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TN valley heavy rain/flooding week of whenever


janetjanet998
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I'm not sure what is going wrong in the models (whether its something in the coding..etc), but even the initializations are off on the hi res short range. We have seen it all winter in the med to long range models. Perfect example of the chaos theory in action...bad initialization = compounded variation in error as time goes. 

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 Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1121 AM CST Fri Feb 22 2019

   Valid 231200Z - 241200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM A PORTION
   OF THE LOWER MISSISSIPPI VALLEY INTO THE TENNESSEE VALLEY...

   ...SUMMARY...
   Scattered severe storms are expected Saturday from a portion of the
   lower Mississippi and Tennessee Valleys and possibly into western
   and central Kentucky.  Damaging wind and tornadoes are the main
   threats, but hail is also possible.

   ...Synopsis...

   By 12Z Saturday, lee cyclogenesis will be well underway over the
   southern High Plains in association with a potent southern-stream
   shortwave trough now located over AZ. This feature will continue
   into the southern and central Plains and then northeastward into the
   middle MS Valley tomorrow. By later Saturday afternoon the cyclone
   will be located over MO with a cold front trailing southward through
   AR and LA. A warm front should extend southeastward from the low
   through western KY into middle TN and GA. The surface low will
   occlude over the Great Lakes while the trailing front reaches the
   central and southern Appalachians by the end of the period. 
    
   ...Lower Mississippi through Tennessee Valley regions...

   As of mid day a quasi-stationary front extends from the northwest
   Gulf through southern portions of the Gulf Coast states. Rich
   low-level moisture with upper 60s to near 70 F dewpoints resides
   south of this front. Farther north a rain-cooled boundary stretches
   from northeast TX through northern portions of MS, AL and GA. A
   broad southerly low-level jet will increase tonight over the lower
   MS Valley within the gradient zone between retreating high pressure
   and the developing lee cyclone. This will promote northward advance
   of the warm front that will eventually merge with the rain-cooled
   boundary farther north. This consolidated boundary should reach
   central AR and western TN later Saturday morning, possibly
   continuing as far north as western KY during the afternoon. Primary
   uncertainty this forecast is degree and northward extent of boundary
   layer destabilization, especially through west and central KY. Most
   recent model runs including the CAMs suggest that much of KY will be
   affected by areas of widespread rain and clouds within zone of
   isentropic ascent north of the warm front, with only a small window
   for modest surface-based destabilization before cold frontal
   passage. The RAP, being the outlier, advances the unstable warm
   sector farther north. In either case, feel that at least a slight
   risk is warranted as far north as KY given the favorable kinematic
   environment and some potential for surface-based destabilization.

   Otherwise, a corridor of modest surface-based instability (500-1000
   J/kg MLCAPE) is expected to evolve in warm sector over the lower MS
   and western TN Valleys within zone of theta-e advection along the
   strengthening low-level jet. A band of thunderstorms will likely
   develop within this warm conveyor belt along and just ahead of the
   cold front from AR into LA by late morning and continue east during
   the afternoon. A strong mid-level jet rotating through base of the
   shortwave trough, coupled with the strengthening 50+ kt low-level
   jet, will promote very favorable wind profiles for severe storms.
   Large 0-2 km hodographs and 50+ kt effective bulk shear will support
   supercells with low-level mesocyclones and bowing structures capable
   of tornadoes and damaging wind, with peak period from afternoon into
   early evening.
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lake  Cumberland getting a train of Moderate rain now...models increase the  rates overnight in this band (or reform it),,location is the only question...flood warnings for the eastern part of the watershed from rainfall this morning.. (up to an inch)

2/22/2019    8 AM    747.88       35,960  +.04
2/22/2019    9 AM    747.98       35,960  +.10
2/22/2019    10 AM    748.00      35,960  +.02
2/22/2019    11 AM    748.05      35,960  +.05
2/22/2019    noon    748.10      35,960   +.05

 

