595  
FXUS63 KIND 131427  
AFDIND  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE INDIANAPOLIS IN  
1027 AM EDT MON JUL 13 2020  
   
UPDATE
 
 
THE AVIATION SECTION HAS BEEN UPDATED BELOW.  
 

 
   
SYNOPSIS
 
 
ISSUED AT 341 AM EDT MON JUL 13 2020  
 
HIGH PRESSURE WILL DRIFT ACROSS THE REGION THROUGH TUESDAY WITH DRY  
AND SEASONABLE WEATHER. HEAT AND HUMIDITY LEVELS WILL GRADUALLY  
RETURN BY WEDNESDAY AND ONLY INCREASE LATE WEEK AND THIS WEEKEND AS  
A BROAD UPPER LEVEL RIDGE STEADILY BUILDS TOWARDS THE OHIO VALLEY. A  
STRONG UPPER LEVEL WAVE WITH A COLD FRONT WILL BRING THE THREAT FOR  
WIDESPREAD THUNDERSTORMS LATE WEDNESDAY INTO WEDNESDAY NIGHT.  
ADDITIONAL DAILY CHANCES FOR SCATTERED STORMS WILL CONTINUE INTO  
THE WEEKEND.  
 

 
   
NEAR TERM /TODAY/
 
 
ISSUED AT 341 AM EDT MON JUL 13 2020  
 
SKIES WERE CLEAR ACROSS THE REGION EARLY THIS MORNING AS HIGH  
PRESSURE EXPANDED SOUTH FROM THE WESTERN GREAT LAKES. 07Z  
TEMPERATURES WERE GENERALLY IN THE 60S.  
 
TODAY IS SHAPING UP TO BE ABOUT AS GOOD OF A DAY AS YOU WILL SEE IN  
MID SUMMER. THE HIGH PRESSURE RIDGE WILL ADVECT SOUTH INTO THE AREA  
THROUGH THE DAY WITH A DRY NORTHERLY FLOW. LOWER DEWPOINTS HAVE  
FILTERED SOUTH INTO THE FORECAST EARLY THIS MORNING AND THE  
NORTHERLY WINDS WILL KEEP HUMIDITY LEVELS LOW ALL DAY WITH DEWPOINTS  
HOVERING IN THE UPPER 50S AND LOWER 60S. SUBSIDENCE INCREASING  
THROUGH THE LOWER LEVELS WILL LIMIT CU DEVELOPMENT LATER TODAY WITH  
SKIES REMAINING MOSTLY SUNNY. JUST A SPECTACULAR DAY FOR MID JULY.  
 
TEMPS...LOW LEVEL THERMALS SUPPORT THE RECENT TRENDS OF GOING A  
TOUCH WARMER THAN GUIDANCE. EXPECT HIGHS TO TOP OUT IN THE LOW TO  
MID 80S.  
 

 
   
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/
 
 
ISSUED AT 341 AM EDT MON JUL 13 2020  
 
FORECAST CHALLENGES WILL BE LIMITED THROUGH MUCH OF THE SHORT TERM  
AS HIGH PRESSURE PERSISTS AS THE DOMINANT INFLUENCE. THE ONLY POINT  
OF INTEREST COMES WEDNESDAY NIGHT AS A SHARP UPPER LEVEL WAVE AND  
ATTENDANT SURFACE LOW SWING ACROSS THE LOWER GREAT LAKES. HINTS  
ALREADY ON THE 00Z MODEL RUNS THAT THE POTENTIAL FOR ROBUST  
CONVECTION EXISTS OVER PARTS OF CENTRAL INDIANA LATE DAY WEDNESDAY  
INTO WEDNESDAY NIGHT.  
 
