Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 301927
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
327 PM EDT SAT AUG 30 2014

.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 327 PM EDT SAT AUG 30 2014

A SERIES OF UPPER LEVEL WAVES TRACKING THROUGH THE REGION WILL BRING
SEVERAL CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH TUESDAY. DRIER
WEATHER WILL RETURN BY MIDWEEK AS HIGH PRESSURE EXPANDS INTO THE
GREAT LAKES. CHANCES FOR STORMS WILL RETURN FOR THE END OF THE WEEK
AND INTO THE WEEKEND AS ANOTHER FRONTAL BOUNDARY MOVES INTO THE OHIO
VALLEY.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 327 PM EDT SAT AUG 30 2014

ABUNDANT CLOUD COVER PERSIST ACROSS CENTRAL INDIANA THIS AFTERNOON
ALTHOUGH STARTING TO SEE SOME BREAKS ACROSS THE REGION. SCATTERED
SHOWERS CONTINUING TO IMPACT SOUTHERN INDIANA AS PLUME OF DEEP GULF
MOISTURE ROTATES AROUND THE BACK SIDE OF THE SOUTHEAST UPPER RIDGE.
TEMPS HAD BEEN HELD DOWN BY CLOUDS SO FAR...RANGING FROM THE MID 70S
TO LOWER 80S AS OF 19Z.

SOUTHEAST RIDGE BEGINNING TO BUCKLE A BIT IN RESPONSE TO THE WAVE
ALOFT MOVING ACROSS THE WESTERN GREAT LAKES. THIS HELPING TO SHIFT
THE MOISTURE PLUME CLOSER TO THE OHIO RIVER...AND HAVE SEEN A
DOWNWARD TREND IN RAINFALL OVER SOUTHERN COUNTIES AS CONVECTION
REFOCUSING OVER WESTERN KENTUCKY AND FAR SOUTHWEST INDIANA IN CLOSER
PROXIMITY TO A WEAK WAVE ALOFT. SCATTERED CONVECTION ALSO DEVELOPING
IN THE VICINITY OF A SUBTLE CONVERGENCE BOUNDARY WITHIN AN
ATMOSPHERE WITH BETTER INSTABILITY AND STEEPER LOW LEVEL LAPSE RATES
TO THE NORTHWEST OF THE FORECAST AREA. WITH BOUNDARY LAYER FLOW
INCREASING AND AN UPPER LEVEL JET DEVELOPING OVER THE LOWER GREAT
LAKES BY EARLY EVENING... EXPECT BOTH OF THESE AREAS OF CONVECTION
TO MOVE INTO THE REGION FROM THE SOUTHWEST AND WEST RESPECTIVELY
OVER THE NEXT SEVERAL HOURS. WILL CONTINUE WITH HIGHEST POPS OVER
WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA AS A RESULT
THROUGH THE EVENING.

WITH PRECIP WATER VALUES IN THE VICINITY OF 2 INCHES...LOCALLY HEAVY
RAINFALL WITH DANGEROUS LIGHTNING REMAIN THE PRIMARY IMPACTS INTO
THE EVENING. WILL NEED TO MONITOR THE STORMS OVER ILLINOIS AS THEY
MOVE E/NE INTO THE REGION. CERTAINLY COULD SEE GUSTY WINDS WITH SOME
OF THE STRONGER STORMS BUT OVERALL...POORER LAPSE RATES AND LESS
INSTABILITY SHOULD KEEP STORMS IN A MULTICELLULAR SUBSEVERE MODE.

CONVECTION WILL GRADUALLY SINK INTO THE SOUTHERN HALF OF THE
FORECAST AREA OVERNIGHT AS LOW PRESSURE OVER NORTHERN LOWER MICHIGAN
SHIFTS EAST AND ENABLES DRIER AIR TO BEGIN ADVECTING IN. ANOTHER
WAVE ALOFT ROTATING INTO THE TENNESSEE VALLEY WILL KEEP PRECIP OVER
SOUTHERN COUNTIES THROUGH DAYBREAK AND WILL MAINTAIN 50-60 POPS
SOUTH OF I-70.

TEMPS...WITH PLENTY OF LOW LEVEL MOISTURE...CLOUDS AND PRECIP...
LEANED TOWARDS WARMER METMOS FOR LOWS TONIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 327 PM EDT SAT AUG 30 2014

FORECAST CHALLENGES FOCUS ON PRECIP CHANCES...PARTICULARLY MONDAY
AND TUESDAY ACROSS THE FORECAST AREA.

LOW PRESSURE WILL CONTINUE TO PULL AWAY INTO QUEBEC WITH WEAK
RIDGING ALOFT BUILDING INTO THE REGION AS THE DAY PROGRESSES.
SHOWERS AND EMBEDDED THUNDER WILL BE ONGOING OVER FAR SOUTHERN
FORECAST AREA IN THE MORNING GRADUALLY SHIFTING EAST OF THE REGION
INTO THE AFTERNOON. MODEL SOUNDINGS STILL SHOW AN UNSTABLE AIRMASS
LINGERING ACROSS THE FORECAST AREA BUT IN THE ABSENCE OF ANY
APPRECIABLE FORCING ALOFT...EXPECT CONVECTION TO BE ISOLATED TO
SCATTERED AT BEST AND FOCUSED ALONG AND SOUTH OF I-70 WHERE DEEPER
MOISTURE WILL LINGER.

