567  
FXUS64 KMRX 050544  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
144 AM EDT MON MAY 5 2025  
   
..NEW AVIATION  
 
   
UPDATE  
 
ISSUED AT 901 PM EDT SUN MAY 4 2025  
 
NO CHANGES TO THE FORECAST THIS EVENING AS AN UPPER LOW CONTINUES  
TO SIT OVER KY AND SOUTHERN IN, WITH VORT LOBES ROTATING AROUND IT  
THAT BRING SOME SHOWERS TO OUR AREA. THIS PATTERN WILL HOLD  
THROUGH TOMORROW. EXPECT TO SEE A WAVE OF SHOWERS WITH A VORT MAX  
IN THE LATE OVERNIGHT AND EARLY MORNING HOURS, THEN SCATTERED  
SHOWERS AND AN ISOLATED THUNDERSTORM TOMORROW AFTERNOON AS WE GET  
SOME INSTABILITY UNDERNEATH THE COLD TEMPERATURES ALOFT, SIMILAR  
TO WHAT WE SAW THIS PAST AFTERNOON. TEMPERATURES WILL BE  
ABNORMALLY COOL TONIGHT, WITH LOWS IN THE 40S.  
 
 
   
SHORT TERM  
 
(THIS EVENING THROUGH MONDAY)  
ISSUED AT 152 PM EDT SUN MAY 4 2025  
 
KEY MESSAGES:  
1. ISOLATED STRONG STORMS ACROSS SOUTHWEST VIRGINIA/NORTHEAST  
TENNESSEE THIS AFTERNOON PRODUCING SMALL HAIL.  
 
2. UNSEASONABLY COOL CONDITIONS TONIGHT AND AGAIN MONDAY WITH  
TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL.  
 
3. AN AREA OF SHOWERS WILL MOVE ACROSS THE AREA ALONG AND NORTH OF  
INTERSTATE 40 FOR MONDAY.  
 
DISCUSSION:  
 
CURRENTLY, ISOLATED CONVECTION ACROSS SOUTHWEST VIRGINIA AND  
NORTHEAST TENNESSEE HAVE PRODUCED SMALL HAIL UP TO PEA SIZE. MAIN  
CULPRIT ARE THE LOW FREEZING LEVEL AND GOOD MID-LEVEL LAPSE RATES.  
HOWEVER, THE BEST MID-LEVEL LAPSE RATES AND MLCAPE PIVOTS NORTH  
INTO THE OHIO VALLEY TODAY.  
 
FOR TONIGHT, UPPER TROUGH WILL CONTINUE TO MOVE SLOWLY EAST ACROSS  
THE KENTUCKY WITH PLENTY OF LOW LEVEL CLOUDS OVER THE AREA. AN  
UNSEASONABLY COOL NIGHT WITH TEMPERATURES DROPPING INTO THE 40S  
MOST LOCATIONS. EVEN MID TO UPPER 30S OVER THE HIGHER ELEVATIONS  
OF THE SMOKY MOUNTAINS.  
 
FOR MONDAY, HREF AND DETERMINISTIC MODELS SHOW INCREASING SHOWERS  
OVER THE NORTHERN HALF OF TENNESSEE INTO SOUTHWEST VIRGINIA. MAIN  
FORCING IS DUE TO INCREASING QG-FORCING WRAPPING AROUND THE UPPER  
LOW. THE GREATEST COVERAGE WILL BE DURING THE MORNING HOURS.  
PLENTY OF SHOWERS (NORTH) AND CLOUD COVER WILL KEEP TEMPERATURES  
ABOUT 10 DEGREES BELOW NORMAL. INSTABILITY IS LIMITED AT BEST SO  
MAINLY SHOWERS.  
 