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BNA 
  
MODERATE TO OCCASIONALLY HEAVY RAINS CONTINUE TO STREAM INTO  
MIDDLE TN THIS MORNING. BIGGEST AREA OF CONCERN IS STILL SOUTH OF  
I-40 AND WEST OF I-24 WHERE THE BULK OF THE RAIN IS FALLING THIS  
MORNING. TO THIS POINT, WE'VE BEEN SPARED ANY EXTREMELY HEAVY RAIN   
BY THE FACT THAT WE REMAIN NORTH OF THE WARM FRONT, WHICH IS STILL  
WAY DOWN IN CENTRAL ALABAMA. THIS IS KEEPING THE INSTABILITY SOUTH  
OF US ALONG WITH THE CONVECTION. HOWEVER, THIS IS GOING TO BE THE  
BIGGEST CONCERN THIS EVENING AS THE WARM FRONT SLOWLY LIFTS  
NORTHWARD. CONVECTION WILL BE OUR BIGGEST ENEMY IN THIS SITUATION  
BECAUSE IT MEANS RAIN RATES WILL QUICKLY INCREASE FROM WHAT IS  
0.5-1.0 IN/HR (WHICH IS CLOSE TO MANAGEABLE) TO 1.0-2.0 IN/HR OR   
MORE.  
  
NOT MUCH HAS CHANGED IN THE OVERALL BIG PICTURE. THIS MORNING'S  
RAINFALL IN THE SOUTHWEST IS ONLY GOING TO SERVE TO EXACERBATE THE  
FLASH FLOOD POTENTIAL LATER THIS AFTERNOON AND TONIGHT WHEN THE  
WARM FRONT LIFTS NORTHWARD. IN THE MEANTIME, IF ANY CONVECTION  
STARTS, FLASH FLOOD WARNINGS ARE LIKELY TO COME OUT QUICKER.  
  
THIS REMAINS A VERY DANGEROUS SITUATION. IF YOU HAVEN'T DONE IT  
ALREADY, PLEASE DEVELOP A PLAN SO THAT YOU AND YOUR LOVED ONES  
HAVE HIGHER GROUND TO RETREAT TO IF FLASH FLOODING BEGINS IN YOUR  
AREA.  
  

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I’m not as educated on this stuff as most of y’all, but it seems like this isn’t materializing much over the valley today. Barely been drizzling much of the morning in Athens. 


Just mostly drizzle to light rain in Knoxville for the most part. Knock on wood but we have escaped the major flooding to this point.


.
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22 minutes ago, PowellVolz said:

 


Just mostly drizzle to light rain in Knoxville for the most part. Knock on wood but we have escaped the major flooding to this point.


.

 

HRRR, RAP and 18z NAM products lift the WF north of you without much rain really...everything NW,,,likely too far NW

 

18z NAMnest destroys the TN/KY state line..NAM central KY

 

18z RAP clueless

 

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REA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NASHVILLE TN  
212 PM CST FRI FEB 22 2019  
  
...POTENTIALLY LIFE-THREATENING FLASH FLOODING POSSIBLE TONIGHT  
AND TOMORROW MORNING...  
   
DISCUSSION  
  
LIGHT TO MODERATE RAIN CONTINUES TO STREAM INTO MIDDLE TN AT   
FORECAST TIME. LATEST SURFACE ANALYSIS WOULD SUGGEST THAT THE WARM   
FRONT, CURRENTLY DRAPED FROM WEST TO EAST OVER CENTRAL MS AND AL, IS   
STARTING TO LIFT NORTHWARD TOWARDS THE MID-STATE AT THIS HOUR.  AS   
IT APPROACHES THE AL-TN STATE LINE THIS EVENING, ELEVATED   
INSTABILITY AND PLENTY OF CONVERGENT LOW-LEVEL WIND FIELDS WILL SPUR   
HEAVY RAINFALL ONCE AGAIN.  PW VALUES THAT ARE UNHEARD OF THIS TIME   
OF YEAR WILL PROVIDE THE NECESSARY MOISTURE AND IT'S DURING THIS   
TIME, WHEN WE START TO SEE SOME WARM FRONT-INDUCED CONVECTION BEGIN,   
THAT IS OUR MAIN CONCERN FOR ADDITIONAL FLASH FLOODING.  THE PROBLEM   
IS, IT'S GOING TO BE DURING HOURS OF DARKNESS.  THIS PRESENTS ADDED   
ISSUES WHEN DEALING WITH FLASH FLOODING: YOU CAN'T SEE IT COMING.   
THE AREA(S) OF CONCERN HAVE NOT CHANGED.  THOSE SOUTH OF I-40 AND   
WEST OF I-24 HAVE THE GREATEST THREAT DUE TO THE HIGHEST RAINFALL   
TOTALS OVER THE LAST COUPLE OF DAYS.  I CAN'T STRESS THIS ENOUGH: IF   
YOU DON'T HAVE A PLAN IN PLACE ALREADY, NOW IS THE TIME TO DO IT. IF   
YOU LIVE IN AN AREA THAT IS ALREADY FLOODED OR YOU KNOW IT CAN FLOOD   
QUICKLY, HAVE A PLACE OF HIGHER GROUND WHERE YOU CAN GO IN A HURRY   
TO ESCAPE RISING FLOOD WATERS.  PLAN, THEN ACT.  DON'T REACT.  
  
