1234snow Posted February 20, 2019 Share Posted February 20, 2019 Camp Creek gust of 123mph was ruled erroneous after quality control. Gust was revised to 81mph. 1 3 Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 20, 2019 Author Share Posted February 20, 2019 you can see these wet areas in old youtube videos too...and even when the lake is low..the concrete is stained...similar to if your ceiling ever leaked then dried Nashville District Verified account @NashvilleCorps Follow Follow @NashvilleCorpsjavascript:void('8') More #NashvilleCorps dispelling rumors today that Wolf Creek Dam in #Jamestown #Kentucky is in danger of imminent failure https://www.lrn.usace.army.mil/Media/News-Releases/Article/1762058/nr-19-006-corps-of-engineers-dispels-wolf-creek-dam-safety-rumors/ … #WaterManagement #DamSafety #USACE #LakeCumberland NR 19-006: Corps of Engineers dispels Wolf Creek Dam safety rumors NASHVILLE, Tenn. (Feb. 20, 2019) – The U.S. Army Corps of Engineers Nashville District is dispelling rumors today that Wolf Creek Dam in Jamestown, Ky., is in danger of imminent failure. A local radio station commentator put out false information this morning that Wolf Creek Dam could fail at any time and local residents downstream needed to formulate an evacuation plan. “This is completely false,” said Kyle Hayworth, Dam Safety Program Manager with the Nashville District. “The dam is not failing. There have been no signs of distress with the project, and our dam safety staff has been and will continue to monitor all of the Cumberland River Basin dams throughout this high-water event.” The Corps of Engineers is also aware of a social media video making its rounds that shows water leaking from the concrete face of the dam, and is addressing similar public fears, letting people know there is no reason for alarm. “The water observed seeping out of the concrete is at a joint where drainage systems relieve internal pressures inside the dam,” said Brad Long, acting chief of the Nashville District’s Civil Design Branch. “It is not a dam safety concern. It will likely continue until the pool elevation returns to normal levels.” The Nashville District is posting the very latest updates on its website and on Lake Cumberland’s Facebook page. The public is highly encouraged to seek out these resources for reliable information about water management, operations at the dam, and impacts around the lake. 2 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 20, 2019 Share Posted February 20, 2019 7 minutes ago, janetjanet998 said: A local radio station commentator put out false information this morning that Wolf Creek Dam could fail at any time and local residents downstream needed to formulate an evacuation plan Whoever that is should face prosecution if it was malicious. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 20, 2019 Share Posted February 20, 2019 18 minutes ago, Holston_River_Rambler said: intense rain seems to have evaporated on radar as it pushed off the platea and of course as soon as I write this, more convective showers start to develop. Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 20, 2019 Author Share Posted February 20, 2019 I didn't see the Euro map mentioned ,,,but 5 more inches from N MS to Jackson KY sounds like Lake Cumberland watershed more info on the latest With the additional rainfall expected this week, reaching elevation 750 is possible. The pool of record is 751.69 set in May 1984. In the history of Wolf Creek Dam, which spans back to 1950, elevation 745 has been exceeded twice – 747.12 in April 1962 and the pool of record. “This winter has been an unprecedented event in that we continue to see rainfall events and have not had enough consecutive dry days to regain storage in the reservoir, nor have downstream conditions been conducive to increasing discharges from the dam,” said Robert Dillingham, hydraulic engineer in the Nashville District Water Management Section. “It remains a priority for the Nashville District to lower Lake Cumberland and regain the flood control storage in the reservoir as soon as downstream conditions allow.” Dillingham said the Nashville District has made preparations downstream to allow releases from Lake Wolf Creek Dam, which will likely be larger than have been observed in several decades. “Releases from the reservoir will be increased and we plan to lower the reservoir as soon as possible,” Dillingham added. “However, considering March and April are historically the highest precipitation months, it could take several months before Lake Cumberland returns to a seasonal elevation.” https://milfeed.com/2019/02/20/corps-of-engineers-dispels-wolf-creek-dam-safety-rumors/ Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 20, 2019 Share Posted February 20, 2019 I'm not saying it looks great in any way, but having 5 - 6" inches fall over half the watershed instead of all the watershed has to be better in some small way. Getting emails from the Euro people so I'm being a little more descriptive with their non-free maps for a bit. Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 20, 2019 Author Share Posted February 20, 2019 20 minutes ago, Holston_River_Rambler said: I'm not saying it looks great in any way, but having 5 - 6" inches fall over half the watershed instead of all the watershed has to be better in some small way. Getting emails from the Euro people so I'm being a little more descriptive with their non-free maps for a bit. I think Corps and river forecast center uses the WPC rainfall maps....if you get training like happened this morning it throws it into chaos, any press releases or forecast released that day are based on the lower general WPC numbers released at 3am...that is why sometimes these people are behind the curve... for example ...look at the Cumberland river level forecast upstream of the lake...even though they were updated this afternoon...they are getting blown away.... Wolf creek Dam was repaired...by putting in a very deep cut off wall to stop seepage and leaking out of the earth part....but at least those leaks and seepage relieved pressure...so it will be interesting to see what happens since the pressure has to go somewhere else... Lewisville Dam near Dallas( big trouble there a few years ago). I know they actually dig pressure release wells...but thats a different set up...(no bedrock there just dirt) I have no idea what will happen if the entire watershed get 5 inches....it will be a nowcast thing to see where training sets up ..again most of the water shed is SE of the lake ..even a few miles north of the actual lake is out of the water shed Link to comment Share on other sites More sharing options...
Math/Met Posted February 20, 2019 Share Posted February 20, 2019 1 hour ago, 1234snow said: Camp Creek gust of 123mph was ruled erroneous after quality control. Gust was revised to 81mph. Glad they did quality control and straightened that out. Are they saying 81mph was the peak gust today? Just wondering because it looked like there were legitimate gusts in the mid to upper 80's based on the plot. Not that it really matters at this point, just wondering if all recorded gusts were higher than actual winds. 2 Link to comment Share on other sites More sharing options...
Blue Ridge Posted February 21, 2019 Share Posted February 21, 2019 PRELIMINARY LOCAL STORM REPORT...SUMMARY NATIONAL WEATHER SERVICE MORRISTOWN TN 346 PM EST WED FEB 20 2019 ..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0700 AM NON-TSTM WND GST COVE MOUNTAIN 35.71N 83.59W 02/20/2019 M87 MPH SEVIER TN MESONET 0630 AM NON-TSTM WND GST CAMP CREEK 36.09N 82.77W 02/20/2019 M81 MPH GREENE TN MESONET CORRECTS PREVIOUS NON-TSTM WND GST REPORT FROM CAMP CREEK. MEASURED GUST AT THE NOAA/ATDD TOWER. EARLIER REPORTED GUST WAS ERRONEOUS. AFTER QUALITY CONTROL OF THE RAW DATA 81 MPH WAS CONFIRMED TO BE THE CORRECT WIND SPEED. 0659 AM NON-TSTM WND GST 4 SE CEDAR CREEK 35.98N 82.84W 02/20/2019 M51 MPH GREENE TN MESONET MESONET STATION PGVT1, NOLICHUCKY (4 SE CEDAR CREEK). 0327 AM NON-TSTM WND GST 1 SE SIGNAL MOUNTAIN 35.12N 85.33W 02/20/2019 M49 MPH HAMILTON TN MESONET MESONET STATION C9567, SIGNAL MOUNTAIN. 1000 AM NON-TSTM WND GST 4 WSW ROAN MOUNTAIN 36.17N 82.15W 02/20/2019 M47 MPH CARTER TN MESONET MESONET STATION D5724, 4 WSW ROAN MOUNTAIN. 0106 AM NON-TSTM WND GST 5 SE POWELLS CROSSROADS 35.13N 85.43W 02/20/2019 M43 MPH MARION TN MESONET MESONET STATION PCFT1, PRENTICE COOPER SF. 0905 AM NON-TSTM WND GST 1 WNW UNICOI 36.20N 82.37W 02/20/2019 M43 MPH UNICOI TN MESONET MESONET STATION UNIT1, WATAUGA (1 WNW UNICOI). Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 21, 2019 Author Share Posted February 21, 2019 following Oroville , DWR said that the peak inflows, or lake level rises, into a lake occur a few hours after peak rainfall rates...then the rate of rise starts to decline without any more rain but .22 feet per hour for a lake the size of Cumberland is crazy, especially at these high levels since it takes more volume of water to raise it per foot the higher it is since the lake is shaped like the letter V the 6pm TVA data is flawed but the NWS river graph hints that may be even higher then a .22 rise between 5 and 6 2/20/2019 3 PM 742.18 25,420. +.18 2/20/2019 4 PM 742.38 25,510 +.20 2/20/2019 5 PM 742.60. 