Serious Flooding Plagues TN Valley Friday Into Saturday.
Modeling is looking very troublesome for those locales in western and middle TN during the day Friday. What’s currently a major severe weather outbreak in the southern Plains states will “congeal” into a major heavy rain event across the mid south as we wrap up the work week. While we here in the mountains should remain free of the extremely heavy rainfall during the day Friday, this heavy rain axis will push itself into our region Friday evening, continuing into Saturday morning. Please stay tuned to www.mountaincityweathercenter.com for the latest information on rainfall amounts in Johnson County, and if you must travel to western or middle TN Friday, please keep abreast of the latest weather situation.
Below are a few links (and text from the NWS) to show just how bad weather conditions are in the middle and western parts of the state:
From the Memphis NWS:
THE
PREDOMINANT SEVERE WEATHER THREATS WITH ANY THUNDERSTORMS THAT
BECOME SEVERE WILL BE DAMAGING WINDS AND LARGE HAIL. HOWEVER…THE
LARGER THREAT AT THIS TIME APPEARS TO BE FLASH FLOOD POTENTIAL AS
PRECIPITABLE WATER VALUES APPROACH 2 INCHES AND K-INDICIES BETWEEN
35 TO 37. ONE TO THREE INCHES OF RAINFALL TONIGHT AND AN
ADDITIONAL ONE TO TWO INCHES ARE POSSIBLE ON FRIDAY. WILL CONTINUE
FLASH FLOOD WATCH WITH HEAVY RAIN POTENTIAL STILL LOOKING GOOD.
THE SEVERE THUNDERSTORM THREAT WILL BE FOCUSED MOSTLY SOUTH OF
I-40 ON FRIDAY AS A COLD FRONT MOVES THROUGH THE MID SOUTH. MOST
UNSTABLE CAPE VALUES WILL RANGE AROUND 1400 J/KG…WITH LI/S
AROUND -4. ONCE AGAIN THE PREDOMINANT SEVERE WEATHER THREATS
APPEAR TO BE DAMAGING WINDS AND LARGE HAIL.
From the Nashville NWS:
AFTER MIDNIGHT…BOUNDARY WILL BEGIN TO MOVE BACK TOWARD THE SE. AS
UPPER LEVEL ENERGY BEGINS TO ACT ON THE BOUNDARY…LOW LEVEL
FORCING AND OVERALL QPF TOTALS WILL BE ON THE INCREASE. GIVEN THE
HIGHER PRECIPITABLE WATER AMOUNTS…WILL NOT ONLY CONTINUE THE FLOOD
WATCH BUT WILL ALSO EXPAND IT SOUTH AND EASTWARD TO INCLUDE ALL OF
THE MID STATE.
OVERNIGHT TONIGHT…WE SHOULD CATCH A BREAK FROM THE HEAVIER
RAINFALL AS THE FRONT REMAINS A GOOD DISTANCE TO OUR NORTH. POPS
HOWEVER WILL STILL BE CATEGORICAL BUT WITH LESS QPF EXPECTED. THE
HEAVIER RAINFALL WILL ARRIVE LATE TONIGHT AND ESPECIALLY DURING THE
DAY ON FRIDAY.
AS FOR SVR POTENTIAL…A SLT RISK IS IN EFFECT FOR THE MID STATE.
WIND ENERGY AND OMEGA PROFILES SUGGEST THAT THE BEST TIME FOR SEVERE
WX WOULD BE FRIDAY MORNING IN ADVANCE OF THE SOUTHWARD MOVING
BOUNDARY. INSTABILITIES HOWEVER…ARE NOT THAT GREAT WITH SHOWALTER
VALUES OF -1. WITHIN THE ZONES AND GRIDS…WILL EMPHASIZE HEAVY
RAINFALL POTENTIAL AND NOT SO MUCH THE SVR POTENTIAL IN THE ZONES.
FOR THE UPCOMING FORECAST…AGAIN…WILL EXPAND THE WATCH TO INCLUDE
THE ENTIRE MID STATE. VALID TIMES WILL BEGIN AT 06Z TONIGHT ACROSS
THE NW ZONE AND 12Z ELSEWHERE. WATCH TERMINATION TIMES WILL BE 06Z
SATURDAY…EXCEPT FOR 00Z SATURDAY FOR THE NW ZONE.
AS FOR QPF AMOUNTS FROM NOW THROUGH SATURDAY MORNING…WE ARE
LOOKING AT 2-3 INCHES WIDESPREAD WITH 4 TO 5 INCH LOCAL AMOUNTS
POSSIBLE.
From the Morristown NWS:
THIS FRONTAL BOUNDARY EXPECTED TO MOVE FURTHER NORTH THIS EVENING AND
SET UP ACROSS THE OH VALLEY TONIGHT. DEEP MOISTURE AND BETTER UVV WILL
REMAIN WEST AND NORTH THROUGH 12Z THUS EXPECT MAINLY SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS. BETTER DYNAMICS WILL MAKE EASTWARD PUSH ON FRIDAY
BRINGING MORE FAVORABLE INSTABILITY AND INCREASING LL FORCING INTO THE
AREA BY MIDDAY. THESE FEATURES ALONG WITH GOOD ML JET STREAK WILL SLOWLY
CROSS THE AREA BRINGING WIDESPREAD SHOWERS AND THUNDERSTORMS LATER
FRIDAY WELL INTO FRIDAY NIGHT. ASSOCIATED COLD FRONT WILL PUSH JUST
EAST OF THE AREA BY 12Z SATURDAY. OVERALL…INGREDIENTS SETTING UP
FOR LOCALLY HEAVY RAINFALL FRIDAY AFTERNOON/NIGHT.
