803
FXUS64 KMRX 160522
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1222 AM EST MON DEC 16 2024
..NEW AVIATION
UPDATE
ISSUED AT 910 PM EST SUN DEC 15 2024
A QUICK EVENING UPDATE TO MODIFY POPS SOME BASED ON CURRENT
TRENDS. DECREASING RAIN CHANCES FOR THE REMAINDER OF THE EVENING
AS MOST OF THE DEEPER MOISTER HAS MOVED OUT. LOW LEVEL MOISTURE
WITH SOME VERY LIGHT RAIN OR DRIZZLE AND FOG WILL STAY TRAPPED
OVER THE TENNESSEE VALLEY AND ADJACENT MOUNTAINS WITH A STRONG LOW
LEVEL INVERSION. SOME WEAK SHORTWAVE ENERGY WILL INCREASE SHOWERS
ACROSS WESTERN AND NORTHERN AREAS LATE TONIGHT FROM ABOUT 9-12Z
MONDAY MORNING. THE SIGNIFICANT PRECIPITATION WILL STAY ACROSS
WESTERN KY AND THE LOWER OHIO VALLEY SO ONLY VERY LIGHT RAINFALL
AMOUNTS POSSIBLE. OTHERWISE TEMPERATURES WILL BE FAIRLY STEADY IN
THE MID TO UPPER 40S TONIGHT. UPDATED FORECAST HAS BEEN SENT.
SHORT TERM
(THIS EVENING THROUGH MONDAY)
ISSUED AT 248 PM EST SUN DEC 15 2024
KEY MESSAGES:
1. DRIZZLE, FOG, AND LOW CLOUDS IN PLACE TONIGHT AND TOMORROW FOR
MOST OF THE AREA.
2. 20 TO 30 MPH WIND GUSTS REMAIN IN PLACE THROUGH TOMORROW FOR THE
HIGHER ELEVATIONS OF THE EAST TN, SOUTHWEST VA, AND SOUTHWEST NC
MOUNTAINS.
DISCUSSION:
THE STRONGEST OF WINDS SHOULD SUBSIDE WITHIN THE NEXT HOUR OR TWO.
THEN, A SOUTHWEST 850 MB JET AROUND 30KTS WILL REMAIN IN PLACE
THROUGH THE PERIOD. THIS MEANS WIND GUSTS FROM 20 TO 30 MPH ARE
EXPECTED ACROSS THE THE HIGHER ELEVATIONS OF THE EAST TN,
SOUTHWEST VA, AND SOUTHWEST NC MOUNTAINS THROUGH MONDAY.
THE BULK OF THE MOISTURE HAS EXITED THE AREA. HOWEVER, DRIZZLE, LOW
CLOUDS, AND SOME FOG WILL REMAIN IN PLACE TONIGHT INTO MONDAY. THIS
IS DUE TO LOW-LEVEL MOISTURE REMAINING TRAPPED IN THE VALLEY DUE TO
A STEEP LOW-LEVEL INVERSION. THE INVERSION BEGINS TO BREAK MONDAY
AFTERNOON SO PARTIAL CLEARING IS POSSIBLE FOR SOME AREAS. BUT
OVERALL, EXPECT MOSTLY CLOUDY SKIES.
TEMPERATURES WILL REMAIN MILD TONIGHT WITH LOWS IN THE MID TO UPPER
40S. HIGH TEMPS ON MONDAY IN THE LOWER 60S.
LONG TERM
(MONDAY NIGHT THROUGH NEXT SUNDAY)
ISSUED AT 248 PM EST SUN DEC 15 2024
KEY MESSAGES:
1. ACTIVE WEATHER PATTERN CONTINUES WITH MULTIPLE CHANCES OF
BENEFICIAL RAIN SHOWERS THROUGH MIDWEEK.
2. ABOVE NORMAL TEMPERATURES THROUGH THE FIRST HALF OF THE WEEK WILL
TRANSITION TO COLDER WEATHER LATE NEXT WEEK AND CONTINUE INTO THE
WEEKEND.
