McMinnWx Posted February 10, 2020 Share Posted February 10, 2020 The 18z NAM seems to think the Valley is going to get around 5 inches between Monday afternoon and Tuesday. Link to comment Share on other sites More sharing options...
dwagner88 Posted February 10, 2020 Share Posted February 10, 2020 21 minutes ago, McMinnWx said: The 18z NAM seems to think the Valley is going to get around 5 inches between Monday afternoon and Tuesday. This is normally when I say that the NAM tends to overdo precip, but that totally contradicts my experience from the weekend snow event. Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 10, 2020 Share Posted February 10, 2020 Yeah I think I it’s just going to depend on where the firehouse sets up. It was showing 6+ in some places south and west. Not a guarantee, but I’d say there is a potential to overperform Link to comment Share on other sites More sharing options...
jaxjagman Posted February 10, 2020 Share Posted February 10, 2020 Impressive Huntsville ECMWF Deterministic FORECAST FOR: MDQ LAT= 34.87 LON= -86.55 ELE= 755 18Z FEB09 6 HR 6 HR FROZN TOTAL SFC 2 M 1000 1000 QPF CVP PCP QPF PCP TMP 500 850 (IN) (IN) (IN) (IN) TYPES (C) THK THK SUN 18Z 09-FEB 13.4 551 134 MON 00Z 10-FEB 0.00 11.3 554 135 MON 06Z 10-FEB 0.01 0.01 0.00 0.01 9.2 556 135 MON 12Z 10-FEB 0.14 0.11 0.00 0.16 8.1 557 135 MON 18Z 10-FEB 0.74 0.53 0.00 0.89 12.1 560 136 TUE 00Z 11-FEB 0.99 0.33 0.00 1.88 14.3 562 138 TUE 06Z 11-FEB 0.68 0.09 0.00 2.56 14.9 563 137 TUE 12Z 11-FEB 1.37 0.14 0.00 3.93 13.6 564 137 TUE 18Z 11-FEB 0.48 0.02 0.00 4.41 14.0 559 135 WED 00Z 12-FEB 0.01 0.00 0.00 4.42 11.5 558 135 WED 06Z 12-FEB 0.10 0.00 0.00 4.53 6.8 558 134 WED 12Z 12-FEB 0.11 0.00 0.00 4.63 7.8 560 135 WED 18Z 12-FEB 0.05 0.00 0.00 4.68 14.4 564 137 THU 00Z 13-FEB 0.03 0.01 0.00 4.71 18.3 567 139 THU 06Z 13-FEB 0.02 0.01 0.00 4.73 19.0 567 139 THU 12Z 13-FEB 1.17 0.11 0.00 5.90 11.0 561 136 Cha ECMWF Deterministic FORECAST FOR: CHA LAT= 35.03 LON= -85.20 ELE= 689 18Z FEB09 6 HR 6 HR FROZN TOTAL SFC 2 M 1000 1000 QPF CVP PCP QPF PCP TMP 500 850 (IN) (IN) (IN) (IN) TYPES (C) THK THK SUN 18Z 09-FEB 10.0 549 133 MON 00Z 10-FEB 0.00 7.6 553 134 MON 06Z 10-FEB 0.00 0.00 0.00 0.00 6.4 554 134 MON 12Z 10-FEB 0.06 0.05 0.00 0.06 6.1 556 134 MON 18Z 10-FEB 0.46 0.17 0.00 0.52 9.6 558 135 TUE 00Z 11-FEB 0.79 0.41 0.00 1.31 11.4 560 137 TUE 06Z 11-FEB 0.93 0.10 0.00 2.24 13.2 562 137 TUE 12Z 11-FEB 1.68 0.15 0.00 3.92 14.0 562 137 TUE 18Z 11-FEB 1.03 0.07 0.00 4.95 17.4 561 137 WED 00Z 12-FEB 0.00 0.00 0.00 4.95 12.5 558 135 WED 06Z 12-FEB 0.06 0.00 0.00 5.01 8.4 558 134 WED 12Z 12-FEB 0.08 0.00 0.00 5.09 7.4 560 135 WED 18Z 12-FEB 0.04 0.00 0.00 5.13 12.7 563 136 THU 00Z 13-FEB 0.06 0.03 0.00 5.19 15.2 565 138 THU 06Z 13-FEB 0.01 0.00 0.00 5.20 17.7 566 138 THU 12Z 13-FEB 0.25 0.05 0.00 5.45 16.9 565 138 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2020 Share Posted February 10, 2020 High Risk out now to almost Chatt...WPC says there is still some uncertainty as to where to put the High Risk, could be moved north or south in further updates. For SE TN: Further downstream we have a Moderate risk across portions of northern GA into southeast TN and the far western Carolinas. Significant flooding is still possible here today/tonight. Slightly lower QPF and the expectation of weaker rates this far northeast, precludes the need for a High risk here. However, a Moderate Risk does cover these areas, which is still a significant and potentially life threatening risk level. 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2020 Share Posted February 10, 2020 Comparing the NAM, 3k, GFS, HRRR, Euro..with what has currently fallen here (.13). The Euro was the only one to have the rainfall into SE Monroe at this point. 1 Link to comment Share on other sites More sharing options...
