848
FXUS64 KMRX 051138
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
719 AM EDT TUE MAY 5 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 129 AM EDT TUE MAY 5 2026
- WIDESPREAD SHOWERS AND STORMS TUESDAY NIGHT THROUGH THURSDAY
MORNING.
- PERIODS OF HEAVY RAIN ARE LIKELY. SOME FLOODING CONCERNS ARE
POSSIBLE GIVEN THE POTENTIAL FOR TRAINING SHOWERS AND STORMS ON
WEDNESDAY.
- A CONDITIONAL SEVERE WEATHER THREAT EXISTS ON WEDNESDAY IF
SURFACE- BASED INSTABILITY CAN DEVELOP.
- SOUTHWESTERLY WINDS WILL BE GUSTY TODAY THROUGH WEDNESDAY
ESPECIALLY IN THE EAST TENNESSEE MOUNTAINS AND FOOTHILLS.
DISCUSSION
ISSUED AT 129 AM EDT TUE MAY 5 2026
IN THE UPPER LEVELS, A RIDGE IS OVER THE GULF. A TROUGH IS OVER THE
NORTHERN STATES. NEARLY ZONAL FLOW WILL BE OVER THE OHIO AND
TENNESSEE VALLEYS TODAY. BY TUESDAY NIGHT, A SURFACE LOW WILL
DEVELOP NEAR OH/PA WITH A DEVELOPING COLD FRONT EXTENDING SOUTHWEST
INTO TEXAS. MINOR WAVES CAN BE SEEN MOVING THROUGH THE UPPER LEVEL
PATTERN. THIS BOUNDARY WILL VERY SLOWLY SAG SOUTHWARD MOVING INTO
MIDDLE TENNESSEE AND EAST KENTUCKY BY WEDNESDAY AFTERNOON/EARLY
EVENING. THIS SLOW MOVING BOUNDARY WILL BRING MULTIPLE ROUNDS OF
SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT
BEFORE ACTIVITY TAPERS OFF ON THURSDAY.
SOUTHWESTERLY WINDS WILL BE GUSTY AHEAD OF THIS SYSTEM. A WIND
ADVISORY MAY BE NEEDED FOR THE EAST TENNESSEE MOUNTAINS AND
FOOTHILLS STARTING TUESDAY EVENING THROUGH WEDNESDAY EVENING. THE
850 MB JET WILL INCREASE TUESDAY EVENING. THE WIND DIRECTION LOOKS
FAVORABLE FOR DOWNSLOPE WIND ENHANCEMENT. GUSTS UP TO 45-50 MPH WILL
BE POSSIBLE IN WIND PRONE SPOTS.
TUESDAY NIGHT:
A FEW STRONG STORMS WILL BE POSSIBLE TUESDAY NIGHT. SEVERE STORMS
WILL DEVELOP UPSTREAM ALONG THE BOUNDARY IN THE EVENING HOURS. THOSE
STORMS WILL NOT GET TO EAST TENNESSEE UNTIL THE OVERNIGHT HOURS AND
WILL HAVE PLENTY OF TIME TO WEAKEN. HRRR STILL SHOWS A FEW STRONG
STORMS POSSIBLE DESPITE LOW INSTABILITY. DEW POINTS WILL BE IN THE
50S TUESDAY NIGHT BUT INCREASING THROUGH THE NIGHT AS LOW LEVEL
SOUTHERLY FLOW INCREASES WITH THE LOW LEVEL JET STRENGTHENING. THE
BEST CHANCE FOR A STRONG STORM WILL BE WEST OF I-75 CLOSER TO THE
BOUNDARY.
