476  
FXUS64 KMRX 181846  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
246 PM EDT SAT APR 18 2026  
   
..NEW DISCUSSION, AVIATION  
 
   
KEY MESSAGES  
 
UPDATED AT 243 PM EDT SAT APR 18 2026  
 
- SHOWERS AND STORMS EXPECTED THIS EVENING PRIMARY THREAT WILL BE  
DAMAGING WINDS AND SMALL HAIL, ESPECIALLY ALONG AND NORTH OF  
INTERSTATE 40.  
 
- DRIER AND MUCH COOLER CONDITIONS ARE EXPECTED SUNDAY INTO MONDAY  
WITH LOW RH'S IN THE 20S AND LOWER 30S RETURNING.  
 
- DRY CONDITIONS WILL CONTINUE THROUGH THE WEEK, ALONG WITH A  
GRADUAL WARMING TREND. LOW RH'S CONTINUE TO BE OF CONCERN.  
 
 
   
DISCUSSION  
 
ISSUED AT 243 PM EDT SAT APR 18 2026  
 
A COLD FRONT IS APPROACHING THE AREA TODAY WITH INCREASING  
SOUTHERLY FLOW OUT AHEAD. SHOWERS AND STORMS, SOME DISCRETE, ARE  
ONGOING AHEAD OF THIS FRONT. HOWEVER... THE FOCUS FOR STRONG TO  
MARGINALLY SEVERE STORMS CONTINUES TO BE IN THE NORTHERN HALF OF  
THE REGION WHERE CAPE UP TO 1,000 J/KG IS POSSIBLE. WHILE  
STRONGER FLOW IS EXPECTED IN THE MID LEVELS, THE 850MB WINDS WILL  
REMAIN GENERALLY LIGHT TO MODERATE WITH LIMITED LOW-LEVEL SHEAR.  
CAPE HAIL GROWTH ZONE IS COULD GROW TO 400 J/KG. SO THERE REMAINS  
A LOW END THREAT FOR DAMAGING WINDS AND HAIL DURING THE EVENING  
HOURS. THE COLD FRONT WILL MOVE THROUGH THE AREA AFTER MIDNIGHT,  
LEADING TO DECREASING RAIN COVERAGE.  
 
TOMORROW THE COLD FRONT WILL MOVED WELL TO THE EAST WITH HIGH  
PRESSURE EXPANDING FROM THE SOUTHWEST. THIS WILL LEAD TO COOLER  
AND DRIER CONDITIONS WITH HIGH TEMPERATURES REMAINING IN THE 60S  
FOR MOST. LOW RELATIVE HUMIDITIES IN THE 20S WILL RETURN, ALONG  
WITH NORTHWESTERLY WINDS. TOMORROW NIGHT WILL BE COOLER FOLLOWING  
THE FRONT WITH SOME PLACES DROPPING INTO THE 30S. NEXT WEEK, HIGH  
PRESSURE WILL BE CENTERED OVERHEAD, LEADING TO A LIGHTER WINDS,  
BUT DRY CONDITIONS WILL CONTINUE. COLD LOW TEMPERATURES CAN BE  
EXPECTED AGAIN MONDAY NIGHT, POTENTIALLY COLD ENOUGH FOR FROST IN  
SOME AREAS. BY TUESDAY, HIGH PRESSURE WILL SHIFT OFF TO THE EAST,  
TURNING WINDS MORE TO SOUTHERLY. THIS WILL BEGIN ANOTHER WARMING  
TREND WITH HIGHS RISING BACK ABOVE NORMAL. RIDGING WILL LEAD TO  
FURTHER STRENGTHENING PRESSURE THROUGH THE END OF THE WEEK WITH  
MOST PLACES RISING BACK INTO THE 80S. UNFORTUNATELY LOW RELATIVE  
HUMIDITIES WILL CONTINUE NEXT WEEK.  
 
 
   
AVIATION  
 
(18Z TAFS)  
ISSUED AT 243 PM EDT SAT APR 18 2026  
 
ISOLD SHRA WILL MOVE INTO THE TN VALLEY IN THE NEXT 2-4 HOURS, WITH  
VCSH POSSIBLE AT ALL TERMINALS FOR A FEW HOURS THEREAFTER.  
INCREASING COVERAGE IN SHRA AND EMBEDDED TSRA EXPECTED LATER  
TONIGHT. FROPA SHOULD OCCUR AROUND OR SHORTLY AFTER 08Z TONIGHT,  
WITH LOW-END VFR OR POSSIBLY SOME MVFR CIGS LINGERING UNTIL DAYBREAK  
OR THEREABOUTS. POST-FRONTAL WINDS SHOULD BE FAIRLY GUSTY TOMORROW  
SO HAVE GUSTS OF 20-22KT AT ALL SITES TO ACCOUNT FOR THAT.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
CHATTANOOGA AIRPORT, TN 48 68 44 75 / 90 0 0 0  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 46 64 43 68 / 100 0 0 0  
OAK RIDGE, TN 46 65 41 69 / 100 0 0 0  
TRI CITIES AIRPORT, TN 44 61 38 62 / 100 10 0 0  
 
 
   
MRX WATCHES/WARNINGS/ADVISORIES  
 
NC...NONE.  
TN...NONE.  
VA...NONE.  
 
 
 
 
DISCUSSION...99  
AVIATION...CD  
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