AP-IN--IND-IN NE Area Forecast Discussion, IN

000

FXUS63 KIND 151436

AFDIND

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE INDIANAPOLIS IN

1036 AM EDT WED JUL 15 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...

ISSUED AT 400 AM EDT WED JUL 15 2015

DRY WEATHER WILL BE THE RULE OVER CENTRAL INDIANA THROUGH THURSDAY

WITH COOLER LESS HUMID AIR AS WELL. THUNDERSTORM CHANCES RETURN LATE

THURSDAY NIGHT IN NORTHWEST INDIANA AND THEN WILL BE IN THE FORECAST

THROUGH THE REST OF THE PERIOD AS THE UPPER RIDGE OVER THE SOUTHERN

U.S. FLATTENS LEAVING A PROGRESSIVE FLOW PATTERN ACROSS THE NORTHERN

U.S.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 1003 AM EDT WED JUL 15 2015

ONGOING FORECAST IN PRETTY GOOD SHAPE.

SATELLITE THIS MORNING SHOWS AN AREA OF STRATOCU STILL LINGERING

ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA. THE AREA APPEARS TO

BE SLOWLY DECAYING AS HEATING RESUMES THIS MORNING. SURFACE

ANALYSIS THIS MORNING SHOWS LOW PRESSURE OVER THE MIDDLE ATLANTIC

STATES PULLING AWAY AS HIGH PRESSURE IN PLACE OVER THE GREAT

LAKES WAS PROVIDING A COOLER NORTHEAST SURFACE FLOW TO CENTRAL

INDIANA.

FORECAST SOUNDINGS SHOW A GOOD CAP IN PLACE TODAY DUE TO A MID

LEVEL INVERSION AND CONVECTIVE TEMPS IN THE UPPER 80S...WHICH WILL

NOT BE REACHED. THUS WILL CONTINUE ONGOING TRENDS IN THE

FORECAST...SKIES BECOMING SUNNY AS THE STRATOCU DECK DECAYS.

ONGOING TEMP FORECAST LOOKS ON THE MARK.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...

ISSUED AT 400 AM EDT WED JUL 15 2015

FORECAST FOCUS IS ON THUNDERSTORM CHANCES LATER IN THE WEEK. MODELS

ARE IN GOOD AGREEMENT AND WILL GENERALLY USE A CONSENSUS UNLESS

OTHERWISE MENTIONED BELOW.

UNDER THE INFLUENCE OF HIGH PRESSURE DRY WEATHER WILL REMAIN THE

RULE THROUGH THE DAY ON THURSDAY. WENT A BIT WARMER THAN GUIDANCE

FOR THURSDAY WITH WARMER TEMPERATURES ADVECTING IN ALOFT FROM THE

SOUTHWEST. BY THURSDAY NIGHT THE UPPER RIDGE FLATTENS AND THIS

SHOULD ALLOW A SHORTWAVE TROUGH TO APPROACH FROM THE NORTHWEST. THE

GFS IS A BIT FASTER WITH THIS FEATURE THAN THE NAM AND PREFER IT/S

TIMING. FRIDAY AND FRIDAY NIGHT LOOK FOR MORE THUNDERSTORM CHANCES

WITH WAVES MOVING THROUGH THE FLAT UPPER RIDGE. NO STRONG FEATURES

TO KEY ON SO WILL STICK CLOSE TO CONSENSUS POPS IN THE LOW CHANCE TO

SLIGHT CHANCE CATEGORY. DO THINK CHANCES WILL BE BEST IN THE NORTH

WITH MORE SUBSIDENCE POSSIBLE HEADING SOUTH CLOSER TO THE UPPER

RIDGE.