25,470. +.22 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 00z NAM is ugly Friday for southern TN and central valley. Front doesn't push as quickly north and stalls, before pushing thru. Tomorrow the front is stalled a little too close for comfort across SE TN...N GA gets hammered. Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 3k NAM very similar, trains storms over the same area Fri Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 00z suite: basically all hi res short range model (NAM/3K/RGEM/HRRR) plus CMC (2-4 for southern M TN & C/S Valley) vs GFS/FV3/ICON (further NW & lighter) thru Fri evening. Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 21, 2019 Author Share Posted February 21, 2019 6 hours ago, janetjanet998 said: following Oroville , DWR said that the peak inflows, or lake level rises, into a lake occur a few hours after peak rainfall rates...then the rate of rise starts to decline without any more rain but .22 feet per hour for a lake the size of Cumberland is crazy, especially at these high levels since it takes more volume of water to raise it per foot the higher it is since the lake is shaped like the letter V the 6pm TVA data is flawed but the NWS river graph hints that may be even higher then a .22 rise between 5 and 6 2/20/2019 3 PM 742.18 25,420. +.18 2/20/2019 4 PM 742.38 25,510 +.20 2/20/2019 5 PM 742.60. 25,470. +.22 WOW...only 8 feet from the record....still climbing fast....hopefully the train will stay south and the last part north....the GFS is disturbing with 2-3+ inches at 760 it spills over the top of the spillway...(again may not get there this time but later in the spring?) .this isn't Oroville where it spills on to a hillside and erodes it away but still.....there will be no flood control at that point.. if it is like any other situation there is a control plan that you do X, Y, and Z when A, B and C happens the control plan likely says no more then X amount of outflow when there is so many inches of future predicted rains for downstream flood control... that is likely why they dropped outflows to 25K from 29K and have delayed the increase to 35K they mentioned last Friday... but every hour of these lower outflows means an extra hour of 5-10 or even 15K cfs(if they eventually increase to the record 40K) that they will have to make up in the future 2/20/2019 6 PM 742.86 25,560. +.26 2/20/2019 7 PM 743.07 25,560. +.21 2/20/2019 8 PM 743.29 25,650. +.22 2/20/2019 9 PM 743.49 25,740 +.2 2/20/2019 10 PM 743.73 25,660. +.24 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 Enhanced Severe risk now for weekend: In phase with the subtropical westerlies, a vigorous short wave impulse of mid-latitude Pacific origins is forecast to accelerate northeast of the southern Plains through the Great Lakes region during this period. Strong cyclogenesis may already be underway by 12Z Saturday near the Texas/Oklahoma Panhandle vicinity, and models continue to indicate that the rapid evolution of a broad and deep cyclone will proceed northeastward into the Great Lakes region by the end of the period. This likely will include the intensification of a cyclonic mid-level jet, including speeds in excess of 100 kt at 500 mb, across the southern Plains Red River Valley, through the middle Mississippi and Ohio Valleys. Across the evolving warm sector, models indicate that south/southwesterly winds will strengthen to 50-70+ kt through the 850-700 mb layer. Although the warm frontal zone probably will surge north of the Ohio River, and into/through the lower Great Lakes region by late Saturday evening, an initial position roughly along the Ohio River west-southwestward into the Ozark Plateau may provide the main focus for severe thunderstorm potential. Early period convection, associated with weak elevated destabilization above the front, may inhibit, or at least slow, boundary-layer destabilization to the north, while leaving a remnant surface boundary. In association with the onset of stronger surface pressure falls, surface dew points are expected to increase through the lower/mid 60s along and south of this boundary. Coupled with strengthening large-scale ascent, this is expected to contribute at least weak boundary-layer destabilization supportive of an evolving organized mesoscale convective system. CAPE on the order of 500+ J/kg appears possible. Given the strength of the environmental wind fields (and shear) within the convective layer, the convective system may be accompanied by considerable potential for strong and damaging wind gusts. It appears that this may initiate over parts of central and eastern Arkansas by midday, before progressing east-northeastward through the lower Ohio Valley by Saturday evening. A few tornadoes, some strong, are also possible, particularly with discrete supercells which may form near/just ahead of mainly the southern flank of the evolving system. More discrete storms, including supercells, may eventually develop as far south as the lower Mississippi Valley through portions of the southern Appalachians by late Saturday night. