A nearly stationary frontal boundary across the Tennessee valley provided the necessary lift and instability for showers and thunderstorms to develop across the area. Several areas of thunderstorms continued to train over northeast Tennessee, resulting in flash flooding across portions of the area.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MRX wrote it up.
A nearly stationary frontal boundary across the Tennessee valley provided the necessary lift and instability for showers and thunderstorms to develop across the area. Several areas of thunderstorms continued to train over northeast Tennessee, resulting in flash flooding across portions of the area.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Morristown, TN wrote its last area forecast discussion before the first event at Sep 24, 7:50 PM EST, 2 hours 30 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 850 PM EDT THU SEP 24 2009 .DISCUSSION...VERY MOIST AIRMASS FOR LATE SEPTEMBER WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S OVER MOST LOCATIONS. AIRMASS REMAINS MARGINALLY UNSTABLE WITH CAPES BETWEEN 500-1000 J/KG. VERY MOIST AND MARGINAL INSTABILITY WILL REMAIN MOST OF THE NIGHT. WILL MAINTAIN A 20-30 PERCENT POPS FOR THE REST OF THE NIGHT. MAIN CONCERN WITH THESE SHOWERS-THUNDERSTORMS WILL BE VERY HEAVY RAIN. WILL NEED TO WATCH FOR ANY TRAINING OF CELLS OVERNIGHT WITH LOCALLIZED HEAVY RAINFALL POSSIBLE GIVEN PWS (FROM BNA SOUNDINGS) AT 2.2 INCHES... WHICH TROPICAL LIKE. HAVE UPPED LOWS ACROSS THE NORTHERN HALF OF THE FORECAST AREA BY A DEGREE OR SO. HAVE ALSO ADDED PATCHY DENSE FOG GIVEN THE VERY MOIST ENVIRONMENT. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 71 85 71 78 63 / 20 40 50 90 50 KNOXVILLE MCGHEE TYSON AIRPORT, TN 70 84 70 76 62 / 20 40 50 90 60 OAK RIDGE, TN 71 84 70 76 62 / 20 40 50 90 50 TRI CITIES AIRPORT, TN 65 83 63 74 55 / 20 40 50 90 70 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && DH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MORRISTOWN TN 352 AM EDT THU SEP 24 2009 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-250800- CHEROKEE-CLAY-SCOTT TN-CAMPBELL-CLAIBORNE-HANCOCK-HAWKINS- SULLIVAN-JOHNSON-MORGAN-ANDERSON-UNION-GRAINGER-HAMBLEN- NORTHWEST COCKE-COCKE SMOKY MOUNTAINS-NORTHWEST GREENE- SOUTHEAST GREENE-WASHINGTON TN-UNICOI-NORTHWEST CARTER- SOUTHEAST CARTER-ROANE-LOUDON-KNOX-JEFFERSON-NW BLOUNT- BLOUNT SMOKY MOUNTAINS-NORTH SEVIER-SEVIER SMOKY MOUNTAINS- SEQUATCHIE-BLEDSOE-RHEA-MEIGS-MCMINN-NORTHWEST MONROE- SOUTHEAST MONROE-MARION-HAMILTON-BRADLEY-WEST POLK-EAST POLK-LEE- WISE-SCOTT-RUSSELL-WASHINGTON- 352 AM EDT THU SEP 24 2009 /252 AM CDT THU SEP 24 2009/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST NORTH CAROLINA...EAST TENNESSEE AND SOUTHWEST VIRGINIA. .DAY ONE...TODAY AND TONIGHT THE SOUTH CHICKAMAUGA CREEK NEAR CHATTANOOGA HAD FALLEN BELOW THE FLOOD STAGE OVERNIGHT...AND CONDITIONS CONTINUED TO IMPROVE AFTER THE RECENT HEAVY RAINS. THUS...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY PATCHY AREAS OF DENSE FOG MAY DEVELOP LATE THURSDAY NIGHT AND LINGER INTO FRIDAY MORNING...REDUCING VISIBILITIES TO BETWEEN ZERO AND ONE HALF MILE. SHOWERS AND THUNDERSTORMS WILL INCREASE FRIDAY NIGHT INTO SATURDAY NIGHT...AS A COLD FRONT APPROACHES. AT THIS TIME...ONLY ISOLATED STRONG TO SEVERE STORMS ARE EXPECTED...WITH STRONG AND GUSTY WINDS THE MAIN THREAT. HOWEVER...THESE SHOWERS AND STORMS MAY PRODUCE A FEW AREAS OF 1 TO 2 INCHES OF RAINFALL. MOTORISTS MAY NEED TO BE ALERT FOR PONDING OF WATER ON ROADWAYS...AND MINOR FLOODING OF LOW LYING AREAS AGAIN THIS WEEKEND. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION SHOULD NOT BE NEEDED...UNLESS THE THREAT OF STRONG TO SEVERE STORMS INCREASES FRIDAY NIGHT INTO SATURDAY NIGHT. TG
The Knoxville radar (KMRX), 116 km away, was scanning. The volume nearest the first event began at 03:17 UTC.
1 flash flood. Local standard time, as filed.
Flash flooding was occurring with several inches of water flooding across Highway 11 east in Bristol, Tennessee.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2009Every state in 2009This day in weather historyWarnings in Tennessee, September 2009
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 198119.