dwagner88 Posted February 10, 2020 Share Posted February 10, 2020 31 minutes ago, TellicoWx said: Comparing the NAM, 3k, GFS, HRRR, Euro..with what has currently fallen here (.13). The Euro was the only one to have the rainfall into SE Monroe at this point. The 18Z GFS yesterday said the rain wouldn't start until mid-afternoon today. I've been discounting it for getting the start time so wrong. 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2020 Share Posted February 10, 2020 43 minutes ago, dwagner88 said: The 18Z GFS yesterday said the rain wouldn't start until mid-afternoon today. I've been discounting it for getting the start time so wrong. Big question mark to me for today is around storm motion and orientation return flow. If the motion/return sets up more oriented ENE across N. AL then the results will be lowered (storms firing/training south of the area cutting off some of the flow from the gulf, plus a downslope component off the plateau)...HRRR/GFS. If it is orientated more NNE across N. AL, then the return up the southern valley will be greater and minimal downsloping (Euro Op/NAM). Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 10, 2020 Author Share Posted February 10, 2020 after the first wave this morning, latest RAP and HRRR have the training more south into AL..missing the TN valley Link to comment Share on other sites More sharing options...
franklin NCwx Posted February 10, 2020 Share Posted February 10, 2020 2 hours ago, dwagner88 said: The 18Z GFS yesterday said the rain wouldn't start until mid-afternoon today. I've been discounting it for getting the start time so wrong. Same here. This wasn't supposed to start until late afternoon here. Started raining steady at 7 am. Link to comment Share on other sites More sharing options...
Stovepipe Posted February 10, 2020 Share Posted February 10, 2020 Knox County schools closed today for the 3rd day in a row for flooding. I imagine they'll be closed tomorrow as well. 1 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted February 10, 2020 Share Posted February 10, 2020 Started raining IMBY according to my weather station at 4am (northern Meigs county) currently since it started I'm sitting at .72 inches for the day with rainfall rates bouncing between .12" up to as high as .29" an hour so far.Sent from my SM-G965U using Tapatalk Link to comment Share on other sites More sharing options...
dwagner88 Posted February 10, 2020 Share Posted February 10, 2020 Looks to me like the Euro has the best grip on reality right now. It is the only one not significantly behind the surface qpf obs. Showed KCHA in the 0.60-0.80 range since start of precip. Actual obs shows we were at 0.81 as of 11:45. It unfortunately has in excess of 5" qpf falling from this first round. It is much lighter with the second round, as it appears to show intense convection over northern MS blocking moisture return in the area Wednesday. We finish out by noon on Thursday with just over 6". 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2020 Share Posted February 10, 2020 High Risk has been extended into NW GA 2 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted February 10, 2020 Share Posted February 10, 2020 Had a leaky chimney. Got up there and fixed it yesterday evening. Very thankful that is done and fingers crossed that the new sealant works! 6" of rain by Thursday. Not good! 1 Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2020 Share Posted February 10, 2020 .91 in the bucket since around 3am this morning. MRX has most of the area in the 4-6 inch range by Thursday. Not sure that flash flooding will be an issue but a lot of slow rising water issues will happen at that point. I'm now at 8.17 inches of rain already for the month and had 7.35 last month. So already 8 inches or so above normal for 2020. Link to comment Share on other sites More sharing options...
