000
FXUS63 KIWX 181015
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
615 AM EDT SAT MAY 18 2013

.SYNOPSIS...
ISSUED AT 610 AM EDT SAT MAY 18 2013

A FRONT WILL REMAIN OVER THE REGION TODAY...BRINGING A CHANCE FOR
THUNDERSTORMS TO MAINLY SOUTHERN PORTIONS OF THE AREA. AFTER A
BREAK FROM THE SHOWERS AND STORMS SUNDAY... MORE RAIN IS EXPECTED
MONDAY THROUGH WEDNESDAY AS MOISTURE FLOW INTO THE AREA INCREASES
AND AS UPPER LEVEL DISTURBANCES MOVE OVER THE AREA. TEMPERATURES
WILL BE ABOVE NORMAL FROM THE MID 70S TO THE MID 80S AND LOWS IN
THE 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EDT SAT MAY 18 2013

A VERY TIGHT MOISTURE GRADIENT CONTINUED OVER THE AREA AGAIN
TODAY...WITH DEW POINTS IN THE 30S NORTH OF THE BOUNDARY TO LOWER
60S FARTHER SOUTH. GIVEN VERY WEAK SYNOPTIC SCALE FORCING AND LIGHT
WIND PROFILES...INCLUDING WIND GENERALLY AROUND OR UNDER 20 KNOTS
INTO THE UPPER LEVELS...CURRENT THINKING SHOWERS AND ISOLATED STORMS
WILL BE HIGHLY DIURNAL TODAY...INCLUDING LATE AFTERNOON AND EARLY
EVENING. CAPE VALUES SHOULD REMAIN VERY LIMITED AND CONVECTION
SHOULD BE MAINLY CONFINED TO THE MUCH HIGHER SFC THETA E AREAS ALONG
AND SOUTH OF THE FRONT. RAISED HIGHS A LITTLE TODAY GIVEN VERY LARGE
DIURNAL TEMPERATURE SWINGS EXPECTED TODAY...ESPECIALLY NORTH OF THE
BOUNDARY. NCEP MOS GUIDANCE FOR HIGHS HAS BEEN RUNNING 2 TO 4
DEGREES TOO COOL.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 416 AM EDT SAT MAY 18 2013

STRONG PACIFIC JET CURRENTLY CRASHING INTO THE WESTERN CONUS WILL
CARVE OUT A VERY LARGE BAROTROPIC LOW PRESSURE SYSTEM EAST OF THE
ROCKIES BY EARLY NEXT WEEK. THE GRADUAL EASTWARD PROGRESSION OF THIS
FEATURE WILL BRING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
TO THE LOCAL FORECAST AREA THROUGH MIDWEEK. BEGINNING WITH SUNDAY
THOUGH...MIDLEVEL RIDGE AXIS DIRECTLY OVER THE GREAT LAKES MAKES FOR
A SOMEWHAT PRECARIOUS PRECIP FORECAST. LOW LEVEL WINDS BEGIN TO VEER
TO A MORE SOUTHERLY DIRECTION DURING THIS TIME...ADVECTING MORE
WARM/MOIST AIR INTO THE REGION. LATEST MOS GUIDANCE SUPPORTS HIGHS
SOLIDLY IN THE MID 80S WITH DEWPOINTS CREEPING INTO THE LOW TO MID
60S. NAM AND GFS MLCAPE FIELDS/FORECAST SOUNDINGS CONTINUE TO SHOW A
MODERATELY UNSTABLE AND WEAKLY CAPPED ENVIRONMENT...THANKS TO STRONG
SOLAR INSOLATION AND INCREASING LOW LEVEL THETA-E ADVECTION.
HOWEVER...WITH THE LACK OF ANY SYNOPTIC SCALE LIFTING MECHANISM...
CONVECTION WILL BE RELIANT ON INEFFICIENT PBL MIXING TO REACH THE
LFC. ALSO...GIVEN PLACEMENT AND EVOLUTION OF RIDGING ALOFT...EXPECT
THE CAP MAY BE A BIT STRONGER THAN WHAT CURRENT BUFR SOUNDINGS
INDICATE. Q VECTOR DIVERGENCE FIELDS SHOW WEAKLY SUBSIDENT AIR MASS
THAT WILL LIKELY INHIBIT CONVECTION. RELATIVELY DRY TROPOSPHERIC
COLUMN SHOULD ALSO TEND TO INHIBIT EXPANDING CONVECTION. ALL OF THAT
BEING SAID...WOULDNT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM
BUT COVERAGE WILL BE VERY LIMITED AND DECIDED TO CUT POPS TO AROUND
10 PERCENT AND REMOVE BLANKET SLIGHT CHANCE WORDING.

SOUTHWESTERLY LLJ BEGINS TO RAMP UP SUNDAY NIGHT AND MONDAY AS THE
APPROACHING MIDLEVEL HEIGHT ANOMALY FORCES A TIGHTENING OF THE LOW
LEVEL GRADIENT. WARM FRONT BEGINS TO REALLY TAKE SHAPE AND LIFT
NORTH SUNDAY NIGHT AS THE RIDGE AXIS SHIFTS EAST. ASSOCIATED
ISENTROPIC ASCENT AND MOISTURE FLUX CONVERGENCE IN REGION OF MODEST
ELEVATED INSTABILITY COULD SPARK OFF A FEW
SHOWERS/THUNDERSTORMS...BUT AGAIN COVERAGE WILL BE LIMITED. CWA WILL
BE FIRMLY IN THE WARM SECTOR BY MONDAY AFTERNOON. 850MB TEMPS LOOK
TO CLIMB TO AROUND 17C...SUPPORTING HIGHS IN THE MID TO UPPER 80S
WITH DEWPOINTS IN THE MID TO UPPER 60S. PRECIP CHANCES WILL HINGE ON
EXACT TIMING OF APPROACHING TROUGH AND ASSOCIATED WEAKENING OF THE
CAPPING INVERSION. LATEST 00Z GFS IS MUCH SLOWER THAN ITS NAM AND
ECMWF COUNTERPARTS AND MAINTAINS A PREDOMINATELY DRY FORECAST.
SYMPATHETIC TO A SLOWER SOLUTION GIVEN OVERALL PATTERN BUT
CONFIDENCE TOO LOW TO MAKE SIGNIFICANT ADJUSTMENTS TO POPS AT THIS
TIME AND WILL GO WITH LOW CHANCE WORDING. IF CONVECTION DOES
OCCUR...SEVERE WEATHER IS A DISTINCT POSSIBILITY GIVEN STRONG
INSTABILITY AND MODERATE SHEAR PROFILES. AS SUCH...SPC HAS PLACED
OUR CWA IN DAY3 SLIGHT RISK TO COVER THIS CONDITIONAL THREAT.

MUCH BETTER PRECIP CHANCES EXPECTED TUES AND WED AS VERTICALLY
STACKED LOW APPROACHES AND LOW LEVEL MOISTURE ADVECTION CONTINUES.
EXPECT SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WITH EXACT TIMING
DEPENDENT ON EVOLUTION OF FRONTAL FEATURES AS WELL AS POTENTIALLY
MEDDLESOME MCS DEVELOPMENT. SEVERE WEATHER REMAINS POSSIBLE DURING
THIS TIME BUT WEAKENING DYNAMICS ALOFT AND INCREASINGLY STABLE
AIRMASS DOES NOT BODE WELL. A FEW LINGERING SHOWERS ARE POSSIBLE ON
THURSDAY BUT 1030 MB CANADIAN SURFACE HIGH IS EXPECTED TO BUILD OVER
THE GREAT LAKES BY THE END OF THE WEEK. THIS SHOULD RESULT IN A
PLEASANT...ALBEIT COOL...MEMORIAL DAY WEEKEND.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 610 AM EDT SAT MAY 18 2013

DRIER AIR HAS SPREAD BACK INTO THE TERMINALS FROM THE EAST AND
NORTHEAST. THERE IS AN OUTSIDE CHANCE FOR A MAINLY LATE AFTERNOON
SHOWER AS TIGHT MOISTURE GRADIENT MOVES NORTH LATER
TODAY AND AS DAYTIME CONDITIONS DESTABILIZE...HOWEVER...FOR NOW
KEPT RAIN OUT OF THE TAFS WITH VFR CONDITIONS.