WEAK HIGH PRESSURE WILL OVERSPREAD THE REGION SUNDAY NIGHT AND
OUTSIDE OF AN ISOLATED SHOWER OR STORM OVER SOUTHEAST FORECAST AREA
WHERE SLIGHTLY BETTER MOISTURE WILL RESIDE...ANTICIPATE DRY WEATHER
ACROSS THE REGION. MONDAY MORNING WILL START OUT DRY AS WELL BEFORE
FOCUS SHIFTS BACK TO THE WEST IN ADVANCE OF A SHARP WAVE ALOFT
MOVING INTO THE UPPER MISSISSIPPI VALLEY AND AN ASSOCIATED COLD
FRONT. THE FRONT WILL MOVE INTO THE WESTERN GREAT LAKES BY MONDAY
EVENING WITH A 30-40KT LOW LEVEL JET ADVECTING DEEPER MOISTURE BACK
INTO THE OHIO VALLEY AHEAD OF THE FRONT. POTENTIAL FOR MORE
ORGANIZED STORMS AND SEVERE CONVECTION MONDAY AFTERNOON AND EVENING
AS BL SHEAR AND STORM RELATIVE HELICITIES ARE MORE PLENTIFUL WITH
THE UPPER LEVEL FEATURE MOVING INTO THE GREAT LAKES.

RAIN AND STORMS WILL CONTINUE MONDAY NIGHT AND TUESDAY MORNING AS
THE FRONT SWEEPS ACROSS CENTRAL INDIANA AND THE OHIO VALLEY. WITH
THE LOW LEVEL JET REMAINING ACROSS THE REGION...EXPECT WIDESPREAD
STORMS WITH LOCALLY HEAVY RAIN TO IMPACT THE FORECAST AREA ALL NIGHT
AND LIKELY POPS REMAIN WARRANTED. PRECIP WILL DIMINISH IN COVERAGE
FROM NORTHWEST TO SOUTHEAST DURING THE COURSE OF THE DAY AS THE
FRONT DROPS SOUTH OF THE OHIO RIVER.

TEMPS...MAVMOS GUIDANCE LOOKED REASONABLE FOR MUCH OF THE PERIOD.
CLOUDS INITIALLY ON SUNDAY WILL LIKELY KEEP HIGHS DOWN A BIT IN THE
UPPER 70S AND LOWER 80S. WITH CONVECTIVE IMPACTS LIKELY HOLDING OFF
UNTIL LATER IN THE AFTERNOON MONDAY...TRENDED TOWARDS WARMER MAV FOR
HIGHS. USED CONSMOS FOR LOWS THROUGH THE PERIOD AS ALL GUIDANCE WAS
SIMILAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 327 PM EDT SAT AUG 30 2014

PRECIP CHANCES WILL GRADUALLY DECREASE AT THE BEGINNING OF THE
EXTENDED PERIOD AS HIGH PRESSURE STRENGTHENS AT THE SURFACE AND
FLOW BECOMES MORE ZONAL ALOFT.  NONETHELESS...KEPT MENTION OF SLIGHT
CHANCE POPS FROM TUESDAY NIGHT THROUGH WEDNESDAY AS A FRONTAL
BOUNDARY STALLS OVER THE TENNESSEE VALLEY.  BY THURSDAY...A WEAK
SHORT WAVE IN THE UPPER FLOW WILL INCREASE PRECIP CHANCES
AGAIN...AND A WARM FRONT AT THE END OF THE EXTENDED PERIOD WILL
INCREASE SHOWER/THUNDERSTORM CHANCES EVEN FURTHER BY THURSDAY
NIGHT.  THIS WARM FRONT WILL ALSO RESULT IN A WARM UP AFTER THE COLD
FRONT EARLIER IN THE LONG TERM PERIOD.  HIGH TEMPERATURES WILL CLIMB
BACK INTO THE UPPER 80S/LOW 90S ON THURSDAY AND FRIDAY.  TUESDAY AND
WEDNESDAY...HIGHS WILL BE CLOSER TO NORMAL WITH READINGS IN THE LOW
TO MID 80S.  OVERNIGHT LOWS WILL TREND FROM THE LOW TO MID 60S AT
THE BEGINNING OF THE EXTENDED PERIOD....TO MID TO UPPER 60S BY THE
END OF THE PERIOD.

&&

.AVIATION /DISCUSSION FOR THE 30/1800Z TAF ISSUANCE/...
ISSUED AT 130 PM EDT SAT AUG 30 2014

SHOWERS/ISOLATED THUNDERSTORMS HAVE BEEN MORE PREVALENT AT KBMG SO
FAR TODAY WHERE MOISTURE IS HIGHEST. ELSEWHERE...REMOVED MENTION
OF THUNDERSTORMS FOR THIS AFTERNOON AND WILL CONTINUE WITH ONLY
MENTION OF RAIN. CONDITIONS WILL MAINLY BE VFR CATEGORY WITH SOME
DETERIORATION TO MVFR AT TIMES DUE TO LOWER CEILINGS/REDUCED
VISIBILITIES WITH ANY PRECIP.

CHANCES FOR CONVECTION WILL INCREASE THIS EVENING AS LOW PRESSURE
MOVES CLOSER TO CENTRAL INDIANA. SO...WILL INCLUDE -TSRA AT ALL
TAF SITES FROM SUN 01-06/07Z. AFTER THAT...THUNDERSTORM CHANCES
WILL BEGIN TO WANE...BUT WIDESPREAD ACTIVITY WILL STILL WARRANT
MENTION OF VCTS THROUGH THE REMAINDER OF TAF PERIOD. MVFR OR WORSE
CAN BE EXPECTED TONIGHT DUE TO REDUCED VISIBILITIES AND LOW CEILINGS.

WINDS WILL BE SOUTHWESTERLY FOR DURATION OF TAF PERIOD...GENERALLY
AT 5 TO 10 KTS. THE EXCEPTION WILL BE THIS AFTERNOON WHEN GUSTS UP
TO 20 KTS WILL BE POSSIBLE.

&&

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

&&

$$

SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD

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