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 21, 2019 Share Posted February 21, 2019 Highway 70 mudslide in Hawkins county. Been a long time since I've heard of a mudslide in our area closing a highway. A wreck associated with it: https://www.wvlt.tv/content/news/Mudslide-shuts-down-High-70-in-Hawkins-County-506145721.html 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 Hwy 70 in Hawkins Co...Pic TDOT. Homes evacuated within 1/2 mile radius and TDOT geologist now on site. Incredible wasn't more hurt due to being during overnight hours. 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 Day 2 WPC FFG: Yet another impulse in the mid levels moving northward from the Gulf of Mexico will move across portions of Mississippi and Louisiana at the start of the Day 2 period...or Friday morning...and then take a more easterly track by the time is reaches the southern portion of the Appalachians. Heaviest rainfall from the system looks in the Tennessee Valey and portions of adjacent states. Model QPF values were generally in the 2 to 3 inch range with a couple isolated amounts in excess of 4 inches. This is consistent with some instability developing in response to deepening moisture, low level flow on the order of 25 kts to 35 kts that accelerates to between 30 kts and 45 kts as well as weakly channeled mid level vorticity. The synoptic set up and the QPF amounts would not garner much attention if the conditions had been dry...but the area has had multiple rounds of moderate to heavy rainfall over the past 5 days or so and Flash Flood Guidance values have been supressed accordingly. Maximum rainfall on Day 2 is expected to be in the Tennessee Valley and Southern States...but flash flooding is a concern in the southern portion of the Appalachians. Rain will be falling in complex terrain and in areas of snow-cover...making the area more vulnerable to flash flooding despite the fact that heaviest rainfall stays to the west. Based on coordination/collaboration with affected offices, have introduced a Moderate Risk of Excessive Rainfall over portions of the Tennesse Valley on Day 2. Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 21, 2019 Author Share Posted February 21, 2019 Time for for some math ( in a hurry I made have made errors) 2/21/2019 4 AM CST 745.00 25,850 2/21/2019 5 AM CST 745.18 25,940 +.18 2/21/2019 6 AM CST 745.36 25,940 +.18 the lake has risen an average of .18 feet per hour ending at 4am and amazing 4.32 feet..the max rolling 24 period will be higher then that even The corps has a major problem..Dale Hollow 655.25. just downstream, has zero outflow right now...and rising fast too.. up almost 2.95 feet on 24 hours..it overflows at 661 feet..came within inches in a few times in the past..outflow of 5,000 keeps the lake steady it seems,,,but that is 5000 that takes away from Wolf Creek outflow If the Cumberland lake averages .14 an hr rise the next 24 hrs 4 am-4am from that 745 level .14 rise per hour ending 10z Friday that's 748.36 no more rain .12 average rise the next 24 hours 751.24 mod-heavy rains widepread training? .16 the next 24 hours 755.08 record smashed light rain to scattered heavy stuff with the line of storms .14 next 24 hours 758.04 no more rain but still rising fast from old rain .04 per hour the next 24 hours 759.4 no rain .02 per hour the next 24 hours 759.88 no rain .01 per hour the next 24 hours 760.12 lake overspills here 10z thursday Feb 28th no rain now some days like tommrow I may have over estimated rises, and some days underestimated ..but you can take away some one day but add it to the next set of numbets. etc etc ...the lake may still be rising at .08 inch per hour or so before the next batch of rain starts adding to it too The above assumes the basin gets trained again..12z NAM (usually NW) keeps that just SE of the basin 2/21/2019 7 AM 745.50 25,940 +.14 2/21/2019 8 AM 745.65 25,940 +.15 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 321 closed again...another slide between Walland and Townsend 1 Link to comment Share on other sites More sharing options...