&&

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

$$

SYNOPSIS...SKIPPER
SHORT TERM...SKIPPER
LONG TERM...AGD
AVIATION...SKIPPER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 180820
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
420 AM EDT SAT MAY 18 2013

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 143 AM EDT SAT MAY 18 2013

A WEAK AREA OF LOW PRESSURE WILL DRIFT INTO THE OHIO VALLEY AND
ACROSS SOUTHERN INDIANA. THIS WILL BRING CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS
THE AREA ON SUNDAY. EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER
THE WESTERN HALF OF THE COUNTRY INTO THE WEEKEND WHICH WILL BRING
WARMER AIR FOR MUCH OF NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF
STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /TODAY/...
ISSUED AT 143 AM EDT SAT MAY 18 2013

MODELS DEPICT A WEAK UPPER LOW PUSHING THROUGH THE OHIO VALLEY AND
SOUTHERN INDIANA...THEN EXITING THE AREA BY LATE THIS AFTERNOON.
APPEARS WEAK FORCING ASSOCIATED WITH THE S/WV AND DAYTIME HEATING
WILL BE THE MAIN FORCING MECHANISMS FOR CONVECTIVE DEVELOPMENT.
GUIDANCE IS SHOWING CHANCES FOR THIS ACTIVITY ALL ACROSS THE
FORECAST AREA...WITH BEST CHANCES SOUTH OF I-70...BUT NOT LIMITED TO
THIS AREA. BUMPED UP POPS AND TRENDED TEMPS AT OR SLIGHTLY ABOVE MOS
DESPITE CLOUD COVER AND PRECIP CHANCES WE SHOULD EASILY BE ABLE TO
ACHIEVE TEMPS RANGING FROM UPPER 70S TO AROUND 80.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 143 AM EDT SAT MAY 18 2013

DRIER AIR WILL QUICKLY BE INFILTRATING BACK INTO THE AREA BY THIS
EVENING...NOT BEFORE A FEW SHOWERS EXIT THE REGION TO THE EAST. WEAK
RIDGING BUILDS BACK OVER THE AREA TONIGHT AND SKIES WILL ATTEMPT TO
CLEAR OUT...BUT SOME MID TO HIGH LEVEL CLOUDS WILL REMAIN. POSSIBLY
SOME PATCHY FOG EARLY SUNDAY MORNING. WILL CONTINUE WITH A DRY
FORECAST STARTING LATE TONIGHT THROUGH EARLY MONDAY. 850 MB TEMPS
STILL LOOK QUITE WARM BY EARLY NEXT WEEK. LOOK FOR HIGH TEMPS IN THE
MID 80S BOTH SUNDAY AND MONDAY. MODELS ARE IN A BIT OF A
DISAGREEMENT WITH REGARD TO THE TIMING OF THE NEXT SYSTEM. FOR NOW
HAVE INTRODUCED SLIGHT CHANCE TO LOW CHANCE POPS STARTING MONDAY
AFTERNOON AND MONDAY NIGHT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 229 AM EDT SAT MAY 18 2013

LONG TERM CONTINUES TO BE DOMINATED BY ONE MAIN SURFACE AND UPPER
LEVEL LOW MOVING EXTREMELY SLOWLY FROM THE NORTHERN PLAINS/UPPER
MIDWEST INTO THE OHIO VALLEY AND THE MIDATLANTIC STATES THROUGH
THE COMING WEEK. BROAD SOUTHWEST FLOW MOVING WARM MOIST AIR INTO
THE AREA WILL MERIT AT LEAST CHANCE POPS MOST ALL PERIODS THROUGH
THE LATE PORTION OF THE WEEK...WITH SOME LIKELIES LATE TUESDAY
INTO WEDNESDAY AS THE HEART OF THE SYSTEM APPROACHES THE AREA.
INITIALIZATION HANDLED THIS WELL AND ONLY A FEW MINOR TWEAKS WERE
REQUIRED.

TEMPS INITIALIZED WELL AND SHOULD BE GRADUALLY COOLING BACK DOWN
TO NEAR OR JUST SLIGHTLY BELOW NORMAL VALUES BY LATE IN THE WEEK
AS COOLER AIR MOVES INTO THE AREA ON THE BACK SIDE OF THE LOW.

&&

.AVIATION /DISCUSSION FOR THE 18/09Z TAF UPDATE/...
ISSUED AT 420 AM EDT SAT MAY 18 2013

FOG HAS BEEN SLOW TO DEVELOP SAVE FOR LAF WHERE CLEARING HAS
OCCURRED. LAF DOWN TO 1SM AND MAY GO LOWER...BUT WILL KEEP 1SM AS
THE LOWEST FOR NOW AND MONITOR. OTHERWISE...HAVE AMENDED IND/HUF/BMG
TO VFR/TEMPO MVFR FOR THE REMAINDER OF THE NIGHT. MAY NEED
ADDITIONAL AMENDMENTS FOR LOWER CONDITIONS IF MORE CLEARING
OCCURS...BUT THIS APPEARS UNLIKELY AT THE MOMENT. PREVIOUS
DISCUSSION FOLLOWS.

ISSUED AT 1241 AM EDT SAT MAY 18 2013

UPPER TROUGH WILL MOVE EAST ACROSS SOUTHERN INDIANA TONIGHT AND
SATURDAY MORNING. WOULD NOT RULE OUT ISOLATED SHOWERS OVERNIGHT AND
ISOLATED TO SCATTERED THUNDERSTORMS AFTER 15Z AS NORTHWEST FLOW
ALOFT DRAWS THE QUASI-STATIONARY SURFACE FRONT SOUTH TO NEAR A
BMG-HUF LINE BY 12Z AND SOUTH OF THE TERMINALS BY 00Z...AND MODELS
SHOW PLENTY OF INSTABILITY. HOWEVER...NO MAJOR FORCING...SO WILL GO
DRY UNTIL 15Z AND THEN VCTS FROM 15Z-20Z AT LAF AND HUF AND 22Z AT
IND AND BMG.

STILL COULD SEE SOME MVFR OR WORSE FOG AND OR CEILINGS AFTER
08Z...BUT IF THICK AC CAN HANG AROUND...IT COULD PREVENT THAT.
CONFIDENCE MEDIUM TO LOW ON MVFR OR WORSE CONDITIONS 08Z-13Z.

LIGHT TO CALM EAST AND SOUTHEAST WINDS TONIGHT SHOULD BE MOSTLY EAST
ON SATURDAY TO THE NORTH OF THE FRONT ESPECIALLY AT IND AND LAF. HUF
AND BMG MAY NOT SEE A WIND SHIFT UNTIL AFTERNOON. AT ANY
RATE...WINDS SHOULD BE LESS THAN 10 KNOTS DURING THE DAYTIME AND
LIGHT TO CALM AT NIGHT.

&&

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

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....NIELD
AVIATION...MK/NIELD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 180818
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
418 AM EDT SAT MAY 18 2013

.SYNOPSIS...
ISSUED AT 220 AM EDT SAT MAY 18 2013

A FRONT WILL REMAIN OVER THE REGION TODAY...BRINGING A CHANCE FOR
THUNDERSTORMS TO MAINLY SOUTHERN PORTIONS OF THE AREA. AFTER A
BREAK FROM THE SHOWERS AND STORMS SUNDAY... MORE RAIN IS EXPECTED
MONDAY THROUGH WEDNESDAY AS MOISTURE FLOW INTO THE AREA INCREASES
AND AS UPPER LEVEL DISTURBANCES MOVE OVER THE AREA. TEMPERATURES
WILL BE ABOVE NORMAL FROM THE MID 70S TO THE MID 80S AND LOWS IN
THE 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EDT SAT MAY 18 2013


A VERY TIGHT MOISTURE GRADIENT CONTINUED OVER THE AREA AGAIN
TODAY...WITH DEW POINTS IN THE 30S NORTH OF THE BOUNDARY TO LOWER
60S FARTHER SOUTH. GIVEN VERY WEAK SYNOPTIC SCALE FORCING AND LIGHT
WIND PROFILES...INCLUDING WIND GENERALLY AROUND OR UNDER 20 KNOTS
INTO THE UPPER LEVELS...CURRENT THINKING SHOWERS AND ISOLATED STORMS
WILL BE HIGHLY DIURNAL TODAY...INCLUDING LATE AFTERNOON AND EARLY
EVENING. CAPE VALUES SHOULD REMAIN VERY LIMITED AND CONVECTION
SHOULD BE MAINLY CONFINED TO THE MUCH HIGHER SFC THETA E AREAS ALONG
AND SOUTH OF THE FRONT. RAISED HIGHS A LITTLE TODAY GIVEN VERY LARGE
DIURNAL TEMPERATURE SWINGS EXPECTED TODAY...ESPECIALLY NORTH OF THE
BOUNDARY. NCEP MOS GUIDANCE FOR HIGHS HAS BEEN RUNNING 2 TO 4
DEGREES TOO COOL.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 416 AM EDT SAT MAY 18 2013

