633
FXUS64 KMRX 170511
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
111 AM EDT THU JUL 17 2025
..NEW AVIATION
SHORT TERM
(THIS EVENING THROUGH THURSDAY)
ISSUED AT 122 PM EDT WED JUL 16 2025
KEY MESSAGES:
1. SCATTERED STORMS ARE EXPECTED THIS AFTERNOON INTO THE EVENING
WITH STRONG WINDS AND LOCALIZED FLOODING POSSIBLE IN SOME STORMS.
2. HOT AND HUMID CONDITIONS WILL CONTINUE WITH HIGHS RISING INTO THE
90S AND HEAT INDEX VALUES AROUND 100 DEGREES.
DISCUSSION:
RADAR SHOWED SCATTERED THUNDERSTORMS CONTINUE TO DEVELOP ACROSS
THE PLATEAU AND FAR EAST TENNESSEE MOUNTAINS. MODERATE INSTABILITY
WITH MLCAPES OF 2500+. DCAPES OF 1000+ AND THETA-E DIFFERENCE OF
30+ INDICATE A POTENTIAL OF STRONG DOWNBURSTS WINDS. PWS OF 1.7 TO
1.9 INCHES INDICATE POTENTIAL OF HEAVY RAINFALL IF TRAINING
OCCURS.
SCATTERED STORMS WILL CONTINUE TO DEVELOP WITH THE GREATEST
COVERAGE ALONG AND NORTH OF INTERSTATE 40.
ISOLATED DOWN TREES/POWER LINES AND FLASH FLOODING POSSIBLE THIS
AFTERNOON AND EVENING.
BESIDES THE CONVECTION, HEAT INDICES HAVE ALREADY CLIMBED IN THE
MID 90S TO LOWER 100S ACROSS MUCH OF THE VALLEY.
FOR THURSDAY, UPPER PATTERN AND ENVIRONMENT STAYS SIMILAR TO
TODAY.
LONG TERM
(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 122 PM EDT WED JUL 16 2025
KEY MESSAGES:
1. DAILY CHANCES FOR SHOWERS AND STORMS WILL CONTINUE THROUGH THE
PERIOD ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. STRONG
AND GUSTY WINDS AND LOCALIZED FLOODING WILL REMAIN POSSIBLE
WITHIN SOME STORMS.
2. HOT AND HUMID CONDITIONS WILL ALSO CONTINUE THROUGH THE PERIOD
WITH HIGHS REACHING INTO THE 90S ACROSS THE VALLEY AND HEAT INDEX
VALUES AROUND 100 DEGREES. AN INCREASE IN HEAT INDICES TO 105
DEGREES POSSIBLE FOR THE LATTER HALF OF NEXT WEEK.
DISCUSSION:
ENSEMBLE CLUSTER ANALYSIS AND DETERMINISTIC MODELS SHOW THE UPPER
RIDGE ACROSS THE TENNESSEE VALLEY AND SOUTHERN APPALACHIANS WILL
SLOWLY RETROGRADE WESTWARD BY LATE WEEKEND IN EARLY NEXT WEEK.
FLOW WILL BECOME MORE NORTHWESTERLY ALLOWING CONVECTION ALONG A
NEAR STATIONARY BOUNDARY OVER THE MID-WEST AND OHIO VALLEY TO MOVE
SOUTHEAST INTO THE TENNESSEE VALLEY AND SOUTHERN APPALACHIANS.
INCREASING COVERAGE OF CONVECTION IS EXPECTED FOR THIS WEEKEND AND
EARLY NEXT WEEK.
FOR THE LATTER HALF OF NEXT WEEK, THE UPPER RIDGE BUILDS BACK INTO
THE OHIO AND TENNESSEE VALLEYS. AN INCREASING POTENTIAL OF HEAT
INDICES REACHING 105 DEGREES. HEAT ADVISORIES MAY BE REQUIRED.
AVIATION
(06Z TAFS)
ISSUED AT 1140 PM EDT WED JUL 16 2025
ONGOING CONVECTION MAINLY AROUND TRI TO START WILL DIMINISH EARLY
IN THE PERIOD, BUT WILL INCLUDE TEMPO THUNDER THERE FOR A FEW
HOURS. GIVEN THE PRECIP THAT OCCURRED THERE, THE CHANCE FOR FOG
AND/OR LOW CIGS LOOKS HIGH ENOUGH TO AT LEAST INCLUDE SEVERAL
HOURS OF MVFR CONDITIONS LATE TONIGHT. ADDITIONAL THUNDERSTORMS
ARE EXPECTED TO BE AROUND LATER TODAY INTO TONIGHT AGAIN, AND WILL
TRY TO TIME HIGHEST PROBABILITY PERIOD WITH PROB30 THUNDER GROUPS
ALL SITES.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 95 75 95 75 / 30 10 30 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 93 75 94 74 / 40 30 40 30
OAK RIDGE, TN 92 74 93 74 / 50 20 40 30
TRI CITIES AIRPORT, TN 90 70 89 70 / 50 50 60 40
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
SHORT TERM...DH
LONG TERM....DH
AVIATION...
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