dwagner88 Posted February 10, 2020 Share Posted February 10, 2020 Up to 1.14" at KCHA. Still running ahead of everything, even the Euro. MRX issued a pre-emptive flood warning for South Chickamauga creek for meeting flood stage at 18 ft. It crested at 23 ft. with less rain last week. Not sure where that forecast comes from. Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2020 Share Posted February 10, 2020 New MCD out for southern valley: Discussion...Moisture is streaming in from the west-southwest within an atmospheric river moving into the region. Precipitable water values are currently 0.8-1.3". Inflow at 850 hPa is west-southwest at 30-50 knots per nearby VAD wind profiles, similar in direction and magnitude to the 850-400 hPa mean wind. MU CAPE remains under 100 J/kg for much of the area, though trends are upward across northern AL. Recent observations show hourly rain totals of 0.15-0.30", roughly 1/5 of the current precipitable water value, due to the lack of instability. With time, hourly rain totals are expected to rise to 0.5-1" as MU CAPE rises to 500+ J/kg across northeast AL and northern GA and convective elements become more common within the mostly stratiform rain areas. Mesoscale guidance generally advertises local amounts ~2", but 3" can't be ruled out during the next several hours. Two week precipitation anomalies are 150-300%+ of average, which has led to fairly saturated soils. Flash flooding is considered possible through 8 pm EDT. 1 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted February 10, 2020 Share Posted February 10, 2020 Just hit the 1" mark imby today. Sent from my SM-G965U using Tapatalk Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2020 Share Posted February 10, 2020 MRX has changed the Flood Watch to a Flash Flood Watch: The National Weather Service in Morristown has issued a * Flash Flood Watch for portions of southwest North Carolina, east Tennessee, and southwest Virginia, including the following areas, in southwest North Carolina, Cherokee and Clay. In east Tennessee, Anderson, Bledsoe, Blount Smoky Mountains, Bradley, Campbell, Claiborne, Cocke Smoky Mountains, East Polk, Grainger, Hamblen, Hamilton, Hancock, Hawkins, Jefferson, Knox, Loudon, Marion, McMinn, Meigs, Morgan, North Sevier, Northwest Blount, Northwest Cocke, Northwest Monroe, Rhea, Roane, Scott, Sequatchie, Sevier Smoky Mountains, Southeast Monroe, Union, and West Polk. In southwest Virginia, Lee. * Through Tuesday evening * Rainfall amounts of 2 to 3 inches with locally higher amounts expected. The heaviest rainfall will occur the rest of this afternoon and early evening across southeast Tennessee and southwest North Carolina with another round Tuesday morning area-wide. * This amount of rainfall could cause flooding. People in the watch area should be aware of the possibility of heavy rainfall. Avoid low lying areas...and be careful when approaching highway dips and underpasses. 1 Link to comment Share on other sites More sharing options...
nrgjeff Posted February 10, 2020 Share Posted February 10, 2020 Rare High Risk and large Moderate Risk of flooding is quite significant for the South. Due to the high impact of this event, please share with your fiends on social media. Make sure the graphic comes up on the post. Date it and make it public too. (just change back to friends your next post.) I went through Thursday, though the High is through Tuesday. This is going to be bad from rivers down to streams and low areas. 3 1 Link to comment Share on other sites More sharing options...
dwagner88 Posted February 10, 2020 Share Posted February 10, 2020 I have to say I'm pretty pleased with the way the convection in central MS and AL has shut off the taps up here. We are having a heavy shower at the moment, but it looks like we may get a couple hour's reprieve after this. The radar is drying out across North Alabama. At some point this evening that front will lift north and bring the convection with it, but this may help limit qpf somewhat this far north. 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2020 Share Posted February 10, 2020 42 minutes ago, dwagner88 said: I have to say I'm pretty pleased with the way the convection in central MS and AL has shut off the taps up here. We are having a heavy shower at the moment, but it looks like we may get a couple hour's reprieve after this. The radar is drying out across North Alabama. At some point this evening that front will lift north and bring the convection with it, but this may help limit qpf somewhat this far north. The concern among alot of mets (including MRX.. the reason they switched from an Areal Flood to Flash Flood Watch) is going up. The first wave has overpefomed even compared to the 06z Euro (Chatt is approaching 1.5"-2" of rain so far). The main show is what's building over MS and the Arklatex. From MRX AFD: For Tonight, this first wave will move east allowing for a lull in the rainfall but another round of jet dynamics along a quasi- stationary over the region for late tonight through Tuesday morning. Models show a regeneration of rainfall coverage and intensity into the flash flood watch area. Favorably high PWs and warm rain process to produce a period of moderate to heavy rains with this next band. There is a good deal of differences on placement and strength of the low-level jet. The NAM is the most aggressive showing strong low-level moisture transport into this boundary while the GFS is weaker. Main question is exactly where this boundary becomes more quasi- stationary. Current thinking is that this boundary will remain across the central/southern areas into the central/southern Tennessee Mountains. Training of moderate to heavy rain is a major concern for these areas as PWs and thermodyanmic profile for favorable warm rain process will be unseasonably high. Given low FFG (saturated ground) and high stream flows, flash flood potential is a major concern through Tuesday morning. Model QPF ensembles depict around 3 inches at CHA and RHP, and 2 inches at TYS through Tuesday. Due to the potential of high rainfall rates and already saturated soils/high stream flows, decided to change the flood watch to a flash flood watch. Several river warnings have been issued as well. 6z Euro: 1 Link to comment Share on other sites More sharing options...
