683  
FXUS64 KMRX 211740  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
1240 PM EST SAT DEC 21 2024  
   
..NEW AVIATION  
 
   
UPDATE  
 
ISSUED AT 1030 AM EST SAT DEC 21 2024  
 
QUICK UPDATE TO END WINTER WEATHER ADVISORY AS MOISTURE HAS  
BECOME QUITE SHALLOW AND ONLY VERY ISOLATED SNOW SHOWERS OR VERY  
NARROW BANDS WERE OCCURRING ACROSS NORTHEAST TENNESSEE AND  
SOUTHWEST VIRGINIA AT THIS HOUR. FLURRIES AND ISOLATED SNOW  
SHOWERS SHOULD CONTINUE ACROSS THE HIGHER EASTERN TENNESSEE  
MOUNTAINS, SOUTHWEST VIRGINIA AND NORTHEAST TENNESSEE A FEW MORE  
HOURS UNTIL THE LOWEST LEVELS SQUEEZE OUT THE REMAINING LOW LEVEL  
MOISTURE. SKIES WERE CLEARING IN THE SOUTHERN VALLEY AND PARTS OF  
THE CENTRAL VALLEY LATE THIS MORNING. TEMPERATURES AT 10 AM EST  
WERE IN THE UPPER 20S ACROSS HIGHER ELEVATIONS OF SOUTHWEST  
VIRGINIA AND LOWER TO MID 30S ELSEWHERE EXCEPT UPPER 30S NEAR  
CHATTANOOGA WHERE SKIES HAD BECOME SUNNY. NOT MUCH WARMING IS  
EXPECTED WITH THE COLD AIR ADVECTION FROM THE NORTH AND NORTHWEST  
WITH WINDS 10 TO 15 MPH AND SOME GUSTS ABOVE 20 MPH AND SLOW  
CLEARING THIS AFTERNOON. MOST HIGHS WILL STAY IN THE 30S EXCEPT IN  
THE SOUTHERN VALLEY NEAR CHATTANOOGA. WIND CHILLS WILL BE IN THE  
20S MOST SITES BUT TEENS HIGHEST ELEVATIONS. UPDATED FORECAST  
SENT.  
 
 
   
SHORT TERM  
 
(TODAY AND TONIGHT)  
ISSUED AT 128 AM EST SAT DEC 21 2024  
 
KEY MESSAGES:  
 
1. COLD THIS WEEKEND.  
 
2. LIGHT SNOW WILL CONTINUE THROUGH THIS MORNING IN THE HIGHER  
ELEVATIONS OF SOUTHWEST VIRGINIA AND EAST TENNESSEE.  
 
DISCUSSION:  
 
SNOW SHOWERS WILL CONTINUE THIS MORNING IN THE HIGHER ELEVATIONS  
OF SOUTHWEST VIRGINIA AND EAST TENNESSEE. THE INTENSITY OF THE  
SNOW WILL BE LIGHTER THIS MORNING AS NORTHWESTERLY FLOW WEAKENS TO  
15 KNOTS AT 850 MB. BY EARLY AFTERNOON, SNOW SHOWERS WILL REALLY  
TAPER OFF AS NORTHWEST FLOW WEAKENS FURTHER. GENERALLY, ANOTHER  
ONE TO TWO INCHES OF ACCUMULATION IS LIKELY AT ELEVATIONS ABOVE  
2500 FEET FROM NOW (2AM EST) THROUGH THE MORNING.  
 
IN THE TENNESSEE VALLEY AND PLATEAU COUNTIES THE WINDOW FOR SNOW  
ACCUMULATIONS HAS PROBABLY CLOSED. TRI-CITIES REPORTED A TRACE OF  
SNOW BUT OTHERWISE IT SEEMS LIKE ONLY FLURRIES HAVE FALLEN IN  
THESE LOCATIONS BASED ON OBS. SOME LIGHT SNOW OR FLURRIES WILL BE  
POSSIBLE THROUGH MORNING BUT LITTLE TO NO ACCUMULATION IS  
EXPECTED OUTSIDE OF THE HIGHER TERRAIN.  
 
OTHERWISE, THIS AFTERNOON AND TONIGHT WILL BE DRY AND COLD WITH  
HIGHS TODAY IN THE UPPER 30S AND LOWER 40S. LOWS TONIGHT WILL BE  
MAINLY IN THE 20S FOR MOST OF THE VALLEY.  
 
