924  
FXUS63 KIWX 021102  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
702 AM EDT TUE SEP 2 2014  
   
SYNOPSIS
 
 
ISSUED AT 700 AM EDT TUE SEP 2 2014  
 
DRIER AND COOLER AIR WILL INFILTRATE THE REGION AS A COLD FRONT  
PUSHES SOUTH INTO THE OHIO VALLEY TODAY. UNTIL THEN SOME RAINFALL  
ASSOCIATED WITH A LARGE CONVECTIVE COMPLEX WILL MOVE THROUGH THE  
REGION...PRIMARIY SOUTH OF ROUTE 24 THIS MORNING. AS HIGH  
PRESSURE CONTINUES TO BUILD INTO THE AREA...LOOK FOR CLEARING  
SKIES THIS AFTERNOON...WITH HIGHS NEAR 80 DEGREES...EXCEPT COOLER  
NEAR LAKE MICHIGAN. LOWS TONIGHT WILL DIP INTO THE MIDDLE TO  
UPPER 50S.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 405 AM EDT TUE SEP 2 2014  
 
WOEFULLY DISHEARTENED BY POORLY MISHANDLED FINER RES MODEL OUTPUT  
WITH RESPECT TO SPASTIC PRIMARY/DERIVED FIELDS THIS AM. NAM12 TOO  
MOIST IN BOUNDARY LAYER AND LATER AFTERNOON INSTABILITY AND  
HRRR3KM EGREGIOUSLY OVERLY ASSERTS MINOR MID LEVEL CONVERGENCE  
WITH HEAVY AMOUNTS IN A STRIPE ACROSS NWRN/NRN CWA THIS AM.  
FOLLOWING LESS NOISY/CONCEPTUALLY FAVORED SREF/GFS THROUGH NEAR  
TERM. ZONE OF MARKED 7-5H QG FGEN OVER WCNTL MI INTO NERN IL TO  
RACE ENEWD INTO MI THUMB/SWRN ONT BY ABOUT 15 UTC. ANTICIPATE  
LITTLE MORE THAN LIGHT SHRA GIVEN LEADING EDGE 850-700MB MOISTURE  
FLUX DIVERGENCE ASSOCIATED WITH DRYING SUB ALTOCU DECK LAYER.  
MEANWHILE TO SOUTH...CONVECTIVE COMPLEX ASSOCIATED WITH WELL  
VEERED 925-8H JETLET NEAR SWRN IN/NCNTL KY ON ORDER OF 45-50KTS.  
WELL VEERED JET FOCUS THROUGH REMAINDER OF AM HOURS TO KEEP HEAVY  
RAFL WELL SOUTH OF CWA...WITH NORTHERN EDGE /PRIMARILY STRATIFORM  
QUALITY RAINSHIELD PASSING THROUGH SRN/SERN CWA WITH STRONG POP  
GRADIENT. GIVEN ML CAPE 250 J/KG ISOPLETH TO REMAIN ALONG/SOUTH  
OF INTERSTATE 70 WAS TEMPTED TO REMOVE TSRA ALTOGETHER...HOWEVER  
MAINTAINED A TOKEN ISOLD/SLIGHT CHANCE MENTION FAR S/SERN CWA  
THROUGH 12 UTC PRIMARILY FOR PSBL ANVIL/PERIPHERAL MCS STRIKE.  
OTHERWISE...GRADUAL INFILTRATION OF DRIER AIR AND PROGRESSION OF  
LONGWAVE TROF LEAVES LITTLE IMPETUS FOR AFTERNOON CONVECTIVE  
DEVELOPMENT AND SIDED DRY/BECOMING MOSTLY SUNNY. AMPLE LONGWAVE  
RADIATIONAL COOLING CONDITIONS BY SUNSET AS CENTRAL PLAINS  
SURFACE RIDGING EDGES EASTWARD INTO SOUTHWEST GREAT LAKES/MID MS  
VLY. GIVEN CLEAR/MCLEAR SKIES AND 925 MB THERMAL TROF POSITIONING  
FROM LAKE HURON SW INTO EASTERN THIRD CWA BY DAYBREAK...HAVE  
FAVORED ONGOING COOL TEMPS/CLOSER TO MAV GUID. WITH STRONG  
SURFACE BASED INVERSION ANTICIPATE POSSIBLE FG  
ISSUE...UNCERTAINTY OF COVERAGE...THOUGH WITH WETTING ACROSS  
SOUTHERN CWA THIS AM...HAVE OPTED TO INTRODUCE AS AREAS OF FOG  
FOR NOW...ALLOWING LATER SHIFTS TO EVALUATE PROBABILITY OF DENSE  
NATURE.  
 

