jaxjagman Posted April 12, 2020 Share Posted April 12, 2020 9 minutes ago, nrgjeff said: Moderate rain moving into Chattanooga. Looking forward to a relaxing stable evening... Just kidding! WF is trying to lift north, but I just can't get excited with my heat pump on while I'm wearing full sweats. Real concerns remain from Mississippi through Alabama and perhaps Georgia though. Warm sector gonna be lit, though very sloppy. Yeah keep seeing some strong inversion setting into the Valley soon by both the HRRR and RAP 1 Link to comment Share on other sites More sharing options...
jaxjagman Posted April 12, 2020 Share Posted April 12, 2020 Have to wait and see but if the lid isn't that strong as advertised or breaks sooner.HREF shows some half way decent updrafts if its to be believed Link to comment Share on other sites More sharing options...
jaxjagman Posted April 12, 2020 Share Posted April 12, 2020 Tornado around Yazoo city,go figure Link to comment Share on other sites More sharing options...
dwagner88 Posted April 12, 2020 Share Posted April 12, 2020 1 hour ago, Holston_River_Rambler said: If that QLCS holds together, the HRRR suggests that it might be making it straight for the southern/ south central parts of the eastern valley HRRR and GFS both have a significant flash flood event tonight. 6”+ qpf. 1 Link to comment Share on other sites More sharing options...
jaxjagman Posted April 12, 2020 Share Posted April 12, 2020 5 minutes ago, dwagner88 said: HRRR and GFS both have a significant flash flood event tonight. 6”+ qpf. Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1200 PM EDT Sun Apr 12 2020 Day 1 Valid 12Z Sun Apr 12 2020 - 12Z Mon Apr 13 2020 ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FROM THE MID SOUTH THROUGH PARTS OF THE TENNESSEE VALLEY TO THE SOUTHERN APPALACHIANS... ...Southern U.S / Moderate Risk Area... In the 16Z update the Moderate Risk is nearly the same as it was. We expanded coverage on the western end, over Arkansas, to account for what was an ideal heavy rain setup in the near term through 19Z as well as some wet antecedent conditions from early morning rainfall. While 00Z hi-res models did not fare well in handling the Texas MCS this morning, the expected axis of greatest rainfall totals did not change too much, as the synoptics will largely dictate that MCS activity rolls eastward along the advancing deep layer warm front, shallow upslope convection boosts totals in the Appalachians, and a separate round of moderate to heavy rain forms this evening ahead of the surface front in the Plains / Midwest. The 06Z NAM Nest had a decent handle on the Texas MCS, and many of the 12Z hi-res solutions looked well initialized. Overall, we prefer the details of the 12Z HRRR, WRF-ARW, and NAM Nest per their simulated reflectivity fields. A QPF blend using these sources and a base layer of broader resolution consensus QPF suggests the emphasis for higher-end rainfall continues to be north of the surface warm front from eastern Arkansas through southern Tennessee and all adjacent states to the south. This is essentially where a more cellular / supercellular regime transitions to one of QLCS activity with broader distribution of heavy rainfall. Rainfall will likely average 2-4 inches here, with local totals above 5 inches. Stronger capping limits the southward extent, and migration of rain-cooled air along the northern periphery limits northward extent of the heavier totals, thus giving us higher confidence in placement. The whole weather system is strongly anomalous, with the strength of the mid-level systems at play 3-4 sigmas below the mean for mid-April and a surface cyclone 4-5 sigmas below the mean -- near record values for April -- from the Mid-South into the Lower Peninsula of MI. Both Precipitable water and Integrated Vapor Transport values are near record levels for this time of year since the cyclone will drive a powerful low-level jet (approaching 80 kts) -- with effective bulk shear to match -- that will invade from the Gulf coast into the lower MS Valley, TN Valley, and southern Appalachians this period. ML CAPE is likely to build towards 3000 J/kg during the afternoon hours within the capped warm sector near LA where 700 hPa temperatures are expected to exceed 9C which should boost convective potential downstream into the evening hours. The synoptic scale system will remain progressive, which will have a tendency to cap the upper magnitude of the rainfall potential. With concerns for episodic training of convection along/near a warm front lifting north through the TN Valley/southern Appalachians, hourly rainfall totals are likely to max out in the 2-3"/hour range within mesocyclones, cell mergers, and periods of training. Swaths of the Mid-South, Southeast, and southern Appalachians shows 50%+ chance of exceeding 3" of rain this period per the 00z HREF probabilities. The 00z HREF probabilities for 5"+ maximize in southwest NC where the chances of exceedance lie above 90%. Link to comment Share on other sites More sharing options...
