680  
FXUS64 KMEG 210139  
AFDMEG  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MEMPHIS TN  
839 PM CDT FRI OCT 20 2017  
   
UPDATE
 
 
IT'S QUIET ACROSS THE MID-SOUTH AT THE CURRENT TIME. AN ABUNDANCE  
OF MID/HIGH CLOUD COVER WILL PERSIST THROUGH THE OVERNIGHT HOURS  
AND INTO SUNDAY WITH LOWER CEILINGS EXPECTED TO DEVELOP TOWARD  
SUNRISE. A DECENT WARM ADVECTION PATTERN IS SETTING UP OVER THE  
WESTERN PORTION OF THE CWA TONIGHT. THIS MAY RESULT IN A FEW  
SHOWERS DURING THE OVERNIGHT HOURS, MAINLY WEST OF THE MISSISSIPPI  
RIVER. A SLIGHT CHANCE OF SHOWERS WAS INCLUDED 6-12Z TONIGHT.  
OTHERWISE, GENERALLY DRY CONDITIONS ARE EXPECTED SATURDAY MORNING  
WITH A SLIGHT CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS.  
INSTABILITY WILL REMAIN LIMITED OVER OUR NECK OF THE WOODS, WITH  
THE MOST LIKELY AREA FOR STRONGER STORMS REMAINING WELL TO OUR  
WEST. CLOUD COVER WAS ALSO INCREASE OVERNIGHT GIVEN THE CURRENT  
SATELLITE TRENDS. OTHERWISE, ONLY MINOR CHANGES WERE MADE TO THE  
FORECAST.  
 
LOOKING AHEAD, A DECENT RAINFALL REMAINS LIKELY, MAINLY DURING THE  
DAY SUNDAY. THE INITIAL BOUT OF SHOWERS AND THUNDERSTORMS WILL  
LIKELY MOVE INTO THE MID-SOUTH AS A QLCS SUNDAY MORNING. ENHANCED  
RAIN CHANCES WILL PERSIST ACROSS THE CWA THROUGH MONDAY AS THE  
ASSOCIATED UPPER-LEVEL TROUGH CLOSES OFF AND SLOWS AS IT TRAVERSES  
THE REGION. RAINFALL AMOUNTS OF 1-3" ARE EXPECTED ACROSS THE MID-  
SOUTH BETWEEN SUNDAY MORNING AND MONDAY AFTERNOON. IT IS WORTH  
NOTING THAT THE WPC DOES HAVE MUCH OF THE MID-SOUTH IN A SLIGHT  
RISK FOR EXCESSIVE RAINFALL ON SUNDAY, SO WE'LL CONTINUE TO  
MONITOR. THAT SAID, 3-HR FLASH FLOOD GUIDANCE EXCEEDS 2.5" ACROSS  
THE ENTIRE CWA AND 4" IN SOME AREAS, SO THE POTENTIAL FOR FLASH  
FLOODING REMAINS SOMEWHAT LIMITED.  
 
JOHNSON  
 

 
   
PREV DISCUSSION
 
/ISSUED 346 PM CDT FRI OCT 20 2017/  
 
DISCUSSION...  
MODELS IN GENERAL AGREEMENT WITH THE PATTERN AS A UPPER LEVEL HIGH  
PUSHES TO THE EAST AS A LARGE AMPLITUDE TROUGH PUSHES TOWARDS THE  
MID-SOUTH. LATE ON SATURDAY THE UPPER LEVEL TROUGH SPLITS AND  
CLOSES OFF A LOW THAT IS GENERALLY SOUTH OF THE AREA AND THIS  
STALLS PRECIPITATION ACROSS THE MID-SOUTH PROVIDING EVEN MORE THAN  
JUST WITH THE FRONTAL PASSAGE ASSOICATED WITH THE UPPER LOW  
TROUGH. HOWEVER, THIS CLOSED UPPER LOW GETS ABSORBED INTO THE  
LARGE UPPER TROUGH AND ALLOWS EVEN A COLDER AIR MASS INTO THE AREA  
MIDWEEK.  
 
THE FRONTAL SYSTEM ON SUNDAY WILL BRING RAIN AND THUNDERSTORMS,  
HOWEVER, THE UPPER LEVEL PATTERN DOESN'T MAKE IT CONDUCIVE FOR  
SEVERE WEATHER AS IT CLOSES OFF AND ANY FORCING IS MOVED SOUTH OF  
THE AREA. THE INSTABILITY EVEN IN THE SOUTHERN PARTS OF THE AREA  
IS FAIRLY WEAK. THIS BEING SAID, THERE STILL MAY BE SOME STRONG  
STORMS ON SUNDAY, HOWEVER, NO SEVERE WEATHER.  
 
THE SECONDARY AIR MASS BEHIND THIS FRONT WILL BRING IN THE COLD  
AIR BY MIDWEEK AND THIS MAY BRING SOME FROST TO THE AREA,  
ESPECIALLY NEAR THE TENNESSEE RIVER.  
 
DRY CONDITIONS AFTER TUESDAY.  
 
TLSJR  
 

 
   
AVIATION
 
 
/00Z TAFS/  
 
VFR CONDITIONS ARE ANTICIPATED OVER THE NEXT 24 HOURS. ONLY HIGH  
CLOUDS ARE EXPECTED THIS AFTERNOON, BUT LOWER CEILINGS (AROUND  
5000 FT) ARE FORECASTS TO DEVELOP LATE TONIGHT AND SHOULD AFFECT  
MOST, IF NOT ALL, FORECAST TERMINALS BY 12Z. WINDS WILL GENERALLY  
REMAIN LIGHT FROM THE SOUTHEAST, BUT MAY APPROACH 7-8 KTS WHICH  
COULD IMPACT N-S OPERATIONS AT KMEM. SOUTH TO SOUTHEAST WINDS WILL  
INCREASE TO 8-12 KTS BY MID/LATE MORNING AND MAY BE GUSTY AT TIMES  
IN SOME AREAS. MOST AREAS WILL REMAIN DRY THOUGH THE PERIOD, BUT A  
FEW SHOWERS MAY AFFECT KJBR LATE TONIGHT AND AGAIN SATURDAY  
AFTERNOON. A STRAY STORM CANNOT BE RULED OUT AT KJBR AFTER 18Z,  
BUT CONFIDENCE REMAINS LOW AT THIS TIME.  
 
JOHNSON  
 

 
   
MEG WATCHES/WARNINGS/ADVISORIES
 
 
AR...NONE.  
MO...NONE.  
MS...NONE.  
TN...NONE.  
 

 
 

 
 
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