237
FXUS64 KMRX 040521
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
121 AM EDT SAT JUL 4 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 116 AM EDT SAT JUL 4 2026
- SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON; SOME MAY BE
STRONG TO SEVERE WITH GUSTY WINDS AND LIGHTNING.
- VERY HOT TEMPERATURES CONTINUE WITH AFTERNOON HEAT INDICES
REACHING 100 TO 105 DEGREES IN MOST VALLEY LOCATIONS, THE HEAT
ADVISORY REMAINS IN EFFECT THROUGH INDEPENDENCE DAY.
- TEMPERATURES DROP TO NORMAL SUMMER VALUES WITH CONTINUED DIURNAL
DAILY RANDOM STORM CHANCES NEXT WEEK.
UPDATE
ISSUED AT 837 PM EDT FRI JUL 3 2026
THUNDERSTORMS ARE STILL CONTINUING AT THIS HOUR PUSHING NORTHWARDS
TOWARD KENTUCKY IN OUR NORTHWESTERN COUNTIES, AND A LONE RANGER
STORM IN BLOUNT. STORMS HAVE CLEARLY POSSESSED STRONG GUSTY TO
SEVERE WINDS, WITH SEVERAL REPORTS OF DOWNED TREES TODAY. ACTIVITY
IS STILL LIKELY TO COME TO AN END OVER THE NEXT LITTLE WHILE AS
THE SUN CONTINUES TO SET, THOUGH STORMS ARE STILL HOLDING THEIR
STRENGTH AS THEY PUSH NORTH. THIS UPDATE WAS TO ADD POPS IN FOR
THE NEXT 2 OR SO HOURS, AND BETTER REFLECT THE MAJOR TEMPERATURE
DROPS THAT HAVE OCCURRED OVER THE WESTERN PORTIONS OF THE AREA.
WEATHER TONIGHT IS STILL LIKELY TO BE DRY AND QUIET ONCE STORMS
EITHER DEPART OR DISSIPATE.
DISCUSSION
ISSUED AT 148 PM EDT FRI JUL 3 2026
THE DOMINANT H5 RIDGE THAT HAS BEEN PRODUCING THE HOT CONDITIONS
THIS WEEK WILL BEGIN TO WEAKEN TODAY AND TOMORROW AS SHORTWAVE
ENERGY ACROSS NORTHERN HALF OF THE CONUS SUPPRESSES THE RIDGE AND
SHIFTS IT OFF THE SOUTHEAST COASTLINE. SATELLITE AND RADAR IMAGERY
ARE ALREADY SHOWING THE EFFECTS OF THIS, WITH SCATTERED CONVECTION
POPPING OFF BY 1PM EDT THIS AFTERNOON ACROSS THE SOUTHERN
APPALACHIAN REGION AND FURTHER SOUTH. EXPECT TO SEE THE CENTRAL AND
SOUTHERN AREAS HAVE THE BEST COVERAGE FOR STORMS THIS AFTERNOON AS
THERE'S A MORE PRONOUNCED WEAKNESS ON THE SOUTHERN PERIPHERY OF THE
RIDGE THERE. INSTABILITY IS SUFFICIENT ENOUGH FOR SOME MARGINALLY
SEVERE STORMS CAPABLE OF DAMAGING WINDS THIS AFTERNOON WITH DCAPES
IN THE 1,000 TO 1,500 J/KG BETWEEN NORTHERN GEORGIA AND THE I-40
CORRIDOR AND MIXED LAYER CAPE VALUES IN EXCESS OF 2,500 J/KG.
