janetjanet998 Posted February 5, 2020 Author Share Posted February 5, 2020 XCESSIVE RAINFALL DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1057 AM EST WED FEB 05 2020 DAY 1 VALID 16Z WED FEB 05 2020 - 12Z THU FEB 06 2020 ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FROM FAR NORTHWEST ALABAMA INTO EAST CENTRAL TO EASTERN TENNESSEE... 1600 UTC UPDATE THE SLIGHT RISK AREA WAS UPGRADED TO MODERATE OVER FAR NORTHWEST ALABAMA INTO EAST CENTRAL TO EASTERN TENNESSEE. THE 1200 UTC ARW AND NMMB TRENDED HEAVIER FROM THIS AFTERNOON INTO THE EARLY HOURS OF THURSDAY ACROSS THESE AREAS. THE LATEST HI RES GUIDANCE IS SHOWING POTENTIAL FOR SEVERAL ROUNDS OF HEAVY RAINS MOVING PARALLEL TO THE SOUTHWEST TO NORTHEAST ORIENTED FRONTAL BOUNDARY THAT IS EXPECTED TO BE NEARLY STATIONARY INTO THE EARLY HOURS OF THURSDAY FROM NORTHERN ALABAMA INTO EASTERN TENNESSEE. STREAM FLOWS AS PER THE NATIONAL WATER MODEL ARE HIGH ACROSS THESE AREAS WITH HI RES CONSENSUS FOR 2-4"+ OF RAIN ACROSS THESE AREAS THROUGH THE END OF THIS FORECAST PERIOD 1200 UTC THURSDAY. IN AREAS OF TRAINING...HOURLY TOTALS OF 1-1.5"+ POSSIBLE. MESOSCALE PRECIPITATION DISCUSSION 0034 NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1201 PM EST WED FEB 05 2020 AREAS AFFECTED...NORTHEAST MS...NORTHERN AL...SOUTH-CENTRAL & EASTERN TN...EXTREME NW GA... CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE VALID 051700Z - 052230Z SUMMARY...SHOWER/THUNDERSTORM COVERAGE CURRENTLY TRAINING THROUGH SATURATED GROUNDS MAY POSE SOME ISOLATED FLOODING CONCERNS, IN ADVANCE OF MORE SIGNIFICANT CONVECTION LATER THIS AFTERNOON INCREASING FLASH FLOODING RISK THROUGH THIS EVENING. DISCUSSION...CURRENTLY A STATIONARY FRONT EXTENDS FROM SW VA ACROSS CENTRAL TN INTO FAR NE MS, WHERE A WEAK SURFACE INFLECTION IS BEGINNING TO LIFT NORTH-NORTHEAST. A SUBTLE SHORTWAVE OVER E AR INTO W TN, WITHIN A SMALL WEDGE OF REDUCED UPPER-LEVEL FLOW/INCREASED DIFFLUENCE IN CENTRAL TN, SUPPORTS THIS WAVE LIFTING NORTH AND INCREASING SOUTHERLY FLOW ACROSS E MS/AL AND GA. AS SUCH INCREASED FLUX MOISTURE CONVERGENCE HAS ENHANCED SHOWERS FROM SE TN ACROSS N AL, SUPPORTING GREATER VERTICAL DEVELOPMENT AND INCREASED CLOUD TOP COOLING NOTED IN GOES-E 10.3UM, WITH TOPS COOLING BELOW -65C ACROSS NW AL AND SE TN ATTM. LOW TO MID-60S TDS AND SOME WEAK FILTERED INSOLATION THROUGH BREAKS IN THE CLOUDS HAS HELPED TO INCREASE INSTABILITY AVAILABLE FOR THIS AREA RECENTLY WITH MLCAPES NOSING ABOVE 500 J/KG INTO N AL WITH GRADIENT UP/OVER 1000 J/KG BUILDING FROM THE SW. THIS IS IN COMBINATION OF STEEPENING LAPSE RATES BUT ALSO INCREASED THETA-E AIR WITH TDS EVEN UP TO 70 ACROSS CENTRAL MS ATTM. CURRENTLY, THUNDERSTORMS ALONG THIS AXIS FROM NW AL INTO SE TN ARE CAPABLE OF 1-1.25"/HR RATES WITH ISOLATED RATES UP TO 1.5"/HR WITH THE STRONGEST CORES. MEAN STEERING FLOW SHOWS DEEP UNIDIRECTIONAL FLOW TO SUPPORT TRAINING, ACROSS THE AREA, THOUGH A SLOW NORTHWARD TREND/PROPAGATION IS EXPECTED DUE TO THE LIFTING NORTHWARD OF THE SURFACE WAVE AND ASSOCIATED SHORTWAVE, PERHAPS LIMITING BEST/IDEAL TRAINING A BIT. STILL, GIVEN LAST 24HR RAINFALL ACROSS THE