STRONG PACIFIC JET CURRENTLY CRASHING INTO THE WESTERN CONUS WILL
CARVE OUT A VERY LARGE BAROTROPIC LOW PRESSURE SYSTEM EAST OF THE
ROCKIES BY EARLY NEXT WEEK. THE GRADUAL EASTWARD PROGRESSION OF THIS
FEATURE WILL BRING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
TO THE LOCAL FORECAST AREA THROUGH MIDWEEK. BEGINNING WITH SUNDAY
THOUGH...MIDLEVEL RIDGE AXIS DIRECTLY OVER THE GREAT LAKES MAKES FOR
A SOMEWHAT PRECARIOUS PRECIP FORECAST. LOW LEVEL WINDS BEGIN TO VEER
TO A MORE SOUTHERLY DIRECTION DURING THIS TIME...ADVECTING MORE
WARM/MOIST AIR INTO THE REGION. LATEST MOS GUIDANCE SUPPORTS HIGHS
SOLIDLY IN THE MID 80S WITH DEWPOINTS CREEPING INTO THE LOW TO MID
60S. NAM AND GFS MLCAPE FIELDS/FORECAST SOUNDINGS CONTINUE TO SHOW A
MODERATELY UNSTABLE AND WEAKLY CAPPED ENVIRONMENT...THANKS TO STRONG
SOLAR INSOLATION AND INCREASING LOW LEVEL THETA-E ADVECTION.
HOWEVER...WITH THE LACK OF ANY SYNOPTIC SCALE LIFTING MECHANISM...
CONVECTION WILL BE RELIANT ON INEFFICIENT PBL MIXING TO REACH THE
LFC. ALSO...GIVEN PLACEMENT AND EVOLUTION OF RIDGING ALOFT...EXPECT
THE CAP MAY BE A BIT STRONGER THAN WHAT CURRENT BUFR SOUNDINGS
INDICATE. Q VECTOR DIVERGENCE FIELDS SHOW WEAKLY SUBSIDENT AIR MASS
THAT WILL LIKELY INHIBIT CONVECTION. RELATIVELY DRY TROPOSPHERIC
COLUMN SHOULD ALSO TEND TO INHIBIT EXPANDING CONVECTION. ALL OF THAT
BEING SAID...WOULDNT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM
BUT COVERAGE WILL BE VERY LIMITED AND DECIDED TO CUT POPS TO AROUND
10 PERCENT AND REMOVE BLANKET SLIGHT CHANCE WORDING.

SOUTHWESTERLY LLJ BEGINS TO RAMP UP SUNDAY NIGHT AND MONDAY AS THE
APPROACHING MIDLEVEL HEIGHT ANOMALY FORCES A TIGHTENING OF THE LOW
LEVEL GRADIENT. WARM FRONT BEGINS TO REALLY TAKE SHAPE AND LIFT
NORTH SUNDAY NIGHT AS THE RIDGE AXIS SHIFTS EAST. ASSOCIATED
ISENTROPIC ASCENT AND MOISTURE FLUX CONVERGENCE IN REGION OF MODEST
ELEVATED INSTABILITY COULD SPARK OFF A FEW
SHOWERS/THUNDERSTORMS...BUT AGAIN COVERAGE WILL BE LIMITED. CWA WILL
BE FIRMLY IN THE WARM SECTOR BY MONDAY AFTERNOON. 850MB TEMPS LOOK
TO CLIMB TO AROUND 17C...SUPPORTING HIGHS IN THE MID TO UPPER 80S
WITH DEWPOINTS IN THE MID TO UPPER 60S. PRECIP CHANCES WILL HINGE ON
EXACT TIMING OF APPROACHING TROUGH AND ASSOCIATED WEAKENING OF THE
CAPPING INVERSION. LATEST 00Z GFS IS MUCH SLOWER THAN ITS NAM AND
ECMWF COUNTERPARTS AND MAINTAINS A PREDOMINATELY DRY FORECAST.
SYMPATHETIC TO A SLOWER SOLUTION GIVEN OVERALL PATTERN BUT
CONFIDENCE TOO LOW TO MAKE SIGNIFICANT ADJUSTMENTS TO POPS AT THIS
TIME AND WILL GO WITH LOW CHANCE WORDING. IF CONVECTION DOES
OCCUR...SEVERE WEATHER IS A DISTINCT POSSIBILITY GIVEN STRONG
INSTABILITY AND MODERATE SHEAR PROFILES. AS SUCH...SPC HAS PLACED
OUR CWA IN DAY3 SLIGHT RISK TO COVER THIS CONDITIONAL THREAT.

MUCH BETTER PRECIP CHANCES EXPECTED TUES AND WED AS VERTICALLY
STACKED LOW APPROACHES AND LOW LEVEL MOISTURE ADVECTION CONTINUES.
EXPECT SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WITH EXACT TIMING
DEPENDENT ON EVOLUTION OF FRONTAL FEATURES AS WELL AS POTENTIALLY
MEDDLESOME MCS DEVELOPMENT. SEVERE WEATHER REMAINS POSSIBLE DURING
THIS TIME BUT WEAKENING DYNAMICS ALOFT AND INCREASINGLY STABLE
AIRMASS DOES NOT BODE WELL. A FEW LINGERING SHOWERS ARE POSSIBLE ON
THURSDAY BUT 1030 MB CANADIAN SURFACE HIGH IS EXPECTED TO BUILD OVER
THE GREAT LAKES BY THE END OF THE WEEK. THIS SHOULD RESULT IN A
PLEASANT...ALBEIT COOL...MEMORIAL DAY WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 416 AM EDT SAT MAY 18 2013

AN EAST FETCH OF VERY DRY AIR FROM CANADA HAS CAUSED A VERY TIGHT
MOISTURE GRADIENT JUST SOUTH OF THE TERMINALS NEAR THE START OF THE
TAF FCST PERIOD. KEPT FOG OUT OF THE TAFS GIVEN DRY AIR ADVECTION
AND GIVEN ONGOING TEMP/DEW PTS SPREADS OF 20 TO 25 DEGREES AT BOTH
SBN AND FWA. THERE IS AN OUTSIDE CHANCE FOR A MAINLY LATE AFTERNOON
SHOWER AS TIGHT MOISTURE GRADIENT MOVES NORTH LATER
TODAY...HOWEVER...FOR NOW KEPT RAIN OUT OF THE TAFS WITH VFR
CONDITIONS.


&&

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

$$

SYNOPSIS...SKIPPER
SHORT TERM...SKIPPER
LONG TERM...AGD
AVIATION...SKIPPER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIWX 180645
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
245 AM EDT SAT MAY 18 2013

.SYNOPSIS...
ISSUED AT 220 AM EDT SAT MAY 18 2013

A FRONT WILL REMAIN OVER THE REGION TODAY...BRINGING A CHANCE FOR
THUNDERSTORMS TO MAINLY SOUTHERN PORTIONS OF THE AREA. AFTER A
BREAK FROM THE SHOWERS AND STORMS SUNDAY... MORE RAIN IS EXPECTED
MONDAY THROUGH WEDNESDAY AS MOISTURE FLOW INTO THE AREA INCREASES
AND AS UPPER LEVEL DISTURBANCES MOVE OVER THE AREA. TEMPERATURES
WILL BE ABOVE NORMAL FROM THE MID 70S TO THE MID 80S AND LOWS IN
THE 60S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

CONVECTION WAS BEGINNING TO FIRE THIS AFTERNOON ACROSS PORTIONS OF
CENTRAL INDIANA...FROM MARION TO LOGANSPORT AND POINTS SOUTHWARD.
THIS INITIAL LINE OF CONVECTION ACROSS OUR SOUTHERN FCST AREA IS
ASSOCIATED WITH AN AREA OF WEAK 925MB TO 850MB FRONTAL LIFT...WITH
THE BOUNDARY ORIENTED FROM NNW TO SE ACROSS THE AREA. COVERAGE
EXPECTED TO REMAIN ISOLATED INITIALLY...WITH MARGINAL LAPSE RATES
AND WEAK FLOW INHIBITING MORE ORGANIZED CONVECTION. DEWPOINTS
QUICKLY DROP FROM THE LOW 60S ACROSS SOUTHERN AREAS TO THE LOWER 40S
ACROSS THE NORTHEAST PORTION OF THE FORECAST AREA...WHICH WILL LIMIT
MUCH NORTHWARD EXTENT OF PRECIPITATION CHANCES THIS AFTERNOON.

MORE ORGANIZED CONVECTION HAS DEVELOPED NEAR INDIANAPOLIS AND POINTS
NORTHWESTWARD...IN AN AREA OF HIGHER DEWPOINTS AND SLIGHTLY MORE
INSTABILITY. PER HRRR/SPC 4KM WRF GUIDANCE...THIS ACTIVITY IS
EXPECTED TO LIFT NORTHWARD INTO THE SOUTHERN AND WESTERN PORTION OF
THE AREA THIS EVENING INTO THE OVERNIGHT. PRECIP ACTIVITY IS
EXPECTED TO QUICKLY WANE WITH THE LOSS OF DAYTIME HEATING...SO
DROPPED POPS SIGNIFICANTLY TOWARD MIDNIGHT AND AFTER. KEPT POPS
UNDER 40 PERCENT THROUGH THE EVENING WITH COVERAGE WORDING...AS
DRIER SURFACE AIRMASS...MARGINAL LAPSE RATES AND WANING INSTABILITY
SHOULD RESULT IN WEAKENING PRECIPITATION AS IT ADVECTS INTO THE
AREA.

