287
FXUS64 KMRX 170539
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
139 AM EDT FRI APR 17 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 134 AM EDT FRI APR 17 2026
- WELL ABOVE NORMAL TEMPERATURES CONTINUE THROUGH SATURDAY.
RECORD HIGHS ARE POSSIBLE.
- SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING LATE THIS
AFTERNOON INTO THIS EVENING. ANOTHER ROUND OF ISOLATED TO
WIDELY SCATTERED SHOWERS AND STORMS POSSIBLE EARLY FRIDAY
MORNING. ISOLATED STORMS COULD PRODUCE STRONG AND GUSTY WINDS
AND SMALL HAIL.
- A COLD FRONT WILL BRING WIDESPREAD SHOWERS AND POSSIBLY A
THUNDERSTORM LATE SATURDAY AND ESPECIALLY SATURDAY NIGHT.
- COOLER TEMPERATURES SUNDAY AND MONDAY, BUT WARMING UP AGAIN
NEXT WEEK. LOW AFTERNOON RELATIVE HUMIDITY EARLY NEXT WEEK.
UPDATE
ISSUED AT 855 PM EDT THU APR 16 2026
ADJUSTED POPS THROUGH 2 AM TO ACCOUNT FOR BOTH THE LINE OF
SHOWERS/STORMS MOVING THROUGH NOW, AND TO BUMP UP WESTERN PORTIONS
OF EAST TENNESSEE IN ACKNOWLEDGEMENT OF THE MCS PUSHING THROUGH
MIDDLE TN. RATHER LOW CONFIDENCE ON THE MCS'S EVOLUTION OVER THE
NEXT 2-3 HOURS, CAMS HAVE BEEN CONSISTENTLY DISSIPATING THE
CLUSTER BEFORE REACHING EAST TENNESSEE, BUT SEVERAL OF THE MEMBERS
WEREN'T SHOWING THIS STOUT OF A CURRENT LOOK. AS FAR AS THE
CURRENT RADAR DEPICTION IN MIDDLE TN, IT IS KICKING OUT A HEALTHY
OUTFLOW BOUNDARY ALONG THE SOUTHERN HALF OF THE CLUSTER, WHICH MAY
SPARK SOME SHOWERS AND STORMS AS IT MOVES THROUGH RELATIVELY
PRISTINE ATMOSPHERE. THE NORTHERN PART WILL ENCOUNTER RAIN COOLED
AIR IN THE NORTHERN PLATEAU AND I WOULD EXPECT WEAKENING BY THEN.
ANY RAIN THAT CAN REACH EAST TENNESSEE WILL BE WELCOME.
DISCUSSION
ISSUED AT 228 PM EDT THU APR 16 2026
SPC MESO ANALYSIS SHOWS A WELL MIXED BOUNDARY LAYER THIS AFTERNOON
PRODUCING BREEZY CONDITIONS. INSTABILITY IS INCREASING ESPECIALLY
OVER THE PLATEAU WITH MLCAPES OF 500-100. DCAPES OF 800-900 WITH DRY
MID-LEVEL AND SUB-CLOUD LAYERS WILL LIKELY PRODUCE STRONG AND GUSTY
WINDS WITH THE STORMS. THERE IS A MARGINAL RISK OF SEVERE STORMS.
A WEAK WAVE OVER WEST TN/AR/MO WILL APPROACH THE REGION BY EARLY
FRIDAY MORNING. CURRENTLY STRONG CONVECTION HAS DEVELOPED WITH THIS
FEATURE. SOME OF THE CAM MODELS SHOW ISOLATE TO WIDELY SCATTERED
STORMS MOVING INTO THE AREA LATE TONIGHT. DUE TO THE COLDER AIR
ALOFT WITH THE UPPER TROUGH, MID-LEVEL LAPSE RATES STEEPEN. THERE IS
A LOW END CONFIDENCE OF ISOLATED STORMS PRODUCING HAIL UP TO ONE-
HALF INCH. GREATEST POTENTIAL NORTH OF INTERSTATE 40.
AFTER THIS WAVE MOVES EAST EARLY FRIDAY, A RETURN TO DRY AND
UNSEASONABLY WARM CONDITIONS TOMORROW WITH LOW AFTERNOON RELATIVE
HUMIDITY.
DAILY RECORD HIGH MAXIMUM TEMPERATURES
DATE CHATTANOOGA KNOXVILLE TRI-CITIES OAK RIDGE
04-17 91(1955) 90(1896) 85(2002) 88(1955)
04-18 90(2002) 90(1896) 87(2002) 89(2002)
FOR SATURDAY (ESPECIALLY LATE) INTO SATURDAY NIGHT, A STRONG UPPER
TROUGH WILL DIG INTO THE GREAT LAKES INTO THE TENNESSEE VALLEY. THE
JET DYNAMICS WITH THIS SYSTEM WILL ENHANCE THE FRONTO-GENETIC
FORCING ALONG THIS INCOMING COLD FRONT PRODUCING WIDESPREAD SHOWERS
AND POSSIBLE A THUNDERSTORM. INSTABILITY AHEAD OF THIS SYSTEM IS
QUITE LIMITED OVER THE TENNESSEE VALLEY. ENSEMBLE ANALYSIS SHOWS QPF
OF 0.25 TO 0.40 INCH WITH THIS SYSTEM. MUCH NEEDED RAINFALL BUT
STILL WILL NOT TOO MUCH FOR OUR ONGOING DROUGHT CONDITIONS.
FOR MUCH OF NEXT WEEK, DRY CONDITIONS RETURN WITH A DRY SURFACE
RIDGE PRODUCING LOW AFTERNOON HUMIDITIES INTO THE 20S AND 30S.
COOLER TEMPERATURES FOR EARLY WEEK BUT QUICKLY MODERATE TO ABOVE
NORMAL TEMPERATURES BY MID-WEEK.
AVIATION
(06Z TAFS)
ISSUED AT 134 AM EDT FRI APR 17 2026
CALM CONDITIONS EXPECTED, WITH POSSIBLE LIGHT SHOWERS TO MOVE
OVER CHA IN THE NEXT 2 HOURS OR SO. TYS UP TO TRI SAW THE MOST
MEASURABLE RAINFALL YESTERDAY EVENING, SO FOG DEVELOPMENT COULD BE
POSSIBLE. LOW CONFIDENCE ON OCCURRENCE, BUT A TEMPO WAS ADDED TO
ACCOUNT FOR THE CHANCE. CLEARING CONDITIONS EXPECTED LATER TODAY
WITH RIDGING AND SFC HIGH PRESSURE BUILDING BACK IN.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 89 63 88 50 / 0 0 10 70
KNOXVILLE MCGHEE TYSON AIRPORT, TN 85 60 86 48 / 0 0 30 80
OAK RIDGE, TN 85 59 86 47 / 0 0 30 80
TRI CITIES AIRPORT, TN 81 55 84 47 / 0 0 30 70
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...WELLINGTON
AVIATION...KS
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