THE UPPER LEVEL RIDGE THAT HAS REMAINED CENTERED OVER THE SOUTHERN  
ROCKIES FOR THE LAST FEW DAYS WILL BEGIN AN EASTWARD SHIFT THROUGH  
THE FIRST HALF OF THE WORK WEEK...EVENTUALLY FLATTENING AND  
STRETCHING OUT INTO THE TENNESSEE VALLEY AND CAROLINAS BY EARLY  
THURSDAY. THE INITIAL PUSH EAST TO THE RIDGE WILL BRING HEIGHT RISES  
INTO THE GREAT LAKES AND OHIO VALLEY ON TUESDAY AS THE SURFACE RIDGE  
SHIFTS EAST OF THE REGION. THIS WILL MAINTAIN WARM AND DRY  
CONDITIONS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT WITH NOTED  
SUBSIDENCE ONCE AGAIN HELPING TO MITIGATE A MORE EXPANSIVE DIURNAL  
CU FIELD TUESDAY AFTERNOON EVEN AS LOW LEVEL FLOW VEERS AROUND TO  
SOUTHERLY.  
 
THE WEATHER PATTERN BEGINS TO ALTER ON WEDNESDAY SETTING THE STAGE  
AS A PRELUDE TO THE ARRIVAL OF THE UPPER WAVE AND THE INCREASING  
THREAT FOR CONVECTION. THE PLACEMENT OF THE SURFACE HIGH PRESSURE  
RIDGE ON THE WEST SIDE OF THE APPALACHIANS SHOULD SERVE TO MAINTAIN  
DRY CONDITIONS ACROSS MUCH OF THE FORECAST AREA FOR A GOOD CHUNK OF  
THE DAY WEDNESDAY WITH A MID LEVEL CAP PRESENT. AT THE SAME  
TIME...PROGRESSIVELY DEEPER MOISTURE WILL BE DRAWN NORTH INTO THE  
REGION BY THE AFTERNOON AS LOW LEVEL FLOW STRENGTHENS AHEAD OF THE  
WAVE ALOFT AND A COLD FRONT TRACKING THROUGH THE MISSOURI VALLEY.  
WHILE SCATTERED CONVECTION WILL BE POSSIBLE DURING THE DAY OVER  
WESTERN COUNTIES AS A WARM FRONT LIFTS OFF TO THE NORTHEAST...THE  
FOCUS FOR CONVECTION WILL BE WEDNESDAY NIGHT WITH THE ARRIVAL OF THE  
UPPER WAVE. MODEL SOUNDINGS SHOW THE CAP WEAKENING BY LATE DAY WITH  
MODEST INSTABILITY PRESENT DUE TO THE STRONG HEATING EXPECTED OVER  
MUCH OF THE AREA WEDNESDAY WITH WARM ADVECTION AND COMPRESSIONAL  
HEATING LIKELY BEING FACTORS IN EVENTUAL HIGH TEMPERATURES.  
 
A CONVECTIVE CLUSTER IS ANTICIPATED IN THE VICINITY OF THE WAVE  
ALOFT AND THE COLD FRONT TO OUR NORTHWEST WEDNESDAY AFTERNOON...  
MIGRATING INTO THE REGION BY THE EVENING. THE INITIAL FOCUS FOR  
SEVERE WEATHER CONCERNS WILL BE OVER NORTHERN COUNTIES IN CLOSER  
PROXIMITY TO THE FORCING ALOFT WITH THE UPPER WAVE AND THE SURFACE  
LOW SET TO TRACK THROUGH THE GREAT LAKES. HOWEVER...THE DEVELOPMENT  
OF A LOW LEVEL JET WILL LIKELY KEEP CONVECTION GOING THROUGH MUCH OF  
THE NIGHT WITH POTENTIAL IMPACTS ENCOMPASSING MOST IF NOT ALL OF  
CENTRAL INDIANA. 30-40KT BL SHEAR WITH NOTABLE INCREASES IN HELICITY  
SHOULD ALLOW FOR SEVERAL HOURS WITH ORGANIZED ROBUST CONVECTION.  
PWATS CLIMBING TO NEAR 2 INCHES WITH A GROWING THREAT FOR WARM RAIN  
PROCESSES TO DEVELOP WILL SUPPORT THE POSSIBILITY OF LOCALLY HEAVY  
RAIN WITH FLOODING CONCERNS SHOULD TRAINING OF STORMS OCCUR. HIGH  
POPS ARE WARRANTED ACROSS MUCH OF THE FORECAST AREA ON WEDNESDAY  
NIGHT.  
 