NOT MUCH CHANGE TO TEMPERATURES OVERNIGHT. LATEST GUIDANCE SUGGESTS
LOWS NEAR 50 ACROSS A GOOD PORTION OF THE NORTHEAST FORECAST AREA.
NOT OUT OF THE QUESTION WITH EASTERLY FLOW OFF LAKE ERIE AND DRY
AIRMASS...HOWEVER EXPECTED MID/HIGH CLOUDS SHOULD PREVENT TEMPS FROM
SUCH A DROP OFF...SO COMPROMISED WITH LOWER TEMPS SLIGHTLY BUT
STAYING ABOVE GUIDANCE.

FRONTAL BOUNDARY EXPECTED TO LINGER FROM WEST TO EAST ACROSS THE
AREA AGAIN TOMORROW. SIMILAR SETUP EXPECTED...WITH AFTERNOON
INSTABILITY LEADING TO SMALL PRECIPITATION CHANCES. ALTHOUGH MODEL
SBCAPE VALUES OF 1500 J/KG ARE EXPECTED TOMORROW...LACK OF
FLOW...WEAK FORCING AND POOR LAPSE RATES SHOULD LIMIT WIDESPREAD
PRECIPITATION CHANCES. KEPT HIGHEST CHANCES ACROSS SOUTHEAST AREAS
IN THE AFTERNOON...IN CLOSEST VICINITY OF SUBTLE MID LVL IMPULSE AND
HIGHEST MOISTURE/INSTABILITY VALUES.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

FCST PERIOD TO BEGIN MAINLY DRY AS 500MB RIDGE MOVES OVER THE AREA.
FLOW WILL BECOME MORE SOUTHERLY DURING THE DAY SUNDAY AND BRING
INCREASING HUMIDITY AS DEWPOINTS RISE TO THE L-M60S. THIS WILL
RESULT IN INCREASING INSTABILITY DURING THE AFTERNOON HOURS AND
STEEPENING LOW LEVEL LAPSE RATES...BUT IN A WEAK FLOW POORLY FORCED
ENVIRONMENT...SO WILL CONTINUE WITH JUST SLIGHT CHANCE WORDING ON
SUNDAY. DECENT MID-UPPER JET DYNAMICS WILL ROUND THE BASE OF THE
UPPER TROF IN THE PLAINS AND SHOULD PROVIDE NEEDED FORCING FOR
NOCTURNAL CONVECTION IN THE MID MS VALLEY SUNDAY NIGHT. PLENTY OF
ELEVATED INSTABILITY WILL BE PRESENT OVER THE CWA WITH CAPES AOA
2000J/KG. STAUNCH THICKNESS RIDGE AND NO INDICATION OF BREAKDOWN IN
THE MID LEVEL RIDGE SHOULD KEEP MOST OF THE CONVECTION WEST OF OUR
AREA BUT WILL STILL CONTINUE WITH SLIGHT CHANCE OVER WESTERN TWO
THIRDS. ANOTHER DAY OF DIURNALLY DRIVEN CONVECTION POSSIBLE ON
MONDAY AS AREA WILL SIT IN AN UNSTABLE AND RELATIVELY UNCAPPED WARM
SECTOR THAT WILL BE AIDED BY INCREASING LOW-MID LEVEL FLOW. FOCUS
THEN SHIFTS TO ARRIVAL...FINALLY...OF VERTICALLY STACKED SYSTEM
TUE-THU. THIS SYSTEM EXPECTED TO BE WEAKENING AS IT MOVES INTO THE
AREA WITH SFC REFLECTION BECOMING QUASI-STATIONARY WED-THU
TIMEFRAME. THIS WILL EXTEND PRECIP CHANCES THROUGH THE DAY THURSDAY
BEFORE FINALLY CLEARING OUT AND MAKING WAY FOR A COOLER DRIER
CANADIAN HIGH PRESSURE SYSTEM TO SETTLE INTO THE GREAT LAKES REGION
BEGINNING FRIDAY...AND HOPEFULLY LEAD TO A PLEASANT MEMORIAL DAY
WEEKEND. GENERALLY FAVORED WARMER TEMPS MAX AND MIN FOR SUN/MON AS
POTENT LOW LEVEL THERMAL RIDGE NUDGES INTO THE REGION AND INCREASING
HUMIDITY TO KEEP NIGHT TIME LOWS TRENDING WARMER. COOLER MORE
SEASONABLE TEMPS BY THE END OF THE PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 240 AM EDT SAT MAY 18 2013

AN EAST FETCH OF VERY DRY AIR FROM CANADA HAS CAUSED A VERY TIGHT
MOISTURE GRADIENT JUST SOUTH OF THE TERMINALS NEAR THE START OF
THE TAF FCST PERIOD. KEPT FOG OUT OF THE TAFS GIVEN DRY AIR
ADVECTION AND GIVEN ONGOING TEMP/DEW PTS SPREADS OF 20 TO 25
DEGREES AT BOTH SBN AND FWA. THERE IS AN OUTSIDE CHANCE FOR A
MAINLY LATE AFTERNOON SHOWER AS TIGHT MOISTURE GRADIENT MOVES
NORTH LATER TODAY...HOWEVER...FOR NOW KEPT RAIN OUT OF THE TAFS
WITH VFR CONDITIONS.

&&

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

$$

SYNOPSIS...SKIPPER
SHORT TERM...NG
LONG TERM...JAL
AVIATION...SKIPPER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 180629
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
229 AM EDT SAT MAY 18 2013

.UPDATE...

THE LONG TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 143 AM EDT SAT MAY 18 2013

A WEAK AREA OF LOW PRESSURE WILL DRIFT INTO THE OHIO VALLEY AND
ACROSS SOUTHERN INDIANA. THIS WILL BRING CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS
THE AREA ON SUNDAY. EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER
THE WESTERN HALF OF THE COUNTRY INTO THE WEEKEND WHICH WILL BRING
WARMER AIR FOR MUCH OF NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF
STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /TODAY/...
ISSUED AT 143 AM EDT SAT MAY 18 2013

MODELS DEPICT A WEAK UPPER LOW PUSHING THROUGH THE OHIO VALLEY AND
SOUTHERN INDIANA...THEN EXITING THE AREA BY LATE THIS AFTERNOON.
APPEARS WEAK FORCING ASSOCIATED WITH THE S/WV AND DAYTIME HEATING
WILL BE THE MAIN FORCING MECHANISMS FOR CONVECTIVE DEVELOPMENT.
GUIDANCE IS SHOWING CHANCES FOR THIS ACTIVITY ALL ACROSS THE
FORECAST AREA...WITH BEST CHANCES SOUTH OF I-70...BUT NOT LIMITED TO
THIS AREA. BUMPED UP POPS AND TRENDED TEMPS AT OR SLIGHTLY ABOVE MOS
DESPITE CLOUD COVER AND PRECIP CHANCES WE SHOULD EASILY BE ABLE TO
ACHIEVE TEMPS RANGING FROM UPPER 70S TO AROUND 80.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 143 AM EDT SAT MAY 18 2013

DRIER AIR WILL QUICKLY BE INFILTRATING BACK INTO THE AREA BY THIS
EVENING...NOT BEFORE A FEW SHOWERS EXIT THE REGION TO THE EAST. WEAK
RIDGING BUILDS BACK OVER THE AREA TONIGHT AND SKIES WILL ATTEMPT TO
CLEAR OUT...BUT SOME MID TO HIGH LEVEL CLOUDS WILL REMAIN. POSSIBLY
SOME PATCHY FOG EARLY SUNDAY MORNING. WILL CONTINUE WITH A DRY
FORECAST STARTING LATE TONIGHT THROUGH EARLY MONDAY. 850 MB TEMPS
STILL LOOK QUITE WARM BY EARLY NEXT WEEK. LOOK FOR HIGH TEMPS IN THE
MID 80S BOTH SUNDAY AND MONDAY. MODELS ARE IN A BIT OF A
DISAGREEMENT WITH REGARD TO THE TIMING OF THE NEXT SYSTEM. FOR NOW
HAVE INTRODUCED SLIGHT CHANCE TO LOW CHANCE POPS STARTING MONDAY
AFTERNOON AND MONDAY NIGHT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 229 AM EDT SAT MAY 18 2013

LONG TERM CONTINUES TO BE DOMINATED BY ONE MAIN SURFACE AND UPPER
LEVEL LOW MOVING EXTREMELY SLOWLY FROM THE NORTHERN PLAINS/UPPER
MIDWEST INTO THE OHIO VALLEY AND THE MIDATLANTIC STATES THROUGH
THE COMING WEEK. BROAD SOUTHWEST FLOW MOVING WARM MOIST AIR INTO
THE AREA WILL MERIT AT LEAST CHANCE POPS MOST ALL PERIODS THROUGH
THE LATE PORTION OF THE WEEK...WITH SOME LIKELIES LATE TUESDAY
INTO WEDNESDAY AS THE HEART OF THE SYSTEM APPROACHES THE AREA.
INITIALIZATION HANDLED THIS WELL AND ONLY A FEW MINOR TWEAKS WERE
REQUIRED.