Santa Clause Posted February 21, 2019 Share Posted February 21, 2019 Just stopping in due to interest like Janet, rough weather ahead through weekend....rain appears to roll back in later tonight. Hoping the best for all involved, but this appears to be prolific event for sure. 1 2 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 21, 2019 Share Posted February 21, 2019 Looks like Cumberland Falls flow has increased dramatically since I was there last week. Much higher and there won't be a waterfall anymore. If you've never been there it's hard to express how high the water would hav to be. 3 Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 21, 2019 Author Share Posted February 21, 2019 1 hour ago, Holston_River_Rambler said: Looks like Cumberland Falls flow has increased dramatically since I was there last week. Much higher and there won't be a waterfall anymore. If you've never been there it's hard to express how high the water would hav to be. all going into the lake of course...looks like the river at williamaburg just upstream from that has peaked for now..but a second peak similar to the one today is in the forecast plots...it will go even higher if training happens again .lots of replies on facebook on that post...I think as time goes on more and more people may question if the lake will over flow...amd there will be hype and panic on social media even it is does all that MAY happen is it will spill over a little and really have no more outflow(since by then inflow should be much lower then now) then it does now assuming the shut the gates and just let it go? but it is going to be a battle all spring to get the flood control storage back in the upper Cumberland basin for any huge spring events 2/21/2019 9 AM 745.92 26,040 +.25 2/21/2019 10 AM 746.05 26,130 +.13 A slight uptick in outflow,(about 500 since this morning),this is what happened when it increased to 29K before but just a drop i the bucket to what is needed edit: outflow increased again 2/21/2019 11 AM 746.20 +.15 28,420 Link to comment Share on other sites More sharing options...
Santa Clause Posted February 21, 2019 Share Posted February 21, 2019 That picture is incredible...having been there once it's astounding to see it like that. Link to comment Share on other sites More sharing options...
jaxjagman Posted February 21, 2019 Share Posted February 21, 2019 ECMWF Deterministic FORECAST FOR: BNA LAT= 36.12 LON= -86.68 ELE= 591 12Z FEB21 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 THU 12Z 21-FEB 4.4 555 132 THU 18Z 21-FEB 0.00 0.00 0.00 0.00 12.1 556 134 FRI 00Z 22-FEB 0.04 0.00 0.00 0.04 8.8 557 134 FRI 06Z 22-FEB 0.21 0.04 0.00 0.25 6.3 558 134 FRI 12Z 22-FEB 0.56 0.12 0.00 0.82 6.3 558 134 FRI 18Z 22-FEB 0.52 0.03 0.00 1.34 8.2 559 135 SAT 00Z 23-FEB 0.21 0.03 0.00 1.54 8.0 559 136 SAT 06Z 23-FEB 0.40 0.07 0.00 1.94 11.1 562 138 SAT 12Z 23-FEB 0.91 0.47 0.00 2.85 14.5 563 138 SAT 18Z 23-FEB 0.32 0.21 0.00 3.17 18.4 563 138 SUN 00Z 24-FEB 0.11 0.04 0.00 3.28 17.3 565 138 SUN 06Z 24-FEB 1.30 0.23 0.00 4.58 14.7 562 136 Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 21, 2019 Author Share Posted February 21, 2019 54 minutes ago, Wmsptwx said: That picture is incredible...having been there once it's astounding to see it like that. well I assumed the rate of rise would level off by now and it looked like that was happening. as the rate fell to .14 feet per hr this morning for a few hours..but the last few hours rate is increasing again( not on TVA site yet but will be soon) It could be the crest wave off the main stem is hitting the lake and this is more then the decline in other inflows.. another wild card is Laruel River lake...this is a dammed up area for Flood control with no spillway in the watershed ..I have seen You-tube videos of it overflowing in the past but can't find any info on its current status...did it just start to overflow? has it