jaxjagman Posted April 12, 2020 Share Posted April 12, 2020 National Weather Service Nashville TN 133 PM CDT Sun Apr 12 2020 .DISCUSSION... Showers have been pounding Middle Tennessee all morning, and a line of enhanced echoes is currently making its way northward across the mid state owing a weak surface trough or a meso-low trying to spin off. The primary center of low pressure is still situated near the Ozarks, and is forecast to move into the Ohio Valley by 06Z while deepening to 991-993 mb. This will contribute to a strong pressure gradient over Middle Tennessee for several hours later this afternoon and tonight, hence the Wind Advisory. Meanwhile, the environment across Middle Tennessee remains capped, especially across the cooler northern zones. The NAM12 forecast sounding for BNA valid at 21Z shows a SBCAPE of 0, but the MUCAPE (900 mb) is nearly 500 J/Kg. The expected 0-3 SRH at the same time is a whopping 1,160 m2/s2. We never really do get any SBCAPE this far north, but the cap does erode somewhat as the surface front approaches, and MUCAPE values should increase to around 1,000 J/kg, so the lift provided by the cold front should be able to tap into that elevated instability. When combined with the enormous shear values, don`t see any need to deviate from the current severe weather messaging of damaging straight-line winds and isolated tornadoes, especially south of I-40. Actual fropa should occur between maybe 02Z and 07Z, with sharp subsidence right behind the front. The surface low passes close enough to Middle Tennessee that we will likely experience a swath of wrap- around moisture toward morning and maybe some lingering showers along the Cumberland Plateau Monday morning. Looking ahead, next week looks to be much cooler than normal with only nominal chances of rain. We could see areas of frost as late as Thursday morning. Expect a pleasant warming trend by next weekend. After tonight, we don`t see any severe weather risk at least through Saturday. Link to comment Share on other sites More sharing options...
TellicoWx Posted April 12, 2020 Share Posted April 12, 2020 18z HRRR continues increasing the UH up the valley Link to comment Share on other sites More sharing options...
jaxjagman Posted April 12, 2020 Share Posted April 12, 2020 Mesoscale Precipitation Discussion 0139 NWS Weather Prediction Center College Park MD 245 PM EDT Sun Apr 12 2020 Areas affected...Northeast LA...Central/Northern MS...Central/Southern TN...Far Northwest GA Concerning...Heavy rainfall...Flash flooding likely Valid 121845Z - 130045Z SUMMARY...Heavy showers and thunderstorms will continue to impact portions of the lower MS Valley and especially the Mid-South this afternoon and into the evening. The threat for flooding and flash flooding will remain elevated given the increasingly wet antecedent conditions, and high rainfall rate potential. DISCUSSION...The latest GOES-16 IR satellite imagery shows an impressively diffluent flow pattern aloft from the lower MS Valley to the Mid-South out ahead of an ejecting mid-level shortwave trough over the southern Plains. This along with area radars confirm an expansive area of cold-topped convection which includes vigorous severe-mode thunderstorms impacting northeast LA and west-central MS, and a notably elevated arc of heavy showers and thunderstorms to the northeast from northern MS, northern AL and through adjacent areas of western and central TN. While being aided by strong synoptic scale ascent, the convection is focusing within a highly favorable thermodynamic environment that is being facilitated by a very strong southwest low-level jet. In fact, as of 1800Z, VAD wind profiler data is depicting flow ranging in the 50 to 70 kt range at 850 mb, and 40 to 50 kts at 925 mb. This is fostering extreme low-level moisture transport and is also transporting a significant amount of warm-sector instability well north over an advancing warm front to promote and sustain the convective threat. Going through the late-afternoon and early evening hours, the greatest rainfall threat will