 
   
LONG TERM  
 
(MONDAY NIGHT THROUGH NEXT SUNDAY)  
ISSUED AT 152 PM EDT SUN MAY 4 2025  
 
KEY MESSAGES:  
 
1. NEAR NORMAL TO BELOW NORMAL HIGH TEMPERATURES THROUGH THE LONG  
TERM.  
 
2. UNSETTLED PATTERN WITH DAILY SHOWER AND THUNDERSTORM CHANCES  
WEDNESDAY THROUGH FRIDAY, BUT A LOW CONFIDENCE FORECAST.  
 
3. POSSIBLE DRYING TREND BY THE WEEKEND.  
 
DISCUSSION:  
 
WE GET A BREAK FROM THE RAIN AND CLOUDS ON TUESDAY AS HIGH PRESSURE  
MAKES A BRIEF RETURN ACROSS THE AREA. HOWEVER, SOME LOW-END  
PROBABILITIES FOR SHOWERS WILL REMAIN IN PLACE ACROSS EXTREME  
NORTHEAST TN AND SOUTHWEST VA. THIS IS DUE TO THE VICINITY OF THE  
UPPER LOW AS IT CONTINUES TO MOVE NORTHEAST AND OUT OF OUR AREA.  
 
THEN, THE REST OF THE PERIOD BECOMES UNSETTLED. THIS IS DUE TO AN  
OMEGA BLOCKING PATTERN THAT SETS UP ACROSS THE COUNTRY ALONG WITH A  
CLOSED LOW TO OUR WEST ACROSS THE CENTRAL PLAINS/MISSOURI RIVER  
VALLEY. THIS MEANS THAT DAILY CHANCES FOR SHOWERS AND A FEW STORMS  
WILL BE IN PLACE FROM WEDNESDAY THROUGH FRIDAY. THIS IS A VERY LOW  
CONFIDENCE FORECAST THOUGH DUE TO THE MESSY PATTERN THAT WILL BE IN  
PLACE. IF THE CLOSED LOW STAYS FAR ENOUGH TO OUR WEST, THE ACTUAL  
WEATHER MAY END UP BEING QUITE A BIT DRIER THAN THE CURRENT FORECAST  
WOULD SUGGEST. SO DON'T CANCEL THOSE OUTDOOR PLANS JUST YET.  
 
MODELS STILL TRENDING TOWARD DRYING CONDITIONS BY THE WEEKEND AS AN  
AREA OF STRONG HIGH PRESSURE BUILDS IN ACROSS THE CENTRAL U.S. THIS  
PLACEMENT OF THE HIGH WOULD KEEP THE REMNANT CLOSED LOW SUPPRESSED  
TO OUR SOUTH, KEEPING US MOSTLY DRY.  
 
 
   
AVIATION  
 
(06Z TAFS)  
ISSUED AT 135 AM EDT MON MAY 5 2025  
 
ASSUMING PERSISTENCE, A FEW LIGHT RAIN SHOWERS WILL ROTATE INTO  
THE AREA BRINGING LIGHT RAIN TO KCHA AND KTYS WITHIN THE NEXT FEW  
HOURS. WHILE TAFS MAINTAIN VFR CONDITIONS, A FEW HOURS OF MVFR ARE  
NOT OUT OF THE QUESTION BEFORE ATMOSPHERIC MIXING BEGINS IN THE  
AFTERNOON. LIGHT WINDS TODAY, A LOW PROBABILITY FOR A MORE  
IMPACTFUL SHOWER BETWEEN 18Z AND 00Z AT KTRI, SCATTERED SHOWERS  
ELSEWHERE, FAVORING NORTHERN AREAS.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
CHATTANOOGA AIRPORT, TN 68 49 76 56 / 10 0 0 20  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 65 48 73 51 / 50 0 10 10  
OAK RIDGE, TN 65 47 73 51 / 50 10 10 10  
TRI CITIES AIRPORT, TN 65 46 69 47 / 70 10 20 10  
 
 
   
MRX WATCHES/WARNINGS/ADVISORIES  
 
NC...NONE.  
TN...NONE.  
VA...NONE.  
 
 
 
 
SHORT TERM...DGS  
AVIATION...WELLINGTON  
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