255
FXUS64 KMRX 252350
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
750 PM EDT MON MAY 25 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 747 PM EDT MON MAY 25 2026
- SHOWERS AND STORMS ARE EXPECTED LATER TODAY AND TONIGHT. THESE
WILL BE EFFICIENT RAINFALL PRODUCING STORMS, WITH THE ABILITY TO
PRODUCE LOCALIZED TORRENTIAL DOWNPOURS AND FLASH FLOODING.
SIMILAR CONDITIONS WILL EXIST TUESDAY.
- DRIER AIR BEGINS TO APPROACH FROM THE NORTH FOR THURSDAY ONWARD.
CURRENT FORECAST MAINTAINS RAIN CHANCES AREA WIDE THROUGH THE
WEEKEND, BUT THE TRENDS SUPPORT A DRIER PATTERN, AT LEAST ACROSS
THE NORTH, AS WE HEAD INTO THE WEEKEND.
DISCUSSION
ISSUED AT 143 PM EDT MON MAY 25 2026
THE NEXT 48 HOURS WILL FEATURE CONTINUED SOUTH-SOUTHWESTERLY FLOW
ALOFT AS WE REMAIN SITUATED BETWEEN A ONCE-CLOSED UPPER LOW OVER
TEXAS THAT WILL OPEN UP AND DRIFT NORTH INTO THE MID-MISSISSIPPI
RIVER VALLEY, AND A SUBTROPICAL RIDGE ALOFT CENTERED OFF THE
SOUTHEAST COASTLINE. GUIDANCE SHOWS HIGH PWAT AIR CONTINUING TO
STREAM NORTH FROM THE GULF INTO THE TENNESSEE VALLEY AND SOUTHERN
APPALACHIAN REGION DURING THIS TIME. THEY'RE HIGHEST TODAY THROUGH
TONIGHT (UPWARDS OF 1.8-1.9" DEPENDING ON THE GUIDANCE SOURCE YOU
LOOK AT), BUT REMAIN ABOVE THE 90TH PERCENTILE EVEN INTO EARLY
WEDNESDAY BEFORE DRIER AIR IMPINGES ON THE CWA FROM THE NORTH DUE
TO A DEEPENING UPPER TROUGH OVER THE NORTHEAST CONUS AND
ASSOCIATED NORTHERLY LOW AND MID LEVEL FLOW. THE LATTER PART OF
THE WEEK WELL BE DRIER AND SLIGHTLY COOLER AS A RESULT OF THAT
DEEPENING TROUGH TO OUR NORTH.
REGARDING THIS AFTERNOON THROUGH TONIGHT, REGIONAL RADAR IMAGERY
THIS AFTERNOON SHOWS A COUPLE OF MCVS LIFTING NORTH FROM THE GULF
COAST. ONE IS IN CENTRAL MISSISSIPPI, JUST WEST OF THE MS/AL STATE
LINE, WHILE ANOTHER IS MOVING NORTH OFF THE GULF COAST AND WILL
BE APPROACHING HATTIESBURG IN THE NEXT FEW HOURS. GUIDANCE SHOWS
MULTIPLE ROUNDS OF CONVECTION DEVELOPING OVER THE REGION OUT IN
ADVANCE OF THESE FEATURES, POSSIBLY INTERACTING WITH A STALLED
FRONTAL BOUNDARY IN PLACE ACROSS THE TN VALLEY. FORECAST SOUNDINGS
SHOW PRIME WARM RAIN PROCESSES THROUGH LATE TONIGHT, WITH SKINNY
CAPE PROFILES WITH MEAGER VALUES, HIGH FREEZING LEVELS, AND HIGH
PWATS. SURFACE OBSERVATIONS UPSTREAM SUPPORT THIS AND HAVE SHOWN
OBSERVED 2"/HR RAINFALL RATES WITH RATHER UNIMPRESSIVE LOOKING
SHOWERS AND THUNDERSTORMS IN SOME CASES. LOCALLY CURRENT 1HR
FLASH FLOOD GUIDANCE IN THE TN VALLEY RANGES FROM MAYBE 1.5" IN
PORTIONS OF THE SOUTHERN VALLEY, TO LESS THAN 1" IN THE NORTHERN
VALLEY NEAR THE I-81 CORRIDOR. EVEN THE 3HR FFGS ARE LESS THAN 2"
ACROSS THE BOARD REALLY. SO I FEEL CONFIDENT IN HAVING THE FLASH
FLOOD WATCH OUT FOR A GOOD CHUNK OF OUR CWA THROUGH LATE TONIGHT.
TO BE CLEAR, THE FLOODING THREAT IS ISOLATED VERSUS WIDESPREAD.