overwhelmingly be over the Mid-South, with an emphasis on northern MS, northern AL, much of central/southern TN and gradually edging into far northwest GA. This is basically where the strongest warm-air advection, deep layer ascent will overlap with the aforementioned extreme moisture and instability transport regime. PWs of 1.75 to 2 inches are forecast, and with a nose of 1000 to 2000 j/kg of MUCAPE. However, farther down to the southwest over areas of central/northeast LA and through central MS, there will be even greater warm-sector instability and deep layer shear that will be conducive for highly organized and severe-mode convection that will in itself be capable of producing very heavy rainfall. Rainfall rates have already been locally observed over 2 inches, and this potential should continue over the next several hours with the deeper and more organized convective cores. The recent runs of the HRRR and the experimental HRRR favor swaths of as much as 2 to 4 inches of rain, with isolated totals of 5+ inches going through 00Z. Additional heavy rainfall potential will exist after 00Z over the Mid-South, with an increasing threat also spreading over the southern Appalachians. Given the increasingly wet antecedent soil conditions, especially over the Mid-South, areas of flooding and flash flooding will remain likely. Orrison Link to comment Share on other sites More sharing options...
yoda Posted April 12, 2020 Share Posted April 12, 2020 URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 109 NWS Storm Prediction Center Norman OK 320 PM CDT Sun Apr 12 2020 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northern and central Alabama Far southern Middle Tennessee * Effective this Sunday afternoon and evening from 320 PM until 1000 PM CDT. * Primary threats include... Several tornadoes and a couple intense tornadoes likely Widespread damaging winds and isolated significant gusts to 80 mph likely Isolated very large hail events to 2 inches in diameter possible SUMMARY...Clusters of severe thunderstorms will spread east-northeast from Mississippi through this evening. Greatest tornado threat will exist across west-central to north-central portions of Alabama into early evening. The tornado watch area is approximately along and 85 statute miles north and south of a line from 45 miles northwest of Tuscaloosa AL to 30 miles east northeast of Gadsden AL. For a complete depiction of the watch see the associated watch outline u Link to comment Share on other sites More sharing options...
McMinnWx Posted April 12, 2020 Share Posted April 12, 2020 Heavy rain in Athens. Link to comment Share on other sites More sharing options...
John1122 Posted April 12, 2020 Share Posted April 12, 2020 Covington MS-Jefferson Davis MS- 421 PM CDT Sun Apr 12 2020 ...TORNADO EMERGENCY FOR LOCATIONS IN THE WARNED AREA... ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CDT FOR SOUTHERN COVINGTON AND SOUTHEASTERN JEFFERSON DAVIS COUNTIES... At 420 PM CDT, a confirmed large and destructive tornado was located near Melba, or 9 miles southwest of Collins, moving northeast at 55 mph. TORNADO EMERGENCY for locations in the warned area. This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW! Link to comment Share on other sites More sharing options...
Runman292 Posted April 12, 2020 Share Posted April 12, 2020 Where is the warm front now? Link to comment Share on other sites More sharing options...
McMinnWx Posted April 12, 2020 Share Posted April 12, 2020 The Laurel, MS tornado looks to be a monster. Link to comment Share on other sites More sharing options...
EastKnox Posted April 12, 2020 Share Posted April 12, 2020 26 minutes ago, Runman292 said: Where is the warm front now? Link to comment Share on other sites More sharing options...
PowellVolz Posted April 12, 2020 Share Posted April 12, 2020 I believe there’s 2 WF. The other one is along the Tennessee boarder. The one pictured to the south is holding back the return flow where the big tornados are churning. . Link to comment Share on other sites More sharing options...
