231  
FXUS63 KIWX 280450  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
1250 AM EDT THU AUG 28 2014  
   
SYNOPSIS
 
 
ISSUED AT 1249 AM EDT THU AUG 28 2014  
 
FAIR WEATHER IS EXPECTED TODAY INTO FRIDAY MORNING AS HIGH  
PRESSURE DROPS SOUTHEAST THROUGH THE GREAT LAKES REGION. A LOW  
PRESSURE SYSTEM AND WARM FRONT WILL BRING INCREASING CHANCES FOR  
SHOWERS AND THUNDERSTORMS TO THE AREA LATER FRIDAY INTO THIS  
WEEKEND. HIGHS TODAY WILL REACH THE UPPER 70S TO NEAR 80...AND THE  
MID 80S ON FRIDAY.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY)  
ISSUED AT 321 PM EDT WED AUG 27 2014  
 
TRANQUIL WX XPCD THIS PD AS HIGH PRES BLDS THROUGH THE ERN LAKES.  
N/NERLY LL FLW WILL CONT TO ADVT IN MUCH DRIER AIR W/SFC TDS FALLING  
IN THE 50S TONIGHT. WILL TWEAK TEMPS OVERNIGHT A BIT HWVR IN LIGHT  
OF UPSTREAM EWD SPILLAGE OF MID/HIGH CLDS. OTRWS PLEASANT WX XPCD TO  
CONT ON THU.  
 

 
   
LONG TERM
 
(THURSDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 321 PM EDT WED AUG 27 2014  
 
A 500MB RIDGE EXPANDING NORTHWESTWARD FROM THE SOUTHEASTERN CONUS  
WILL KEEP WEATHER QUIET THURSDAY NIGHT BEFORE MORE ACTIVE WEATHER  
RETURNS FOR THE WEEKEND. SURFACE HIGH PRESSURE WILL LINGER OVER  
LOWER MI AND THE OHIO VALLEY THROUGH LATE THURSDAY EVENING BEFORE  
DRIFTING INTO THE NEW ENGLAND STATES.  
 
MEANWHILE...A TROUGH OVER THE SOUTHWESTERN U.S. TODAY WILL DRIFT  
EASTWARD INTO THE CENTRAL PLAINS AND MERGE WITH A SHORTWAVE CROSSING  
THE NORTHERN PLAINS BY FRIDAY AFTERNOON...THEN LIFT NORTHEASTWARD  
INTO NORTHERN LOWER MI AND SOUTHERN ONTARIO BY SUNDAY MORNING. THIS  
WILL BRING A SURFACE TROUGH AND LOW PRESSURE CENTER ACROSS THE GREAT  
LAKES REGION THROUGH THE WEEKEND.  
 
ON FRIDAY...THE CWA REMAINS UNDER THE EXITING HIGH PRESSURE RIDGE  
THROUGH THE EARLY AFTERNOON. ADDITIONALLY...THE BEST MOISTURE  
TRANSPORT/CONVERGENCE FOCUSES ALONG AN AXIS TO THE NORTH OF THE CWA  
AS THE CENTER OF WEAK SFC LOW DEVELOPS OVER MN/WI/IOWA FRIDAY  
MORNING. THINK THE RIDGE WILL SUPPRESS ANY PRECIPITATION FOR THE  
FIRST PORTION OF THE DAY. AS HIGH PRESSURE EXITS TO THE EAST LATE  
FRIDAY AFTERNOON AND EVENING...THE WARM FRONT ASSOCIATED WITH THE  
SFC LOW LIFTS NORTHEASTWARD ACROSS THE GREAT LAKES. GIVEN WEAK  
ISENTROPIC ASCENT ON THE 310K SFC AND 1-2K J/KG OF MUCAPE EXPECT  
CHANCES FOR SOME SHOWER/T STORM DEVELOPMENT.  
 
