Windspeed Posted August 17, 2021 Share Posted August 17, 2021 Going to resurrect this thread for the Fred and frontal related heavy rains over the eastern Tennessee Valley this week and weekend. Looks like it's going to be a mess for some folks despite a much-needed soaker. 1 Link to comment Share on other sites More sharing options...
Windspeed Posted August 17, 2021 Share Posted August 17, 2021 Latest HRRR.. Link to comment Share on other sites More sharing options...
dwagner88 Posted August 17, 2021 Share Posted August 17, 2021 34 minutes ago, Windspeed said: Latest HRRR.. That’s a big miss by the globals on the precip shield. They had it more correct 48 hours ago. Link to comment Share on other sites More sharing options...
Windspeed Posted August 17, 2021 Share Posted August 17, 2021 That’s a big miss by the globals on the precip shield. They had it more correct 48 hours ago. Yeah I hope you've got a boat. Looks like Chattanooga area totals are going to exceed forecast. Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted August 17, 2021 Share Posted August 17, 2021 Any updates from @TellicoWx NWS Morristown used this image on one of their social media platforms, even though I think it is from WATE Link to comment Share on other sites More sharing options...
Windspeed Posted August 18, 2021 Share Posted August 18, 2021 Link to comment Share on other sites More sharing options...
Windspeed Posted August 18, 2021 Share Posted August 18, 2021 Link to comment Share on other sites More sharing options...
dwagner88 Posted August 18, 2021 Share Posted August 18, 2021 Looking at our area, we have had a couple of minor mud slides in Polk and eastern McMinn counties. Eastern McMinn in particular seems to have been hit pretty hard. I can believe that 10” total from Monroe. 1 Link to comment Share on other sites More sharing options...
dwagner88 Posted August 21, 2021 Share Posted August 21, 2021 Western parts of middle TN have been hit with catastrophic flash flooding this morning. Dual pol estimates max out at over 17” of rain near McEwen TN. Link to comment Share on other sites More sharing options...
WestTennWX Posted August 22, 2021 Share Posted August 22, 2021 22 hours ago, dwagner88 said: Western parts of middle TN have been hit with catastrophic flash flooding this morning. Dual pol estimates max out at over 17” of rain near McEwen TN. There is a tragedy unfolding in Humphreys county as we speak. 15 now confirmed dead, and dozens still missing. Many of the dead and missing are children. Not a lot of media coverage on this, unfortunately. Some of the photos coming out of Waverly are just breathtaking. NWS Nashville recorded a record shattering 17.02 inches of rain in a 24 hour period. Some of the worst Flash Flooding I have ever seen. https://www.radionwtn.com/2021/08/22/death-toll-climbs-many-missing-in-flood-emergency-area-first-responders-on-scene/ https://www.newschannel5.com/news/photos-heavy-rainfall-causes-severe-flooding-in-middle-tennessee#id33 1 Link to comment Share on other sites More sharing options...
Witness Protection Program Posted August 23, 2021 Share Posted August 23, 2021 Take a look at the topography on Google Maps. It's a small drainage area, a narrow valley about 1.5-2 miles wide that only extends 11 miles up creek from Waverly. If I read correctly, 20 of the 21 deaths were in town. Red roofs were public housing: Unfortunately much of the town, including public housing, is in the floodplain right up against the creek. This is the 4th major flood starting with 1984, but this was the worst. Apparently few with flood insurance. If the gov't is going to bail them out, then buy out property and force all rebuilding to be out of the 500-year floodplain. A big part of the small town also got destroyed in the infamous explosion during clean up from a train derailment in 1978. https://en.wikipedia.org/wiki/Waverly,_Tennessee,_tank_car_explosion 1 Link to comment Share on other sites More sharing options...
John1122 Posted August 23, 2021 Share Posted August 23, 2021 It's terrible but that 17 inch rain total is one of the most impressive weather stats in state history. The flood that absolutely devastated this area was 8 inches in 4 hours. I can't imagine the result if we'd added 9 more inches onto that. 1 Link to comment Share on other sites More sharing options...
WestTennWX Posted August 23, 2021 Share Posted August 23, 2021 Pretty much a worst case scenario for that area. I live about 50 miles west and have been down that way a few times, it is indeed a flood plain. No way would I rebuild there. This area has a past history of flooding, but what made this exceptional was the massive amount of rain upstream. Residents keep referring to it as a tidal wave. 1 Link to comment Share on other sites More sharing options...