TEMPS...LOW LEVEL THERMALS SUPPORT GOING ABOVE GUIDANCE FOR HIGHS  
BOTH TUESDAY AND WEDNESDAY AS TEMPERATURES STEADILY WARM. MID AND  
UPPER 80S WILL BE COMMON TUESDAY...WITH THE POTENTIAL FOR MANY AREAS  
TO RETURN TO THE LOW 90S ON WEDNESDAY AS 850MB TEMPS RISE ABOVE 20C.  
THE COMPRESSIONAL HEATING ASPECT MENTIONED ABOVE AHEAD OF THE  
APPROACHING COLD FRONT MAY ALSO ENABLE TEMPERATURES TO OVERPERFORM  
WEDNESDAY. LOWS IN THE UPPER 50S AND LOWER 60S TONIGHT WILL RISE  
STEADILY BACK INTO THE LOWER 70S BY WEDNESDAY NIGHT. THE AIR WILL  
HAVE A NOTICEABLY MORE HUMID FEEL TO IT ONCE AGAIN BY WEDNESDAY  
AFTERNOON AND NIGHT.  
 

 
   
LONG TERM /THURSDAY THROUGH MONDAY/
 
 
ISSUED AT 306 AM EDT MON JUL 13 2020  
 
HIGH PRESSURE LOOKS TO BUILD IN THURSDAY BEHIND WEDNESDAY'S LOW  
PRESSURE SYSTEM. HAVE KEPT SOME POPS TOWARDS THE EAST TO SHOW  
UNCERTAINTY IN THE LOW'S PROGRESSION, BUT CONDITIONS SHOULD BE DRY  
IN THE WAKE OF THE LOW. NO SIGNIFICANT DISTURBANCE IS EXPECTED  
WITHIN THE LONG TERM, HOWEVER DEW POINTS IN THE LOW 70S AND NEAR DRY  
ADIABATIC AFTERNOON LAPSE RATES IN THE LOW LEVELS WILL PROMOTE  
ISOLATED DIURNAL CONVECTION FRIDAY THROUGH MONDAY.  
 
WEDNESDAY'S DISTURBANCE SHOULD ALSO AID IN THE PROGRESSIONS OF AN  
UPPER LEVEL RIDGE, SUPPLEMENTING HIGHER THAN NORMAL TEMPERATURES  
THROUGHOUT THE LONG TERM. THURSDAY THROUGH SATURDAY WILL BE HOT,  
BUT EXCESSIVE HEAT LOOKS MORE LIKELY ON SUNDAY AND MONDAY AS THE  
AXIS OF THE UPPER LEVEL RIDGE CENTERS OVER THE OHIO VALLEY.  
CURRENT FORECAST CALLS FOR HIGHS IN THE MID 90S WITH HEAT INDEX  
VALUES IN THE MID 100S. MODELS HAVE BEEN DEPICTING AN INCREASE IN  
HEAT TOWARDS THE END OF THE LONG TERM FOR THE LAST FEW DAYS, WITH  
THE SIGNAL WEAKENING AS THE FORECAST NEARS. HOWEVER, A MORE  
MERIDIONAL UPPER LEVEL PATTERN AS SHOWN IN THE LATEST RUNS WOULD  
BE MORE CONDUCIVE TOWARDS AFTERNOON TEMPERATURES IN THE MID 90S.  
 

 
   
AVIATION (DISCUSSION FOR THE 131500Z TAF UPDATE)
 
 
ISSUED AT 1027 AM EDT MON JUL 13 2020  
 
UPPED WINDS A BIT BASED ON LATEST DATA. ADDED A FEW CUMULUS AS  
WELL.  
 
PREVIOUS DISCUSSION FOLLOWS....  
 
VFR CONDITIONS EXPECTED OVER THE ENTIRE TAF PERIOD.  
 
HIGH PRESSURE WILL BUILD OVER CENTRAL INDIANA TODAY. SKIES LOOK TO  
REMAIN CLEAR. WINDS WILL BE LIGHT OUT OF THE NORTH THROUGHOUT THE  
DAY AND BECOME MORE VARIABLE TONIGHT.  

 
   
IND WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SYNOPSIS...RYAN  
NEAR TERM...RYAN  
SHORT TERM...RYAN  
LONG TERM....UPDIKE  
AVIATION...UPDIKE/50  
 
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