AREA, PARTICULARLY FURTHER NORTH AND EAST INTO THE CUMBERLAND PLATEAU...LOWERED FFG VALUES AND SATURATED SOILS EXIST ALLOWING FOR INCREASED/NEARLY COMPLETE HYDROPHOBIC RUN-OFF OF THESE 1-2" TOTALS. AS SUCH, THERE IS A LOW POSSIBILITY OF ISOLATED FLASH FLOODING OVER THE NEXT FEW HOURS ACROSS N AL AND S-CENT/SE TN. STILL, REGARDLESS OF FLOODING WITH THESE CELLS, THEY WILL CONTINUE TO FURTHER SATURATE THE GROUNDS FOR ADDITIONAL CONVECTION EXPECTED BY LATE AFTERNOON EARLY EVENING. STRONGER HEIGHT-FALLS AT THE LEADING EDGE OF STRONGER POSITIVE TILT FULL-LATITUDE SYNOPTIC TROF WILL SUPPORT INCREASING UPPER LEVEL JET DYNAMIC ASCENT AND DPVA TO OVER-WASH THE AREA. THIS WILL SUPPORT FURTHER UPSTREAM/BACKBUILDING REDEVELOPMENT TO OCCUR ALONG/NEAR THE SURFACE INFLECTION IN N MS, WITH SOUTHWARD EXPANSION AFTER DARK. STILL, GIVEN THE PLACEMENT OF THE SURFACE WAVE, ENHANCED LOW LEVEL FLOW AND MOISTURE/THETA-E FLUX...INSTABILITY WILL INCREASE TO 1500-2000 J/KG TOWARD 19Z, ALLOWING FOR STRONGER/BROADER CONVECTIVE CORES. THESE CORES WILL CROSS N MS/N AL INTO TN LATER THIS EVENING INCREASING THE PROBABILITY FOR FLASH FLOODING GIVEN THE GROUND CONDITIONS ARE BEING COMPROMISED CURRENTLY (IF NOT EXCEEDED ALREADY BY 20Z) 2 Link to comment Share on other sites More sharing options...
John1122 Posted February 5, 2020 Share Posted February 5, 2020 Currently at 2.08 inches since Monday evening. Creeks are high and rising and it's pouring down now with a tongue of 3-4 more inches expected through tomorrow. All this coming off the rainiest year ever here, which followed the prior rainiest year ever with the GFS forecasting 12-16 inches of rain for the area over the next 2 weeks. I've had 162 inches of rain in the past 25 months. That's an average of 6.5 inches of rain per month for over 2 consecutive years. That came on the heels of one of the worst droughts we've seen here. The weather is nothing but extremes these days. Extreme warmth, extreme drought, extreme rains, and on the rare times it's managed to get wintry and cold, it was extreme those winters too. Link to comment Share on other sites More sharing options...
ShawnEastTN Posted February 5, 2020 Share Posted February 5, 2020 Currently sitting at 2.48" since midnight, and .30" yesterday. Imby Northern Meigs County. Think Morristown forecast amounts are far too low for this event! Sent from my SM-G965U using Tapatalk Link to comment Share on other sites More sharing options...
Kentucky Posted February 5, 2020 Share Posted February 5, 2020 2.25 for the event, so far in Corbin Link to comment Share on other sites More sharing options...
nrgjeff Posted February 5, 2020 Share Posted February 5, 2020 Lookout Valley west of Chattanooga, flooding on I-24 per Covenant Transport Met. I-24 was closed as of 3pm Eastern Wednesday. Link to comment Share on other sites More sharing options...
TellicoWx Posted February 5, 2020 Share Posted February 5, 2020 Big time flooding here in Monroe Co..houses starting to flood, roads impassable, and starting to evacuate some people in the county. Link to comment Share on other sites More sharing options...
