 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of central and eastern Kentucky western North Carolina eastern Tennessee southwestern Virginia * Effective this Wednesday afternoon and evening from 115 PM until 800 PM EDT. * Primary threats include... A couple tornadoes possible Isolated damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms now forming near an upper disturbance over northern middle Tennessee are expected to increase in coverage and intensity through the remainder of the afternoon, while developing northeastward and eastward across the watch area. Large hail and locally damaging wind gusts will be possible in strongest storms, along with a risk for tornadoes. The tornado watch area is approximately along and 105 statute miles north and south of a line from 40 miles west northwest of Crossville TN to 40 miles southeast of Jackson KY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). Link to comment Share on other sites More sharing options...
nrgjeff Posted June 14, 2017 Share Posted June 14, 2017 Slight chance (risk) of anything interesting in Tennessee on Thursday. Models continue to settle on a solution of one or two MCS(s) with some straight line wind potential. It will be nothing like May 27. Derecho checklist is not met Thursday. WAA is missing at 850/700 mb. Height falls are not great enough at 500 mb. Speed lacks at 200 mb. Do not need much, but this is pathetic June gloom, lol. Road to a better set-up might be a CIV (convectively induced vort max) coming out of the Plains or Mississippi Valley overnight. Otherwise I think 1-2 MCSs seems reasonable given the instability and boundaries left over from previous rain. If CAMs converge on a more likely corridor ENH risk for straight winds would not surprise me. I cannot see anything higher though. On the flip side there is a road to Marginal. Too much midday convection ahead of any MCS would stabilize/overturn the atmosphere, #2017ing in some circles. Morning update: And sure enough 2017ing. Rain from Nebraska to South Carolina. Hopefully it is not the case August 21. Link to comment Share on other sites More sharing options...
jaxjagman Posted June 17, 2017 Author Share Posted June 17, 2017 On 6/14/2017 at 11:49 AM, nrgjeff said: Slight chance (risk) of anything interesting in Tennessee on Thursday. Models continue to settle on a solution of one or two MCS(s) with some straight line wind potential. It will be nothing like May 27. Derecho checklist is not met Thursday. WAA is missing at 850/700 mb. Height falls are not great enough at 500 mb. Speed lacks at 200 mb. Do not need much, but this is pathetic June gloom, lol. Road to a better set-up might be a CIV (convectively induced vort max) coming out of the Plains or Mississippi Valley overnight. Otherwise I think 1-2 MCSs seems reasonable given the instability and boundaries left over from previous rain. If CAMs converge on a more likely corridor ENH risk for straight winds would not surprise me. I cannot see anything higher though. On the flip side there is a road to Marginal. Too much midday convection ahead of any MCS would stabilize/overturn the atmosphere, #2017ing in some circles. Morning update: And sure enough 2017ing. Rain from Nebraska to South Carolina. Hopefully it is not the case August 21. Nothing much happened here.Some winds maybe 20-30.Some nice rain though with numerous lightning strikes around.Wind shear was weak as you mentioned. Link to comment Share on other sites More sharing options...
nrgjeff Posted June 18, 2017 Share Posted June 18, 2017 We had a good shelf cloud in Chattanooga on Thursday. However the GOES-16 vis loop from the day is probably more fun to watch. Today (Sunday) looks similar. Nah, it sucked. This is one of the least inspiring severe seasons I can remember. Link to comment Share on other sites More sharing options...
nrgjeff Posted June 21, 2017 Share Posted June 21, 2017 Cindy keeps severe hope alive. From SPC Day 2 valid Thursday: ...ArkLaMiss and surrounding region... Models indicate a zone of stronger low and deep-layer shear will spread north in association with the migration of the northeast quadrant of Cindy---resulting in a conditional risk for mini supercells capable of isolated tornadoes. Models vary considerably but some convection-allowing model guidance indicates cellular storms developing within a corridor of 500-1250 J/kg MLCAPE with enlarged hodographs. A couple of tornadoes are possible with the stronger/more persistent low-level mesocyclones. I agree with the outside risk for something more than typical mini-sups with tropical systems. If clouds break up in Mississippi, as forecast between the cyclone and the slug of moisture into Alabama, instability will verify. Much of the wind shear is of course the LLJ, and it is somewhat unidirectional above. However NWP hints a just a bit of veering at the upper levels. If the upper levels can veer 30-40 degrees from the LLJ, hodographs would elongate. We'll see if all this happens. NWP may be allowing too much influence from the upper level westerlies to the north. If NWP is right though, Thursday could indeed feature a couple real mesocyclones. Link to comment Share on other sites More sharing options...
mempho Posted June 23, 2017 Share Posted June 23, 2017 Possible brown ocean effect tonight with Cindy? Sent from my SM-G900R7 using Tapatalk Link to comment Share on other sites More sharing options...
jaxjagman Posted June 23, 2017 Author Share Posted June 23, 2017 Finally Comcast is up and running here this afternoon.Been running slow as a turtle for past few days.Every time a tried to post i'd freeze up it's been so slow. Not much of any severe here.Little bit of wind and rain other than that ...blah Link to comment Share on other sites More sharing options...
nrgjeff Posted June 25, 2017 Share Posted June 25, 2017 Cindy was a total loss up here. Birmingham tornado had decent contrast Thursday, for a tropical grungefest. Friday was lining up well in Alabama, but of course 2017'ed into Tenn. Oh Comcast! Thank God we have EPB Fiber from our local power company. Tennessee legislature needs to stop blocking more municipal fiber projects. City's rights! Link to comment Share on other sites More sharing options...