Witness Protection Program Posted August 24, 2021 Share Posted August 24, 2021 Some speculation that a massive debris buildup at the railroad and highway bridge 3 miles upstream of Waverly may have created that 'tidal wave' when it gave way. The long RR fill parallel to the creek acted like a dam, given the relatively narrow opening of the concrete RR bridge. This vid shows where it was overtopped and partially breached: 1 Link to comment Share on other sites More sharing options...
jaxjagman Posted September 20, 2021 Share Posted September 20, 2021 Areas around Tullahoma and Manchester has gotten around 10",about 6 " here so far,that is per RS estimation Mesoscale Precipitation Discussion 0995 NWS Weather Prediction Center College Park MD 1146 AM EDT Mon Sep 20 2021 Areas affected...western/Middle Tennessee, northern Alabama, northern Mississippi Concerning...Heavy rainfall...Flash flooding likely Valid 201545Z - 202200Z Summary...Flash flooding is likely today as slow-moving convection develops and moves over moist soils from prior rainfall. Discussion...A cluster of slow-moving showers and thunderstorms was observed over Middle Tennessee this morning. Meanwhile, additional showers and isolated thunderstorms were deepening to the south/southwest acrosss portions of Alabama, Mississippi, and western Tennessee. The environment supporting the ongoing convection was characterized by weak low-level confluence (southerly 850mb flow across Middle Tennessee and south-southwesterly 850mb flow across Mississippi), abundant moisture (near 2 inch PW values), and increasing surface-based instability (500-2000 J/kg MUCAPE - highest in Mississippi). Weak flow aloft was contributing to slow movement of ongoing convection, which was already resulting in a few areas of 1"/hr rainfall rates near the Nashville area. Three-hour rainfall totals around 2-3 inches have also been observed southwest of Nashville Metro. Although the ongoing convective cluster near Nashville may pose a few localized flash flood issues this morning, a higher flash-flood risk is possible later this afternoon as convective coverage increases in tandem with the peak diurnal cycle. Models and high-resolution guidance suggest that the greatest coverage of storms this afternoon will exist from northern Alabama into Middle Tennessee. These areas also have very low FFG values (generally less than 1.5"/hr thresholds, with spots as low as 0.5"/hr). These thresholds should easily be exceeded with convection this evening, especially given the slow storm motions and efficient rainfall production expected. Within the discussion area, the greatest likelihood of flash flooding will exist where FFGs are lowest (Middle Tennessee, Alabama, and far northwest Georgia). Farther west, flash flooding is still possible (Mississippi, western Tennessee) given the favorable atmospheric conditions, although FFGs are higher as this region hasn't experienced the heavier antecedent rainfall as areas farther east. Cook ATTN...WFO...BMX...FFC...HUN...JAN...LMK...MEG...MRX...OHX... PAH... ATTN...RFC...LMRFC...OHRFC...SERFC...NWC... Link to comment Share on other sites More sharing options...
jaxjagman Posted October 4, 2021 Share Posted October 4, 2021 https://storymaps.arcgis.com/stories/13b68e35b8fd48e0b0188f1645992b98 1 Link to comment Share on other sites More sharing options...
nrgjeff Posted October 6, 2021 Share Posted October 6, 2021 Thank you for posting. That's just awful. TVA employees impacted, but I know it's much worse for many people. Fatalities were shocking not associated with vehicles. That's a tragic and rare flood. Link to comment Share on other sites More sharing options...
jaxjagman Posted December 20, 2021 Share Posted December 20, 2021 US National Weather Service Nashville Tennessee 53m · For Official Release: New 24-hour Record Rainfall for the State of Tennessee The State Climate Extremes Committee (SCEC) in coordination with the National Weather Service in Nashville, Tennessee and the Tennessee State Climate Office at Eastern Tennessee State University has confirmed that 20.73" of rain in 24 hours is a new State Record. This new 24-hour Precipitation Record occurred on August 21, 2021 at the McEwen, TN Wastewater Treatment Plant. It breaks a previous record of 13.60" in Milan, TN on September 13, 1982. The SCEC carefully reviewed the meteorology and equipment conditions for this event. A unanimous vote of 5-0 determined that the 20.73" observed in McEwen, TN on August 21, 2021 was valid and constituted a State Record for 24-hour total precipitation. Catastrophic flooding occurred in Waverly, TN and surrounding areas as a result of this record rainfall. 2 Link to comment Share on other sites More sharing options...
nrgjeff Posted February 18, 2022 Share Posted February 18, 2022 I'm going to resurrect this thread for heavy rain expected next week. Saves the winter thread for any threats of winter precip. Somewhat stationary front will set up over our Region. Several impulses will come out early to midweek. Mostly above freezing, we can focus on flooding threats. Then the main energy brings what could be more severe weather late week. QPF moves with the tracks of the waves. Totals should be robust. Pattern makes it hard to dodge the heavy rain, unless the frontal position shifts markedly. 3 1 2 Link to comment Share on other sites More sharing options...
