688
FXUS64 KMRX 251519 AAA
AFDMRX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MORRISTOWN TN
1119 AM EDT MON MAY 25 2026
..NEW UPDATE
KEY MESSAGES
UPDATED AT 1052 AM EDT MON MAY 25 2026
- ANOTHER ROUND OF SHOWERS AND STORMS ARE EXPECTED LATER TODAY AND
TONIGHT. THESE WILL BE EFFICIENT RAINFALL PRODUCING STORMS, THUS
TORRENTIAL DOWNPOURS AND ISOLATED FLASH FLOODING COULD OCCUR.
- DAILY CHANCES OF SHOWERS AND STORMS EXIST EACH DAY THROUGH THE
FORECAST PERIOD.
- CONDITIONS WILL ALSO BE NOTABLY HUMID FOR THE NEXT SEVERAL DAYS.
UPDATE
ISSUED AT 1052 AM EDT MON MAY 25 2026
WANTED TO MAKE A QUICK UPDATE TO THE FORECAST DISCUSSION TO
HIGHLIGHT SOME POTENTIAL FOR FLOODING AGAIN THIS AFTERNOON AND
EVENING. REGIONAL RADAR IMAGERY SHOWS AN ACTIVE MCV LIFTING NORTH
ACROSS FAR SOUTHERN MS THIS MORNING, CURRENTLY LOCATED ROUGHLY
BETWEEN JACKSON AND HATTIESBURG MISSISSIPPI. THIS IS FORECAST TO
TURN NORTHEAST WITH TIME, LIFTING TO THE NORTHERN GEORGIA/ALABAMA
AREA AND PERHAPS EVEN THE SOUTHERN TN VALLEY BY LATE THIS
EVENING. SOME CONVECTIVE INITIATION IS EXPECTED MAINLY OVER THE
TERRAIN THIS AFTERNOON, WITH SHOWERS AND EMBEDDED THUNDERSTORMS
INCREASING IN COVERAGE ACROSS LOWER ELEVATION AREAS AS THE REMNANT
MCV APPROACHES LATER THIS EVENING. PWATS ARE ALREADY IN THE 90TH
PERCENTILE FOR THIS TIME OF YEAR AND ARE FORECAST TO RISE LATER
THIS EVENING JUST AHEAD OF THE MCV. FORECAST SOUNDINGS SHOW HIGH
FREEZING LEVELS (GENERALLY ABOVE 13-14K FT AGL), WITH THIN AND
MEAGER CAPE PROFILES, ALL OF WHICH WILL SUPPORT EFFICIENT RAINFALL
PROCESSES AND THE POTENTIAL FOR HEAVY RAINS AND ISOLATED FLASH
FLOODING.
THE CURRENT DAY 1 EXCESSIVE RAINFALL OUTLOOK HIGHLIGHTS FAR
SOUTHEAST TN AND OUR WESTERN NORTH CAROLINA COUNTIES IN A SLIGHT
RISK AREA. HOWEVER, IT'S WORTH NOTING THAT THE AFOREMENTIONED MCV
WAS FURTHER WEST THAN A LOT OF GUIDANCE FORECAST IT TO BE, WHICH
LIKELY HAS DOWNSTREAM IMPLICATIONS IN TERMS OF RAINFALL TOTALS AND
FLASH FLOODING POTENTIAL. THUS, I WOULD NOT BE SURPRISED TO SEE
SOME ADJUSTMENTS MADE TO THAT SLIGHT RISK AREA WHEN THE DAY 1 ERO
IS UPDATED HERE SHORTLY. GIVEN THE HIGH PWATS IN PLACE AND THE
FORECAST SOUNDINGS AT HAND, RAINFALL RATES IN EXCESS OF 2"/HR AND
THE LIKELIHOOD OF EXCEEDING BOTH 1HR AND 3HR FLASH FLOOD GUIDANCE
SEEMS FAIRLY HIGH. I STILL THINK THE FLASH FLOODING THREAT IS MORE
ON THE ISOLATED SIDE, BUT I'M GIVING STRONG CONSIDERATION TO
ISSUING ANOTHER FLASH FLOOD WATCH FOR AT LEAST A PORTION OF OUR
CWA. WILL MAKE THAT DECISION BY NOON OR SO, BUT FOR NOW I WANTED
TO GET SOME UPDATED THOUGHTS OUT REGARDING THE HYDRO CONCERNS
LATER TODAY.
DISCUSSION
ISSUED AT 139 AM EDT MON MAY 25 2026
WE STAY IN A WET PATTERN FOR MUCH OF THE PERIOD. THE WEAK FRONTAL
BOUNDARY TO OUR NORTH AND NORTHWEST WILL MEANDER A BIT BUT NOT MAKE
MUCH PROGRESS THROUGH MID-WEEK, AND DEEP SOUTH AND SOUTHWEST FLOW
ALOFT WILL KEEP PLENTY OF GULF MOISTURE FEEDING INTO OUR AREA.
