694
FXUS64 KMRX 120517
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
117 AM EDT SUN JUL 12 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 140 PM EDT SAT JUL 11 2026
- MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
THROUGH SUNDAY NIGHT. ANY AREAS IMPACTED BY REPEATED STORMS
COULD SEE SIGNIFICANT RAINFALL AND EXPERIENCE FLASH FLOODING. AS
SUCH, A FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY NIGHT.
- A FEW STRONG TO SEVERE STORMS COULD OCCUR TODAY AND SUNDAY. THE
PRIMARY THREAT WOULD BE GUSTY WINDS.
- MORE TYPICAL SUMMER WEATHER TUESDAY ONWARDS WITH NORMAL
TEMPERATURES AND ONLY A LOW PM CHANCE OF THUNDERSTORMS.
DISCUSSION
ISSUED AT 140 PM EDT SAT JUL 11 2026
SYNOPTICALLY SPEAKING, A SEMI-CLOSED UPPER TROUGH SITUATED FROM THE
OHIO VALLEY WESTWARD TO THE OZARKS OF MISSOURI, WILL CONTINUE TO
DRIFT SOUTHWARD OVER THE NEXT 48 HOURS OR SO. MEANWHILE, UPPER
RIDGING WILL EXPAND FROM THE ROCKIES NORTHEASTWARD INTO THE NORTHERN
PLAINS DURING THAT SAME PERIOD, ULTIMATELY CREATING A QUASI-REX
BLOCK TYPE PATTERN OVER THE GREAT LAKES AND OHIO VALLEY AREAS AS THE
AFOREMENTIONED TROUGH CONTINUES TO MEANDER SOUTH AND GETS TRAPPED
BENEATH THE EXPANDING RIDGE. LOCALLY, THIS MEANS CONTINUED CHANCES
FOR SHOWER AND THUNDERSTORM ACTIVITY AS IMPULSES EMANATE EASTWARD
FROM THAT UPPER TROUGH/SEMI-CLOSED LOW TO OUR WNW, UNTIL THIS
FEATURE FINALLY PUSHES SOUTH OF THE REGION BY TUESDAY. GIVEN THE
HIGH PWAT AIR MASS IN PLACE AND STORM MOTIONS BEING LARGELY
PARALLEL TO UPPER FLOW, TRAINING CONVECTION WILL AND THE RISK OF
FLASH FLOODING WILL CONTINUE TO BE A RISK FOR MUCH OF THE
FORECAST AREA THROUGH SUNDAY NIGHT. AS WE GET INTO MONDAY AND
TUESDAY, THE UPPER TROUGH AXIS BECOMES INCREASINGLY SITUATED
OVERHEAD, MEANING THE FOCUS FOR STRONGER CONVECTION AND HEAVIER
RAINS WILL SHIFT INCREASINGLY SOUTH OF US. FOR THESE REASONS, I
DON'T SEE A NEED TO EXTEND THE FLASH FLOOD WATCH BEYOND SUNDAY
NIGHT, BUT I DID CHANGE THE EXPIRATION TIME TO 06Z MONDAY TO
ACCOUNT FOR ONE LAST BATCH OF LATE EVENING/NOCTURNAL STORMS THAT
MIGHT MOVE THROUGH TOMORROW.
WITH REGARDS TO SEVERE STORMS POTENTIAL THIS AFTERNOON AND EVENING,
I THINK OUR CHANCES ARE FAIRLY LIMITED. SPC MESOANALYSIS PAGE
INDICATES THERE IS SOMEWHERE IN THE NEIGHBORHOOD OF 1,500 J/KG OF
MLCAPE IN THE SOUTHERN VALLEY. THIS SEEMS REASONABLE GIVEN THE
CURRENT RADAR MOSAIC AND STRONG STORMS ALONG THE TN/GA BORDER AREA
THIS AFTERNOON. THOSE STORMS ALSO HAVE A LIGHT SOUTHWARD MOTION TO
THEM WHICH SHOULD CARRY THEM OUT OF OUR CWA BY 3-4PM. FURTHER NORTH,
THE ATMOSPHERE WAS REALLY WORKED OVERNIGHT AND EARLIER TODAY, AND
CLOUD COVER THROUGH THE DAY HAS LIMITED INSTABILITY. ALL IN ALL, I
THINK THE SEVERE CHANCES ARE LOW THROUGH THIS EVENING. CAM GUIDANCE
INDICATES LITTLE IN THE WAY OF ADDITIONAL CONVECTION DEVELOPING
LATER ON TOO WHICH LENDS CONFIDENCE TO MY THOUGHTS HERE. HOWEVER,
IT'S NOT AS OPTIMISTIC ON THE FLOODING SIDE. ANOTHER ROUND OF
NOCTURNAL CONVECTION IS EXPECTED IN OUR CWA TONIGHT AND THEN AGAIN
SUNDAY NIGHT. IT'S DIFFICULT TO SAY EXACTLY WHERE STORMS MAY ALIGN,
BUT RAINFALL AMOUNTS HAVE EXCEEDED 3-5" IN A FEW SPOTS OVER THE LAST
24 HOURS THAT HAVE BEEN AFFECTED BY TRAINING STORMS. IT'S NOT OUT OF
THE QUESTION TO SAY SOMETHING SIMILAR COULD HAPPEN TONIGHT OR
SUNDAY, AND THUS THE RISK OF FLOODING CONTINUES. THERE IS JUST
LOW CONFIDENCE IN WHERE EXACTLY THE GREATEST THREAT RESIDES.
