100
FXUS64 KMRX 171737
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1237 PM EST WED DEC 17 2025
..NEW DISCUSSION, AVIATION
KEY MESSAGES
UPDATED AT 1233 PM EST WED DEC 17 2025
- STRONG MOUNTAIN WINDS, WIDESPREAD SHOWERS, AND ISOLATED THUNDER IN
THE SOUTH ARE EXPECTED THURSDAY AFTERNOON INTO EARLY FRIDAY MORNING.
- COLDER TEMPERATURES BEHIND A FRONT ON FRIDAY, BUT REBOUND
QUICKLY OVER THE WEEKEND AND REMAIN MILD NEXT WEEK WITH MAINLY
DRY CONDITIONS.
DISCUSSION
ISSUED AT 1233 PM EST WED DEC 17 2025
OVER THE NEXT 48 HOURS, A STRONG, DEEP UPPER TROUGH AND ASSOCIATED
SURFACE COLD FRONT WILL AFFECT THE AREA. ALTHOUGH THE CENTER OF THE
SURFACE LOW WILL REMAIN WELL NORTH, IN THE NORTHERN PORTIONS OF THE
GREAT LAKES, THE STRONG AMPLIFICATION OF THE UPPER TROUGH AND UPPER
JET POSITIONING WILL RESULT IN A PRETTY DYNAMIC SYSTEM IN THE OH/TN
VALLEYS. TODAY AND TONIGHT, THE LOW LEVEL AIR MASS WILL BE QUITE
DRY, BUT LOW LEVELS WILL GRADUALLY MOISTEN THROUGH THURSDAY WITH
ISENTROPIC LIFT AND WARM ADVECTION. THE PRESSURE GRADIENT ALONG
THE APPALACHIANS STARTS TO TIGHTEN THURSDAY MORNING, AND SOME OF
THE HIGHER PEAKS, SUCH AS COVE MOUNTAIN, MAY START TO SEE GUSTS
NEAR 40 MPH AS EARLY AS 12Z. GUSTS IN THE 40-50 MPH RANGE WILL
BECOME MORE COMMON IN THE MID TO LATE AFTERNOON FOR AREAS IN THE
MOUNTAINS AND FOOTHILLS THAT TEND TO BE AFFECTED BY MOUNTAIN WAVE
WINDS. A FEW ISOLATED SPOTS COULD REACH HIGH WIND CRITERIA
THURSDAY NIGHT, BUT CONFIDENCE ON THAT IS STILL LOW. WILL HOLD OFF
ON ISSUING ANY WIND ADVISORIES FOR NOW SINCE WE HAVE OVER 24
HOURS BEFORE ITS EXPECTED START TIME. IF A LOW LEVEL INVERSION
THURSDAY MORNING ERODES IN THE AFTERNOON, THEN VALLEY LOCATIONS
WILL LIKELY SEE SOME STRONG WINDS AS WELL.
RAIN WITH THIS SYSTEM ARRIVES THURSDAY AFTERNOON AS ISENTROPICALLY-
DRIVEN SCATTERED SHOWERS IN SOUTHERN SECTIONS, WITH INCREASING
COVERAGE AND A NORTHWARD SPREAD THROUGH THE EVENING AS QG FORCING
BUILDS IN EARNEST. A FEW THUNDERSTORMS ARE POSSIBLE ACROSS THE
SOUTHERN TIER BETWEEN 00-06Z, WHERE SOME FORECAST SOUNDINGS
INDICATE WEAK ELEVATED INSTABILITY. DESPITE LIMITED INSTABILITY,
THE STRONG LOW- LEVEL JET COULD ALLOW HEAVIER SHOWERS TO MIX DOWN
GUSTS OF 30–40 MPH, PARTICULARLY AS THE MAIN AXIS FORCING MOVES
THROUGH. HOWEVER, THE RISK OF DAMAGING WINDS REMAINS LOW. ON THE
BACKSIDE OF THE SYSTEM EARLY FRIDAY MORNING, LIGHT SNOW MAY OCCUR
IF COLD AIR ADVECTION AND NORTHWEST FLOW ALIGN WITH LINGERING
MOISTURE. ANY ACCUMULATIONS WOULD LIKELY BE VERY LIGHT GIVEN THE
SHORT DURATION OF OVERLAP BETWEEN THE EXITING MOISTURE AND THE
BUILDING COLD AIR.
COLDER TEMPERATURES FOLLOW THE STRONG COLD FRONT ON FRIDAY, WITH
HIGHS IN THE 40S. HIGHS REBOUND BACK TO THE 50S FOR SATURDAY AND
SUNDAY, AND SHOULD BE MOSTLY IN THE 50S FOR NEXT WEEK. THERE ARE
SOME WEAK DISTURBANCES SHOWN IN THE MODELS THAT BRING LOW RAIN
CHANCES NEXT WEEK, MAINLY TUESDAY-WEDNESDAY, BUT THESE APPEAR TO
HAVE LITTLE TO NO IMPACTS, IF THEY HAPPEN AT ALL.
AVIATION
(18Z TAFS)
ISSUED AT 1233 PM EST WED DEC 17 2025
HIGH AND MIDLEVEL CLOUDS WILL BE OVER THE AREA TODAY AND TONIGHT.
LOWER CIGS WILL INCREASE AT CHA TOMORROW MORNING, BUT SHOULD REMAIN
VFR UNTIL THE LAST FEW HOURS OF THIS TAF PERIOD WHEN SHOWERS BEGIN
TO MOVE IN WITH MVFR CIGS. LLWS MAY DEVELOP AT CHA TOMORROW MORNING -
THIS APPEARS BORDERLINE BUT WILL GO AHEAD AND ADD IT TO THE CHA
TAF.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 40 60 36 50 / 0 90 100 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 35 62 36 46 / 0 90 100 0
OAK RIDGE, TN 34 59 33 45 / 0 80 100 0
TRI CITIES AIRPORT, TN 34 60 35 42 / 0 80 100 0
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...DGS
AVIATION...DGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page