McMinnWx Posted April 12, 2020 Share Posted April 12, 2020 5 minutes ago, PowellVolz said: I believe there’s 2 WF. The other one is along the Tennessee boarder. The one pictured to the south is holding back the return flow where the big tornados are churning. . Is that other one going to lift this far north? Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted April 12, 2020 Share Posted April 12, 2020 To me it looks like there may be a piece of that airmass beyond the lower warm front that makes it into the southern valley, but it will be close to the time the main front swings through. Very heavy rain right now really working over the atmosphere. And that QLCS we were talking about earlier seems to have turned more east, rather than coming up towards Chatt, so some of the convection is perpendicular to the valley now. Hard to say with the line back in MS now though. 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted April 12, 2020 Share Posted April 12, 2020 Is that other one going to lift this far north? I don’t believe it will but it might not matter either way because the atmosphere is not mixed anymore because of all the rain. I think central Ga to SC is the new track. . 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted April 12, 2020 Share Posted April 12, 2020 To me it looks like there may be a piece of that airmass beyond the lower warm front that makes it into the southern valley, but it will be close to the time the main front swings through. Very heavy rain right now really working over the atmosphere. And that QLCS we were talking about earlier seems to have turned more east, rather than coming up towards Chatt, so some of the convection is perpendicular to the valley now. Hard to say with the line back in MS now though. I’m not even seeing the pre cold front storms that are supposed to hit after midnight across Tennessee getting going. HRRR had it, lost it and now has it again but I’m not sure it happens now. . 1 Link to comment Share on other sites More sharing options...
Runman292 Posted April 12, 2020 Share Posted April 12, 2020 1 minute ago, PowellVolz said: I’m not even seeing the pre cold front storms that are supposed to hit after midnight across Tennessee getting going. HRRR had it, lost it and now has it again but I’m not sure it happens now. . The pre cold front storms are entering Arkansas now. Link to comment Share on other sites More sharing options...
PowellVolz Posted April 12, 2020 Share Posted April 12, 2020 The pre cold front storms are entering Arkansas now.You are correct. I didn’t look far enough west. My bad. . Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted April 13, 2020 Share Posted April 13, 2020 Absolutely pouring right now. One of the heaviest rains I've ever experienced. Visibility down to >.10 mile with fog. Link to comment Share on other sites More sharing options...
PowellVolz Posted April 13, 2020 Share Posted April 13, 2020 This cell south of Chattanooga might lay down a monster . Link to comment Share on other sites More sharing options...
Uncle Nasty Posted April 13, 2020 Share Posted April 13, 2020 This is about 20 miles south of us. We are getting pelted with rain and lightningSent from my moto z4 using Tapatalk Link to comment Share on other sites More sharing options...
PowellVolz Posted April 13, 2020 Share Posted April 13, 2020 Most likely a large tornado on the ground moving towards Dalton Ga. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted April 13, 2020 Share Posted April 13, 2020 Bowing storm aiming at Dayton. The northern edge may hit me. Link to comment Share on other sites More sharing options...
Runman292 Posted April 13, 2020 Share Posted April 13, 2020 Tornado Watch for Southeast TN until 2:00 AM. Link to comment Share on other sites More sharing options...
yoda Posted April 13, 2020 Share Posted April 13, 2020 Severe Tstorm Watch coming for W TN -- https://www.spc.noaa.gov/products/watch/ww0114.html URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 114 NWS Storm Prediction Center Norman OK 820 PM CDT Sun Apr 12 2020 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Arkansas Northeast Louisiana Missouri Bootheel Northwest Mississippi Western Tennessee * Effective this Sunday night and Monday morning from 820 PM until 100 AM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Scattered large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...A fast-moving line of thunderstorms over Arkansas will track across the watch area this evening, posing a risk of damaging wind gusts and hail. Link to comment Share on other sites More sharing options...
PowellVolz Posted April 13, 2020 Share Posted April 13, 2020 Bowing storm aiming at Dayton. The northern edge may hit me. I’m wondering where the northern most WF is. I hope it didn’t make it across the valley. These storms might rotate more off of it. The line moving off the plateau has breaks and offsets which sometimes indicates mesos imbedded in the line. . Link to comment Share on other sites More sharing options...
yoda Posted April 13, 2020 Share Posted April 13, 2020 Tornado Warning Polk County in E TN Link to comment Share on other sites More sharing options...
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