097  
FXUS64 KMRX 222041  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
341 PM EST WED JAN 22 2020  
   
SHORT TERM (TONIGHT THROUGH THURSDAY)
 
 
HIGH PRESSURE AT THE SURFACE AND RIDGING ALOFT WILL KEEP  
CONDITIONS DRY OVERNIGHT AND THROUGH THE FIRST HALF OF THURSDAY.  
LOWS TONIGHT SHOULD BE A BIT WARMER THEN PREVIOUS NIGHTS WITH  
LOWS IN THE UPPER 20S TO MID 30S. A SERIES OF SHORTWAVE ALOFT WILL  
TRAVEL THROUGH CYCLONIC FLOW ALOFT WITH TWO AREAS OF LOW PRESSURE  
ACROSS THE NORTHERN AND SOUTHERN PLAINS. ISENTROPIC ASCENT IN THE  
305-295K LAYER WILL INCREASE ON THURSDAY LEADING TO A GRADUAL  
INCREASE IN PRECIPITATION MAINLY AFTER 12-15Z. WITH THE SHORTWAVE  
TROUGH STILL ACROSS MUCH OF THE MIDSOUTH AND MIDDLE MISSISSIPPI  
RIVER THE BETTER FORCING WILL REMAIN WEST WHICH SHOULD KEEP MUCH  
OF THE PRECIPITATION ON THE LIGHTER SIDE UNTIL THIS FORCING  
APPROACHES CLOSER. HIGHS ON THURSDAY WILL RISE INTO THE MID 40S  
TO NEAR 50.  
 
DIEGAN  
   
LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)
 
 
BY THURSDAY EVENING A STRONG FRONT WILL BE APPROACHING FROM THE  
SOUTHWEST IN RESPONSE TO A STRONG DISTURBANCE OVER SOUTHERN IOWA AND  
NORTHERN MISSOURI. WITH THE APPROACHING FRONT, A 40-60KT LOW LEVEL  
JET WILL TRAVERSE THE MOUNTAINOUS REGION, WITH THE FLOW ORIENTED  
FAVORABLY TO SUPPORT A MOUNTAIN WAVE EVENTS. THIS EVENT LOOKS FAIRLY  
IMPRESSIVE, WITH THE JET NEARLY PERFECTLY ALIGNED PERPENDICULAR TO  
THE MOUNTAIN RANGE. GIVEN EVEN THE LOW END OF FORECAST WINDS IS  
SUPPORTIVE OF MARGINAL HIGH WINDS, FEEL IT IS WARRANTED TO GO AHEAD  
AN ISSUE A HIGH WIND WATCH FOR THE EAST TENNESSEE MOUNTAINS.  
 
ON THE BACK SIDE OF THIS SYSTEM, FRIDAY NIGHT INTO SATURDAY MORNING,  
TEMPERATURES ALOFT WILL COOL ENOUGH TO SUPPORT SOME SNOW MIXING DOWN  
INTO THE MOUNTAINS. THE PROBLEM IS THAT THE SATURATED LAYER WILL NOT  
EXTEND UP INTO THE DENDRITIC SNOW GROWTH REGION BY SHORTLY AFTER  
MIDNIGHT FRIDAY NIGHT. THUS IT WILL BE MOSTLY A NORTHWEST FLOW  
EVENT, WITH ACCUMULATIONS LIMITED TO MAINLY THE HIGHER ELEVATIONS  
AROUND 3,500 FT AND HIGHER. CURRENTLY ONLY HAVE PERHAPS 1-3 INCHES  
IN THE FORECAST FOR THOSE AREAS AS MOISTURE BECOMES LIMITED VERY  
QUICKLY.  
 
BEYOND SATURDAY MORNING, IT LOOKS LIKE A RELATIVELY DRY FORECAST.  
THERE IS ANOTHER DISTURBANCE THAT COMES THROUGH LATE SUNDAY, BUT IT  
LOOKS FAR ENOUGH SOUTH THAT ANY PRECIPITATION ASSOCIATED WITH IT  
WILL ALSO WIND UP TO OUR SOUTH, SO KEPT A DRY FORECAST FOR THE  
LATTER HALF OF THE WEEKEND. THE NEXT SYSTEM LOOKS TO ARRIVE  
ON WEDNESDAY.  
 
CD  
 

 
   
AVIATION
 
 
18Z TAF DISCUSSION.  
 
VFR CONDITIONS WILL CONTINUE TO IMPACT ALL TAF SITES THROUGH THE  
NEXT 24 HOURS. CLOUDS WILL SLOWLY INCREASE TONIGHT AND ON THURSDAY  
WITH LOWERING VFR CIGS. WINDS WILL REMAIN LIGHT THROUGH THE  
PERIOD.  
 
DIEGAN  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 34 47 41 51 37 / 0 60 80 80 10  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 31 48 40 50 37 / 0 20 60 80 10  
OAK RIDGE, TN 30 47 38 49 36 / 0 30 80 80 20  
TRI CITIES AIRPORT, TN 28 51 36 50 35 / 0 10 30 90 20  
 

 
   
MRX WATCHES/WARNINGS/ADVISORIES
 
 
NC...NONE.  
TN...HIGH WIND WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY  
AFTERNOON FOR BLOUNT SMOKY MOUNTAINS-COCKE SMOKY MOUNTAINS-  
JOHNSON-SEVIER SMOKY MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST  
GREENE-SOUTHEAST MONROE-UNICOI.  
 
VA...NONE.  

 
 

 
 
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