Windspeed Posted February 10, 2020 Share Posted February 10, 2020 And here we go... Link to comment Share on other sites More sharing options...
dwagner88 Posted February 10, 2020 Share Posted February 10, 2020 1 hour ago, TellicoWx said: The concern among alot of mets (including MRX.. the reason they switched from an Areal Flood to Flash Flood Watch) is going up. The first wave has overpefomed even compared to the 06z Euro (Chatt is approaching 1.5"-2" of rain so far). The main show is what's building over MS and the Arklatex. From MRX AFD: Oh I have no doubt that there will be significant urban and flash flooding tomorrow morning, but I don’t think we are going to see 24 hour totals over 5” like earlier runs of the Euro and NAM were showing last night. I have 1.76” in the gauge at the house, and all of the streams are now bankfull. The next round will put them over the edge. Link to comment Share on other sites More sharing options...
nrgjeff Posted February 11, 2020 Share Posted February 11, 2020 We got almost an inch more overnight. Apparently it all ran off. @dwagner88 was I seeing things or the creek was almost up to the bridge by Food City Jenkins and EB Rd? Link to comment Share on other sites More sharing options...
dwagner88 Posted February 11, 2020 Share Posted February 11, 2020 1 hour ago, nrgjeff said: We got almost an inch more overnight. Apparently it all ran off. @dwagner88 was I seeing things or the creek was almost up to the bridge by Food City Jenkins and EB Rd? It got pretty close. I know Davidson Rd was closed this morning. It is further downstream on that creek and is subject to backup from South Chickamauga. Storm total for me when I left the house this morning was 2.76", which is quite a bit less than the globals were showing during the day Monday. The HRRR and RAP were correct in showing lighter amounts overnight. 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 12, 2020 Share Posted February 12, 2020 MDT Flash Flood risk for Middle and East Tn: Link to comment Share on other sites More sharing options...
nrgjeff Posted February 12, 2020 Share Posted February 12, 2020 I'm ready to see that MDT Red on the SPC charts instead of the WPC charts. Can it just be April yet? 12Z QPF progs are not quite as bad East, but still there Mid-Tenn. Trouble there is double whammy of daytime rain and then the squall line. 1 Link to comment Share on other sites More sharing options...
jaxjagman Posted February 12, 2020 Share Posted February 12, 2020 Mesoscale Precipitation Discussion 0051 NWS Weather Prediction Center College Park MD 552 PM EST Wed Feb 12 2020 Areas affected...Portions of the TN & OH Valleys Concerning...Heavy rainfall...Flash flooding possible Valid 122251Z - 130451Z Summary...A band of heavy rainfall is expected to move across central portions of TN and KY. Hourly rain totals to 1" and local amounts of 2" are expected. Discussion...A developing atmospheric river extending from the Mid-South towards the Ohio River Valley along with increased low level moisture convergence/frontogenesis has led to a band of heavy rainfall producing hourly rain totals to 1" per KY mesonet observations. This band is progressive, though it is moving over and into an area with two week precipitation at 200-300% of average, more to the south across northern AL, which has led to saturated soils. Precipitable water values of 1-1.3" lie here per GPS values. Inflow at 850 hPa is south-southwest at 55-80 knots per VAD wind profiles. MU CAPE is negligible per SPC mesoanalyses. The best guess is that increasing moisture convergence/ frontogenesis has played the main role in hourly rain totals approaching the precipitable water value. The 18z HREF probabilities of 0.5"+ per hour increase to likely as the band moves eastward across central KY and Middle TN with a small percent chance of 1" an hour. KY mesonet obs suggest the HREF probability guidance, as well as WSR 88D hourly rainfall totals, are underperforming here. Local amounts of 2" are possible before the line accelerates as it reaches into eastern KY and eastern TN, which could cause issues over saturated soils and area coal fields. Roth Link to comment Share on other sites More sharing options...
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