FXUS64 KMRX 061920
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
220 PM EST SUN DEC 6 2009

.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...CURRENT SURFACE 
ANALYSIS SHOWS A LARGE DOME OF HIGH PRESSURE CENTERED OVER THE 
CENTRAL APPALACHIANS...WITH A LOW PRESSURE SYSTEM OVER THE SOUTHERN 
PLAINS. THIS LOW IS PROGGED TO MOVE NORTHEAST TOWARDS THE GREAT 
LAKES REGION TONIGHT...AND WILL PUSH A WEAK COLD FRONT ACROSS THE TN 
RIVER VALLEY ON MONDAY. MODELS ARE IN GOOD AGREEMENT THAT ANY 
ISOLATED SHOWERS WITH THIS COLD FRONT WILL AFFECT THE FORECAST AREA 
BY LATE MORNING OR EARLY AFTERNOON...SO EXPECT ONLY LIQUID PRECIP 
WITH THIS FRONT. MODELS REMAIN IN GOOD AGREEMENT WITH DEVELOPING A 
STRONG LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS ON TUESDAY... 
WITH A STRONG WARM AIR ADVECTION PATTERN DEVELOPING OVER THE 
FORECAST AREA. AS A RESULT...A WARM FRONT IS PROGGED TO MOVE NORTH 
TOWARDS THE FORECAST AREA ON TUESDAY...AND SHOULD PRODUCE AN 
EXTENSIVE AREA OF RAIN AS THIS FRONT GRADUALLY MOVES NORTHEAST 
ACROSS THE FORECAST AREA. THIS LOW PRESSURE SYSTEM WILL STRENGTHEN 
FURTHER AS IT QUICKLY MOVES INTO THE LOWER OHIO RIVER VALLEY TUESDAY 
NIGHT...CREATING A PATTERN THAT WILL BE VERY CONDUCIVE TO MOUNTAIN 
WAVE FORMATION IN THE WESTERN FOOTHILLS OF THE SOUTHERN 
APPALACHIANS. MODELS ARE IN GOOD AGREEMENT THAT A STRONG (UP TO 70 
KT) 850 MB JET WILL MOVE INTO THE FORECAST AREA BY 06Z WEDNESDAY... 
WITH A DEEP LOW-LEVEL STABLE LAYER DEVELOPING OVER THE MOUNTAINS 
WITH A STRONG VEERING WIND PROFILE INCREASING WITH HEIGHT. THUS...IT 
APPEARS LIKELY THAT ANOTHER HIGH-END WIND EVENT INDUCED BY MOUNTAIN 
WAVES (SIMILAR TO LAST WEDNESDAY'S EVENT) WILL DEVELOP TUESDAY NIGHT 
ACROSS THE WESTERN FOOTHILLS. MODEL SOUNDINGS ALSO REVEAL SOME 
MARGINAL INSTABILITY DEVELOPING AFTER MIDNIGHT OVER MOST OF THE 
FORECAST AREA...SO WILL MENTION A SLIGHT CHANCE FOR TSTORMS TUESDAY 
NIGHT. AS FOR TEMPS...GUIDANCE NUMBERS ARE IN GOOD AGREEMENT FOR 
TONIGHT AND MONDAY AND LOOK REASONABLE. WILL TREND TOWARDS THE 
WARMER NAM NUMBERS FROM MONDAY NIGHT THROUGH TUESDAY NIGHT...DUE TO 
THE EXPECTED STRONG WARM AIR ADVECTION PATTERN.

.LONG TERM (WEDNESDAY THROUGH SUNDAY)...SCATTERED SHOWERS WILL 
LINGER OVER THE AREA ON WEDNESDAY...AS A WEATHER SYSTEM MOVES AWAY 
FROM THE REGION. WITH COOLER AIR SLIDING IN BEHIND THE SYSTEM... 
HIGHER ELEVATIONS AND POSSIBLY NORTHERN LOCATIONS COULD SEE RAIN MIX 
WITH OR CHANGE OVER TO LIGHT SNOW WEDNESDAY NIGHT AS THE PRECIP 
EXITS THE AREA. HIGH PRESSURE BUILDS IN THURSDAY AND FRIDAY FOR DRY 
CONDITIONS. MODEL CONSISTENCY REMAIN POOR FOR THE END OF THE 
EXTENDED. COULD SEE A WEAK FRONT MOVE THROUGH FRIDAY NIGHT OR 
SATURDAY. WILL LEAVE LOW POPS FOR NOW...THOUGH CONFIDENCE LOW. DRY 
ON SUNDAY.
&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN   31  49  38  52  48 /   0  30  10  90 100 
KNOXVILLE AIRPORT, TN     30  48  35  51  45 /   0  20  10  80 100 
OAK RIDGE, TN             30  48  35  51  45 /   0  20  10  80 100 
TRI CITIES AIRPORT, TN    26  47  31  49  40 /   0  20  10  60 100 
&&

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

$$

DMG/MJB