SATURDAY INTO SUNDAY THE MAIN UPPER LEVEL TROUGH/ASSOCIATED SURFACE  
LOW LIFTS FROM THE CENTRAL PLAINS INTO ONTARIO. BEST FORCING/PER  
850-500MB QVECTOR CONVERGENCE AND STRONG ISENTROPIC ASCENT AT 305K/  
MOVES THROUGH SATURDAY THROUGH SUNDAY MORNING. AS A RESULT...HAVE  
HIGH CHANCE TO LIKELY POPS ACROSS THE AREA THROUGH THIS TIME. KEPT  
THUNDERSTORMS IN AS WELL GIVEN DECENT INSTABILITY...ESPECIALLY FOR  
SUNDAY AFTERNOON WHERE MODELS SUGGEST UPWARDS OF 2000 J/KG OF MUCAPE  
FOR THE WESTERN AND SOUTH CENTRAL PORTIONS OF THE CWA. AS FAR AS  
SEVERE CHANCES THINKING THEY WILL BE FAIRLY LIMITED GIVEN WEAK 0-6  
KM SHEAR...BUT THE POTENTIAL FOR HEAVY RAIN IS MORE SIGNIFICANT.  
WITH PWATS BETWEEN 1.5 AND 2 INCHES...AND CORFIDI VECTORS ORIENTED  
PARALLEL TO THE APPROACHING FRONTAL BOUNDARY SAT AFT/SAT EVE COULD  
SEE FLOODING PROBLEMS AS THE FRONT APPROACHES...MAINLY IN THE  
NORTHWESTERN AND CENTRAL CWA.  
 
SUNDAY NIGHT A BRIEF RIDGE ALOFT WILL SLIDE INTO THE CWA BEHIND THE  
EXITING SHORTWAVE/SFC LOW PRESSURE TROUGH...ALLOWING FOR A BRIEF  
BREAK IN PRECIPITATION. BY LATE MONDAY MORNING...A MORE POTENT  
TROUGH WILL AID IN THE DEVELOPMENT OF A SURFACE LOW OVER MINNESOTA.  
THIS LOW WILL LIFT NORTHEASTWARD INTO HUDSON BAY BY TUESDAY  
MORNING...BRINGING A SURFACE TROUGH/COLD FRONT ACROSS THE GREAT  
LAKES REGION FOR THE START OF THE WORK WEEK. MOISTURE  
CONVERGENCE/STRONG ISENTROPIC ASCENT AT 305-310K ARE IN PLACE MONDAY  
AFTERNOON THROUGH LATE TUESDAY MORNING...SO HAVE KEPT THE GOING  
HIGHER CHANCE POPS FOR THAT TIME PERIOD. STORMS LATE MONDAY  
AFTERNOON COULD BECOME SEVERE...WITH AROUND 1500-2000 J/KG MUCAPE  
AND 30-50 KTS 0-6 KM SHEAR OVER MUCH OF THE CWA. KEPT CONSENSUS  
CHANCE POPS IN FOR TUESDAY...WHICH WILL MAINLY BE IN THE MORNING  
WITH THE EXITING FRONT.  
 
HIGH PRESSURE BUILDS IN BY TUESDAY EVENING UNDER RELATIVELY ZONAL  
FLOW ALOFT...AND WILL DRIFT ACROSS THE OHIO VALLEY THROUGH THURSDAY  
NIGHT. BOTH THE GFS/ECMWF HAVE HIGH PRESSURE HOLDING STRONG...SO  
PULLED CONSENSUS SLIGHT CHANCE/CHANCE POPS TUESDAY NIGHT AND  
WEDNESDAY.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)  
ISSUED AT 1249 AM EDT THU AUG 28 2014  
 
MAINLY VFR THROUGH THE PERIOD AS LIGHT NORTHEASTERLY WINDS  
GRADUALLY VEER MORE EASTERLY WITH TIME UNDER SFC HIGH PRESSURE  
DROPPING SOUTHEAST INTO THE LOWER LAKES. ONLY EXCEPTION MAY BE  
NEAR DAYBREAK AT FWA WHERE MVFR STRATUS/FOG MAY DEVELOP.  
OTHERWISE...SCT-BKN CIRRUS CANOPY TODAY WILL GIVE WAY TO A BKN-  
OVC MID LEVEL CLOUD DECK TONIGHT.  
 

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

 
 

 
 
SYNOPSIS...STEINWEDEL  
SHORT TERM...T  
LONG TERM...MCD  
AVIATION...STEINWEDEL  
 
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)  
 
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:  
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA  
WWW.TWITTER.COM/NWSIWX  
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab IN Page
The Nexlab OH Page
The Nexlab MI Page Main Text Page