695
FXUS64 KMRX 220258
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
958 PM EST SAT DEC 21 2024
..NEW UPDATE
UPDATE
ISSUED AT 953 PM EST SAT DEC 21 2024
THIS EVENING, CLOUD COVER HAS LINGERED FOR MANY PLACES, ESPECIALLY
FURTHER NORTH AND EAST. WITH HIGH PRESSURE TO OUR NORTH, A NOTABLE
MSLP GRADIENT HAS ALSO REMAINED IN PLACE. THE COMBINATION OF CLOUD
COVER AND PERSISTENT WINDS HAS LED TO AN INCREASE IN OVERNIGHT
TEMPERATURES, ESPECIALLY FURTHER NORTH AND EAST. THIS TREND HAS
ALREADY BEEN SEEN IN THE HOURS AFTER SUNSET AND WAS CARRIED FOR
THE REMAINDER OF THE NIGHT. HOWEVER, TEMPERATURES WILL STILL BE
NOTABLY COLD TONIGHT WITH TEMPERATURES EXPECTED TO DROP WELL INTO
THE 20S AND EVEN TEENS IN SOME LOCATIONS.
SHORT TERM
(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM EST SAT DEC 21 2024
KEY MESSAGES:
1. COLD TONIGHT AND SUNDAY.
2. WINDS DECREASING TONIGHT ALONG WITH CLOUDS.
3. SLIGHTLY WARMER SUNDAY BUT STILL SEVERAL DEGREES BELOW NORMAL.
LESS WIND CHILL EFFECT WITH LIGHT NORTH TO NORTHEAST WINDS.
DISCUSSION:
LOW CLOUDS WERE SLOWLY DECREASING ACROSS EAST CENTRAL AND
NORTHEAST TENNESSEE AT MID AFTERNOON BUT HOLDING TIGHT ACROSS
SOUTHWEST VIRGINIA AS LOW LEVEL MOISTURE IS SLOWLY ERODING.
MID AFTERNOON TEMPERATURES WERE IN THE MID 30S TO LOWER 40S. FOR
TONIGHT AND SUNDAY THE CLOUDS SHOULD KEEP DECREASING INTO THE
EVENING AND THEN BECOME MOSTLY CLEAR AS HIGH PRESSURE BUILDS
SOUTHEAST FROM THE UPPER MIDWEST AND WESTERN GREAT LAKES. WINDS
HAVE BEEN GUSTY AT TIMES THIS AFTERNOON UP TO 20 MPH OR SO WITH
WIND CHILLS IN THE 20S TO LOWER 30S. TONIGHT WINDS WILL BE LIGHT
AND LOWS IN THE UPPER TEENS AND 20S. SUNDAY HIGHS WILL BE A FEW
DEGREES WARMER AND WITH LIGHTER WINDS.
LONG TERM
(SUNDAY NIGHT THROUGH NEXT SATURDAY)
ISSUED AT 252 PM EST SAT DEC 21 2024
KEY MESSAGES:
1. WARMING TREND NEXT WEEK WITH LOW CHANCES FOR LIGHT RAIN ON
CHRISTMAS.
2. DAILY PRECIPITATION CHANCES AND ABOVE NORMAL TEMPERATURES LINGER
LATE WEEK AND INTO THE WEEKEND, HOWEVER, MUCH UNCERTAINTY EXISTS
WITH ANY FINER DETAILS AT THIS TIME.
DISCUSSION:
PLENTY OF SUNSHINE AMONG A QUASI-ZONAL UPPER LEVEL PATTERN WILL
ALLOW FOR A WARMING TREND INTO THE NEW WORK WEEK ALL WHILE SURFACE
HIGH PRESSURE MAINTAINS A PRECIPITATION FREE FORECAST THROUGH
CHRISTMAS EVE. A WEAK SHORTWAVE WILL PROPAGATE THROUGH MEAN FLOW
ALOFT INTO CHRISTMAS DAY. WHILE LOW RAIN CHANCES MAKE A RETURN, THE
DISTURBANCE IS EXPECTED TO WEAKEN AS IT TRANSLATES EASTWARD AND
MINIMAL SYNOPTIC SUPPORT WILL REDUCE PRECIPITATION EFFICIENCY.
ENSEMBLE PROBABILITIES OF 24-HR PRECIPITATION GTE 0.10" GENERALLY
PEAK AROUND 25%. OTHERWISE, ABOVE NORMAL TEMPERATURES AND INCREASING
CLOUDS WILL ACCOMPANY THE LIGHT RAIN CHANCES FOR CHRISTMAS DAY.
AS WE APPROACH THE TAIL-END OF THE WEEK AND INTO THE WEEKEND,
FORECAST UNCERTAINTY QUICKLY RAMPS UP. A SERIES OF SHORTWAVES WILL
ENHANCE LONG-WAVE TROUGHING AND CYCLOGENESIS TO OUR WEST BUT THE
EXACT LOCATION OF THESE FEATURES ARE HIGHLY VARIABLE AMONG OUR LONG-
RANGE AND MORE COARSE WEATHER MODELS. SCENARIOS IN WHICH
AFOREMENTIONED FEATURES ARE IN CLOSER PROXIMITY RESULT IN ENHANCED
UPGLIDE AND LINGERING PRECIPITATION CHANCES, HOWEVER, MODELS THAT
PLACE THE FEATURES FURTHER NORTHWEST SUGGEST A DRY PERIOD TO END THE
WEEK. OVERALL, THE FINER DETAILS REMAIN UNCERTAIN BUT ANY LINGERING
PRECIPITATION INTO THE LATE WEEK AND WEEKEND WILL FALL AS RAIN AMONG
CONTINUED ABOVE NORMAL TEMPERATURES.
AVIATION
(00Z TAFS)
ISSUED AT 604 PM EST SAT DEC 21 2024
CURRENT CLOUD COVER OVER THE SITES WILL GRADUALLY DIMINISH THROUGH
THE EVENING WITH MOST OF THE AREA EXPECTED BE CLEAR BY AROUND
MIDNIGHT. WINDS WILL REMAIN FROM A NORTHERLY TO NORTHEASTERLY
DIRECTION THROUGH THE TAF PERIOD. MOSTLY CLEAR CONDITIONS ARE ALSO
EXPECTED.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 27 46 29 50 / 0 0 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 25 42 25 49 / 0 0 0 0
OAK RIDGE, TN 24 42 25 47 / 0 0 0 0
TRI CITIES AIRPORT, TN 21 37 22 47 / 0 0 0 0
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
SHORT TERM...TD
LONG TERM....KRS
AVIATION...BW
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page