TEMPS INITIALIZED WELL AND SHOULD BE GRADUALLY COOLING BACK DOWN
TO NEAR OR JUST SLIGHTLY BELOW NORMAL VALUES BY LATE IN THE WEEK
AS COOLER AIR MOVES INTO THE AREA ON THE BACK SIDE OF THE LOW.

&&

.AVIATION /DISCUSSION FOR THE 18/06Z TAFS/...
ISSUED AT 1241 AM EDT SAT MAY 18 2013

UPPER TROUGH WILL MOVE EAST ACROSS SOUTHERN INDIANA TONIGHT AND
SATURDAY MORNING. WOULD NOT RULE OUT ISOLATED SHOWERS OVERNIGHT AND
ISOLATED TO SCATTERED THUNDERSTORMS AFTER 15Z AS NORTHWEST FLOW
ALOFT DRAWS THE QUASI-STATIONARY SURFACE FRONT SOUTH TO NEAR A
BMG-HUF LINE BY 12Z AND SOUTH OF THE TERMINALS BY 00Z...AND MODELS
SHOW PLENTY OF INSTABILITY. HOWEVER...NO MAJOR FORCING...SO WILL GO
DRY UNTIL 15Z AND THEN VCTS FROM 15Z-20Z AT LAF AND HUF AND 22Z AT
IND AND BMG.

STILL COULD SEE SOME MVFR OR WORSE FOG AND OR CEILINGS AFTER
08Z...BUT IF THICK AC CAN HANG AROUND...IT COULD PREVENT THAT.
CONFIDENCE MEDIUM TO LOW ON MVFR OR WORSE CONDITIONS 08Z-13Z.

LIGHT TO CALM EAST AND SOUTHEAST WINDS TONIGHT SHOULD BE MOSTLY EAST
ON SATURDAY TO THE NORTH OF THE FRONT ESPECIALLY AT IND AND LAF. HUF
AND BMG MAY NOT SEE A WIND SHIFT UNTIL AFTERNOON. AT ANY
RATE...WINDS SHOULD BE LESS THAN 10 KNOTS DURING THE DAYTIME AND
LIGHT TO CALM AT NIGHT.

&&

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

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....NIELD
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 180544
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
144 AM EDT SAT MAY 18 2013

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

&&

.SYNOPSIS...

ISSUED AT 143 AM EDT SAT MAY 18 2013

A WEAK AREA OF LOW PRESSURE WILL DRIFT INTO THE OHIO VALLEY AND
ACROSS SOUTHERN INDIANA. THIS WILL BRING CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS
THE AREA ON SUNDAY. EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER
THE WESTERN HALF OF THE COUNTRY INTO THE WEEKEND WHICH WILL BRING
WARMER AIR FOR MUCH OF NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF
STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /TODAY/...

ISSUED AT 143 AM EDT SAT MAY 18 2013

MODELS DEPICT A WEAK UPPER LOW PUSHING THROUGH THE OHIO VALLEY AND
SOUTHERN INDIANA...THEN EXITING THE AREA BY LATE THIS AFTERNOON.
APPEARS WEAK FORCING ASSOCIATED WITH THE S/WV AND DAYTIME HEATING
WILL BE THE MAIN FORCING MECHANISMS FOR CONVECTIVE DEVELOPMENT.
GUIDANCE IS SHOWING CHANCES FOR THIS ACTIVITY ALL ACROSS THE
FORECAST AREA...WITH BEST CHANCES SOUTH OF I-70...BUT NOT LIMITED TO
THIS AREA. BUMPED UP POPS AND TRENDED TEMPS AT OR SLIGHTLY ABOVE MOS
DESPITE CLOUD COVER AND PRECIP CHANCES WE SHOULD EASILY BE ABLE TO
ACHIEVE TEMPS RANGING FROM UPPER 70S TO AROUND 80.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

ISSUED AT 143 AM EDT SAT MAY 18 2013

DRIER AIR WILL QUICKLY BE INFILTRATING BACK INTO THE AREA BY THIS
EVENING...NOT BEFORE A FEW SHOWERS EXIT THE REGION TO THE EAST. WEAK
RIDGING BUILDS BACK OVER THE AREA TONIGHT AND SKIES WILL ATTEMPT TO
CLEAR OUT...BUT SOME MID TO HIGH LEVEL CLOUDS WILL REMAIN. POSSIBLY
SOME PATCHY FOG EARLY SUNDAY MORNING. WILL CONTINUE WITH A DRY
FORECAST STARTING LATE TONIGHT THROUGH EARLY MONDAY. 850 MB TEMPS
STILL LOOK QUITE WARM BY EARLY NEXT WEEK. LOOK FOR HIGH TEMPS IN THE
MID 80S BOTH SUNDAY AND MONDAY. MODELS ARE IN A BIT OF A
DISAGREEMENT WITH REGARD TO THE TIMING OF THE NEXT SYSTEM. FOR NOW
HAVE INTRODUCED SLIGHT CHANCE TO LOW CHANCE POPS STARTING MONDAY
AFTERNOON AND MONDAY NIGHT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 220 PM EDT FRI MAY 17 2013

ENSEMBLES ARE COMING INTO BETTER AGREEMENT TODAY WITH RESPECT TO THE
EVOLVING WEATHER PATTERN NEXT WEEK. MAIN FEATURE DURING THIS PERIOD
WILL BE AN UPPER LOW THAT IS EXPECTED TO MOVE SLOWLY EAST FROM THE
PLAINS...CROSSING THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK.
ENSEMBLES SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE ON
TUESDAY AND WEDNESDAY...SO WILL GO WITH HIGHER POPS AT THOSE TIMES.
SOME OF THE SLOWER MEMBERS LINGER A PRECIPITATION THREAT INTO
THURSDAY...SO WILL GO WITH CHANCE POPS AT THAT TIME.

MOST THE ENSEMBLES NOW AGREE THAT THE UPPER TROUGH SHOULD BE EAST OF
THE AREA BY NEXT FRIDAY...WITH A STRONG UPPER RIDGE BUILDING INTO
THE PLAINS AND MIDWEST. WILL GO DRY FOR NEXT FRIDAY.

&&

.AVIATION /DISCUSSION FOR THE 18/06Z TAFS/...
ISSUED AT 1241 AM EDT SAT MAY 18 2013

UPPER TROUGH WILL MOVE EAST ACROSS SOUTHERN INDIANA TONIGHT AND
SATURDAY MORNING. WOULD NOT RULE OUT ISOLATED SHOWERS OVERNIGHT AND
ISOLATED TO SCATTERED THUNDERSTORMS AFTER 15Z AS NORTHWEST FLOW
ALOFT DRAWS THE QUASI-STATIONARY SURFACE FRONT SOUTH TO NEAR A
BMG-HUF LINE BY 12Z AND SOUTH OF THE TERMINALS BY 00Z...AND MODELS
SHOW PLENTY OF INSTABILITY. HOWEVER...NO MAJOR FORCING...SO WILL GO
DRY UNTIL 15Z AND THEN VCTS FROM 15Z-20Z AT LAF AND HUF AND 22Z AT
IND AND BMG.

STILL COULD SEE SOME MVFR OR WORSE FOG AND OR CEILINGS AFTER
08Z...BUT IF THICK AC CAN HANG AROUND...IT COULD PREVENT THAT.
CONFIDENCE MEDIUM TO LOW ON MVFR OR WORSE CONDITIONS 08Z-13Z.

LIGHT TO CALM EAST AND SOUTHEAST WINDS TONIGHT SHOULD BE MOSTLY EAST
ON SATURDAY TO THE NORTH OF THE FRONT ESPECIALLY AT IND AND LAF. HUF
AND BMG MAY NOT SEE A WIND SHIFT UNTIL AFTERNOON. AT ANY
RATE...WINDS SHOULD BE LESS THAN 10 KNOTS DURING THE DAYTIME AND
LIGHT TO CALM AT NIGHT.


&&

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

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 180441
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1241 AM EDT SAT MAY 18 2013

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 220 PM EDT FRI MAY 17 2013

A WEAK AREA OF LOW PRESSURE OVER SOUTHEAST MISSOURI WILL DRIFT INTO
THE OHIO VALLEY TONIGHT AND ACROSS SOUTHERN INDIANA ON SATURDAY.
THIS WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN PARTS OF STATE TONIGHT AND SATURDAY.

A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON
SUNDAY...HOWEVER WITH A CONTINUED WARM AND HUMID AIR MASS IN PLACE
AN ISOLATED SHOWER OR STORM CANNOT BE RULED OUT ON SUNDAY.

EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER THE WESTERN HALF OF
THE COUNTRY INTO THE WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF
NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY
INTO MID WEEK.

