004  
FXUS63 KIWX 212257  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
657 PM EDT TUE OCT 21 2014  
   
SYNOPSIS
 
 
ISSUED AT 653 PM EDT TUE OCT 21 2014  
 
A RIDGE OF HIGH PRESSURE WILL MOVE SLOWLY SOUTHEAST ACROSS THE  
WESTERN GREAT LAKES REGION TONIGHT AND WEDNESDAY AS LOW PRESSURE  
STRENGTHENS ALONG THE MID-ATLANTIC COAST. THIS WILL RESULT IN FAIR  
WEATHER ACROSS OUR AREA WITH TEMPERATURES A BIT BELOW NORMAL OVER  
THE NEXT 24 HOURS. LOWS TONIGHT WILL BE IN THE MIDDLE TO UPPER 30S... WITH  
HIGHS ON WEDNESDAY IN THE MID 50S.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH WEDNESDAY)  
ISSUED AT 357 PM EDT TUE OCT 21 2014  
 
SECONDARY PUSH OF CAA NOW WELL UNDERWAY WITH THE PASSAGE OF THIS  
MORNING'S SHORTWAVE AND ASSOCIATED SURFACE PRESSURE TROUGH. REGIONAL  
LOW LEVEL WINDS HAVE GRADUALLY VEERED TO A MORE NNE DIRECTION...  
ADVECTING COOL/DRY AIR INTO THE AREA AND LEADING TO AN UNFAVORABLE  
TRAJECTORY FOR LAKE ENHANCEMENT IN OUR CWA. MIDLEVEL HEIGHTS ARE  
ALSO BEGINNING TO RISE AS HIGH AMPLITUDE/SHORT WAVELENGTH RIDGE  
FOLDS INTO THE GREAT LAKES. ASSOCIATED AVA WILL GENERATE STRONG  
SUBSIDENCE AND SUPPORT THE MAINTENANCE OF A DECENT SURFACE  
ANTICYCLONE OVER THE REGION TONIGHT THROUGH TOMORROW. LIGHT RAIN  
SHOWERS HAVE GRADUALLY DISSIPATED THIS AFTERNOON AS EXPECTED AND DRY  
CONDITIONS SHOULD PERSIST THROUGH TOMORROW. ONLY POSSIBLE EXCEPTION  
MAY BE SOME LAKE EFFECT SHOWERS OFF OF HURON IN OUR FAR EASTERN  
ZONES BUT CHANCES APPEAR VERY SLIM AND WILL MAINTAIN DRY FORECAST.  
CAA HAS KEPT A LID ON AFTERNOON TEMPS AND EXPECT OVERNIGHT LOWS TO  
TAKE A SIMILAR DIP. EXPECT GRADUAL CLEARING IN OUR WESTERN  
COUNTIES...WITH A LIGHT NE WIND ALLOWING OVERNIGHT LOWS TO DROP INTO  
THE LOW TO MID 30S. CLOUDS LINGER A BIT LONGER IN THE EAST AND WILL  
HOLD WITH TEMPS IN THE MID TO UPPER 30S THERE. GROWING SEASON HAS  
ENDED ACROSS THE CWA SO NO HEADLINES WARRANTED. STRATOCU WILL  
GRADUALLY DISSIPATE IN EVEN OUR EASTERN COUNTIES BY TOMORROW  
AFTERNOON AND EXPECT SOME MODERATION OF THERMAL PROFILES DESPITE  
WEAK NORTHEAST FLOW. INHERITED FORECAST OF MID 50S IS IN LINE WITH  
LATEST GUIDANCE AND NO MAJOR CHANGES NECESSARY.  
 

 
   
LONG TERM
 
(WEDNESDAY NIGHT THROUGH TUESDAY)  
ISSUED AT 357 PM EDT TUE OCT 21 2014  
 
A WEAKENING UPPER LEVEL SYSTEM WILL MOVE ACROSS THE AREA LATE  
THURSDAY INTO THURSDAY NIGHT. UPPER LEVEL SUPPORT/DIFFERENTIAL  
VORTICITY ADVECTION IN THE 500/300 MB LAYER WILL BE WANING AS THE  
UPPER LEVEL TROF MOVES ACROSS THE AREA IN LIGHT OF THE BUILDING  
UPPER LEVEL RIDGE IN THE SYNOPTIC SCALE. MADE SOME MINOR ADJUSTMENTS  
TO THE ONGOING GRIDS/FORECAST WITH A SLIGHT CHANCE FOR SHOWERS OVER  
WEST AREAS GIVEN THE LACK OF DEEP SATURATION AND WEAK LIFT PER 305K  
ISENTROPIC SURFACE. VERY LITTLE RAINFALL IS EXPECTED. TEMPERATURES  
SHOULD WARM TO MUCH ABOVE NORMAL BY EARLY NEXT WEEK. GIVEN ECMWF AND  
GFS 850 MB TEMPS 13C TO 16C...HIGHS SHOULD BE ABLE TO CLIMB TO AT  
LEAST AROUND 70 DEGREES WITH LITTLE IF ANY RAIN EXPECTED THROUGH THE  
DAY MONDAY. THE ECMWF AND GFS HAVE COME INTO BETTER AGREEMENT WITH  
THE TIMING OF THE FRONT TUESDAY. TEMPERATURES SHOULD BE MILD MONDAY  
NIGHT WITH A CHANCE FOR RAIN MONDAY NIGHT AND TUESDAY AS THE FRONT  
MOVES INTO THE AREA. GUT FEELING IS RAIN CHANCES MAY NEED TO BE  
RAISED TUESDAY GIVEN AVAILABLE MOISTURE...FRONTAL LIFT AND UPPER  
LEVEL JET SUPPORT.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)  
ISSUED AT 653 PM EDT TUE OCT 21 2014  
 
NRN EDGE OF STRATO CU DECK MOVG SOUTH/20KT ACROSS SWRN MI SHOULD  
MOVE THROUGH KSBN THIS EVE. KFWA WILL REMAIN IN THE CYCLONIC FLOW  
ASSOCIATED WITH THE DEEPENING LOW DROPPING SE THROUGH THE MID-  
ATLANTIC STATES A LITTLE LONGER... BUT SHOULD ALSO LOOSE LOW CIGS  
OVERNIGHT. THE WRN EDGE OF THIS STRATO CU DECK SHOULD MAKE SLOW  
EASTWARD PROGRESS WEDNESDAY AS LOW CONTS TO DEEPEN AND SOME WEAK  
LOW LEVEL DIURNAL INSTABILITY DEVELOPS WHICH SHOULD BE SUFFICIENT  
FOR FEW-SCT CU AT KFWA BUT DOUBTFUL IF LOW CIGS WILL REDEVELOP  
THIS FAR WEST. LIGHT N-NE GRADIENT WINDS EXPECTED THROUGH THE  
PERIOD.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
MI...NONE.  
OH...NONE.  
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EDT WEDNESDAY FOR LMZ043-046.  
 

 
 

 
 
SYNOPSIS...JT  
SHORT TERM...AGD  
LONG TERM...SKIPPER  
AVIATION...JT  
 
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