ONLY MODERATE CONFIDENCE ABOUT GOING WITH GUIDANCE HIGHS IN THE 90S

FOR FRIDAY WITH SOME POTENTIAL FOR CLOUDS/THUNDERSTORMS TO GET IN

THE WAY OF PEAK HEATING. HOWEVER GIVEN THE STRONG WARM ADVECTION AT

850 MB AND THOSE TEMPERATURES CLIMBING TO 20-22C WILL STICK WITH

GUIDANCE HIGHS IN THE 90S.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...

ISSUED AT 305 AM EDT WED JUL 15 2015

THE EXTENDED WILL FEATURE TEMPERATURE AND POP CHALLENGES AS MODELS

AGREE THAT THE UPPER PATTERN WILL RETURN TO WHAT IS WAS LAST WEEKEND

AND THE START OF THIS WEEK. THAT IS...AN UPPER DOME OF HIGH PRESSURE

WILL RETROGRADE BACK TO THE SOUTHERN PLAINS THIS COMING WEEKEND AND

AMPLIFY ALLOWING NORTHWEST FLOW AND PERIODIC CHANCES FOR MESOSCALE

SYSTEMS TO MOVE THROUGH THE LOWER GREAT LAKES AND OHIO VALLEY. THE

DETERMINISTIC MODELS HAVE HANDLED THE PATTERN BETTER OF LATE AS THE

ENSEMBLE MEANS HAVE BEEN LESS PROGRESSIVE THEREBY NOT HANDLING THE

PERSISTENT AND UNUSUAL PATTERN AS WELL. ACTIVE EASTERN PACIFIC

TROPICAL SYSTEM MAY BE PARTIALLY TO BLAME PER THE WPC EXTENDED

DISCUSSION.

WITH THAT SAID...THE BEST CHANCES FOR THUNDERSTORMS LOOK TO BE LATE

WEEKEND INTO EARLY NEXT WEEK AS A FRONTAL SYSTEM DROPS SOUTHEAST

OVER CENTRAL INDIANA MONDAY OR LATER AND MOISTURE STREAMS OVER TOP

THE SOUTHERN PLAINS RIDGE...FROM DELORES. IN ADDITION...SOUTHWEST

GULF LOW LEVEL FLOW...ALBEIT IT MODEST...WILL PRECEDE THE FRONTAL

SYSTEM...BRINGING VERY WARM AND HUMID CONDITIONS TO CENTRAL INDIANA

THIS WEEKEND. COULD SEE PLUS 90 DEGREE TEMPERATURES AND PLUS 100

DEGREE HEAT INDICES...ESPECIALLY OVER THE SOUTHWEST COUNTIES.

CONSEQUENTLY...MAY NEED HEAT HEADLINES EVENTUALLY FOR THIS WEEKEND.

&&

.AVIATION /UPDATE TO 151200Z TAFS/...

ISSUED AT 1030 AM EDT WED JUL 15 2015

HAVE AMENDED ALL TAFS. KIND HAS LIFTED ABOVE 1000 FT WITH A BROKEN

SKY WHILE REMAINING SITES ARE BELOW 1000 FT. SATELLITE SHOWS

THINNING OF DECK IN PROGRESS BUT STILL SHOULD TAKE UNTIL 1530Z-

1600Z BEFORE OVERCAST BECOMES BROKEN AND AS HEATING CONTINUES

THESE DECKS SHOULD RISE ABOVE 1000 FT.

BY 151800Z CLOUDS SHOULD HAVE FULLY EVOLVED INTO A SCATTERED TO

BROKEN CUMULUS CLOUD COVER AT OR ABOVE 3000 FEET.

WINDS TO REMAIN FROM NNE UNDER 10 KTS AND GRADUALLY BECOME MORE NE

TO E OVERNIGHT.

STILL ANTICIPATE MVFR FOG BEFORE DAYBREAK THURSDAY 160800Z.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

NONE.

&&

$$

SYNOPSIS...CP

NEAR TERM...PUMA

SHORT TERM...CP

LONG TERM...MK

AVIATION...TUCEK

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Delivered by Weather Underground Inc. Wed Jul 15 2015 10:36AM EDT