&&

.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1007 PM EDT FRI MAY 17 2013

ONLY SCATTERED SHOWERS REMAIN ACROSS THE FORECAST AREA AS PREVIOUS
CONVECTION HAS MODIFIED THE ATMOSPHERE. THERE REMAINS SOME LINGERING
INSTABILITY ACROSS THE NORTHWEST FORECAST AREA...BUT RECENT TRENDS
SHOW CONVECTION THERE IS WEAKENING TOO.

WEAK UPPER TROUGH WILL CONTINUE TO GENERATE SOME SCATTERED SHOWERS
TONIGHT. WATER VAPOR SATELLITE SHOWS SOME UPPER ENERGY ACROSS
ILLINOIS THAT WILL MOVE INTO THE AREA LATER TONIGHT AS WELL. THUS
FEEL THAT LOW POPS SHOULD CONTINUE THROUGH THE NIGHT. HOWEVER HAVE
REMOVED THUNDER MENTION WITH LOSS OF MOST INSTABILITY.

CLOUDS WILL REMAIN ACROSS MUCH OF THE AREA OVERNIGHT WITH THE UPPER
TROUGH...HOWEVER THERE WILL BE SOME BREAKS AS CAN BE CURRENTLY SEEN
IN SATELLITE IMAGERY. THESE BREAKS SHOULD ALLOW SOME PATCHY FOG TO
FORM DUE TO THE RAIN TODAY. THUS HAVE ADDED PATCHY FOG TO THE
FORECAST.

ONLY MADE MINOR TWEAKS TO TEMPERATURES.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 220 PM EDT FRI MAY 17 2013

MAIN FORECAST CHALLENGE WILL BE POPS

GFS AND NAM SUGGEST A WEAK UPPER LOW PUSHING THROUGH THE OHIO
VALLEY AND SOUTHERN INDIANA SATURDAY AND EXITING THE AREA BY LATE
SATURDAY AFTERNOON. FORECAST SOUNDINGS INDICATE THAT BEST DRYING
DOES NOT ARRIVE UNTIL TOWARD 00Z. TIME HEIGHTS MEANWHILE KEEP A
VERY MOIST AIR MASS IN PLACE ACROSS THE AREA ALONG WITH WEAK
SUBSIDENCE ALOFT. LOWER LEVEL Q VECTORS ALSO INDICATE DIVERGENCE.
THUS ONLY WEAK FORCING ASSOCIATED WITH THE SHORT WAVE AND DAYTIME
HEATING WILL BE OUR TRIGGERING MECHANISMS. BEST FORCING IN THIS
REGARD WILL BE FOUND ACROSS THE SOUTHERN PARTS OF THE FORECAST
AREA THUS WILL ONLY RAISE POPS ACROSS THOSE SPOTS DURING THE DAY
ON SATURDAY. FARTHER NORTH WILL TREND POPS AT OR BELOW MAVMOS AND
ALSO TREND POPS LOWER AS THE LATE AFTERNOON PROGRESSES AS THE
UPPER LOW DEPARTS. WILL TREND HIGHS AT OR BELOW MAVMOS GIVEN THE
EXPECTED CLOUDS AND POSSIBLE PRECIPITATION.

FORECAST SOUNDINGS ON SATURDAY NIGHT AND SUNDAY SHOW MUCH DRIER
AIR ARRIVING ACROSS CENTRAL INDIANA AS DEW POINTS FALL
DRAMATICALLY THROUGH THE COLUMN. THE PREVIOUSLY MENTIONED UPPER
LOW ALSO CONTINUES TO EXIT THE AREA AS WEAK RIDGING BUILDS ACROSS
THE AREA FOR SUNDAY.THUS WILL TREND TOWARD A DRY FORECAST FOR
SATURDAY NIGHT. ON SUNDAY FORECAST SOUNDING ARE NOW HINTING AT A
GOOD CAP IN PLACE AS 700MB TEMPS APPROACH 9-10C BY 00Z MONDAY. THUS
CONFIDENCE FOR A DRY FORECAST ON SUNDAY HAS GROWN. AS FOR TEMPS...A
BLEND WILL WORK NICELY.

GFS AND NAM CONTINUE TO SUGGEST STRONG RIDGING ALOFT OVER THE
REGION ON SUNDAY NIGHT AND MONDAY. MEANWHILE 850MB TEMPS CONTINUE
A SLOW CLIMB TOWARD 18C-20C BY 18Z MONDAY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE LOWER 90S WHICH MAY BE TOO WARM TO TRIGGER
ANY INITIATION. THUS WITHOUT STRONG DYNAMICS AVAILABLE A WARM
SUNDAY NIGHT AND A SUMMER LIKE MONDAY WILL BE EXPECTED. WILL TREND
BOTH LOWS AND HIGHS AT OR ABOVE MAVMOS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 220 PM EDT FRI MAY 17 2013

ENSEMBLES ARE COMING INTO BETTER AGREEMENT TODAY WITH RESPECT TO THE
EVOLVING WEATHER PATTERN NEXT WEEK. MAIN FEATURE DURING THIS PERIOD
WILL BE AN UPPER LOW THAT IS EXPECTED TO MOVE SLOWLY EAST FROM THE
PLAINS...CROSSING THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK.
ENSEMBLES SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE ON
TUESDAY AND WEDNESDAY...SO WILL GO WITH HIGHER POPS AT THOSE TIMES.
SOME OF THE SLOWER MEMBERS LINGER A PRECIPITATION THREAT INTO
THURSDAY...SO WILL GO WITH CHANCE POPS AT THAT TIME.

MOST THE ENSEMBLES NOW AGREE THAT THE UPPER TROUGH SHOULD BE EAST OF
THE AREA BY NEXT FRIDAY...WITH A STRONG UPPER RIDGE BUILDING INTO
THE PLAINS AND MIDWEST. WILL GO DRY FOR NEXT FRIDAY.

&&

.AVIATION /DISCUSSION FOR THE 18/06Z TAFS/...
ISSUED AT 1241 AM EDT SAT MAY 18 2013

UPPER TROUGH WILL MOVE EAST ACROSS SOUTHERN INDIANA TONIGHT AND
SATURDAY MORNING. WOULD NOT RULE OUT ISOLATED SHOWERS OVERNIGHT AND
ISOLATED TO SCATTERED THUNDERSTORMS AFTER 15Z AS NORTHWEST FLOW
ALOFT DRAWS THE QUASI-STATIONARY SURFACE FRONT SOUTH TO NEAR A
BMG-HUF LINE BY 12Z AND SOUTH OF THE TERMINALS BY 00Z...AND MODELS
SHOW PLENTY OF INSTABILITY. HOWEVER...NO MAJOR FORCING...SO WILL GO
DRY UNTIL 15Z AND THEN VCTS FROM 15Z-20Z AT LAF AND HUF AND 22Z AT
IND AND BMG.

STILL COULD SEE SOME MVFR OR WORSE FOG AND OR CEILINGS AFTER
08Z...BUT IF THICK AC CAN HANG AROUND...IT COULD PREVENT THAT.
CONFIDENCE MEDIUM TO LOW ON MVFR OR WORSE CONDITIONS 08Z-13Z.

LIGHT TO CALM EAST AND SOUTHEAST WINDS TONIGHT SHOULD BE MOSTLY EAST
ON SATURDAY TO THE NORTH OF THE FRONT ESPECIALLY AT IND AND LAF. HUF
AND BMG MAY NOT SEE A WIND SHIFT UNTIL AFTERNOON. AT ANY
RATE...WINDS SHOULD BE LESS THAN 10 KNOTS DURING THE DAYTIME AND
LIGHT TO CALM AT NIGHT.

&&

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

&&

$$

SYNOPSIS...PUMA
NEAR TERM...50
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 180220
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1020 PM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 220 PM EDT FRI MAY 17 2013

A WEAK AREA OF LOW PRESSURE OVER SOUTHEAST MISSOURI WILL DRIFT INTO
THE OHIO VALLEY TONIGHT AND ACROSS SOUTHERN INDIANA ON SATURDAY.
THIS WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN PARTS OF STATE TONIGHT AND SATURDAY.

A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON
SUNDAY...HOWEVER WITH A CONTINUED WARM AND HUMID AIR MASS IN PLACE
AN ISOLATED SHOWER OR STORM CANNOT BE RULED OUT ON SUNDAY.

EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER THE WESTERN HALF OF
THE COUNTRY INTO THE WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF
NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY
INTO MID WEEK.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 1007 PM EDT FRI MAY 17 2013

ONLY SCATTERED SHOWERS REMAIN ACROSS THE FORECAST AREA AS PREVIOUS
CONVECTION HAS MODIFIED THE ATMOSPHERE. THERE REMAINS SOME LINGERING
INSTABILITY ACROSS THE NORTHWEST FORECAST AREA...BUT RECENT TRENDS
SHOW CONVECTION THERE IS WEAKENING TOO.

