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Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

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000
FXUS64 KMRX 221355
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
955 AM EDT WED MAY 22 2013

.DISCUSSION...
-- Changed Discussion --
CURRENT SURFACE ANALYSIS SHOWS A WEAK COLD FRONT OVER THE MS RIVER
VALLEY...WITH AN OUTFLOW BOUNDARY OVER THE FORECAST AREA FROM LAST
NIGHT`S CONVECTION OVER MIDDLE TN. THE LOCAL AIR MASS REMAINS VERY
HUMID THIS MORNING...WITH THE GFS AND NAM MODELS BOTH REVEALING A
MODERATELY UNSTABLE AIR MASS DEVELOPING THIS AFTERNOON AS AN UPPER-
LEVEL TROUGH SWINGS EASTWARD ACROSS THE TN RIVER VALLEY. MODEL
SOUNDINGS ALSO INDICATE A DECENT MID LEVEL WIND FLOW BETWEEN 20 AND
40 KT...SO IT APPEARS THERE WILL BE A GOOD CHANCE FOR SEVERE WEATHER
THIS AFTERNOON AND EVENING. MODELS ALSO INDICATE 0-1 KM HELICITY
VALUES INCREASING AND LCL HEIGHTS LOWERING THIS EVENING...ESPECIALLY
OVER NORTHEAST TN AND SOUTHWEST VA...SO WILL PLAN TO MENTION THE
POSSIBILITY OF AN ISOLATED TORNADO OR TWO IN THE HAZARDOUS WEATHER
OUTLOOK. WILL ALSO PLAN TO MENTION THE POSSIBILITY OF LOCALLY HEAVY
RAINFALL...SINCE PRECIPITABLE WATER VALUES WILL REMAIN HIGH THIS
AFTERNOON (BETWEEN 1.5 AND 1.75 INCHES).

OVERALL...CURRENT FORECAST APPEARS TO BE ON TRACK...BUT WILL UPDATE
THIS MORNING TO REMOVE ANY MORNING PRECIP WORDING...AND TO TWEAK
TEMPS A LITTLE ACCORDING TO THE LATEST TRENDS. WILL ALSO UPDATE THE
HAZARDOUS WEATHER OUTLOOK WITH THE THOUGHTS MENTIONED ABOVE.-- End Changed Discussion --
&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --CHATTANOOGA AIRPORT, TN 83 63 83 57 73 / 70 60 20 20 0
KNOXVILLE AIRPORT, TN 83 62 80 56 71 / 70 60 50 30 10
OAK RIDGE, TN 83 62 80 55 72 / 70 60 50 30 10
TRI CITIES AIRPORT, TN 82 60 78 54 67 / 70 60 60 50 10-- End Changed Discussion --
&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

DMG

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