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000
FXUS63 KIND 311417
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1017 AM EDT THU JUL 31 2014

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 318 AM EDT THU JUL 31 2014

A LOW PRESSURE SYSTEM WILL LINGER OVER EASTERN CANADA THROUGH THE
END OF THE WEEK...TRIGGERING DAILY SHOWERS AND ISOLATED
THUNDERSTORMS OVER CENTRAL INDIANA. THE SYSTEM WILL START TO PUSH
EAST ON FRIDAY...BUT A TROUGH WILL DEEPEN IN THE UPPER FLOW BEHIND
IT...CAUSING LINGERING SHOWER/THUNDERSTORM ACTIVITY THROUGH SATURDAY
AFTERNOON. HIGH PRESSURE WILL STRENGTHEN OVER THE AREA ON SATURDAY
NIGHT AND BRING DRY CONDITIONS THROUGH THE BEGINNING OF NEXT WEEK.
IN THE EXTENDED...A FRONT WILL STALL OVER THE AREA BRINGING THE
NEXT CHANCE FOR PRECIP STARTING TUESDAY.

&&

.NEAR TERM /REST OF TODAY/...
ISSUED AT 1000 AM EDT THU JUL 31 2014

.UPDATE...MAIN CHANGES WERE TO DROP MENTION OF FOG AND TO LOWER SKY
COVER A LITTLE THROUGH EARLY AFTERNOON AS RAP SOUNDING INDICATES
CONVECTIVE TEMPERATURES IN THE MIDDLE 80S.  RAPID REFRESH INDICATES
SOME CONVECTION POSSIBLE ACROSS NORTHERN INDIANA BY MID TO LATE
AFTERNOON WITH LITTLE OVER CENTRAL SECTIONS.  NOT ENOUGH TO MAKE ANY
CHANGES TO OUR CURRENT POPS HOWEVER. NO SIGNIFICANT CHANGES MADE TO
TEMPERATURES.

PREVIOUS NEAR TERM DISCUSSION FOLLOWS...

THE MAIN FOCUS WILL BE SHOWER/THUNDERSTORM ACTIVITY THIS AFTERNOON
AND EVENING.

THE SYNOPTIC SET UP WILL REMAIN UNCHANGED THROUGH THE NEAR TERM
PERIOD...A BROAD LOW PRESSURE SYSTEM CENTERED OVER EASTERN ONTARIO
AND A LARGE RIDGE OF HIGH PRESSURE OVER THE WESTERN U.S. THIS WILL
BE CONDUCIVE TO MORE SHOWER/THUNDERSTORM CHANCES THIS AFTERNOON
AND EVENING. HOWEVER...WITH NO NOTICEABLE WAVES IN THE UPPER FLOW
LIKE THE LAST FEW DAYS...CHANCES FOR DEVELOPMENT WILL BE LESS
LIKELY TODAY. AS A RESULT...WILL ONLY CARRY SLIGHT CHANCE POPS
OVER THE NORTHERN TWO-THIRDS OF THE FORECAST AREA FROM THU 18Z-FRI
00Z.

TEMPS...AS WINDS TAKE ON MORE OF A WESTERLY COMPONENT
TODAY...TEMPS WILL START THEIR WEAK WARMING TREND BACK INTO
THE LOW 80S. THIS WAS HANDLED BEST BY ALLBLEND.

EARLY THIS MORNING...FOG DEVELOPMENT WILL BE POSSIBLE IN AREAS
THAT RECEIVED RAIN YESTERDAY...BUT THIS WILL BE DEPENDENT ON CLOUD
COVER OVER THE NEXT FEW HOURS.  WILL CONTINUE TO MONITOR.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...

ISSUED AT 318 AM EDT THU JUL 31 2014

THE MAIN FOCUS CONTINUES TO BE DIURNALLY DRIVEN
SHOWERS/THUNDERSTORMS THROUGH THE SHORT TERM PERIOD.

DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS WILL COME TO AN END THIS
EVENING...AND CONDITIONS WILL BE DRY TONIGHT AS HAS BEEN THE
PATTERN OVER THE LAST SEVERAL NIGHTS. FRIDAY AND FRIDAY
NIGHT...PRECIP CHANCES WILL INCREASE AS A WAVE DEEPENS OVER
CENTRAL INDIANA...PROVIDING NECESSARY LIFT IN THE MID LEVELS.
SCATTERED SHOWER AND THUNDERSTORM ACTIVITY IN ASSOCIATION WITH
THAT WAVE WILL LINGER INTO SATURDAY...BUT SUBSIDENCE WILL
STRENGTHEN OVER CENTRAL INDIANA ON SATURDAY NIGHT...BRINGING AN
END TO THE PRECIP. CONFIDENCE IS LOW IN DRY FORECAST FOR SATURDAY
NIGHT THOUGH...LINGERING SHOWERS MAY HAVE TO BE ADDED TO THE
EASTERN COUNTIES IF UPPER WAVE STALLS.

TEMPS...HIGHS WILL TOP OFF IN THE LOW TO MID 80S WITH LOWS IN THE
60S THROUGH THE PERIOD WITH LIGHT AND VARIABLE WINDS...STUCK CLOSE
TO GUIDANCE.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

ISSUED AT 318 AM EDT THU JUL 31 2014

EXTENDED MODELS IN GOOD AGREEMENT THAT THE PERSISTENT BROAD UPPER
TROUGH WILL BE EAST OF LIFTING NORTHEAST ON SUNDAY AS THE JAMES BAY
VORTEX WEAKENS AND BECOMES ABSORBED BY THE ICELANDIC LOW. IN
ADDITION...THE WESTERN RIDGE BECOMES SUPPRESSED BY ENERGY COMING OUT
OF SOUTHWESTERN CANADA NEXT WEEK AS THE FORMER ATTEMPTS TO BUILD
INTO THE WABASH VALLEY. MEANWHILE...NORTHWEST FLOW ALOFT IN THE WAKE
OF THE UPPER TROUGH WILL ATTEMPT TO STEER A BACKDOOR FRONT SOUTH
ACROSS OUR AREA EARLY TO MID WEEK OF NEXT WEEK. INCREASING MOISTURE
ALONG WITH THE FRONT NEARBY SUGGEST THUNDERSTORM CHANCES FROM THE
REGIONAL BLEND LOOK REASONABLE BY TUESDAY AND MAINLY ACROSS OUR
NORTHERN COUNTIES PER THE 00Z GFS AND 12Z ECMWF AS THE SOUTHWESTERN
UPPER RIDGE SHOULD KEEP THE FRONT FROM DROPPING MUCH FURTHER BEFORE
STALLING OUT. PRIOR TO TUESDAY...SHOULD BE MOSTLY DRY AND WARMER
WITH MORE SEASONABLE AFTERNOON HIGHS IN THE 80S PER THE REGIONAL
BLEND OUTPUT.

&&

.AVIATION /DISCUSSION FOR THE 311200Z TAF ISSUANCE/...

ISSUED AT 1016 AM EDT THU JUL 31 2014

1415Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

THE FOG SHOULD BE GONE AT LAF BY 12Z AS HAS BEEN THE CASE THE LAST
FEW DAYS. THEN...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD
EXCEPT FOR PERHAPS MORE FOG...MAINLY AT LAF AFTER 06Z TONIGHT. WOULD
NOT RULE OUT A THUNDERSTORM AT IND AND LAF THIS AFTERNOON AND AT IND
FRIDAY AFTER 16Z AHEAD OF AN UPPER WAVE...HOWEVER CHANCES BOTH THIS
AFTERNOON AND FRIDAY TOO LOW TO MENTION.

WINDS WILL BE SOUTHWEST AND WEST TODAY LESS THAN 10 KNOTS AND LIGHT
TO CALM TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD/JH
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...SMF

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