been all along? not yet? I'm not sure if TVA is legally bind to keep the combined runoff flows from Wolf Creek, Dale Hollow and the 500 sq miles of local runoff maxed 40.000 cfs..the articles I found just implies that is procedure but as I pointed out they are wasting time and water but not moving outflow up to 35,000 now...as they planned last friday Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 21, 2019 Author Share Posted February 21, 2019 8 minutes ago, jaxjagman said: ECMWF Deterministic FORECAST FOR: BNA LAT= 36.12 LON= -86.68 ELE= 591 12Z FEB21 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 THU 12Z 21-FEB 4.4 555 132 THU 18Z 21-FEB 0.00 0.00 0.00 0.00 12.1 556 134 FRI 00Z 22-FEB 0.04 0.00 0.00 0.04 8.8 557 134 FRI 06Z 22-FEB 0.21 0.04 0.00 0.25 6.3 558 134 FRI 12Z 22-FEB 0.56 0.12 0.00 0.82 6.3 558 134 FRI 18Z 22-FEB 0.52 0.03 0.00 1.34 8.2 559 135 SAT 00Z 23-FEB 0.21 0.03 0.00 1.54 8.0 559 136 SAT 06Z 23-FEB 0.40 0.07 0.00 1.94 11.1 562 138 SAT 12Z 23-FEB 0.91 0.47 0.00 2.85 14.5 563 138 SAT 18Z 23-FEB 0.32 0.21 0.00 3.17 18.4 563 138 SUN 00Z 24-FEB 0.11 0.04 0.00 3.28 17.3 565 138 SUN 06Z 24-FEB 1.30 0.23 0.00 4.58 14.7 562 136 if that train sets up the typical WSW to ENE fashion then I assume the cumberland watershed above(SE of the lake) the lake gets that too..or at least a toned down version Link to comment Share on other sites More sharing options...
TellicoWx Posted February 21, 2019 Share Posted February 21, 2019 12z Euro: 1 1 Link to comment Share on other sites More sharing options...
nrgjeff Posted February 21, 2019 Share Posted February 21, 2019 Friday Excessive Rainfall Outlook is upgraded to High for parts of North Alabama, southern Middle Tennessee, northeast Mississippi and other adjacent areas of Tenn. Link to comment Share on other sites More sharing options...
janetjanet998 Posted February 21, 2019 Author Share Posted February 21, 2019 18z NAM best case for Cumberland as it keep the train south(current obs and short range models agree) and north with the last part 18 minutes ago, nrgjeff said: Friday Excessive Rainfall Outlook is upgraded to High for parts of North Alabama, southern Middle Tennessee, northeast Mississippi and other adjacent areas of Tenn. ...THERE IS A HIGH RISK OF FLASH FLOODING OVER PORTIONS OF SOUTH CENTRAL TN...NORTHEAST MISSISSIPPI AND FAR NORTHERN ALABAMA... ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL OVER PARTS OF THE LOWER MISSISSIPPI VALLEY TO THE TENNESSEE VALLEY DUE TO ANTECEDENT CONDITIONS PLUS ADDITIONAL RAINFALL... 21z update... After collaborating with WFOs JAN/MEG/OHX/HUN, a High Risk was assigned to portions of south central TN, northeast MS and far northern Alabama for Day 2. The main reason for the upgrade is the saturated antecedent conditions across these areas. In many spots, rivers are in flood, and the most recent National Water Model showed a large area of very high streamflows from previous activity. The aforementioned offices indicated that as little as 1.00 inches of rainfall in three hours could have significant impacts. As surface low pressure tracks from the TX Panhandle into the Mid MS Valley, a 35/45 knot low level southwest flow transports 1.50 inch precipitable water air (which is between two and three standard deviations above the mean) and 500 J/KG of MUCAPE along a frontal boundary moving north across the Lower MS and TN Valleys. The combination of moisture and instability could result in convection with hourly rainfall rates in excess of 1.00 (as seen in the 12z NAM CONUS Nest and the 12z WRF ARW) over the aforementioned areas. This would be sufficient to cause significant flooding issues where storms training (which is possible, given that the 850-300 mb mean wind becomes better aligned with the propagation vectors). Hayes Link to comment Share on other sites More sharing options...
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