621
FXUS64 KMRX 111053 AAA
AFDMRX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MORRISTOWN TN
653 AM EDT TUE AUG 11 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 645 AM EDT TUE AUG 11 2026
- SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY THROUGH THE
END OF THE WORK WEEK, WITH THE BEST CHANCE OF RAIN DURING EACH
AFTERNOON.
- THERE WILL BE POTENTIAL FOR A FEW STORMS TO BECOME STRONG TO
SEVERE EACH AFTERNOON 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 117 AM EDT TUE AUG 11 2026
A CLUSTER OF THUNDERSTORMS CAN BE NOTED ACROSS PORTIONS OF OHIO
AS LATEST SATELLITE IMAGERY PAINTS MOSTLY CLEAR SKIES ACROSS THE
SOUTHERN APPALACHIANS THIS EVENING. MOSTLY CLEAR SKIES WILL LIKELY
RESULT IN SOME PATCHY FOG ACROSS CWA, THOUGH, LATEST HREF
PROBABILITIES OF VISIBILITY LESS THAN 4 MILES IS NOT NEARLY AS
WIDESPREAD AS WHAT WAS OBSERVED THIS PAST MORNING. THIS IS LIKELY
DUE TO THE LACK OF PRECIP OBSERVED ACROSS THE AREA TODAY. WHILE
MOSTLY DRY, THE NAM3KM HAS BEEN INITIALIZING THE ACTIVITY TO OUR
NORTH FAIRLY WELL THIS EVENING AND SUGGEST A FEW MORNING
SHOWER/STORMS CANNOT BE RULED OUT IN SW VA/NE TN, WITH THE VERY
LOW CHANCE OF SOME STRONG WIND GUSTS.
ON THE SYNOPTIC SCALE, WE ARE GENERALLY EXPECTED TO REMAIN IN A
NORTHWEST FLOW PATTERN THROUGH THURSDAY AS WE SIT BENEATH THAT
TRANSITION ZONE BETWEEN A STRONG RIDGE AXIS TO OUR WEST AND A
TROUGH AXIS TO OUR NORTH AND EAST. UNFORTUNATELY, THIS PATTERN
PROMOTES LOWER CONFIDENCE LEVELS WHEN REALLY TRYING TO HONE IN ON
EXACT HAZARDS AND TIMING OF EXPECTED ROUNDS OF SHOWERS AND
THUNDERSTORMS, AS EACH ROUND(OR LACK THEREOF) CAN IMPACT THE NEXT.
LATEST HI-RES GUIDANCE SUGGEST THE POTENTIAL FOR CONVECTIVE
INITIATION IN THE EARLY TO MID-AFTERNOON. IF THESE STORMS ARE ABLE
TO DEVELOP, AMPLE INSTABILITY WILL PROMOTE POTENTIAL FOR DAMAGING
WIND GUSTS, ISOLATED FLOODING, AND PERHAPS SMALL HAIL AS THE
PRIMARY HAZARDS. WHILE I SUPPOSE THE THREAT OF A BRIEF SPIN-UP IS
NOT ZERO WITH THE AFTERNOON ACTIVITY, SHEAR IS MORE BORDERLINE AT
THAT TIMEFRAME. A MORE PRONOUNCED VORT MAX IS EXPECTED TO SWING
INTO THE OHIO VALLEY THIS EVENING/TONIGHT, WITH THE POTENTIAL FOR
AN MCS TO BRING INCREASED COVERAGE OF SHOWERS AND STORMS. THOUGH
TIMING IS FAIRLY BROAD WITH THE LATEST HREF SUITE DEPICTING
REALLY ANYTIME BETWEEN ABOUT 00-12Z, OR SOME MODELS NOT EVEN
INITIALIZING THIS SECOND ROUND. DAMAGING WIND AND FLOODING WILL
REMAIN THE PRIMARY HAZARD, BUT WITH ENHANCED SHEAR DUE TO AN
INCREASE IN THE LOW-LEVEL JET, A SPIN-UP OR TWO WOULD BE POSSIBLE
CONDITIONAL ON THE ACTIVITY NOT MOVING THROUGH TOO LATE INTO THE
OVERNIGHT SO THAT A SURFACE INVERSION BEGINS TO DEVELOP.
ADDITIONAL ROUNDS OF SHOWERS AND STORMS ARE POSSIBLE WEDNESDAY AND
THURSDAY, AS MORE BOUTS OF ENERGY TRANSLATE THROUGH MEAN FLOW,
BUT TIMING IS HIGHLY UNCERTAIN. WITH A WARM AND MOIST AIRMASS,
CANNOT RULE OUT LOCALIZED FLOODING AND STRONG TO DAMAGING WINDS
WITH ANY ACTIVITY.
THE UPPER LEVEL RIDGE WILL SHIFT EASTWARD FRIDAY INTO THE
WEEKEND, AND WHILE SOME PRECIPITATION CHANCES CONTINUE, THE CHANCE
FOR ANY ORGANIZED MCSS TRENDS DOWNWARD WHILE TEMPERATURES TREND
SLIGHTLY WARMER.
AVIATION
(12Z TAFS)
ISSUED AT 645 AM EDT TUE AUG 11 2026
NOT EXCEPTIONALLY CONFIDENT IN TIMING STORMS TODAY, BUT CURRENT
THINKING IS TO SIDE MORE WITH THE 3KM NAM GUIDANCE IN BRINGING AN
MCS THROUGH EAST TENNESSEE BETWEEN ROUGHLY 20-22Z IN THE NORTH
AND MAYBE 00-02Z IN THE SOUTH OR THEREABOUTS. I'D SAY CONFIDENCE
IN OCCURRENCE IS HIGH ENOUGH TO HAVE A TEMPO OR EVEN PREVAILING
GROUP IN, BUT THE UNCERTAINTY IN TIMING MADE A PROB30 GROUP THE
MORE REASONABLE APPROACH. THE ENVIRONMENT WILL SUPPORT STRONG
STORMS SO VSBY BELOW 3SM AND CIGS AT/BELOW BKN025 SEEM LIKELY. DO
HAVE SOME REDUCED VSBY LATE IN THE PERIOD AT KTRI, WHICH WILL BE
BEHIND THE STORMS. THEY MAY CLEAR OUT FOR LONG ENOUGH FOR FOG TO
DEVELOP, BUT I DIDN'T TAKE THEM TOO LOW FOR THE TIME BEING AS
THERE MAY BE ANOTHER ROUND OF STORMS MOVE IN OVERNIGHT TONIGHT.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 93 74 94 75 / 40 20 30 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 91 73 92 74 / 20 40 40 40
OAK RIDGE, TN 91 72 92 73 / 20 30 40 30
TRI CITIES AIRPORT, TN 88 69 88 70 / 40 60 60 50
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...KRS
AVIATION...CD
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