383
FXUS64 KMRX 201740
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1240 PM EST FRI DEC 20 2024
..NEW AVIATION
UPDATE
ISSUED AT 1130 AM EST FRI DEC 20 2024
FOG HAS LIFTED BY LATE MORNING ACROSS THE PLATEAU AND SOUTHERN
VALLEY AREA. CLOUDS WERE ALSO INCREASING FROM THE NORTHWEST AS
NORTHWEST FLOW SYSTEM BEGINS TO MOVE INTO THE AREA. TEMPERATURES
ARE IN THE LOWER TO MID 40S ACROSS MUCH OF THE AREA AND THIS WILL
BE CLOSE TO THE HIGH TEMPERATURES WITH TEMPERATURES STEADY NEXT
FEW HOURS AS CLOUDS INCREASE. HAVE INCREASED POPS MOUNTAIN AREAS
FOR THE AFTERNOON AND ADJUSTED TEMPERATURES AND DEW POINTS TO
CURRENT TRENDS. RAIN WAS MOVING INTO CENTRAL AND EASTERN KY AT
THIS HOUR AND EXPECT PRECIPITATION TO MOVE INTO NORTHERN PLATEAU
AND SOUTHWEST VIRGINIA COUNTIES BY EARLY TO MID AFTERNOON. UPDATED
THE WINTER WEATHER ADVISORY PRODUCT AS WELL WITH NO CHANGES TO
THE PRODUCT.
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 219 AM EST FRI DEC 20 2024
KEY MESSAGES:
1. A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE MOUNTAIN ZONES
OF SOUTHWEST VIRGINIA AND EAST TENNESSEE FROM THIS AFTERNOON
THROUGH SATURDAY MORNING.
2. COOLER TEMPERATURES TODAY WITH BREEZY CONDITIONS IN THE
AFTERNOON. WIND GUSTS NEAR 40 MPH POSSIBLE IN THE HIGHEST
ELEVATIONS THIS AFTERNOON AND EVENING.
DISCUSSION:
A POTENT SHORTWAVE TROUGH IS MOVING THROUGH THE REGION TODAY
BRINGING STRONG NORTHWEST FLOW TO THE REGION THIS AFTERNOON AND
TONIGHT. THIS AFTERNOON SHOWERS WILL MOVE INTO REGION MAINLY NORTH
OF I-40. IN THE HIGHER ELEVATIONS OF EAST TENNESSEE AND SOUTHWEST
VIRGINIA IT WILL BE COLD ENOUGH TO START GETTING SNOW IN THE
AFTERNOON HOURS. 850 MB NORTHWESTERLY FLOW WILL PEAK AROUND 20 TO
30 KNOTS FROM THE LATE AFTERNOON HOURS THROUGH SATURDAY MORNING.
BY LATE SATURDAY MORNING NORTHWEST FLOW WILL BE LIGHTER AND SNOW
WILL TAPER OFF. THE TENNESSEE VALLEY MAY SEE SOME FLAKES FROM
KNOXVILLE NORTHWARD BUT LITTLE TO NO ACCUMULATION (GENERALLY LESS
THAN HALF AN INCH) IS EXPECTED. THE PLATEAU COUNTIES MAY SEE AN
INCH IN THE HIGHEST SPOTS BUT MOST LOCATIONS WILL PROBABLY BE
AROUND HALF AN INCH OR LESS. THE MORE SIGNIFICANT SNOW TOTALS WILL
BE IN THE HIGHEST ELEVATIONS OF THE SOUTHWEST VIRGINIA AND EAST
TENNESSEE MOUNTAINS WHERE A WINTER WEATHER ADVISORY IS IN EFFECT.
GENERALLY, HIGHER ELEVATIONS ABOVE 2500 FEET WILL SEE 2 TO 4
INCHES AND THE HIGHEST PEAKS IN THE SMOKIES COULD SEE UP TO 6 OR 7
INCHES. ALL THE AFOREMENTIONED SNOW TOTALS ARE FOR THE ENTIRE
EVENT.
WESTERLY WINDS WILL BE GUSTY THIS AFTERNOON WITH GUSTS AROUND 25
MPH IN THE VALLEY. IN THE EAST TENNESSEE MOUNTAINS GUSTS UP TO 40
MPH ARE EXPECTED IN THE HIGHEST ELEVATIONS THIS AFTERNOON AND
EVENING. WITH A WESTERLY OR NORTHWESTERLY WIND DIRECTION, WE WILL
NOT HAVE DOWNSLOPING ON THIS SIDE OF THE MOUNTAINS. THEREFORE, A
WIND ADVISORY IS NOT EXPECTED WITH THOSE HIGHEST GUSTS ON THE
HIGHEST PEAKS.