BUT I THINK IT IS JUSTIFIED GIVEN WHAT OCCURRED YESTERDAY. THE
MAIN QUESTION IS WHETHER IT NEEDS TO BE EXTENDED TO COVER THE
CONVECTION THAT IS LIKELY TOMORROW IN ESSENTIALLY THE SAME AIR
MASS AND SYNOPTIC SETUP. PWATS ARE SLIGHTLY LESS TOMORROW, BUT
STILL ABOVE THE 90TH PERCENTILE FOR THIS TIME OF YEAR, AND WE'LL
LIKELY HAVE CONVECTION ASSOCIATED WITH THAT TRAILING MCV LIFTING
INTO NORTHERN AL AND THE SOUTHERN CUMBERLAND PLATEAU (OR SOMEWHERE
IN THAT GENERAL AREA) TOMORROW MORNING. WILL LET THE EVENING
SHIFT MAKE THE DECISION ON WHETHER TO EXTEND OR NOT, BUT DON'T BE
SURPRISED IF IT IS.
THIS WET PATTERN CONTINUES INTO WEDNESDAY, BUT PWATS BEGIN TO
DECLINE BY THAT TIME AND BOTH CONVECTIVE COVERAGE AND INTENSITY
SHOULD FOLLOW SUITE.
AGAIN, AS MENTIONED, THE LATTER PARTS OF THE WEEK WILL SEE A
TROUGH DEEPEN ACROSS THE NORTHEAST CONUS AND SUBSEQUENTLY DRIER
NORTHERLY FLOW BEGIN TO SPREAD INTO THE CWA. CURRENT NBM GUIDANCE
MAINTAINS SOME RAIN CHANCES OVER MUCH OF THE CWA THU ONWARD, WITH
THE HIGHER CHANCES IN THE SOUTH. THAT SEEMS REASONABLE FOR THE
TIME BEING, BUT DETERMINISTIC GUIDANCE IS ALREADY SHOWING THE
FOCUS OF RAINFALL CHANCES SHIFTING SOUTH IN RESPONSE TO THE DRIER
AIR SO I WOULDN'T BE SURPRISED TO SEE THOSE POPS COME DOWN AS
TIME GOES ON...ESPECIALLY ACROSS THE NORTHERN PARTS OF THE CWA.
AVIATION
(00Z TAFS)
ISSUED AT 747 PM EDT MON MAY 25 2026
ADDITIONAL RAIN IS MOVING SOUTH TO NORTH ACROSS THE SOUTHERN HALF
OF THE AREA CURRENTLY, AND IS EXPECTED TO CONTINUE TO SWEEP TO THE
NORTH THROUGH THE NEXT SEVERAL HOURS. OVERNIGHT CIGS ARE PRETTY
UNCERTAIN, OBSERVATIONS TO THE SOUTH ARE BETTER THAN WHAT WOULD
OTHERWISE BE EXPECTED, AND GUIDANCE IS SPLIT ON HOW POOR
CONDITIONS TREND OVERNIGHT. PERSISTED THE BULK OF THE PREVIOUS
TAFS. CATEGORICAL CONDITIONS SHOULD IMPROVE BY 18Z TOMORROW
THOUGH WITH THE CAVEAT OF ANOTHER ROUND OF SCATTERED RA AND TS TO
BEGIN THEREAFTER.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 66 79 66 82 / 90 80 80 90
KNOXVILLE MCGHEE TYSON AIRPORT, TN 65 80 65 81 / 80 70 80 90
OAK RIDGE, TN 64 79 64 81 / 90 80 80 100
TRI CITIES AIRPORT, TN 62 81 62 80 / 60 80 60 90
MRX WATCHES/WARNINGS/ADVISORIES
NC...FLOOD WATCH UNTIL 3 AM EDT TUESDAY FOR CHEROKEE-CLAY.
TN...FLOOD WATCH UNTIL 3 AM EDT /2 AM CDT/ TUESDAY FOR ANDERSON-
BLEDSOE-BLOUNT SMOKY MOUNTAINS-BRADLEY-COCKE SMOKY
MOUNTAINS-EAST POLK-GRAINGER-HAMBLEN-HAMILTON-JEFFERSON-
KNOX-LOUDON-MARION-MCMINN-MEIGS-NORTH SEVIER-NORTHWEST
BLOUNT-NORTHWEST CARTER-NORTHWEST COCKE-NORTHWEST GREENE-
NORTHWEST MONROE-RHEA-ROANE-SEQUATCHIE-SEVIER SMOKY
MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-SOUTHEAST
MONROE-UNICOI-WASHINGTON TN-WEST POLK.
VA...NONE.
DISCUSSION...CD
AVIATION...WELLINGTON
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