THE HEAVIEST OF THE RAINFALL SHOULD MOVE NORTH OF THE MID-STATE   
BEFORE THE NOON HOUR TOMORROW.  WHILE SOME LIGHT RAIN IS POSSIBLE   
DURING THE EARLY AFTERNOON HOURS, IT'S MORE LIKELY THAT WE'LL SEE   
SOMEWHAT OF A BREAK FROM THE RAIN FOR SEVERAL HOURS BEFORE ANY   
THREAT OF SEVERE WEATHER SATURDAY EVENING.  THIS WILL BE THE BIG   
QUESTION OF THE FORECAST:  HOW MUCH OF A BREAK CAN WE GET?  IS THERE   
ANY CHANCE WE SEE BREAKS IN THE CLOUDS? AND EVEN IF WE DON'T SEE ANY   
BREAKS IN THE CLOUDS, WILL THE WARM AIR ADVECTION START EARLY ENOUGH   
AND BE STRONG ENOUGH TO PROVIDE THE NECESSARY INSTABILITY FOR   
WIDESPREAD SEVERE WEATHER TOMORROW EVENING?  BOTH THE GFS AND NAM   
SUGGEST THE WAA WILL BE STRONG ENOUGH TO BRING 500-800 J/KG INTO   
AREAS OF MIDDLE TN SOUTH OF I-40 AND WEST OF I-65.  THIS IS   
TROUBLESOME BECAUSE OF THE AMOUNT OF LOW-LEVEL SHEAR THAT WILL BE   
AROUND.  FORECAST HODOGRAPHS HAVE QUITE THE CURVE IN THEM IN THE   
LOWEST LEVELS OF THE ATMOSPHERE, BUT IF WE DON'T REALIZE THE   
INSTABILITY, WE'RE MOST LIKELY GOING TO BE DEALING WITH A BROKEN   
QLCS THAT WILL HAVE EMBEDDED ROTATION.  ALL OF THAT SAID, HERE'S THE   
KICKER:  WE DON'T NEED WINDS OF 60-70 MPH TO HAVE PROBLEMS TOMORROW   
EVENING.  AS WET AS THE GROUND IS AND WILL BE, WINDS OF 40-50 MPH   
ARE LIKELY TO TOPPLE TREES JUST AS EASY.  SO, NO MATTER THE   
EVOLUTION OF THIS SYSTEM, IF WE DO SEE ANY WINDS TOMORROW EVENING,   
IT'LL LIKELY BE A LONG NIGHT.  PAY CLOSE ATTENTION TO DEW POINTS IN   
THE MORNING ACROSS NORTHEASTERN MS AND NORTHERN AL. IF THEY START   
CREEPING TOWARDS 55-60 DEGREES, THE LIKELIHOOD OF SEVERE WEATHER   
WILL BE THAT MUCH GREATER HERE IN MIDDLE TN.  
  
HERE'S THE GOOD NEWS IN ALL OF THIS: MODELS ARE STILL SHOWING AT   
LEAST 3 DRY DAYS AFTER THIS IS ALL OVER.  I'M GOING TO CARRY VERY   
SMALL POPS FROM WEDNESDAY ON AS THE GFS AND EURO CONTINUE TO HOLD   
THEIR GROUND WITH VERY DIFFERENT SOLUTIONS.  IF THE EURO VERIFIES,   
WE COULD BE LOOKING AT 5+ DAYS OF DRY WEATHER.  FINGERS CROSSED...  
  

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Top 5 crest now expected at Cairo and Paducah on the OHIO

56.5 cario and 53.5 at Paducah

this is all depended if the heavy rain one make it more north I think...if not they will be lower

they are dumping huge amounts out of the Kentucky Lake and Barkley but they have no choice...

 

420,000 cfs!!