LONG TERM
(SATURDAY THROUGH THURSDAY)
ISSUED AT 219 AM EST FRI DEC 20 2024
KEY MESSAGES:
1. COLD THROUGH THE WEEKEND.
2. SLOW WARMING TREND NEXT WEEK WITH RAINY CONDITIONS AROUND
CHRISTMAS AND BEYOND.
DISCUSSION:
BY THE END OF THE DAY ON SATURDAY THE LINGERING PRECIPITATION SHOULD
BE WELL OUT OF OUR AREA AND WE'LL MOVE INTO A QUIET WEATHER PERIOD
THROUGH MID-WEEK. RIDGING IN THE MID LEVELS WILL BEGIN TO BUILD OVER
SEVERAL DAYS, AND WE SHOULD GET TO SEE SEVERAL DAYS WORTH OF
SUNSHINE TO START THE WEEK OFF WITH. TEMPERATURES WILL START OFF
CHILLY OVER THE WEEKEND WITH MANY VALLEY LOCATIONS BARELY EKING OUT
OF FREEZING TEMPERATURES SATURDAY/SUNDAY... BUT GRADUALLY WE'LL SEE
TEMPERATURES WARM 3-5 DEGREES EACH DAY THROUGH AT LEAST
CHRISTMAS.
A WHITE CHRISTMAS DOES NOT LOOK TO BE IN THE CARDS THIS YEAR AS
TEMPERATURES WILL CLIMB INTO THE 50'S AND NEAR 60 IN SOUTHEAST TN
CHRISTMAS AFTERNOON. LATE ON CHRISTMAS DAY INTO THE NIGHT TIME HOURS
A LOW PRESSURE SYSTEM WILL SWING THROUGH THE SOUTHEAST INTO THE OHIO
VALLEY BRINING WITH IT A QUICK SHOT OF RAIN. MODELS ARE IN FAIRLY
GOOD AGREEMENT THAT TEMPERATURES WILL BE WARM ENOUGH THAT EVEN IN
THE MOUNTAINS WE'LL SEE ALL PRECIPITATION AS LIQUID. RAIN WILL
LIKELY ONLY STICK AROUND THROUGH THURSDAY NIGHT BEFORE THE SYSTEM
MOVES OUT... QPF AMOUNTS ARE EXPECTED TO BE VERY LIGHT WITH HOW FAST
THIS SYSTEM WILL LIKELY MOVE THROUGH.
HOWEVER ANOTHER SYSTEM COULD BE RIGHT ON IT'S HEELS WITH ANOTHER
TROUGH/LOW DEVELOPING OVER THE CENTRAL US. TIMING AND STRENGTH IS
MUCH MORE UNCERTAIN FOR THIS SECONDARY SYSTEM, BUT RIGHT NOW CHANCES
ARE LIKELY WE'LL SEE A WET AND OVERCAST WEEKEND AS WE HEAD TOWARDS
THE NEW YEARS.
AVIATION
(18Z TAFS)
ISSUED AT 1235 PM EST FRI DEC 20 2024
MOSTLY MVFR CIGS EXPECTED AT TRI AND TYS THROUGH FORECAST PERIOD.
VFR CONDITIONS MAY OCCUR A FEW MORE HOURS AT CHA UNTIL MVFR CIGS
SET IN LATE THIS AFTERNOON/EARLY EVENING. WESTERLY WINDS ARE BREEZY
THIS AFTERNOON WITH GUSTS AROUND 20 KNOTS POSSIBLE THROUGH EARLY
EVENING. LIGHT RAIN SHOWERS POSSIBLE THIS AFTERNOON NEAR TYS AND
MORE LIKELY FOR A FEW HOURS AT TRI. RAIN WILL TURN TO LIGHT SNOW
FOR A FEW HOURS NEAR TRI THIS EVENING WITH LITTLE TO NO
ACCUMULATION EXPECTED. CLOUD CEILINGS STAY MVFR OVERNIGHT AFTER
PRECIPITATION ENDS BUT LIFT TO VFR BY AROUND 15 TO 18Z.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 32 43 27 45 / 10 0 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 30 40 23 42 / 20 10 0 0
OAK RIDGE, TN 30 39 23 40 / 20 0 0 0
TRI CITIES AIRPORT, TN 28 36 18 37 / 50 10 0 0
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...WINTER WEATHER ADVISORY UNTIL 1 PM EST SATURDAY FOR BLOUNT SMOKY
MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-SEVIER SMOKY
MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-UNICOI.
VA...WINTER WEATHER ADVISORY UNTIL 1 PM EST SATURDAY FOR LEE-RUSSELL-
WASHINGTON VA-WISE.
SHORT TERM...TD
AVIATION...TD
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page