947  
FXUS63 KIWX 201109  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
609 AM EST MON NOV 20 2017  
   
SYNOPSIS
 
 
ISSUED AT 609 AM EST MON NOV 20 2017  
 
MOSTLY SUNNY AND BECOMING WINDY THIS AFTERNOON. AFTERNOON HIGHS WILL  
BE IN THE MID 40S. SOUTHWEST BREEZES CONTINUE TONIGHT WITH LOWS IN  
THE MID 30S.  
 
SLIGHT CHANCE OF A SHOWER LATE TUESDAY OTHERWISE DRY AND SEASONABLE  
WEDNESDAY THROUGH FRIDAY.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 212 AM EST MON NOV 20 2017  
 
SURFACE ANALYSIS HAS HIGH PRESSURE CENTERED OVER THE TN AND LOWER  
OH VALLEY AND WILL PROVIDE A QUIET WEATHER PATTERN IN THE SHORT  
TERM. PATTERN ALOFT FLATTENING TO MORE ZONAL FLOW AS MORE PACIFIC  
ENERGY STREAMS ONSHORE IN WESTERN US. THIS WILL HAVE SURFACE RIDGE  
AXIS SHIFTING QUICKLY EASTWARD TODAY TO THE VIRGINIAS AND  
CAROLINAS BY THIS AFTERNOON. BREEZY SW FLOW ON BACKSIDE OF HIGH  
WILL HAVE AREA IN LOW LEVEL WAA AND SEND TEMPS BACK INTO THE MID  
40S. FAIR AND SEASONABLE TONIGHT WITH LOWS IN THE MID 30S.  
 

 
   
LONG TERM
 
(TUESDAY THROUGH SUNDAY)  
ISSUED AT 212 AM EST MON NOV 20 2017  
 
PROGRESSIVE LOW AMPLITUDE PATTERN ALOFT WILL HAVE AN ACTIVE  
NORTHERN STREAM ACROSS SOUTHERN CANADA THROUGH THE LONG TERM  
PERIOD. EACH SYSTEM WILL DRAG A COLD FRONT ACROSS THE LOWER 48  
THAT WILL BE LACKING IN BOTH MASS CONVERGENCE ALONG THE FRONT AND  
MOISTURE RETURN FROM THE GULF. RESULT WILL BE LOW CHANCE POPS  
AHEAD OF THE FRONT AND WEAK LAKE EFFECT SETUP IN ITS WAKE.  
TEMPERATURES THROUGH THE PERIOD WILL SEE WARM-UPS INTO THE 40S  
AHEAD OF EACH SYSTEM THEN COOLING BACK INTO THE 30S BEHIND THEM.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)  
ISSUED AT 609 AM EST MON NOV 20 2017  
 
VFR THIS PERIOD AS SFC RIDGING DRIFTS EWD THROUGH THE TN VALLEY.  
FAIRLY VIGOROUS RETURN FLOW THOUGH BY AFTN WITH SWRLY GUSTS AOA  
25KTS.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
MI...NONE.  
OH...NONE.  
LM...GALE WATCH FROM THIS AFTERNOON THROUGH TUESDAY EVENING FOR  
LMZ043-046.  
 
SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LMZ043-  
046.  
 

 
 

 
 
SYNOPSIS...T  
SHORT TERM...JAL  
LONG TERM...JAL  
AVIATION...T  
 
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