845
FXUS64 KMRX 211831
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
231 PM EDT TUE APR 21 2026
..NEW DISCUSSION
KEY MESSAGES
UPDATED AT 230 PM EDT TUE APR 21 2026
- UNSEASONABLY WARM AND DRY CONDITIONS WILL CONTINUE THROUGH
FRIDAY. HIGHS WILL BE AROUND 10 DEGREES ABOVE NORMAL. LOW
AFTERNOON RELATIVE HUMIDITY EACH DAY WITH 20S AND 30S EXPECTED.
- INCREASING MOISTURE AND INSTABILITY THIS WEEKEND WITH LIKELY
CHANCES OF SHOWERS AND POSSIBLY STORMS, ESPECIALLY SATURDAY.
- ANOTHER ROUND OF STORMS ANTICIPATED FOR MONDAY AND TUESDAY. THERE
IS A THREAT FOR STRONG TO SEVERE STORMS.
DISCUSSION
ISSUED AT 230 PM EDT TUE APR 21 2026
FOR TONIGHT AND WEDNESDAY, A SHORT-WAVE WILL MOVE ACROSS THE UPPER
OHIO VALLEY INTO THE CENTRAL APPALACHIANS. THIS WAVE WILL PRODUCE AN
AREA OF SHOWERS AND THUNDERSTORMS THAT WILL APPROACH SOUTHWEST
VIRGINIA TOWARD WEDNESDAY MORNING. AT THIS TIME, THE DYNAMICS AND
MOISTURE WILL STAY NORTH OF THE REGION WITH SURFACE RIDGING, SO DRY
CONDITIONS ARE ANTICIPATED. LOW AFTERNOON RELATIVE HUMIDITY WILL
WITH VALUES IN THE 20S.
FOR THURSDAY AND FRIDAY, UPPER RIDGE BUILDS OVER THE AREA PRODUCING
MOSTLY DRY AND UNSEASONABLY WARM CONDITIONS. HIGHS WILL BE AROUND 10
DEGREES ABOVE NORMAL. LOW AFTERNOON RELATIVE HUMIDITY WILL CONTINUE
WITH VALUES IN THE 20S/30S.
FOR FRIDAY NIGHT THROUGH SATURDAY, A NORTHERN STREAM (GREAT
LAKES/OHIO VALLEY) AND SOUTHERN STREAM WAVES (CENTRAL GULF COAST
STATES) PRODUCE AN AREA OF SHOWERS AND POSSIBLY A THUNDERSTORM.
SINCE LIMITED PHASING IS EXPECTED WITH THESE WAVES, AND INSTABILITY
AND DYNAMICS ARE LIMITED, CONFIDENCE IS LOW ON QPF AMOUNTS.
CURRENTLY EXPECTING FROM 0.25 TO 0.50 INCH BUT ENSEMBLE
PROBABILITIES SUGGEST LESSER AMOUNTS.
ANOTHER SYSTEM MOVES INTO THE TENNESSEE VALLEY AND SOUTHERN
APPALACHIANS EARLY NEXT WEEK. THE SHORT-WAVE AND JET DYNAMICS WILL
THIS WAVE IS STRONGER AND TAPS INTO GULF MOISTURE. JOINT ENSEMBLE
PROBABILITY OF CAPE/SHEAR SUGGEST A GREAT THREAT OF STRONG TO SEVERE
STORMS POSSIBLE. WILL NEED TO WATCH THE EVOLUTION OF THIS SYSTEM
CLOSE AS WE MOVE INTO THE WEEKEND FOR POSSIBLE MESSAGING OF SEVERE
STORMS. CIPS ANALOG ALSO SUGGEST THE POTENTIAL OF SEVERE STORMS.
AVIATION
(18Z TAFS)
ISSUED AT 141 PM EDT TUE APR 21 2026
VFR CONDITIONS WILL PREVAIL THROUGH THE NEXT 24 HOURS AT ALL TAF
SITES. INCREASING LOW LEVEL JET OVERNIGHT WITH 850MB WINDS OF
30-35 KNOTS WILL PRODUCE A CHANCE OF LLWS AT TRI BUT CONFIDENCE IS
NOT HIGH ENOUGH TO INCLUDE. WESTERLY WINDS WILL INCREASE AT TRI
TOMORROW MORNING TO 12-14 KNOTS AND GUSTY.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 53 83 54 84 / 0 0 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 51 81 54 82 / 0 0 0 10
OAK RIDGE, TN 50 82 52 83 / 0 0 0 10
TRI CITIES AIRPORT, TN 44 78 49 79 / 0 0 0 10
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...DH
AVIATION...DH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page