195
FXUS64 KMRX 181824
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
224 PM EDT MON MAY 18 2026
..NEW DISCUSSION
KEY MESSAGES
UPDATED AT 224 PM EDT MON MAY 18 2026
- VERY WARM TEMPERATURES FOR TUESDAY WITH HIGHS 10 TO 15 DEGREES
ABOVE NROMAL.
- INCREASING CHANCES FOR SHOWERS AND STORMS RETURN WEDNESDAY.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY FROM
THURSDAY THROUGH THE WEEKEND ESPECIALLY ACROSS THE HIGHER
ELEVATIONS.
DISCUSSION
ISSUED AT 224 PM EDT MON MAY 18 2026
MAIN WEATHER FEATURE THROUGH TUESDAY NIGHT WILL REMAIN AN UPPER
RIDGE OVER THE SOUTHEAST UNITED STATES INTO THE SOUTHERN
APPALACHIANS. MAIN IMPACT WILL BE MOSTLY DRY AND UNSEASONABLY VERY
WARM TEMPERATURES. HIGHS WILL BE 10 TO 15 DEGREES ABOVE NORMAL. NEAR
RECORD HIGHS ANTICIPATED.
FOR WEDNESDAY, ENSEMBLE CLUSTER ANALYSIS SHOWS A SHORT-WAVE TROUGH
MOVED EAST OF GREAT LAKES AND UPPER OHIO VALLEY. THIS WAVE WILL
WEAKEN THE UPPER RIDGE OVER THE REGION AND ALLOW A FRONTAL BOUNDARY
TO APPROACH THE AREA. LOWER HEIGHTS AND BETTER PWS WILL ALLOW FOR
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS ESPECIALLY OVER THE
PLATEAU COUNTIES. INSTABILITY WITH REMAIN MARGINAL WITH CAPES OF
1000-1500, MID-LEVEL LAPSE RATES OF 6 DEGREES OR LESS WITH LITTLE TO
NO SHEAR. AT THIS TIME SEVERE STORMS ARE NOT ANTICIPATED.
FOR THURSDAY, FRONTAL BOUNDARY REMAINS NEAR THE REGION WITH PWS OF
1.5-1.7 INCHES SO MOISTURE RETURNS OVER THE AREA. DEPENDING WHERE
FRONTAL RESIDES (GFS SUGGESTS ACROSS NORTHEAST TENNESSEE AND
SOUTHWEST VIRGINIA) THAT IS WHERE THE HIGHEST CHANCES OF CONVECTION
WILL BE. INSTABILITY AND SHEAR REMAIN LIMITED WITH LITTLE TO NO
SEVERE THREAT, BUT FAIRLY GOOD COVERAGE OF SHOWERS AND STORMS WITH
MUCH NEEDED RAINFALL. QPF FOR WEDNESDAY THROUGH THURSDAY WILL RANGE
FROM 0.10 TO 0.50 INCH.
FOR FRIDAY, FRONTAL BOUNDARY LIFTS NORTH AS AN UPPER TROUGH/JET
MOVES NORTHEAST INTO THE MID-WEST AND OHIO VALLEY PRODUCING PRESSURE
FALLS THERE. THE INCREASE IN SOUTHERLY BOUNDARY JET WILL PULL
FRONTAL BOUNDARY NORTH. PLENTY OF MOISTURE AND INSTABILITY REMAINS
SO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING INTO THE AFTERNOON
ESPECIALLY ACROSS THE TERRAIN FEATURES.
FOR SATURDAY THROUGH MONDAY, THE SOUTHERN APPALACHIANS WILL REMAIN
WITH PLENTY OF MOISTURE AND AFTERNOON INSTABILITY WITH AN UPPER
TROUGH ACROSS THE SOUTHERN PLAINS. THIS UPPER TROUGH WILL SLOWLY
MOVE TOWARD THE TENNESSEE VALLEY. ENSEMBLES AND DETERMINISTIC MODELS
SHOW BETTER INSTABILITY WITH POSSIBLE SHORT-WAVES EJECTING OUT THE
TROUGH ACROSS THE REGION. THERE IS A GREATER THREAT OF STRONGER
AFTERNOON STORMS DURING THIS PERIOD.
AVIATION
(18Z TAFS)
ISSUED AT 108 PM EDT MON MAY 18 2026
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECASTS. WINDS WILL
BE GUSTY UP TO 20 KTS POSSIBLE THIS AFTERNOON AND TUESDAY
AFTERNOON.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 68 89 68 88 / 0 10 10 70
KNOXVILLE MCGHEE TYSON AIRPORT, TN 67 90 68 88 / 0 0 0 30
OAK RIDGE, TN 66 88 65 86 / 0 0 10 60
TRI CITIES AIRPORT, TN 62 89 63 87 / 0 0 0 40
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...DH
AVIATION...DH
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