AS MENTIONED, BY TUESDAY THE UPPER LOW SHIFTS SOUTH OF US AND WE
LOSE THE FOCUS FOR REPEATED STORMS AND HEAVY RAINS. RAIN CHANCES
REMAIN IN THE FORECAST THOUGH, PRIMARILY FOR DIURNALLY DRIVEN
AFTERNOON SHOWERS AND THUNDERSTORMS. WITH THE RIDGE BUILDING TO
OUR NORTH THESE WILL BE MORE SCATTERED IN NATURE. WE'LL ALSO WARM
UP MOVING INTO THE MID/LATE WEEK TIME FRAME, WITH HIGHS CLIMBING
BACK INTO THE UPPER 80S.
AVIATION
(06Z TAFS)
ISSUED AT 1213 AM EDT SUN JUL 12 2026
SHOWERS AND STORMS WILL BE AROUND DURING THE PERIOD. THERE
CONTINUES TO BE UNCERTAINTY IN EXACT TIMING, BUT IT CURRENTLY
APPEARS THAT THUNDERSTORMS ARE LIKELY EARLY IN THE PERIOD
ESPECIALLY TRI AND CHA, FOLLOWED BY A SEVERAL HOUR PERIOD OF
LOWER PROBABILITY OF THUNDER BEFORE THUNDER CHANCES PICK UP AGAIN
THIS AFTERNOON ALL SITES. WILL COVER THE HIGHER PROBABILITY TIMES
WITH TEMPO AND PROB30 THUNDER GROUPS. VFR CONDITIONS ARE EXPECTED
FOR MUCH OF THE PERIOD ALL SITES, WITH MVFR OR LOWER CONDITIONS
EXPECTED WITH SOME OF THE SHOWERS AND STORMS.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 86 70 83 70 / 70 60 80 60
KNOXVILLE MCGHEE TYSON AIRPORT, TN 83 69 82 68 / 80 80 90 20
OAK RIDGE, TN 82 68 83 68 / 80 80 80 20
TRI CITIES AIRPORT, TN 79 66 80 64 / 90 40 70 10
MRX WATCHES/WARNINGS/ADVISORIES
NC...FLOOD WATCH THROUGH LATE TONIGHT FOR CHEROKEE-CLAY.
TN...FLOOD WATCH THROUGH LATE TONIGHT FOR ANDERSON-BLEDSOE-BLOUNT
SMOKY MOUNTAINS-BRADLEY-CAMPBELL-CLAIBORNE-COCKE SMOKY
MOUNTAINS-EAST POLK-GRAINGER-HAMBLEN-HAMILTON-HANCOCK-
HAWKINS-JEFFERSON-JOHNSON-KNOX-LOUDON-MARION-MCMINN-MEIGS-
MORGAN-NORTH SEVIER-NORTHWEST BLOUNT-NORTHWEST CARTER-
NORTHWEST COCKE-NORTHWEST GREENE-NORTHWEST MONROE-RHEA-
ROANE-SCOTT TN-SEQUATCHIE-SEVIER SMOKY MOUNTAINS-SOUTHEAST
CARTER-SOUTHEAST GREENE-SOUTHEAST MONROE-SULLIVAN-UNICOI-
UNION-WASHINGTON TN-WEST POLK.
VA...FLOOD WATCH THROUGH LATE TONIGHT FOR LEE-RUSSELL-SCOTT VA-
WASHINGTON VA-WISE.
DISCUSSION...CD
AVIATION...99
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