814  
FXUS64 KMRX 041909  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
309 PM EDT WED OCT 4 2023  
   
..NEW SHORT TERM, LONG TERM
 
 
   
SHORT TERM
 
 
(THIS EVENING THROUGH THURSDAY)  
ISSUED AT 258 PM EDT WED OCT 4 2023  
 
KEY MESSAGES:  
 
1. DRY WEATHER CONTINUES, PATCHY FOG AGAIN POSSIBLE NEAR RIVERS  
IN THE MORNING.  
 
DISCUSSION:  
 
MORE CLOUD COVERAGE THIS AFTERNOON THAN THIS TIME YESTERDAY! ALWAYS  
NEAT TO SEE THE CUMULUS CLOUDS CURL IN THE LOW LEVEL FLOW AROUND THE  
SOUTHERN END OF THE MOUNTAINS UP INTO MIDDLE TENNESSEE. CIRRUS  
DEBRIS FROM STORMS WEST OF THE MISSISSIPPI RIVER IS BEGINNING TO  
STREAM IN OVERHEAD AND WILL CONTINUE TO DO SO AHEAD OF THE INCOMING  
SYSTEM.  
 
THE UPPER LEVEL RIDGE AXIS THAT HAS PROVIDED US WITH THE DRY WARM  
WEATHER WILL SLIDE EASTWARD AS A LARGE SCALE TROUGH MOVES ACROSS  
THE PLAINS AND THE FIRST REAL COLD FRONT OF FALL APPROACHES OUR  
AREA. WHILE TOMORROW IS EXPECTED TO REMAIN DRY THROUGH THE  
AFTERNOON, CLOUD COVERAGE WILL BE ON THE INCREASE AND TEMPERATURES  
WILL BE SLIGHTLY COOLER THAN TODAY.  
 

 
   
LONG TERM
 
 
(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)  
ISSUED AT 258 PM EDT WED OCT 4 2023  
 
KEY MESSAGES:  
 
1. SOME SHOWERS AROUND FRIDAY INTO FRIDAY NIGHT, AND MAYBE A FEW  
RUMBLES OF THUNDER IN SPOTS.  
 
2. MAJOR COOL DOWN OVER THE WEEKEND FOLLOWED BY A GRADUAL WARMING  
TREND.  
 
DISCUSSION:  
 
WE START THE PERIOD WITH AN UPPER TROUGH AXIS TO OUR WEST AND A  
SURFACE COLD FRONT APPROACHING. MOISTURE WILL BE INCREASING THURSDAY  
NIGHT AND SHOWERS WILL MOVE INTO AT LEAST WESTERN PORTIONS OF THE  
AREA BEFORE DAYBREAK. THERE IS STILL SOME UNCERTAINTY ON THE TIMING  
OF THE FRONT, BUT CURRENT INDICATIONS ARE THAT IT WILL LIKELY SWEEP  
THROUGH DURING THE FRIDAY/FRIDAY EVENING TIME FRAME. SOME  
MODEL/ENSEMBLE DATA SUGGEST LIMITED CAPE OF A FEW HUNDRED J/KG MAY  
BE AVAILABLE, SO A FEW AREAS MAY HEAR A RUMBLE OR TWO OF THUNDER  
MAINLY SOUTHERN HALF AND/OR NORTHERN PLATEAU AS THE FRONT MOVES  
THROUGH. QPF STILL LOOKS LIMITED WITH MOST LOCATIONS THAT RECEIVE  
RAIN EXPECTED TO GET LESS THAN A QUARTER OF AN INCH, AND MUCH OF THE  
AREA WILL LIKELY SEE LESS THAN A TENTH OF AN INCH.  
 
A LARGE CLOSED UPPER LOW WILL DEVELOP OVER THE EASTERN GREAT  
LAKES/NE US REGION SATURDAY/SATURDAY NIGHT AND WILL BE SLOW TO LIFT  
NORTHEAST. THIS WILL KEEP OUR REGION IN A NORTHWEST FLOW ALOFT  
REGIME INTO MID WEEK. MUCH COOLER AIR WILL MOVE IN BEHIND THE FRONT  
FOR THE WEEKEND, WITH TEMPERATURES AROUND 10 TO 15 DEGREES BELOW  
NORMAL COMMON, FOLLOWED BY A SLOW WARMING TREND MONDAY THROUGH  
WEDNESDAY. THERE MAY EVEN BE PATCHY FROST IN A FEW COLDER SPOTS  
LATE SATURDAY NIGHT OR MORE LIKELY LATE SUNDAY NIGHT.  
 
SOME MODEL/ENSEMBLE DATA SUGGESTS THERE COULD BE A FEW LIGHT SHOWERS  
AROUND AT SOME POINT DURING THE MONDAY THROUGH WEDNESDAY TIME FRAME  
AS WEAK SHORT WAVE ENERGY MOVES THROUGH THE NORTHWEST FLOW ALOFT.  
HOWEVER, GIVEN THE VERY POOR MODEL AGREEMENT ON ANY PRECIPITATION  
OCCURRING AND THE EXPECTED VERY LIMITED MOISTURE AVAILABLE FOR ANY  
SHORT WAVE TO WORK WITH, WILL GO WITH THE DRY NBM FORECAST DURING  
THE ENTIRE SATURDAY THROUGH WEDNESDAY PERIOD.  
 

 
   
AVIATION
 
 
(18Z TAFS)  
ISSUED AT 112 PM EDT WED OCT 4 2023  
 
DRY WITH LIGHT WINDS THROUGH THE TAF PERIOD FOR ALL SITES, VFR  
THROUGH THE PERIOD AT CHA AND TYS. PUT MVFR VISIBILITY IN AGAIN  
FOR TRI BETWEEN 9-13Z FOR BRIEF PATCHY FOG IN THE MORNING. FOG MAY  
BE PRESENT ELSEWHERE NEAR RIVERS AND LAKES.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 64 82 65 78 / 0 10 30 40  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 62 83 63 76 / 0 10 20 40  
OAK RIDGE, TN 62 82 63 76 / 0 10 20 40  
TRI CITIES AIRPORT, TN 56 80 59 72 / 0 0 20 30  
 

 
   
MRX WATCHES/WARNINGS/ADVISORIES
 
 
NC...NONE.  
TN...NONE.  
VA...NONE.  

 
 

 
 
SHORT TERM...WELLINGTON  
AVIATION...WELLINGTON  
 
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