McMinnWx Posted February 5, 2020 Share Posted February 5, 2020 Rain has slowed here in Athens, but several roads are flooded or starting to flood. Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 5, 2020 Share Posted February 5, 2020 front yard, day 1: several creeks crossing the roads in my area of Morgan county (Mossy Grove) 1 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted February 5, 2020 Share Posted February 5, 2020 I've now passed the 3" mark since midnight, sitting at 3.16" Sent from my SM-G965U using Tapatalk Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 5, 2020 Share Posted February 5, 2020 Euro precip projections. Up close and personal: EPS city plots: Link to comment Share on other sites More sharing options...
ShawnEastTN Posted February 5, 2020 Share Posted February 5, 2020 Euro precip projections. Up close and personal: EPS city plots: Crazy stuff, verbatim that puts just at or just under 13" of rain in my back yard over 10 days. Being winter there just isn't anything to drink up that water from the soil. Could make last February's flooding look trivial.Sent from my SM-G965U using Tapatalk Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 5, 2020 Share Posted February 5, 2020 2 minutes ago, ShawnEastTN said: Could make last February's flooding look trivial. Hard to believe, but here we are. Link to comment Share on other sites More sharing options...
John1122 Posted February 5, 2020 Share Posted February 5, 2020 Extremely heavy rain currently falling. My power just came back on after going out around 4pm. Crossed the 3 inch mark as of 6:15. Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 18z GEFS has a nearly 13" MEAN lollipop in SW NC: Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 This looks pleasant: 1 Link to comment Share on other sites More sharing options...
1234snow Posted February 6, 2020 Share Posted February 6, 2020 Really concerned about the Plateau counties into SE KY tonight and into the morning. If the 18z HI-RES NAM is to be believed 4-6” of rain will fall by tomorrow afternoon. 23z HRRR shifts the axis of the heavy rain of 4-5” from over Chattanooga up the spine of the mountains. Anyway you slice it someone in our forum area will have some very dangerous flash flooding. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 Yeah, first edge of that mess is hitting me now. Heaviest rain of the day and lightning now. Link to comment Share on other sites More sharing options...
1234snow Posted February 6, 2020 Share Posted February 6, 2020 Yeah, first edge of that mess is hitting me now. Heaviest rain of the day and lightning now. The line appears to be making good progress eastward. I guess time till tell where it may get hung up at. Link to comment Share on other sites More sharing options...
John1122 Posted February 6, 2020 Share Posted February 6, 2020 Just heard thunder rumble. Snow countdown clock is on. 3 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 Apparently you have to have a special camera to catch lightning. I had my phone set up and got a super vivid flash and this was all it took: All you can see is a little bit of light through the trees, and you better be in a dark room, lol 1 Link to comment Share on other sites More sharing options...
1234snow Posted February 6, 2020 Share Posted February 6, 2020 0z 12km NAM: Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 Wow. In only 27 hours... looks like 6-7 in the southern, eastern great valley this is one heck of a system. Link to comment Share on other sites More sharing options...
1234snow Posted February 6, 2020 Share Posted February 6, 2020 0z HI-RES NAM is wanting to move the line into the mountains by morning. Link to comment Share on other sites More sharing options...
TellicoWx Posted February 6, 2020 Share Posted February 6, 2020 8 minutes ago, Holston_River_Rambler said: Wow. In only 27 hours... looks like 6-7 in the southern, eastern great valley this is one heck of a system. Yeah, not liking the 0z runs so far or the 01z HRRR here for SE TN. Models upped the totals. Alot of people this afternoon were talking about how the worse was over cause of the break...afraid alot are going to be caught off gaurd. Link to comment Share on other sites More sharing options...
John1122 Posted February 6, 2020 Share Posted February 6, 2020 It is absolutely dumping down in buckets out there now with fairly frequent thunder in the area. Link to comment Share on other sites More sharing options...
TellicoWx Posted February 6, 2020 Share Posted February 6, 2020 01z HRRR would be a big problem here Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 Top of the line rolling through now. Sounds like a tropical downpour. More vivid lightning https://giphy.com/gifs/XdD1lHWteTEi6MPD0B Link to comment Share on other sites More sharing options...
dwagner88 Posted February 6, 2020 Share Posted February 6, 2020 4” overnight will pretty much shut Chattanooga down at this point. We already had quite a bit of flooding with the first round mid morning today. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 Euro backed off on the rain totals overnight, but not by too much: Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 6, 2020 Share Posted February 6, 2020 Downtown Sunbright from 8 hours ago. from Morgan County today facebook page: 1 Link to comment Share on other sites More sharing options...
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