698  
FXUS63 KIWX 292350  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
750 PM EDT MON MAY 29 2017  
   
SYNOPSIS
 
 
ISSUED AT 748 PM EDT MON MAY 29 2017  
 
SCATTERED SHOWERS AND ISOLATED STORMS WILL DIE OFF THROUGH THE  
EVENING HOURS, WITH PRIMARILY PARTLY CLOUDY SKIES OVERNIGHT.  
SEASONABLY COOL AND MAINLY DRY OTHERWISE THROUGH THE MIDDLE OF THE  
WEEK WITH HIGHS ON TUESDAY AND WEDNESDAY RANGING BETWEEN THE  
UPPER 60S TO MIDDLE 70S. SHOWER AND THUNDERSTORM CHANCES THEN  
INCREASE LATE THIS WEEK AS A FRONTAL BOUNDARY SETS UP OVER THE  
AREA.  
 

 
   
SHORT TERM
 
(LATE THIS AFTERNOON THROUGH WEDNESDAY)  
ISSUED AT 248 PM EDT MON MAY 29 2017  
 
AN UPPER LEVEL LOW OVER LAKE SUPERIOR AND ONTARIO WILL  
WOBBLE/BROADEN SLOWLY TOWARD JAMES BAY THROUGH THE MIDDLE OF THE  
WEEK. SEVERAL MINOR/LOW AMPLITUDE SHORTWAVES AND ASSOCIATED SFC  
TROUGHS WILL PIVOT THROUGH THE REGION ON THE SOUTHERN FRINGE OF THIS  
FEATURE BRINGING LOW CHANCES FOR SCATTERED SHOWERS TO THE LOCAL AREA  
LATE THIS AFTERNOON/EARLY EVENING AND AGAIN TUESDAY  
AFTERNOON/EVENING. DIURNAL HEATING/STEEP LOW LEVEL LAPSE RATES WITH  
DEWPOINTS IN THE LOW-MID 50S ARE PROVIDING NEARLY 500 J/KG OF  
SURFACE BASED CAPE THIS AFTERNOON. THIS COULD RESULT IN SOME HEAVIER  
SHOWERS/ISO THUNDER WITH WIND GUSTS > 30 MPH. WITH THAT SAID,  
CONVECTION WILL LIKELY BE DISORGANIZED AND LOW COVERAGE GIVEN  
SCARCITY OF MOISTURE AND WEAK LOW LEVEL CONVERGENCE ALONG EASTWARD  
ADVANCING SECONDARY TROUGH. BEST CHANCES (STILL ONLY 20-30%) INTO  
THE EARLY EVENING WILL BE ACROSS NE IN/SC LOWER MI/NW OH. COOLER  
CONDITIONS AND A MORE SHALLOW MOIST/CONVECTIVE LAYER WITH THE NEXT  
SHORTWAVE NOT ARRIVING UNTIL TUESDAY NIGHT WILL RESULT IN LESSER  
CHANCES FOR ANY DIURNALLY DRIVEN SHOWERS ON TUESDAY. SEASONABLY COOL  
AND MAINLY DRY OTHERWISE THE MAIN STORY TUESDAY INTO WEDNESDAY.  
 

 
   
LONG TERM
 
(WEDNESDAY NIGHT THROUGH MONDAY)  
ISSUED AT 248 PM EDT MON MAY 29 2017  
 
SIGNIFICANT HEIGHT RISES/SUBSIDENCE AS LOWER HEIGHTS REFOCUS INTO  
QUEBEC WILL ALLOW HEIGHT PRESSURE TO BRIEFLY BUILD WITH FAIR  
WX/CLEAR SKIES WEDNESDAY NIGHT INTO THURSDAY MORNING. LOW LEVEL  
MOISTURE STREAMING NORTHEAST ON THE BACKSIDE OF THIS AREA OF HIGH  
PRESSURE WILL BRING PERIODIC SHOWER/STORM CHANCES BACK INTO THE  
FORECAST LATER THURSDAY THROUGH FRIDAY NIGHT NEAR A DEVELOPING  
BAROCLINIC ZONE. SEVERAL CONVECTIVE SYSTEMS COULD IMPACT THE LOCAL  
AREA DURING THIS TIME, BEST CHANCES LATER FRIDAY/FRIDAY NIGHT AS A  
LARGE SCALE VORT LOBE DROPS SOUTH THROUGH THE GREAT LAKES. LOCALLY  
HEAVY RAIN AND SEVERE WEATHER MAY BECOME A CONCERN, WITH CONFIDENCE  
AT THIS FCST RANGE LOW.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)  
ISSUED AT 745 PM EDT MON MAY 29 2017  
 
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS NORTHERN  
INDIANA THIS EVENING TO DIE OFF WITH SUNSET AND SHOULD REMAIN AWAY  
FROM BOTH KFWA/KSBN AIRFIELDS. OTHERWISE ATTENTION FOCUSES ON  
INCREASED MIXING DEPTH WITH DIURNAL HEATING BY MIDDAY TUESDAY  
WITH SOME INCREASED GUSTINESS TO WSW-W SURFACE FLOW. CHANCES FOR  
ISOLATED WEAK CONVECTION AGAIN TUESDAY AFTERNOON REMAINS TOO LOW  
FOR INCLUSION AT THIS TIME.  
 

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

 
 

 
 
SYNOPSIS...MURPHY  
SHORT TERM...STEINWEDEL  
LONG TERM...STEINWEDEL  
AVIATION...MURPHY  
 
VISIT US AT WWW.WEATHER.GOV/IWX  
 
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:  
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA  
WWW.TWITTER.COM/NWSIWX  
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA  
 
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