WEAK UPPER TROUGH WILL CONTINUE TO GENERATE SOME SCATTERED SHOWERS
TONIGHT. WATER VAPOR SATELLITE SHOWS SOME UPPER ENERGY ACROSS
ILLINOIS THAT WILL MOVE INTO THE AREA LATER TONIGHT AS WELL. THUS
FEEL THAT LOW POPS SHOULD CONTINUE THROUGH THE NIGHT. HOWEVER HAVE
REMOVED THUNDER MENTION WITH LOSS OF MOST INSTABILITY.

CLOUDS WILL REMAIN ACROSS MUCH OF THE AREA OVERNIGHT WITH THE UPPER
TROUGH...HOWEVER THERE WILL BE SOME BREAKS AS CAN BE CURRENTLY SEEN
IN SATELLITE IMAGERY. THESE BREAKS SHOULD ALLOW SOME PATCHY FOG TO
FORM DUE TO THE RAIN TODAY. THUS HAVE ADDED PATCHY FOG TO THE
FORECAST.

ONLY MADE MINOR TWEAKS TO TEMPERATURES.


&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

MAIN FORECAST CHALLENGE WILL BE POPS

GFS AND NAM SUGGEST A WEAK UPPER LOW PUSHING THROUGH THE OHIO
VALLEY AND SOUTHERN INDIANA SATURDAY AND EXITING THE AREA BY LATE
SATURDAY AFTERNOON. FORECAST SOUNDINGS INDICATE THAT BEST DRYING
DOES NOT ARRIVE UNTIL TOWARD 00Z. TIME HEIGHTS MEANWHILE KEEP A
VERY MOIST AIR MASS IN PLACE ACROSS THE AREA ALONG WITH WEAK
SUBSIDENCE ALOFT. LOWER LEVEL Q VECTORS ALSO INDICATE DIVERGENCE.
THUS ONLY WEAK FORCING ASSOCIATED WITH THE SHORT WAVE AND DAYTIME
HEATING WILL BE OUR TRIGGERING MECHANISMS. BEST FORCING IN THIS
REGARD WILL BE FOUND ACROSS THE SOUTHERN PARTS OF THE FORECAST
AREA THUS WILL ONLY RAISE POPS ACROSS THOSE SPOTS DURING THE DAY
ON SATURDAY. FARTHER NORTH WILL TREND POPS AT OR BELOW MAVMOS AND
ALSO TREND POPS LOWER AS THE LATE AFTERNOON PROGRESSES AS THE
UPPER LOW DEPARTS. WILL TREND HIGHS AT OR BELOW MAVMOS GIVEN THE
EXPECTED CLOUDS AND POSSIBLE PRECIPITATION.

FORECAST SOUNDINGS ON SATURDAY NIGHT AND SUNDAY SHOW MUCH DRIER
AIR ARRIVING ACROSS CENTRAL INDIANA AS DEW POINTS FALL
DRAMATICALLY THROUGH THE COLUMN. THE PREVIOUSLY MENTIONED UPPER
LOW ALSO CONTINUES TO EXIT THE AREA AS WEAK RIDGING BUILDS ACROSS
THE AREA FOR SUNDAY.THUS WILL TREND TOWARD A DRY FORECAST FOR
SATURDAY NIGHT. ON SUNDAY FORECAST SOUNDING ARE NOW HINTING AT A
GOOD CAP IN PLACE AS 700MB TEMPS APPROACH 9-10C BY 00Z MONDAY. THUS
CONFIDENCE FOR A DRY FORECAST ON SUNDAY HAS GROWN. AS FOR TEMPS...A
BLEND WILL WORK NICELY.

GFS AND NAM CONTINUE TO SUGGEST STRONG RIDGING ALOFT OVER THE
REGION ON SUNDAY NIGHT AND MONDAY. MEANWHILE 850MB TEMPS CONTINUE
A SLOW CLIMB TOWARD 18C-20C BY 18Z MONDAY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE LOWER 90S WHICH MAY BE TOO WARM TO TRIGGER
ANY INITIATION. THUS WITHOUT STRONG DYNAMICS AVAILABLE A WARM
SUNDAY NIGHT AND A SUMMER LIKE MONDAY WILL BE EXPECTED. WILL TREND
BOTH LOWS AND HIGHS AT OR ABOVE MAVMOS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

ENSEMBLES ARE COMING INTO BETTER AGREEMENT TODAY WITH RESPECT TO THE
EVOLVING WEATHER PATTERN NEXT WEEK. MAIN FEATURE DURING THIS PERIOD
WILL BE AN UPPER LOW THAT IS EXPECTED TO MOVE SLOWLY EAST FROM THE
PLAINS...CROSSING THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK.
ENSEMBLES SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE ON
TUESDAY AND WEDNESDAY...SO WILL GO WITH HIGHER POPS AT THOSE TIMES.
SOME OF THE SLOWER MEMBERS LINGER A PRECIPITATION THREAT INTO
THURSDAY...SO WILL GO WITH CHANCE POPS AT THAT TIME.

MOST THE ENSEMBLES NOW AGREE THAT THE UPPER TROUGH SHOULD BE EAST OF
THE AREA BY NEXT FRIDAY...WITH A STRONG UPPER RIDGE BUILDING INTO
THE PLAINS AND MIDWEST. WILL GO DRY FOR NEXT FRIDAY.


&&

.AVIATION /DISCUSSION FOR THE 180300Z IND TAF UPDATE/...
ISSUED AT 1020 PM EDT FRI MAY 17 2013

NO CHANGES NEEDED TO TAF.

PREVIOUS DISCUSSION FOLLOWS...

ELONGATED UPPER WAVE ON THE FRONT SIDE OF AN UPPER TROUGH NEAR THE
INDIANA AND ILLINOIS BORDER WILL CONTINUE TO LIFT NORTHEAST AND
SHOULD BE NORTH OF LAF BY ISSUANCE TIME. WIDESPREAD BAND OF
THUNDERSTORMS WAS OCCURING JUST NORTH OF THE WAVE AND SHOULD REMAIN
THAT WAY...SO SHOULD NOT PRESENT A PROBLEM FOR ANY OF THE TAF SITES
AFTER 00Z. HOWEVER...ANOTHER WAVE WAS LIFTING NORTHEAST NEAR THE
OHIO RIVER AND SHOULD MOVE SOUTHEASTERN AND EAST CENTRAL INDIANA
OVERNIGHT. THIS FEATURE WAS CURRENTLY HELPING TO PRODUCE ISOLATED TO
SCATTERED SHOWERS ACROSS SOUTH CENTRAL INDIANA. WOULD NOT RULE A
SHOWER OR THUNDERSTORM AT IND AND BMG WITH THIS FEATURE...BUT
CHANCES APPEAR TOO LOW TO GO WITH ANYTHING MORE THAN VCSH OR VCTS
THROUGH JUST BEYOND SUNSET. BY 02Z...ALREADY MARGINAL INSTABILITY
SHOULD BE ABOUT SPENT. FOR THE REST OF THE NIGHT...WITH THE LOW
LEVELS OF THE ATMOSPHERE MOIST...AND LIGHT WINDS...SHOULD SEE AT
LEAST MVFR FOG AND OR CEILINGS AFTER 08Z...IMPROVING BACK TO VFR
AFTER 13Z SATURDAY. WOULD NOT RULE OUT A FEW MORE STORMS ON SATURDAY
AFTER 15Z AS THE UPPER TROUGH MOVES ACROSS...AND INSTABILITY ONCE
AGAIN INCREASES. IN ADDITION...FRONT JUST TO THE NORTH OF LAF COULD
SETTLE BACK SOUTH OVERNIGHT AS THE UPPER FLOW BECOMES NORTHWEST.
WINDS WILL CONTINUE TO 10 KNOTS OR LESS EXCEPT PERHAPS IN THE
THUNDERSTORMS. WINDS WILL SHIFT FROM SOUTHEAST TO EAST AFTER 06Z AS
THE FRONT SETTLES SOUTH OF THE TERMINALS.

&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...50
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 180207
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1007 PM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 220 PM EDT FRI MAY 17 2013

A WEAK AREA OF LOW PRESSURE OVER SOUTHEAST MISSOURI WILL DRIFT INTO
THE OHIO VALLEY TONIGHT AND ACROSS SOUTHERN INDIANA ON SATURDAY.
THIS WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN PARTS OF STATE TONIGHT AND SATURDAY.

A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON
SUNDAY...HOWEVER WITH A CONTINUED WARM AND HUMID AIR MASS IN PLACE
AN ISOLATED SHOWER OR STORM CANNOT BE RULED OUT ON SUNDAY.

EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER THE WESTERN HALF OF
THE COUNTRY INTO THE WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF
NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY
INTO MID WEEK.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 1007 PM EDT FRI MAY 17 2013

ONLY SCATTERED SHOWERS REMAIN ACROSS THE FORECAST AREA AS PREVIOUS
CONVECTION HAS MODIFIED THE ATMOSPHERE. THERE REMAINS SOME LINGERING
INSTABILITY ACROSS THE NORTHWEST FORECAST AREA...BUT RECENT TRENDS
SHOW CONVECTION THERE IS WEAKENING TOO.