THE FLOOD WATCH THAT HAS BEEN IN EFFECT WILL NOT BE EXTENDED AT THIS
TIME AS THE HEAVIER PRECIPITATION IS WANING, AND MODELS SUGGEST A
LULL BEFORE ACTIVITY PICKS UP AGAIN MONDAY AFTERNOON AND/OR MONDAY
EVENING IN RESPONSE TO ANOTHER WEAK IMPULSE MOVING OVER THE AREA AND
AN UPTICK IN UPPER DIVERGENCE. HOWEVER, EXACT TIMING OF PEAK
COVERAGE IS STILL UNCERTAIN. MODELS SHOW PWAT VALUES NEAR 1.6-
1.9"INCHES (NEAR DAILY MAX OF KBNA SOUNDING CLIMATOLOGY) MONDAY, AND
SHEAR GENERALLY LOOKS LOW WHILE MID LEVEL LAPSE RATES ARE LESS THAN
6C/KM. RAIN RATES SHOULD BE HIGH BUT THE SEVERE THREAT LOOKS LOW
WITH MONDAY'S CONVECTION. HOWEVER, ENOUGH INSTABILITY MAY DEVELOP
FOR US TO SEE A FEW STORMS BRING STRONG WIND GUSTS IN ADDITION TO
VERY HEAVY DOWNPOURS THAT COULD RESULT IN LOCALIZED FLOODING.
AS WE MOVE INTO MID-WEEK, WE WILL CONTINUE TO SEE ROUNDS OF SHOWERS
AND STORMS WITH TIMING INFLUENCED BY ADDITIONAL WEAK IMPULSES IN THE
FLOW, BUT WITH AFTERNOONS EXPECTED TO SEE THE HIGHEST CHANCES
OVERALL. LOCALIZED FLOODING WILL BE A CONCERN FOR ANY AREAS THAT SEE
REPEATED OR PROLONGED PERIODS OF HEAVY RAIN GIVEN THE ABUNDANT
MOISTURE. WHILE TEMPERATURES WILL GENERALLY BE SEASONABLE, THE HIGH
DEWPOINTS WILL LEAD TO HUMID AND STICKY FEELING CONDITIONS AT LEAST
THROUGH MID WEEK.
HIGHER UNCERTAINTY FOR THE THURSDAY THROUGH SUNDAY PERIOD AS MODELS
ARE NOT IN GOOD AGREEMENT. THE FRONTAL BOUNDARY IS FORECAST TO SAG
SOUTH INTO OR POSSIBLY THROUGH OUR AREA, THEN WILL LIKELY STALL AND
NUDGE BACK NORTH AGAIN. HOWEVER, FUTURE TIMING AND LOCATION OF THE
FRONT IS STILL HIGHLY UNCERTAIN. DEPENDING ON HOW FAR SOUTH THE
FRONT MAKES IT, THERE MAY BE A DRIER PERIOD ESPECIALLY NORTH
SOMETIME IN THE THURSDAY/FRIDAY TIME FRAME. HOWEVER, OVERALL, THE
NBM ENSEMBLE APPROACH OF KEEPING SHOWERS AND STORMS IN THE FORECAST
OUR AREA IN THE THURSDAY THROUGH SUNDAY TIME FRAME LOOKS
REASONABLE.
AVIATION
(12Z TAFS)
ISSUED AT 728 AM EDT MON MAY 25 2026
CIGS ARE MOSTLY MVFR ACROSS THE REGION. SOME PATCHY FOG HAS BEEN
OBSERVED BUT CONDITIONS ARE ALREADY IMPROVING. VFR CONDITIONS WILL
LIKELY RETURN BY MID TO LATE MORNING. SHOWERS WILL LIKELY END
SOON NEAR TRI BEFORE DEVELOPING AGAIN LATE THIS MORNING OR EARLY
AFTERNOON. THE BEST CHANCE FOR SHOWERS THIS AFTERNOON WILL BE NEAR
TRI, ACTIVITY WILL BE MORE ISOLATED NEAR TYS AND CHA. ANOTHER
ROUND OF SHOWERS AND STORMS WILL MOVE INTO THE REGION THIS
EVENING. THE BEST CHANCE FOR THUNDER WILL BE NEAR CHA. THUNDER
WAS LEFT OUT FOR TRI AND TYS BUT MAY BE ADDED LATER IF CONFIDENCE
INCREASES.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 80 66 81 66 / 90 80 70 70
KNOXVILLE MCGHEE TYSON AIRPORT, TN 80 65 81 66 / 80 90 80 70
OAK RIDGE, TN 79 64 80 64 / 70 90 80 70
TRI CITIES AIRPORT, TN 79 62 81 63 / 70 80 80 50
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...CD
AVIATION...MCD
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page