Matthew70 Posted February 19, 2022 Share Posted February 19, 2022 I’m hoping the models are overdoing the rainfall amounts. Especially for the first system. We get those type of amounts Id say it’s a good bet many schools will be closed Wednesday if not Tuesday. Maybe even half a day on Tuesday. Rivers are already high. 2 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 20, 2022 Share Posted February 20, 2022 GFS seems to be trending a bit north with the worst rainfall this week. WPC seems to like that solution: Looks pretty much like the NBM, but hedging on the higher side. Seems reasonable to me. Will be interesting to see exactly where the firehose sets up. Link to comment Share on other sites More sharing options...
Weathertree2 Posted February 20, 2022 Share Posted February 20, 2022 5 minutes ago, Holston_River_Rambler said: GFS seems to be trending a bit north with the worst rainfall this week. WPC seems to like that solution: Looks pretty much like the NBM, but hedging on the higher side. Seems reasonable to me. Will be interesting to see exactly where the firehose sets up. Does not look good any way you slice it honestly; essentially all of the rain we got last week ran off; any amount of rain will not be good for my area, north of Nashville Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 20, 2022 Share Posted February 20, 2022 1 minute ago, Weathertree2 said: Does not look good any way you slice it honestly; essentially all of the rain we got last week ran off; any amount of rain will not be good for my area, north of Nashville Euro was still a little bit south with the firehouse, so yeah somebody in the TN Valley watershed is going to get it. Hopefully nothing like the 14" amounts come to fruition anywhere. 1 Link to comment Share on other sites More sharing options...
Weathertree2 Posted February 20, 2022 Share Posted February 20, 2022 1 hour ago, Holston_River_Rambler said: Euro was still a little bit south with the firehouse, so yeah somebody in the TN Valley watershed is going to get it. Hopefully nothing like the 14" amounts come to fruition anywhere. Me too but it is setting us up for a Spring that could be bad as far as flooding goes Link to comment Share on other sites More sharing options...
jaxjagman Posted February 20, 2022 Share Posted February 20, 2022 Hydrologic Outlook National Weather Service Nashville TN 516 AM CST Sun Feb 20 2022 ...Flooding Possible Washingtons Birthday through Friday... Moderate to heavy rainfall will impact Middle Tennessee Washingtons Birthday through Friday afternoon as two distinct weather systems move across mid state region. As of this time, total rainfall amounts will range from around 3 inches southwest to approaching 6 inches northwest through Friday afternoon. Currently corridor of heaviest rainfall amounts look to be across northern portions of mid state region as Tuesday progresses. There may be a brief lull in rainfall on Wednesday. However, another round of heavy rainfall is expected to arrive Wednesday Night and last through at least Thursday night, with heaviest rainfall amounts expected Thursday night. Soil moisture continues to remain relative high especially across northern portions of mid state region. Due to this rainfall potentially causing additional rises on rivers, several rivers across area could reach action if not flood stage as week progresses. Flash flooding could also be possible across mid state region. While the exact location of higher rainfall amounts not yet totally certain, it is imperative that if you have interest near areas that are known to flood, that you pay close attention to rainfall forecasts over the upcoming week. Updated information concerning this rainfall event will be provided during morning hours on Washingtons Birthday. Link to comment Share on other sites More sharing options...
Matthew70 Posted February 20, 2022 Share Posted February 20, 2022 53 minutes ago, jaxjagman said: Hydrologic Outlook National Weather Service Nashville TN 516 AM CST Sun Feb 20 2022 ...Flooding Possible Washingtons Birthday through Friday... Moderate to heavy rainfall will impact Middle Tennessee Washingtons Birthday through Friday afternoon as two distinct weather systems move across mid state region. As of this time, total rainfall amounts will range from around 3 inches southwest to approaching 6 inches northwest through Friday afternoon. Currently corridor of heaviest rainfall amounts look to be across northern portions of mid state region as Tuesday progresses. There may be a brief lull in rainfall on Wednesday. However, another round of heavy rainfall is expected to arrive Wednesday Night and last through at least Thursday night, with heaviest rainfall amounts expected Thursday night. Soil moisture continues to remain relative high especially across northern portions of mid state region. Due to this rainfall potentially causing additional rises on rivers, several rivers across area could reach action if not flood stage as week progresses. Flash flooding could also be possible across mid state region. While the exact location of higher rainfall amounts not yet totally certain, it is imperative that if you have interest near areas that are known to flood, that you pay close attention to rainfall forecasts over the upcoming week. Updated information concerning this rainfall event will be provided during morning hours on Washingtons Birthday. Definitely will be some river flooding along with certain areas this week. My back yard will be a small pond & swamp for sure. Link to comment Share on other sites More sharing options...
