018
FXUS64 KMRX 161731
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
131 PM EDT TUE SEP 16 2025
..NEW AVIATION
DISCUSSION
ISSUED AT 132 AM EDT TUE SEP 16 2025
KEY MESSAGES:
1. ISOLATED TO SCATTERED SHOWERS AND STORM CHANCES TODAY(20-45%),
WITH DRY CONDITIONS THE REMAINDER OF THE WEEK.
2. MOSTLY SEASONABLE TEMPERATURES TUESDAY AND WEDNESDAY BECOMING
INCREASINGLY ABOVE NORMAL WITH HIGHS IN THE UPPER 80S TO LOW 90S
FOR THE LATTER HALF OF THE WEEK.
DISCUSSION:
AN UPPER LOW REMAINS CENTERED NEAR THE NORTH & SOUTH CAROLINA
BORDER. THE CYCLONIC FLOW IS PROMOTING ADVECTION OF MID TO HIGH
LEVEL CLOUDS ATOP THE FORECAST AREA, ESPECIALLY EAST OF I75, AND
WILL HELP LIMIT PATCHY FOG COVERAGE DUE TO POOR RADIATIONAL
COOLING CONDITIONS. OVERALL, RATHER QUIET AS WE HEAD THROUGH THE
EARLY AM HOURS OUTSIDE OF PERHAPS AN OCCASIONAL SHOWER.
PRECIPITATION CHANCES WILL GRADUALLY INCREASE(20-45%) LATE MORNING
INTO THE PM HOURS AS A SUBTLE IMPULSE TRAVERSES MEAN FLOW ALOFT. THE
GREATEST PRECIP CHANCES WILL GENERALLY BE ALONG THE CUMBERLAND
PLATEAU, E TENNESSEE MOUNTAINS, AND IN VICINITY OF THE I-75
CORRIDOR. LATEST RAP AND NAMBUFR SOUNDINGS SUGGEST MLCAPE WILL BE
BETWEEN 500-1000J/KG WITH WEAKER MID-LEVEL LAPSE RATES IN THE SOUTH
SIDE OF 6C/KM. NO SIG WEATHER IS EXPECTED DUE TO THE MARGINAL AT
BEST THERMO PROFILE, THOUGH, EFFECTIVE BULK SHEAR NEAR 15-20KTS MAY
AID IN THE DEVELOPMENT OF A FEW THUNDERSTORMS.
THE CENTER OF THE CLOSED UPR LOW WILL LIFT NORTHEASTWARD AND
EVENTUALLY DISSOLVE WEDNESDAY INTO THURSDAY. A PRECIP FREE
FORECAST RETURNS AS TEMPERATURES BEGIN TO SLOWLY TREND FROM
SEASONABLE VALUES TO A FEW DEGREES ABOVE NORMAL, ESPECIALLY AS
SHORTWAVE RIDGING BECOMES MORE PROMINENT BY FRIDAY AND SATURDAY.
BY THIS TIME PORTIONS OF THE SOUTHERN VALLEY MAY EVEN SEE HIGH
TEMPERATURES ENCROACH INTO THE LOW 90S.
DETERMINISTIC LONG RANGE MODELS LACK AGREEMENT ON THE
POSITION/AMPLITUDE OF A POTENTIAL POSITIVELY TILTED SHORTWAVE TROUGH
FOR THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK. POPS MAKE A
RETURN AREA WIDE BUT CONFIDENCE IS LOW THIS FAR OUT, THUS, GENERALLY
LIMITED TO 30% OR LESS.
AVIATION
(18Z TAFS)
ISSUED AT 128 PM EDT TUE SEP 16 2025
A FRONTAL BOUNDARY IS PULLING WESTWARD ACROSS SOUTHWEST VIRGINIA
WITH EASTERLY WINDS WITH DEWPOINTS IN THE 40S/50S EAST OF THIS
BOUNDARY AND SOUTHWEST WINDS AND DEWPOINTS IN THE 60S WEST.
THIS BOUNDARY ALONG WITH SPOKES OF ENERGY ROTATING AROUND MID-
ATLANTIC UPPER LOW WILL PRODUCE ISOLATED TO SCATTERED SHOWERS. SPC
MESO-ANALYSIS SHOWS MLCAPES OF 500-1000 SO ENOUGH INSTABILITY TO
PRODUCE EMBEDDED THUNDER.
THIS CONVECTIVE ACTIVITY WILL EFFECT THE TAF SITES THROUGH EARLY
EVENING. OTHERWISE VFR CONDITIONS ARE EXPECTED WITH A GOOD DEAL OF
MID AND HIGH LEVEL CLOUDS.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 64 87 62 89 / 10 10 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 62 84 60 86 / 20 10 0 0
OAK RIDGE, TN 61 84 59 86 / 10 10 0 0
TRI CITIES AIRPORT, TN 57 80 56 83 / 10 10 0 0
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...DH
AVIATION...DH
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