 
   
LONG TERM
 
(WEDNESDAY THROUGH MONDAY)  
ISSUED AT 405 AM EDT TUE SEP 2 2014  
 
WEAK SFC HIGH PRESSURE CENTER WILL WORK SLOWLY ESE TOWARD THE  
EASTERN OH VALLEY ON WEDNESDAY PROVIDING THE AREA WITH DRY/FAIR  
WX AND HIGHS INTO THE LOW-MID 80S GIVEN AMPLE INSOLATION AND 850  
MB TEMPS NEAR 15C. NORTHERN STREAM WILL REMAIN ACTIVE/PROGRESSIVE  
THROUGH THE REMAINDER OF THE PERIOD AS NEXT MID LEVEL TROUGH AXIS  
(SOON TO DROP INTO THE PAC NW) PROPAGATES ENE ALONG THE US/CANADA  
BORDER LATE THIS WEEK. THETA-E/WARM FRONT SURGE IN RESPONSE TO  
ATTENDANT CENTRAL PLAINS TO UPPER MIDWEST SFC TROUGH DEVELOPMENT  
BRINGS CONVECTIVE CHANCES INTO QUESTION BY LATER WEDNESDAY  
NIGHT/THURSDAY MORNING. WITH THAT SAID CONTINUED WITH INHERITED  
DRY/10 POP FCST IN LIGHT OF CONSISTENT ECMWF DRY SIGNAL WITH MORE  
PRONOUNCED MOISTURE CONVERGENCE SETTING UP NORTHWEST OF THE FA ON  
NOSE OF LLJ. THURSDAY AFTN/NIGHT SHOULD FEATURE MAINLY  
DRY/HOT/HUMID CONDITIONS WITH CAPPED WARM SECTOR BECOMING FIRMLY  
ESTABLISHED. DEPENDING ON CLOUD/CONVECTIVE TRENDS TEMPS MAY MAKE  
A RUN AT 90F THURSDAY IN THE WEST AS SW FLOW DEEPENS AND 850 MB  
TEMPS INCREASE TO 20-21C.  
 
MODELS REMAIN IN GOOD AGREEMENT IN SAGGING A TRAILING/WEAKENING  
COLD FRONT INTO A MOIST/UNSTABLE ENVIRONMENT FRIDAY-FRIDAY EVE.  
CONTINUED TO UNDERCUT LIKELY CONSENSUS BLEND POPS FOR STORMS  
GIVEN WEAK MID LEVEL FORCING/LAPSE RATES IN PART TO NORTHERLY  
TRACK OF MAIN PV ANOMALY THRU ONTARIO. LOCALLY HEAVY RAINFALL  
WILL BE POSSIBLE IF CONVECTION FIRES GIVEN HIGH MOISTURE  
CONTENT/POOLING...WITH NOT MUCH OF A SEVERE RISK GIVEN POST-  
FRONTAL LAG OF STRONGER MID LVL FLOW. OTHERWISE...THIS WEEKEND  
INTO EARLY NEXT WEEK WILL BE CHARACTERIZED BY DRY (EXCEPT FOR  
VERY LOW SHOWER CHC SOUTHEAST SATURDAY IF SLOWER FRONTAL PASSAGE  
COMES TO FRUITION) AND MUCH COOLER WEATHER IN RESPONSE TO  
BUILDING HIGH PRESSURE IN WAKE OF COLD FRONT.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)  
ISSUED AT 649 AM EDT TUE SEP 2 2014  
 
RAIN SHIELD TO CONTINUE EASTWARD ADVANCE THROUGH NWRN OHIO WITH  
LITTLE MORE THAN LIGHT RAIN WITH VFR MET CONDITIONS FOR KFWA. A  
FEW SHRA NIVOF KSBN...IMMEDIATELY ALONG FRONTAL BOUNDARY/COLLOCATED  
MID LEVEL CONVERGENCE AXIS. AGAIN DO NOT ANTICIPATE MUCH IF ANY  
AVIATION RELATED CONCERN APART FROM WET RY/TEMPO MVFR CIGS...BUT  
MAINTAIN OPTIMISM ABOVE FUELING/ALTERNATE CRITERIA. FOCUS THEN  
SHIFTS TO POTENTIAL BR/FG DEVELOPMENT TOWARD DAYBREAK WEDNESDAY.  
WETTED GROUND/HIGHER XOVER TEMP AT KFWA SUGGESTS GREATER LIKLIHOOD  
FOR DETERIORATING CONDITONS THAN ACROSS NWRN IN/VCNTY KSBN.  
ADDRESS POTENTIAL FOR IFR VSBSY IN TEMPO PERIOD FOR OUTLOOK/PLANNING  
PURPOSES AT KFWA.  
 

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

 
 

 
 
SYNOPSIS...MURPHY  
SHORT TERM...MURPHY  
LONG TERM...STEINWEDEL  
AVIATION...MURPHY  
 
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