jaxjagman Posted February 20, 2022 Share Posted February 20, 2022 3 hours ago, Matthew70 said: Definitely will be some river flooding along with certain areas this week. My back yard will be a small pond & swamp for sure. Yeah downtown Franklin might be under water,we will see.Euro seemed tohave back down somewhat this afternoon 1 Link to comment Share on other sites More sharing options...
Matthew70 Posted February 20, 2022 Share Posted February 20, 2022 3 hours ago, jaxjagman said: Yeah downtown Franklin might be under water,we will see.Euro seemed tohave back down somewhat this afternoon I saw where OHX NWS only has 3-4” now for area. That’s not nearly as much as first thought. Guess models have backed off a lot. Link to comment Share on other sites More sharing options...
jaxjagman Posted February 21, 2022 Share Posted February 21, 2022 37 minutes ago, Matthew70 said: I saw where OHX NWS only has 3-4” now for area. That’s not nearly as much as first thought. Guess models have backed off a lot. Little more convection shown this afternoon,most of us should see a fllood watch it seems right now < Day 2 Outlook WPC Day 3 Excessive Rainfall OutlookRisk of 1 to 6 hour rainfall exceeding flash flood guidance at a point Updated: 2027 UTC Sun Feb 20, 2022Valid: 12 UTC Feb 22, 2022 - 12 UTC Feb 23, 2022 Forecast Discussion Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 340 PM EST Sun Feb 20 2022 Day 3 Valid 12Z Tue Feb 22 2022 - 12Z Wed Feb 23 2022 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE MID-MISSISSIPPI, TENNESSEE AND OHIO VALLEYS... ...Mississippi and Ohio River Valleys... Showers and thunderstorms should be ongoing across Missouri/Arkansas into the Lower Ohio Valley at the start of the period, ahead of a shortwave trough tracking from the Central Plains into the Upper Midwest. While instability is expected to be weak across the region Tuesday morning, standardized precipitable water (PW) anomalies of +3 will be present along with confluent 850 mb flow of 40-60 kt. Areas of WSW to ENE training are likely early in the period with rainfall totals of 1-2 inches in an hour atop a region of the nation that has high soil moisture values (over 90th percentiles for 10-40 cm depth) and low flash flood guidance values. Weakening of forcing and moisture values through 00Z Wednesday should transition the event to more of a longer duration and less intense rainfall for the latter half of the outlook period. Model guidance was mixed with placement, but the 12Z NAM appeared too heavy and north with its axis of QPF. Better deterministic and ensemble placement for 2-4 inches of rain was located closer to the Ohio River, with magnitude of rainfall and probabilities lowering with eastward extent into Ohio, West Virginia and southwestern Pennsylvania. However, flash flood guidance values of only 1-2 inches in 3 and 6 hours was present across the central Appalachians, and these values might be exceeded despite the lower rainfall intensity later in the period. ...Lower Mississippi to Tennessee Valleys... As a surface low tracks northeastward from the Midwest into New England Tuesday/Tuesday night, a southwestward trailing cold front will extend across the Lower Ohio Valley to Southern Plains. Moisture return ahead of the cold front combined with daytime heating should allow for increasing instability from the Lower Mississippi Valley into Tennessee, Mississippi and Alabama. Southwest to northeast oriented convergence, parallel to the deeper-layer mean flow, will be in place across the southern U.S. which should support an axis of training convection, mainly from 21Z Tuesday through 12Z Wednesday. Rainfall rates of 1-2 inches in an hour are likely given the moisture and instability in place, and training could support 2-4 inches of rain. Model agreement on this axis was good on its occurrence but not as good with placement. Therefore, the existing Slight Risk area inherited from continuity was expanded a bit into southwestern Tennessee and northeastern Mississippi, in accord with the latest model spread. With the increasing signal for 3-4+ inches, there may be a need to upgrade to a Moderate Risk as the event gets closer, but confidence in its placement is too low at this time. Otto 1 Link to comment Share on other sites More sharing options...
dwagner88 Posted February 23, 2022 Share Posted February 23, 2022 Flooding problems area wide this morning. Probably the worst since the March 2020 tornado night. 1 1 Link to comment Share on other sites More sharing options...
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