Alert archive / Tennessee / Flash Flood Watches in 2015

Flash Flood Watch 4, NWS Morristown, TN

December 27, 201519 counties in Tennessee; Cherokee County, Clay County, North Carolina

NWS Morristown, TN issued this flash flood watch at Dec 27, 2015, 6:20 PM EST for 19 counties in Tennessee; Cherokee County, Clay County, North Carolina. It took effect at Dec 28, 2015, 1:00 PM EST. It was in force for 26 hr.

The area

The counties it named.

The facts

Issued
Dec 27, 2015, 6:20 PM EST (23:20 UTC)
In effect from
Dec 28, 2015, 1:00 PM EST
Expired
Dec 29, 2015, 2:57 PM EST
In force
26 hr
Issued by
NWS Morristown, TN
Flood severity
None
All 21 counties

Cherokee County, NC, Clay County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Cocke County, TN, Hamilton County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN

The radar

The Knoxville radar (KMRX), 115 km from the middle of the area, began a volume at 23:19 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.3 hours before the alert went out and 199 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2015-12-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 187 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2015-12-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 324 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
187 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
710 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
324 m²/s²
0-3 km storm-relative helicity
373 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, 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 this flash flood watch went out at Dec 27, 6:03 PM EST, 17 minutes earlier.

Area forecast discussion, Dec 27, 6:03 PM EST, 17 minutes before
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Hazardous weather outlook, Dec 27, 3:17 PM EST, 3 hours 3 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MORRISTOWN TN
317 PM EST SUN DEC 27 2015

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-282030-
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-
317 PM EST SUN DEC 27 2015 /217 PM CST SUN DEC 27 2015/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST NORTH
CAROLINA...EAST TENNESSEE AND SOUTHWEST VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

NO HAZARDOUS WEATHER IS EXPECTED.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY...

WITH ABUNDANT RECENT RAINFALL...THE GROUND WILL REMAIN NEAR
SATURATION AS THE NEXT SYSTEM MOVES IN MONDAY INTO MONDAY NIGHT.
THIS COULD LEAD TO ADDITIONAL LOCALIZED FLOODING AS SCATTERED
SHOWERS AND THUNDERSTORMS MOVE ACROSS THE REGION. A FEW
THUNDERSTORMS MAY BECOME STRONG OR SEVERE MONDAY AFTERNOON INTO
EARLY MONDAY NIGHT.

AS THE SYSTEM MOVES ACROSS THE AREA MONDAY AFTERNOON AND EVENING...
STRONG WINDS WILL DEVELOP ACROSS THE SOUTHERN APPALACHIANS. THE
HIGHER ELEVATIONS AND ADJACENT FOOTHILLS...SUCH AS CAMP CREEK...
TENNESSEE...MAY EXPERIENCE STRONG AND GUSTY WINDS IN EXCESS OF 60
MPH BEGINNING MONDAY AFTERNOON AND CONTINUING THROUGH MONDAY
NIGHT.

ANOTHER SYSTEM MOVES IN ON WEDNESDAY BUT THERE IS QUITE A BIT OF
UNCERTAINTY WITH THE TRACK. IF THE TRACK IS FURTHER WEST...AS SOME
LATEST MODEL RUNS ARE SHOWING...WE COULD RECEIVE ADDITIONAL
MODERATE TO LOCALLY HEAVY RAINFALL DURING THE DAY ON WEDNESDAY. THE
HEAVIEST PRECIP WOULD LIKELY OCCUR ACROSS THE EASTERN
MOUNTAINS...ADJACENT FOOTHILLS...AND ESPECIALLY ACROSS OUR TWO
SOUTHWEST NORTH CAROLINA COUNTIES. A MORE WESTERN TRACK WOULD POSE
FLOODING RISK DUE TO RECENT RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED MONDAY AFTERNOON AND EVENING.

The office that day

Everything else NWS Morristown, TN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 27, 10:56 AM ESTHigh Wind WatchMRXBlount, Carter, Cocke, Greene, Johnson, Monroe and 3 more16 hr

Nearby

Flash Flood Watches in Tennessee, 2015Flash Flood Watches in North Carolina, 2015Every flash flood watch in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.