WEDNESDAY:
DEEP LAYER SOUTHWESTERLY FLOW CONTINUES TO PUMP MOISTURE FROM THE
GULF INTO THE REGION. BY WEDNESDAY AFTERNOON, PRECIPITABLE WATER
VALUES WILL REACH 1.7 INCHES IN THE TENNESSEE VALLEY. EXCEEDING THE
90TH PERCENTILE WHICH IS AROUND 1.4 INCHES FOR MAY 6. MULTIPLE
ROUNDS OF HEAVY RAIN MAY LEAD TO SOME FLOODING ISSUES ESPECIALLY
ALONG AND SOUTH OF I-40 WHERE RAIN AMOUNTS ARE EXPECTED TO BE
HIGHER. THE SOUTHERN HALF OF THE REGION HAS BEEN THE HARDEST HIT
WITH DROUGHT CONDITIONS.
WEDNESDAY AFTERNOON/EVENING MAY BE THE BEST CHANCE FOR STRONG TO
SEVERE STORMS TO DEVELOP WITH THE COLD FRONT IN GOOD PROXIMITY AND
EFFECTIVE SHEAR AROUND 50 KNOTS. INSTABILITY MAY BE A LIMITING FACTOR
WITH CLOUD COVER LINGERING ALL DAY WEDNESDAY BUT WITH CAPE EXPECTED
TO BE AROUND 500 J/KG AND DEW POINTS IN THE 60S SEVERE STORMS CANNOT
BE RULED OUT. A LOW END TORNADO THREAT MAY BE POSSIBLE WITH 0-1 KM
SHEAR EXPECTED TO BE NEAR 20 KNOTS.
WEDNESDAY NIGHT THROUGH THURSDAY:
AT THE MOMENT, IT LOOKS LIKE THE COLD FRONT WILL MOVE THROUGH THE
REGION OVERNIGHT WEDNESDAY NIGHT. THE THREAT FOR SEVERE STORMS AND
FLASH FLOODING MAY LINGER INTO THE OVERNIGHT HOURS BUT LATE INTO THE
NIGHT THE THREAT WILL DECREASE AS THE FRONT PASSES.
SHOWERS WILL LINGER ON THURSDAY MORNING AS THE FRONT IS STILL VERY
SLOW TO MOVE AND WILL LIKELY BE JUST SOUTH OF THE REGION. THE
FLOODING THREAT WILL BE OVER AFTER THE FRONT MOVES THROUGH WITH A
MUCH DRIER AIR MASS MOVING IN WITH DEW POINTS IN THE 50S. THUNDER IS
ALSO NOT EXPECTED. BY THURSDAY AFTERNOON, A SHORTWAVE WILL MOVE
THROUGH THE TENNESSEE VALLEY KICKING THE FRONT OUT BUT KICKING OFF
ANOTHER ROUND OF SHOWERS. HIGH PRESSURE WILL BE CENTERED OVER THE
REGION THURSDAY NIGHT.
FRIDAY THROUGH MONDAY:
ANOTHER SYSTEM IS POSSIBLE SUN/MON, BUT LOOKS LIKE IT WILL MOVE
THROUGH MUCH FASTER. HIGHS WILL BE MAINLY IN THE 70S.
AVIATION
(12Z TAFS)
ISSUED AT 641 AM EDT TUE MAY 5 2026
VFR CONDITIONS EXPECTED FOR THE PERIOD OVERALL, BUT SOME SHOWERS AND
PERHAPS A THUNDERSTORMS (MAINLY CHA) WILL BE POSSIBLE LATE WHICH MAY
BRING MVFR (OR LOWER) CONDITIONS. WINDS WILL BECOME GUSTY DURING THE
DAY ESPECIALLY TYS FROM THE SW. LLWS LOOKS BORDERLINE TONIGHT AS
SURFACE WINDS SUBSIDE ESPECIALLY CHA/TRI, AND IT MAY NEED TO BE
ADDED LATER BUT WILL BE LEFT OUT FOR NOW AS CONFIDENCE OF IT MEETING
CRITERIA IS CURRENTLY NOT HIGH.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 80 63 77 61 / 10 50 90 100
KNOXVILLE MCGHEE TYSON AIRPORT, TN 79 61 75 58 / 10 70 90 100
OAK RIDGE, TN 78 60 73 56 / 20 70 100 90
TRI CITIES AIRPORT, TN 78 58 73 56 / 10 70 100 90
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...MCD
AVIATION...99
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