121  
FXUS64 KMRX 250547  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
1247 AM EST THU DEC 25 2025  
   
..NEW DISCUSSION, AVIATION
 
 
   
KEY MESSAGES
 
 
UPDATED AT 1239 AM EST THU DEC 25 2025  
 
- UNSEASONABLE WARM WEATHER TODAY THROUGH THE WEEKEND. NEAR  
RECORD TEMPERATURES POSSIBLE ACROSS CHATTANOOGA.  
 
- LOW RAIN CHANCES ACROSS SOUTHWEST VIRGINIA AND NORTHEAST  
TENNESSEE FOR TODAY THROUGH FRIDAY NIGHT.  
 
- WIDESPREAD RAIN FOR SUNDAY NIGHT AND MONDAY MORNING WITH A  
STRONG COLD FRONT.  
 
- MUCH COLDER AIRMASS MOVES INTO THE TENNESSEE VALLEY AND  
SOUTHERN APPALACHIANS FOR LATE SUNDAY AND ESPECIALLY EARLY NEXT  
WEEK. WIND CHILLS MAY DROP BELOW ZERO ACROSS THE HIGHER  
ELEVATIONS MONDAY NIGHT.  
 

 
   
DISCUSSION
 
 
ISSUED AT 1239 AM EST THU DEC 25 2025  
 
CURRENTLY HAVE A GOOD DEAL OF CLOUD COVER OVER THE REGION BUT  
WITH SOME BREAKS ALLOWING PATCHY FOG DEVELOPMENT. DUE TO THE LOW  
DEWPOINT DEPRESSIONS, DO EXPECT PATCHY FOG TO CONTINUE OVERNIGHT.  
 
MAIN WEATHER STORY FOR THE REST OF THE WEEK INTO THE FIRST HALF OF  
THE WEEKEND WILL BE A STRONG RIDGE OF HIGH PRESSURE AND ANOMALY HIGH  
HEIGHTS OVER THE SOUTHERN HALF OF THE UNITED STATES. THIS RIDGE WILL  
PRODUCE UNUSUAL WARMTH FOR LATE DECEMBER WITH HIGHS AROUND 20  
DEGREES ABOVE NORMAL. NEAR RECORD HIGHS ARE POSSIBLE TODAY,  
FRIDAY AND SATURDAY ACROSS CHATTANOOGA AREA.  
 
CHRISTMAS DAY:  
 
FORECAST HIGH NORMAL HIGH RECORD HIGH  
CHATTANOOGA: 73 52 75  
KNOXVILLE AIRPORT: 69 49 76  
TRI-CITIES: 64 48 74  
 
A SERIES OF JET STREAKS WILL MOVE QUICKLY WITH THE FAST FLOW FROM  
THE OHIO VALLEY INTO THE CENTRAL APPALACHIANS FOR TODAY THROUGH  
FRIDAY NIGHT. A BACK DOOR FRONTAL BOUNDARY WILL ALSO APPROACH  
SOUTHWEST VIRGINIA TODAY AND BE NEAR THE AREA TONIGHT AND FRIDAY  
BEFORE LIFTING NORTH. DUE TO INCREASING ISENTROPIC LIFT WITH EACH  
WAVE AND SOME FRONTO-GENETIC FORCING, RAIN SHOWERS CHANCES ARE  
EXPECTED FOR MAINLY SOUTHWEST VIRGINIA AND NORTHEAST TENNESSEE.  
HREF/REFS/LREF AND DETERMINISTIC MODELS SHOW ONLY LIGHT QPF AMOUNTS  
WITH THESE SYSTEMS AND GENERALLY LESS THAN 0.20 INCH.  
 
A MAJOR PATTERN CHANGE WILL OCCUR LATE THIS WEEKEND AND ESPECIALLY  
EARLY NEXT WEEK. ENSEMBLE CLUSTER ANALYSIS AND DETERMINISTIC  
MODELS SHOW A DIGGING UPPER TROUGH OVER THE EASTERN THIRD OF THE  
NATION. A STRONG 300MB JET OF 160-165KTS DIGS INTO THE OHIO VALLEY  
AND CENTRAL APPALACHIANS PRODUCING A GOOD DEAL OF JET DYNAMICS AS  
A STRONG FRONTAL BOUNDARY MOVES INTO THE AREA LATE SUNDAY NIGHT  
AND MONDAY MORNING. WIDESPREAD SHOWERS IS EXPECTED ESPECIALLY  
EARLY MONDAY MORNING.  
 
MUCH COLDER AIRMASS QUICKLY MOVES INTO THE REGION FOR MONDAY AND  
TUESDAY WITH HIGHS 30+ DEGREES COLDER THAN THIS WEEK. HIGHS MONDAY  
WILL BE EARLY IN THE MORNING THEN TEMPERATURES FALLING DURING THE  
DAY.  
 
WIND CHILLS MAY DROP BELOW ZERO ACROSS THE HIGHER ELEVATIONS MONDAY  
NIGHT WITH SINGLE DIGITS AND TEENS IN THE VALLEY. COLD AIRMASS WILL  
SETTLE INTO THE REGION FOR TUESDAY. A SLOW MODERATION WILL BEGIN  
WEDNESDAY.  
 

 
   
AVIATION
 
 
(06Z TAFS)  
ISSUED AT 1239 AM EST THU DEC 25 2025  
 
WIDESPREAD LOW-END VFR OR MVFR CIGS ARE EXPECTED OVERNIGHT AND  
THROUGH MUCH OF THE DAY FOR KTYS AND KTRI, WITH SOME CHANCES FOR  
PERIODS OF SHRA AT KTRI BEYOND 10Z AS AN UPPER JET GLANCES BY  
ALOFT. THOUGH SOME GUIDANCE SUPPORTS SOME BRIEF MVFR CIGS AT KCHA  
JUST AFTER DAYBREAK, I THINK THEY WILL REMAIN PRIMARILY VFR  
THROUGH THE PERIOD SO THE FORECAST REFLECTS THAT.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 72 57 73 60 / 0 10 0 20  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 69 58 71 59 / 20 10 20 40  
OAK RIDGE, TN 68 57 68 59 / 10 10 20 40  
TRI CITIES AIRPORT, TN 64 55 65 56 / 50 50 40 70  
 

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

 
 

 
 
DISCUSSION...DH  
AVIATION...CD  
 
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