DISCUSSION:
A SHORTWAVE WILL BRING ADDITIONAL RAINFALL CHANCES AS IT TRANSLATES
NORTH & EASTWARD THROUGH THE OHIO RIVER VALLEY MONDAY NIGHT. LATEST
ENSEMBLE PROBABILITIES FOR 12-HOUR PRECIPITATION GREATER THAN OR
EQUAL TO 0.25" ARE 40% OR LESS. FURTHERMORE, THOSE RELATIVELY HIGHER
PROBABILITIES ARE CONFINED ALONG THE CUMBERLAND PLATEAU, WITH
LOCATIONS EASTWARD 20% OR LESS, SUGGESTING RAIN FALL AMOUNTS WILL
REMAIN LIGHT AS UPPER-LEVEL FORCING IS LIMITED. BREEZY WINDS IN
EXCESS OF 20MPH ARE EXPECTED ACROSS HIGHER TERRAIN OF SOUTHWEST VA,
THE NORTHERN PLATEAU AND THE EAST TENNESSEE MOUNTAINS MON NIGHT
THROUGH MID-MORNING AS A SWLY LLJ AMPLIFIES TO NEAR 40KTS.
A LULL IN ACTIVITY IS EXPECTED BEFORE AN ADDITIONAL SYSTEM BRINGS A
RETURN OF RAIN CHANCES MIDDAY WEDNESDAY AND EVENING. FORCING WITH
THIS SYSTEM WILL BE MORE FAVORABLE AS A SURFACE FRONT WILL BE
PRESENT AND EVENTUALLY PASS THROUGH THE REGION OVERNIGHT. THE
ENHANCED SYNOPTIC SUPPORT WILL LEAD TO MORE APPRECIABLE RAINFALL
TOTALS, WITH PROBABILITIES FOR 0.50" OR MORE BETWEEN 50-70% ACROSS
THE ENTIRE COUNTY WARNING AREA. LATEST GFS SOUNDINGS DEPICT MINOR
INSTABILITY LESS THAN 500J/KG SO A FEW RUMBLES OF THUNDER CANNOT BE
TOTALLY RULED OUT. THUNDER WORDING HAS BEEN RESTRICTED TO OUR
NORTHERN FRINGES IN CLOSER PROXIMITY TO UPPER SUPPORT.
A POST-FROPA AIR MASS WILL FILTER NOTABLY COOLER TEMPERATURES INTO
THE AREA THURSDAY MORNING ONWARDS. A REINFORCING SHORTWAVE WILL KICK
ANOTHER (MOSTLY DRY) FRONT THROUGH THE REGION AT THE TAIL-END OF THE
WEEK. THIS WILL PROMOTE A CONTINUED COOLING TREND TO WELL BELOW
NORMAL INTO THE WEEKEND.
AVIATION
(06Z TAFS)
ISSUED AT 1217 AM EST MON DEC 16 2024
WILL SEE MAINLY IFR OR LOWER CONDITIONS WITH LOW CLOUDS/FOG AND
SOME PATCHES OF LIGHT RAIN/DRIZZLE TO START AT CHA AND TYS, WHILE
TRI IS MORE LIKELY TO START WITH IFR/MVFR CONDITIONS. TYS/TRI
WILL LIKELY SEE CONDITIONS IMPROVE TO VFR BY EARLY AFTERNOON WHILE
CHA WILL BE SLOWER TO IMPROVE BUT SHOULD MAKE IT TO AT LEAST
MVFR, THEN ALL SITES WILL SEE CONDITIONS DETERIORATE AGAIN AS
ANOTHER ROUND OF LIGHT RAIN BEGINS TO MOVE IN LATE IN THE PERIOD.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 60 55 64 55 / 20 90 40 60
KNOXVILLE MCGHEE TYSON AIRPORT, TN 63 54 63 53 / 40 90 30 60
OAK RIDGE, TN 60 52 62 52 / 50 90 20 60
TRI CITIES AIRPORT, TN 61 50 60 48 / 40 90 20 40
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
SHORT TERM...TD
LONG TERM....KRS
AVIATION...
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