 
   
LONG TERM  
 
(SUNDAY THROUGH FRIDAY)  
ISSUED AT 128 AM EST SAT DEC 21 2024  
 
KEY MESSAGES:  
 
1. SUN ALERT!  
 
2. WARMING TREND NEXT WEEK WITH CHANCES FOR RAIN THE SECOND HALF OF  
THE WEEK INCLUDING CHRISTMAS.  
 
DISCUSSION:  
 
ONE MORE DAY OF WELL BELOW SEASONAL NORMAL TEMPERATURES WILL OCCUR  
ON SUNDAY AS THE WINDS THROUGHOUT MUCH OF THE ATMOSPHERE REMAINS OUT  
OF THE NORTH TO NORTHWEST. THE BIG ORANGE FIREBALL IN THE SKY WILL  
MAKE TRIUMPHANT RETURN ON SUNDAY AS WE FINALLY LOOK TO KICK OUT THE  
VAST MAJORITY OF THESE CLOUDS FOR AT LEAST A FEW DAYS. SO WHILE THE  
TEMPERATURES ON SUNDAY WONT TECHNICALLY BE THAT DIFFERENT COMPARED  
TO FRIDAY/SATURDAY THE LIGHT WINDS AND SUN WILL PROBABLY MAKE IT  
FEEL MUCH NICER THAN WE'VE EXPERIENCED IN A WHILE. NOT A BAD WAY TO  
START OUR SLOW PROCESSION OF LONGER DAYS OF SUNLIGHT AFTER WE'VE  
PAST THE WINTER SOLSTICE.  
 
WARMING TREND WILL CONTINUE THROUGH CHRISTMAS AS WINDS SLOWLY TURN  
MORE SOUTHERLY IN THE LOW LEVELS AND MID LEVEL RIDGING HELPS WARM  
THE ATMOSPHERE. THE SECOND HALF OF CHRISTMAS DAY WILL SEE  
PRECIPITATION CHANCES RETURN AS A WEAK BOUNDARY TRIES TO MOVE  
THROUGH AS A WEAKENING SHORTWAVE LIFTS THROUGH THE OHIO VALLEY. THIS  
SYSTEM LOOKS LIKE IT WILL REALLY BE LOSING ENERGY AND LIFTING OUT OF  
THE AREA AT THE SAME TIME, AND ANY PRECIPITATION THAT WE GET ON  
CHRISTMAS DAY IS EXPECTED TO BE VERY LIGHT WITH LESS THAN A TENTH OF  
AN INCH OF RAIN EXPECTED, MAINLY SOUTH OF INTERSTATE 40.  
 
ANOTHER TROUGH/LOW WILL MOVE NORTH THROUGH THE WESTERN TENNESEE AND  
OHIO VALLEYS HEADING INTO THE WEEKEND. CERTAINTY ON THE STRENGTH AND  
TIMING OF THIS SYSTEM IS STILL A BIT LOW AT THIS TIME, BUT  
TEMPERATURES ARE LOOKING LIKE THEY'LL REMAIN WARM AND ANY  
PRECIPITATION IS EXPECTED TO FALL AS RAIN.  
 
 
   
AVIATION  
 
(18Z TAFS)  
ISSUED AT 1235 PM EST SAT DEC 21 2024  
 
THIS AFTERNOON CEILINGS WILL LINGER FEW MORE HOURS AT TRI AND TYS  
AND SHOULD BE VFR WITH POSSIBLE BRIEF MVFR PERIOD. GUSTY NORTH  
WINDS AT CHA FOR COUPLE HOURS EARLY THEN DECREASING. THEN VFR  
CONDITIONS TONIGHT AND SUNDAY AT ALL SITES.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
CHATTANOOGA AIRPORT, TN 27 45 29 50 / 0 0 0 0  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 23 42 25 49 / 0 0 0 0  
OAK RIDGE, TN 23 41 24 46 / 0 0 0 0  
TRI CITIES AIRPORT, TN 18 37 21 46 / 0 0 0 0  
 
 
   
MRX WATCHES/WARNINGS/ADVISORIES  
 
NC...NONE.  
TN...NONE.  
VA...NONE.  
 
 
 
 
SHORT TERM...TD  
AVIATION...TD  
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