INSTABILITY ISN'T A PROBLEM TODAY BUT LACK OF SHEAR AND A FORCING
MECHANISM TO CONGEAL STORMS INTO SOMETHING MORE THAN A SMALL,
SINGULAR UPDRAFT, MEANS THAT THE OVERALL THREAT OF SEVERE STORMS IS
LOW. IF SOME SORT OF CLUSTERING HAPPENS, THEN SOME NOTABLE DAMAGING
WINDS COULD OCCUR, BUT THE THREAT SEEMS ISOLATED OVERALL. AREAS
NORTH OF THE I-40 CORRIDOR ARE MORE FIRMLY BENEATH THE CENTER OF THE
RIDGE SO I WOULD EXPECT COVERAGE TO BE MORE ISOLATED IN THAT REGION.
INSTABILITY IS A LITTLE LESS THERE TOO, SO STORM SEVERITY SHOULD BE
LOWER STILL.
STORM COVERAGE TOMORROW LOOKS DIURNALLY DRIVEN AND TERRAIN FOCUSED
LIKE IS TYPICAL IN THE SUMMERTIME - LIKELY LESS THAN WHAT WE'LL
EVENTUALLY SEE THIS AFTERNOON. POPS REFLECT THIS. IT SHOULD BE A TAD
COOLER THOUGH AS THE H5 HEIGHTS CONTINUE TO FALL. STILL, IT WILL BE
WARM AND DEWPOINTS WILL REMAIN ENTIRELY TOO HIGH IF YOU ASK ME. WITH
DEWPOINTS IN THE LOW TO MID 70S AND FORECAST HIGHS IN THE MID 90S,
HEAT INDEX VALUES OF 100 DEGREES OR MORE SEEM HIGHLY LIKELY. THE
HEAT ADVISORY WAS EXTENDED INTO SATURDAY AND I DON'T SEE ANY REASON
TO DEVIATE FROM THAT. THE COMBINATION OF THE JULY 4TH HOLIDAY
ACTIVITIES AND THE FORECAST HEAD INDICES JUSTIFY THE ADVISORY.
OTHERWISE, AS WE MOVE FROM SUNDAY INTO EARLY NEXT WEEK, THE LOSS OF
THE PROMINENT RIDGE WILL LEAD TO A DECREASE IN THE TEMPERATURES BACK
TO NORMAL RANGES. GUIDANCE ISN'T IN GREAT AGREEMENT ON THE DETAILS
OF THE UPPER PATTERN, BUT GENERALLY INDICATES A CONTINUED DAILY
PATTERN OF DIURNAL ACTIVITY, WITH POTENTIALLY A WEAK SHORTWAVE
EDGING INTO THE MID SOUTH REGION BY MIDWEEK. NOTHING PARTICULARLY
SIGNIFICANT ON THE HORIZON, JUST REGULAR JULY.
AVIATION
(06Z TAFS)
ISSUED AT 116 AM EDT SAT JUL 4 2026
SHOWERS AND STORMS HAVE DIMINISHED OVERNIGHT WITH THE MAIN CONCERN
BEING FOG DEVELOPMENT, MOST LIKELY AT CHA IN THE MORNING HOURS.
REDUCTIONS TO MVFR OR IFR CAN BE EXPECTED. THROUGHOUT THE DAY,
MOSTLY CLEAR CONDITIONS ARE EXPECTED WITH FAIRLY LIGHT WINDS.
SHOWERS AND STORMS ARE LIKELY AGAIN BUT MUCH LATER IN THE DAY THAN
YESTERDAY. THE MOST LIKELY TIME FOR IMPACT WILL BE FROM ABOUT 22Z
TO 04Z WITH PROB30S MAINTAINED.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 75 95 74 92 / 20 60 20 70
KNOXVILLE MCGHEE TYSON AIRPORT, TN 73 94 73 91 / 20 60 40 70
OAK RIDGE, TN 73 94 72 91 / 20 60 40 80
TRI CITIES AIRPORT, TN 70 94 69 90 / 20 50 30 70
MRX WATCHES/WARNINGS/ADVISORIES
NC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR CHEROKEE-CLAY.
TN...HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING 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...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LEE-RUSSELL-SCOTT
VA-WASHINGTON VA-WISE.
DISCUSSION...WELLINGTON
AVIATION...BW
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