205  
FXUS63 KIWX 191953  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
353 PM EDT SUN APR 19 2015  
   
SYNOPSIS
 
 
ISSUED AT 130 PM EDT SUN APR 19 2015  
 
LOW PRESSURE WILL MOVE NORTH FROM THE OHIO RIVER TO THE GREAT  
LAKES THIS AFTERNOON AND TONIGHT. RAIN WILL SPREAD NORTH ACROSS  
THE AREA DURING THE AFTERNOON. TEMPERATURES WILL FALL INTO THE 50S  
AFTER THE RAIN BEGINS. OVERNIGHT LOWS WILL REMAIN IN THE 50S AS  
WELL. THE RAIN SHOULD DIMINISH THIS EVENING BUT MORE RAIN IS  
EXPECTED MONDAY.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH MONDAY)  
ISSUED AT 351 PM EDT SUN APR 19 2015  
 
REGIONAL RADAR MOSAIC SHOWS LARGE AREA OF RAIN ASSOCIATED WITH  
NEGATIVELY TILTED SHORT WAVE AND DEEPENING SURFACE LOW MOVING  
THROUGH THE REGION. SFC LOW EXPECTED TO CONTINUE STRENGTHENING INTO  
THE EVENING AS IT MOVES NORTH NEAR THE IN/IL BORDER. IMPRESSIVE  
MOISTURE ADVECTION AND NEGATIVE TILT TO SYSTEM PROVIDING STRONG LIFT  
AND DEEP MOISTURE PROFILES. CONVECTION OVER SOUTHERN CONUS MAY HAVE  
ROBBED SOME MOISTURE BUT AS SYSTEM STRENGTHENS FURTHER THINK THIS  
WILL BE OVERCOME THROUGH EARLY EVENING WITH PCPN AMOUNTS OF HALF TO  
THREE QUARTERS INCH POSSIBLE.  
 
DRY SLOT SEEN ON SATELLITE AND IN RADAR MOSAIC WILL MOVE INTO THE  
AREA DURING THE MID TO LATE EVENING WITH PCPN DIMINISHING. MAY SEE  
SOME DRIZZLE OR VERY LIGHT SHOWERS AT TIMES OVERNIGHT BUT PCPN  
CHANCES INCREASE AGAIN TOWARD DAYBREAK AS SECONDARY WAVE OVER OK  
THIS AFTERNOON WORKS NORTHEAST. EXPECT SHOWERS TO DEVELOP EARLY  
MONDAY WITH LIKELY TO CATEGORICAL POPS WARRANTED THROUGH AT LEAST  
MID AFTERNOON UNTIL THIS WAVE PASSES.  
 
TEMPS WERE FALLING INTO THE 50S WITH ONSET OF RAIN AND LATEST  
GUIDANCE SUGGEST THEY WILL REMAIN THERE THROUGH THE NIGHT. MAY SEE A  
SMALL RISE IN TEMPS MONDAY...ESPECIALLY EAST PRIOR TO DEEPER COLD  
AIR ADVECTION.  
 

 
   
LONG TERM
 
(MONDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 351 PM EDT SUN APR 19 2015  
 
THE SECOND UPPER LEVEL TROF IN AS MANY DAYS WILL BE MOVING ACROSS  
THE FORECAST AREA AT THE START OF THIS PERIOD MONDAY NIGHT. LEFT A  
CHANCE FOR LINGERING SHOWERS OVER EASTERN AREAS INCLUDING MAINLY  
NORTHWEST OHIO AS THIS SYSTEM MOVES EAST. FOR THE REST OF THE  
PERIOD...VERY CHILLY AIR WILL SPREAD OVER THE UPPER GREAT LAKES  
REGION AS A NEGATIVE HEIGHT ANOMALY REMAINS OVER SOUTHEAST CANADA.  
THERMAL PROFILES SUPPORT A MIX OF PRECIPITATION AT TIMES...WITH A  
MIX OF SLEET POSSIBLE LATE TUESDAY GIVEN EXTREMELY COLD TEMPERATURES  
ALOFT FOR THIS TIME OF YEAR WITH THE WET BULB ZERO REMAINING BELOW  
3K FEET. THE GFS HAS TRENDED THE LOW LEVEL MORE UNSTABLE TUESDAY  
AFTERNOON DURING THE PAST FEW RUNS WITH LAPSE RATES FROM ABOUT 8.5C  
TO 10C PER KM FROM THE SURFACE TO 600 MB WITH LIMITED CAPE NOW  
SHOWING UP. KEPT A CHANCE FOR SHOWERS NORTHEAST AREAS TUESDAY  
AFTERNOON GIVEN THESE CONDITIONS. LEFT SLEET OUT FOR NOW GIVEN  
LINGERING UNCERTAINTIES ABOUT PRECIP TYPE WITH AFTERNOON  
TEMPERATURES CLIMBING INTO THE LOW TO MID 50S.  
 
GIVEN SOME RECENT ADVANCEMENT CONCERNING SPRING GROW IN SENSITIVE  
PLANTS AND FRUIT TREES DUE TO WARM TEMPERATURES...HAVE UPDATED THE  
HAZARDOUS WEATHER OUTLOOK EARLIER TODAY TO HIGHLIGHT FROST AND  
FREEZE CONCERNS DURING THIS WEEK. HAVE TRENDED DOWN MOST HIGH AND  
LOW TEMPS IN ACCORDANCE WITH THE LATEST SUPERBLEND GIVEN GFS AND  
ECMWF 850 MB TEMPS STAYING BELOW ZERO AFTER TUESDAY. HIGHS SHOULD BE  
MAINLY IN THE LOW TO MID 50S AND LOWS IN THE LOW TO MID 30S...WITH  
SOME MID TO UPPER 20S POSSIBLE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)  
ISSUED AT 130 PM EDT SUN APR 19 2015  
 
RADAR SHOWS LARGE AREA OF RAIN GRADUALLY MOVING NORTH AND SHOULD  
BEGIN TO REACH TERMINAL SITES EARLY THIS AFTERNOON. DRY LOWER  
LEVELS INITIALLY KEEPING CIGS IN THE VFR RANGE BUT EXPECT THESE TO  
LOWER AS RAIN PERSISTS AND AREA OF LOW PRESSURE MOVES CLOSER AND  
INTENSIFIES. MVFR CONDITIONS FOLLOWED BY IFR EXPECTED TOWARD LATE  
AFTERNOON OR EARLY EVENING. DRY SLOT WORKS IN MID TO LATE EVENING.  
COULD SEE BRIEF IMPROVEMENT DEPENDING ON STRENGTH OF DRYING BUT  
FOR NOW STAYED WITH SOLID IFR CIGS OVERNIGHT. SECOND WAVE MOVES IN  
MONDAY MORNING WITH NEXT BATCH OF RAIN SHOWERS EXPECTED DURING THE  
DAY.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
MI...NONE.  
OH...NONE.  
LM...NONE.  

 
 

 
 
SYNOPSIS...LASHLEY  
SHORT TERM...LASHLEY  
LONG TERM...SKIPPER  
AVIATION...LASHLEY  
 
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