769
FXUS64 KMRX 081827
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
227 PM EDT SAT AUG 8 2026
..NEW DISCUSSION
KEY MESSAGES
UPDATED AT 225 PM EDT SAT AUG 8 2026
- SHOWERS AND THUNDERSTORMS WILL BE AROUND EACH DAY THROUGH NEXT
SATURDAY, WITH THE AFTERNOONS GENERALLY THE PERIOD OF MOST
ACTIVITY.
- THERE WILLBE POTENTIAL FOR A FEW STORMS TO BECOME STRONG TO
SEVERE EACH AFTERNOON AT LEAST THROUGH TUESDAY (AND POSSIBLY
BEYOND), WITH DAMAGING WINDS AND LOCALIZED FLOODING THE MAIN
THREATS.
- TEMPERATURES WILL BE GENERALLY NOT BE FAR EITHER SIDE OF NORMAL
FOR THIS TIME OF YEAR.
DISCUSSION
ISSUED AT 225 PM EDT SAT AUG 8 2026
A WEAK MID/UPPER LEVEL CIRCULATION NEAR THE AR/TN BORDER IS
DRIFTING SLOWLY EAST. A WEAK MIDLEVEL DEFORMATION ZONE OUT AHEAD
OF IT IS ENHANCING SHOWER AND THUNDERSTORM ACTIVITY OVER OUR AREA
TODAY. FLOW IS WEAK AND PWAT VALUES HIGH, AND LIKE RECENT DAYS
THESE SLOW-MOVING STORMS CAN PRODUCE LOCALLY HEAVY RAINFALL AND
GUSTY WINDS. SUNDAY LOOKS SIMILAR AS THE WEAK MID/UPPER LOW
TRANSITIONS TO AN OPEN WAVE AND CONTINUES TO DRIFT EAST. WEAK
FLOW, PWAT VALUES IN THE 1.8 TO 2 INCH RANGE AND MLCAPE VALUES
GENERALLY IN THE 1000-1500 J/KG RANGE POINT TO ANOTHER DAY WITH A
POTENTIAL FOR A FEW STORMS TO BECOME STRONG TO MARGINALLY SEVERE,
WITH STRONG WINDS THE PRIMARY THREAT ALONG WITH LOCALIZED
FLOODING.
MODELS HAVE NOT BEEN CONSISTENT ON HOW QUICKLY THE TROUGH WILL EXIT
EAST, BUT THE TREND HAS IT MOVING EAST MORE QUICKLY LEADING TO THE
PATTERN BECOMING MORE NORTHWESTERLY ALOFT FOR MONDAY AND TUESDAY
WITH A BROAD UPPER TROUGH CENTERED TO OUR EAST AND A BROAD HIGH
PRESSURE RIDGE TO OUR WEST. THIS BRINGS SLIGHTLY DRIER AIR ALOFT TO
THE AREA, STEEPER MID-LEVEL LAPSE RATES, AND AFTERNOON MLCAPE VALUES
MORE IN THE 1500 TO 2000 J/KG RANGE. SHEAR STILL GENERALLY LOOKS
WEAK, BUT GIVEN THE BETTER THERMODYNAMIC PROFILE STORMS MONDAY AND
TUESDAY COULD POSE A SLIGHTLY HIGHER THREAT OF BECOMING STRONG TO
SEVERE WITH DAMAGING WINDS STILL THE PRIMARY THREAT.
MODELS DIVERGE FOR THE LATER PERIODS WITH CLUSTER ANALYSIS SHOWING
ONE CAMP OF ENSEMBLE MEMBERS KEEPING US IN MORE OF A NORTHWEST FLOW
ALOFT WHILE ANOTHER CAMP BUILDS THE RIDGE EAST WITH THE JET
DISPLACED FURTHER NORTH, THUS CONFIDENCE ON THE DETAILS IS LOW.
CONVECTIVE COVERAGE WILL BE INFLUENCED BY WHICH CAMP IS MORE CORRECT
AS WELL AS ANY SHORT WAVES MOVING THROUGH THE FLOW. ENSEMBLES
SUGGEST AT LEAST A SLIGHT UPTICK IN SHEAR ESPECIALLY NORTH BY MID-
WEEK WHICH IS MORE CONSISTENT WITH THE NORTHWEST FLOW CAMP OF WHICH
SOME (INCLUDING THE LATEST RUNS OF THE OPERATIONAL GFS) BRING A
SIGNIFICANT WAVE AND A COLD FRONT INTO AND THROUGH THE AREA LATE IN
THE WORK WEEK. OVERALL, DAILY CHANCES FOR SHOWERS AND STORMS CAN BE
EXPECTED, BUT SPECIFICS ON TIMING AND SEVERE/FLOODING POTENTIAL WILL
HAVE TO WAIT UNTIL WE GET CLOSER.
AVIATION
(18Z TAFS)
ISSUED AT 104 PM EDT SAT AUG 8 2026
SCATTERED SHOWERS AND THUNDERSTORMS AROUND THIS AFTERNOON WILL BE
INCLUDED AS PROB30 THUNDER GROUPS ALL SITES. FOG/LOW CIG
DEVELOPMENT POTENTIAL TONIGHT WILL BE INFLUENCED BY THE AS YET
UNKNOWN DETAILS OF RAIN OCCURRENCE/TIMING/AMOUNTS AT EACH SITE,
BUT WILL CARRY A TEMPO GROUP FOR MVFR VSBY IN FOG AT CHA FOR LATE
TONIGHT WHERE THE ENSEMBLE DATA SUGGESTS THE HIGHEST CHANCE. OTHER
THAN WITH THE FOG AND ANY SHOWERS/STORMS, VFR CONDITIONS ARE
EXPECTED.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 72 91 73 91 / 20 40 10 70
KNOXVILLE MCGHEE TYSON AIRPORT, TN 71 90 72 90 / 20 30 10 40
OAK RIDGE, TN 71 89 72 90 / 20 30 10 40
TRI CITIES AIRPORT, TN 68 87 69 88 / 20 20 20 30
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...99
AVIATION...99
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