----------------------------------------

Lake Cumberland

2/22/2019    2 PM    748.20       36,200.  +.06
2/22/2019    3 PM    748.26       36,200.  +.06
2/22/2019    4 PM    748.30       36,220.  +.04

 

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TN River at Savannah forecast crest now 393.81. which would be 3rd all time

1) 401.20 ft on 03/21/1897
(2) 396.11 ft on 03/20/1973
(3) 392.70 ft on 01/02/1927
(4) 392.42 ft on 02/06/1957
(5) 392.29 ft on 02/16/1948
(6) 391.61 ft on 01/13/1946
(7) 390.70 ft on 05/12/2003
(8) 390.42 ft on 12/12/2004
(9) 389.05 ft on 04/10/1936
(10) 389.00 ft on 01/14/1974

 

392    Second floor of houses on stilts is flooding all along the river. North end of Dorthy Lane at Campsite is beginning to flood. Many houses are flooded at Campsite.
  

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Mesoscale Precipitation Discussion 0065
NWS Weather Prediction Center College Park MD
1045 PM EST Fri Feb 22 2019

Areas affected...Southeast AR...Northern MS...Far Northwest
AL...Southwest to South-Central TN

Concerning...Heavy rainfall...Flash flooding likely

Valid 230345Z - 230945Z

Summary...There will be concerns for life-threatening/significant
flooding and flash flooding overnight as additional rounds of
heavy showers and thunderstorms arrive over exceedingly
wet/saturated soil conditions.

Discussion...The large scale synoptic pattern features a deep
trough and associated closed low beginning to exit the Four
Corners region and moving out across the southern High Plains.
Downstream of this is a deep layer warm advection pattern over the
Lower MS Valley with a strong subtropical jet oriented
southwest/northeast from the eastern Pacific up across the
northwest Gulf of Mexico and across the Mid-South. Meanwhile, a
quasi-stationary frontal zone is draped across the Gulf Coast
states.

There continues to be more than enough forcing in place for
numerous showers and thunderstorms across areas of the Lower MS
Valley and Mid-South as persistent southwest low level flow in the
850/925 mb overruns the front and transports plenty of moisture
and instability in an elevated fashion. Additionally, much of this
region is situated underneath favorable right-entrance region jet
dynamics which is fostering deep layer ascent in conjunction with
favorable thermodynamics.

The latest radar imagery is showing heavy showers and
thunderstorms beginning to gradually become better
organized/focused again over areas of southeast AR and up across
northern MS. Cloud top cooling seen in GOES-16 IR satellite
imagery is suggestive of stronger forcing and most likely related
to not only an increase in divergent flow aloft, but also
strengthening of the low level jet.

Hires models from the 00Z cycle, including numerous runs of the
HRRR, support an axis of training showers and thunderstorms going
through 09Z across especially areas of southeast AR, northern MS,
and into areas of southwest to south-central TN. This will be
supported by largely unidirectional flow in the 850/500 mb layer,
but one major contributing factor to the rainfall threat overnight
will be the increasing low level jet which is forecast to reach
upwards of 50 kts across northern MS by 09Z. Enhanced moisture
transport will result from this and the PWATs are forecast to rise
to locally over 1.75 inches.

Radar trends tend to favor the QPF axis of the 00Z ARW and last
couple runs of the HRRR a bit more versus the 00Z ARW2/NAM-conest
solutions, and the MPD threat area closely follows a consensus of
these solutions for this period.

Very heavy rainfall totals overnight are expected, with as much as
an additional 3 to 5 inches of rain expected. In fact, the latest
HREF probabilistic output favors rainfall rates approaching 2
inches/hr within the stronger convective elements.

Unfortunately, the soil conditions are saturated and there are
already locally significant runoff problems/flooding ongoing. The
additional rainfall tonight will only exacerbate the situation
further and it appears that life-threatening/significant flooding
and flash flooding will be likely. Will continue to monitor the
situation closely.

Orrison
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Sometimes a pic is better than a model. This image of the SE radars tells alot. You can see the surface front drifting north over north central AL/GA, surging the moisture north (light blue shading near the radar sights south of the front. The 850 front drapped sw-ne across MS to the N Plateau. Where the surface front catches the 850 front...its unloading a tremendous amount of the gulf moisture. Very bad setup...anywhere N of the entire southern TN border.

southmissvly (1).gif

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9 minutes ago, TellicoWx said:

Sometimes a pic is better than a model. This image of the SE radars tells alot. You can see the surface front drifting north, surging the moisture north (light blue shading near the radar sights south of the front. The 850 front drapped sw-ne across MS to the N Plateau. Where the surface front catches the 850 front...its unloading a tremendous amount of the gulf moisture. Very bad setup...anywhere N of the entire southern TN border.

southmissvly (1).gif

Actually what you see is from an Inverted trough,the WF that was suppose to lift is still in Central Alabama

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