Blue Ridge Posted June 26, 2017 Share Posted June 26, 2017 Narrow, weak squall line formed as the foremost portion of rain moved through Friday evening. No thunder, just enhanced winds (gusts 40+). Looked like half of the Bluegrass State was under a FFW at one point. Re: internet, my parents reside in Erwin, TN, where the local utility is rolling out gig fiber service. Prior to this, Comcast was the only game in town. Think I have finally convinced them to ditch Comcast and switch... Link to comment Share on other sites More sharing options...
Carvers Gap Posted July 27, 2017 Share Posted July 27, 2017 Anyone have the timing for the rain/storms for NE TN tomorrow? When is the fropa? Link to comment Share on other sites More sharing options...
jaxjagman Posted August 26, 2017 Author Share Posted August 26, 2017 Looking ahead into next year,spring time.Jamstec is showing a Nina that develops early into spring time lasting into 2019 #yucknextspring# Link to comment Share on other sites More sharing options...
nrgjeff Posted August 28, 2017 Share Posted August 28, 2017 Day ahead high-res models choked. Flooding rain is in progress in Jackson, Tenn. plus points west and east just north of I-40. Trouble is a northern stream short wave interacting with another departing jet max. Mid-level convergence is strong. WPC_Metwatch_750 Monday 28 Aug. Link to comment Share on other sites More sharing options...
jaxjagman Posted August 29, 2017 Author Share Posted August 29, 2017 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Tue Aug 29 2017 Valid 311200Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE TENNESSEE/MISSISSIPPI/ALABAMA REGION AND VICINITY... ...SUMMARY... Risk for a couple of tornadoes will likely persist Friday across parts of the central Gulf Coast states and into the Tennessee Valley, in association with tropical system Harvey. ...Synopsis... The western ridge/eastern trough upper pattern is forecast to become temporarily disturbed, as a short-wave trough crossing the northern Intermountain region begins to dig southeast into the Plains, while at the same time Harvey shifts slowly northeast across the lower Mississippi -- and later the Tennessee -- Valleys. Otherwise, a cold front is forecast to move east across the Northeast/New England and south across the Ohio Valley and central Plains region. ...Tennessee/Mississippi/Alabama and parts of surrounding states... As tropical system Harvey continues moving slowly northeast across the lower Mississippi Valley toward the Tennessee Valley area while gradually weakening, low-level shear within the northeast quadrant of the broad low-level circulation will remain sufficiently strong to support risk for a few tornadoes. Risk should shift gradually northeast in conjunction with Harvey's motion, away from the coast and eventually spreading into the Mid South region. Link to comment Share on other sites More sharing options...
nrgjeff Posted August 29, 2017 Share Posted August 29, 2017 Wednesday through Friday high low level helicity will present the risk for isolated tornadoes. SPC is right that Wednesday lapse rates may be a little weak. 12Z NAM amps up Thursday, but it is the NAM. Friday disco is above. Tropical cyclones don't have fronts, is a myth over land. Harvey will interact with the left overs of a boundary that will lift from the Gulf Coast. These low dewpoints are nice, unless the retreating boundary goes ape crazy Thursday. More likely it'll be a slop fest with only a couple tornadoes. This is still Dixie. However the helicity and low level shear will be there. Previous tropical system produced in Alabama and Tennessee. This one may be similar. One thing slightly more potent here is the true retreating boundary. Progs have 850 down to surface more backed. However, the cyclone will be a week old which should mitigate the above. Hopefully I'm here tomorrow to discuss. Had to drop the hammer in Southeast, but it was justified. Link to comment Share on other sites More sharing options...
jaxjagman Posted August 29, 2017 Author Share Posted August 29, 2017 1 hour ago, nrgjeff said: Wednesday through Friday high low level helicity will present the risk for isolated tornadoes. SPC is right that Wednesday lapse rates may be a little weak. 12Z NAM amps up Thursday, but it is the NAM. Friday disco is above. Tropical cyclones don't have fronts, is a myth over land. Harvey will interact with the left overs of a boundary that will lift from the Gulf Coast. These low dewpoints are nice, unless the retreating boundary goes ape crazy Thursday. More likely it'll be a slop fest with only a couple tornadoes. This is still Dixie. However the helicity and low level shear will be there. Previous tropical system produced in Alabama and Tennessee. This one may be similar. One thing slightly more potent here is the true retreating boundary. Progs have 850 down to surface more backed. However, the cyclone will be a week old which should mitigate the above. Hopefully I'm here tomorrow to discuss. Had to drop the hammer in Southeast, but it was justified. Tell us how you really feel .Remind me not to ever piss you off Link to comment Share on other sites More sharing options...
Carvers Gap Posted August 29, 2017 Share Posted August 29, 2017 1 hour ago, jaxjagman said: Tell us how you really feel .Remind me not to ever piss you off Yeah, man. LOL. I am kind of scared fo talk about the PDO now. Link to comment Share on other sites More sharing options...
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