WEAK UPPER TROUGH WILL CONTINUE TO GENERATE SOME SCATTERED SHOWERS
TONIGHT. WATER VAPOR SATELLITE SHOWS SOME UPPER ENERGY ACROSS
ILLINOIS THAT WILL MOVE INTO THE AREA LATER TONIGHT AS WELL. THUS
FEEL THAT LOW POPS SHOULD CONTINUE THROUGH THE NIGHT. HOWEVER HAVE
REMOVED THUNDER MENTION WITH LOSS OF MOST INSTABILITY.

CLOUDS WILL REMAIN ACROSS MUCH OF THE AREA OVERNIGHT WITH THE UPPER
TROUGH...HOWEVER THERE WILL BE SOME BREAKS AS CAN BE CURRENTLY SEEN
IN SATELLITE IMAGERY. THESE BREAKS SHOULD ALLOW SOME PATCHY FOG TO
FORM DUE TO THE RAIN TODAY. THUS HAVE ADDED PATCHY FOG TO THE
FORECAST.

ONLY MADE MINOR TWEAKS TO TEMPERATURES.


&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

MAIN FORECAST CHALLENGE WILL BE POPS

GFS AND NAM SUGGEST A WEAK UPPER LOW PUSHING THROUGH THE OHIO
VALLEY AND SOUTHERN INDIANA SATURDAY AND EXITING THE AREA BY LATE
SATURDAY AFTERNOON. FORECAST SOUNDINGS INDICATE THAT BEST DRYING
DOES NOT ARRIVE UNTIL TOWARD 00Z. TIME HEIGHTS MEANWHILE KEEP A
VERY MOIST AIR MASS IN PLACE ACROSS THE AREA ALONG WITH WEAK
SUBSIDENCE ALOFT. LOWER LEVEL Q VECTORS ALSO INDICATE DIVERGENCE.
THUS ONLY WEAK FORCING ASSOCIATED WITH THE SHORT WAVE AND DAYTIME
HEATING WILL BE OUR TRIGGERING MECHANISMS. BEST FORCING IN THIS
REGARD WILL BE FOUND ACROSS THE SOUTHERN PARTS OF THE FORECAST
AREA THUS WILL ONLY RAISE POPS ACROSS THOSE SPOTS DURING THE DAY
ON SATURDAY. FARTHER NORTH WILL TREND POPS AT OR BELOW MAVMOS AND
ALSO TREND POPS LOWER AS THE LATE AFTERNOON PROGRESSES AS THE
UPPER LOW DEPARTS. WILL TREND HIGHS AT OR BELOW MAVMOS GIVEN THE
EXPECTED CLOUDS AND POSSIBLE PRECIPITATION.

FORECAST SOUNDINGS ON SATURDAY NIGHT AND SUNDAY SHOW MUCH DRIER
AIR ARRIVING ACROSS CENTRAL INDIANA AS DEW POINTS FALL
DRAMATICALLY THROUGH THE COLUMN. THE PREVIOUSLY MENTIONED UPPER
LOW ALSO CONTINUES TO EXIT THE AREA AS WEAK RIDGING BUILDS ACROSS
THE AREA FOR SUNDAY.THUS WILL TREND TOWARD A DRY FORECAST FOR
SATURDAY NIGHT. ON SUNDAY FORECAST SOUNDING ARE NOW HINTING AT A
GOOD CAP IN PLACE AS 700MB TEMPS APPROACH 9-10C BY 00Z MONDAY. THUS
CONFIDENCE FOR A DRY FORECAST ON SUNDAY HAS GROWN. AS FOR TEMPS...A
BLEND WILL WORK NICELY.

GFS AND NAM CONTINUE TO SUGGEST STRONG RIDGING ALOFT OVER THE
REGION ON SUNDAY NIGHT AND MONDAY. MEANWHILE 850MB TEMPS CONTINUE
A SLOW CLIMB TOWARD 18C-20C BY 18Z MONDAY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE LOWER 90S WHICH MAY BE TOO WARM TO TRIGGER
ANY INITIATION. THUS WITHOUT STRONG DYNAMICS AVAILABLE A WARM
SUNDAY NIGHT AND A SUMMER LIKE MONDAY WILL BE EXPECTED. WILL TREND
BOTH LOWS AND HIGHS AT OR ABOVE MAVMOS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

ENSEMBLES ARE COMING INTO BETTER AGREEMENT TODAY WITH RESPECT TO THE
EVOLVING WEATHER PATTERN NEXT WEEK. MAIN FEATURE DURING THIS PERIOD
WILL BE AN UPPER LOW THAT IS EXPECTED TO MOVE SLOWLY EAST FROM THE
PLAINS...CROSSING THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK.
ENSEMBLES SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE ON
TUESDAY AND WEDNESDAY...SO WILL GO WITH HIGHER POPS AT THOSE TIMES.
SOME OF THE SLOWER MEMBERS LINGER A PRECIPITATION THREAT INTO
THURSDAY...SO WILL GO WITH CHANCE POPS AT THAT TIME.

MOST THE ENSEMBLES NOW AGREE THAT THE UPPER TROUGH SHOULD BE EAST OF
THE AREA BY NEXT FRIDAY...WITH A STRONG UPPER RIDGE BUILDING INTO
THE PLAINS AND MIDWEST. WILL GO DRY FOR NEXT FRIDAY.


&&

.AVIATION /DISCUSSION FOR THE 180000Z TAF ISSUANCE/...
ISSUED AT 605 PM EDT FRI MAY 17 2013

ELONGATED UPPER WAVE ON THE FRONT SIDE OF AN UPPER TROUGH NEAR THE
INDIANA AND ILLINOIS BORDER WILL CONTINUE TO LIFT NORTHEAST AND
SHOULD BE NORTH OF LAF BY ISSUANCE TIME. WIDESPREAD BAND OF
THUNDERSTORMS WAS OCCURING JUST NORTH OF THE WAVE AND SHOULD REMAIN
THAT WAY...SO SHOULD NOT PRESENT A PROBLEM FOR ANY OF THE TAF SITES
AFTER 00Z. HOWEVER...ANOTHER WAVE WAS LIFTING NORTHEAST NEAR THE
OHIO RIVER AND SHOULD MOVE SOUTHEASTERN AND EAST CENTRAL INDIANA
OVERNIGHT. THIS FEATURE WAS CURRENTLY HELPING TO PRODUCE ISOLATED TO
SCATTERED SHOWERS ACROSS SOUTH CENTRAL INDIANA. WOULD NOT RULE A
SHOWER OR THUNDERSTORM AT IND AND BMG WITH THIS FEATURE...BUT
CHANCES APPEAR TOO LOW TO GO WITH ANYTHING MORE THAN VCSH OR VCTS
THROUGH JUST BEYOND SUNSET. BY 02Z...ALREADY MARGINAL INSTABILITY
SHOULD BE ABOUT SPENT. FOR THE REST OF THE NIGHT...WITH THE LOW
LEVELS OF THE ATMOSPHERE MOIST...AND LIGHT WINDS...SHOULD SEE AT
LEAST MVFR FOG AND OR CEILINGS AFTER 08Z...IMPROVING BACK TO VFR
AFTER 13Z SATURDAY. WOULD NOT RULE OUT A FEW MORE STORMS ON SATURDAY
AFTER 15Z AS THE UPPER TROUGH MOVES ACROSS...AND INSTABILITY ONCE
AGAIN INCREASES. IN ADDITION...FRONT JUST TO THE NORTH OF LAF COULD
SETTLE BACK SOUTH OVERNIGHT AS THE UPPER FLOW BECOMES NORTHWEST.
WINDS WILL CONTINUE TO 10 KNOTS OR LESS EXCEPT PERHAPS IN THE
THUNDERSTORMS. WINDS WILL SHIFT FROM SOUTHEAST TO EAST AFTER 06Z AS
THE FRONT SETTLES SOUTH OF THE TERMINALS.

&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...50
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 172352
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
752 PM EDT FRI MAY 17 2013

.SYNOPSIS...
ISSUED AT 441 PM EDT FRI MAY 17 2013

A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY SHIFT NORTH
TONIGHT...BRINGING A CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS
TO PORTIONS OF NORTHERN INDIANA. THIS FRONT WILL REMAIN IN THE
REGION THROUGH SATURDAY BEFORE SHIFTING NORTH OF THE AREA SUNDAY.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE BY
TUESDAY INTO WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

CONVECTION WAS BEGINNING TO FIRE THIS AFTERNOON ACROSS PORTIONS OF
CENTRAL INDIANA...FROM MARION TO LOGANSPORT AND POINTS SOUTHWARD.
THIS INITIAL LINE OF CONVECTION ACROSS OUR SOUTHERN FCST AREA IS
ASSOCIATED WITH AN AREA OF WEAK 925MB TO 850MB FRONTAL LIFT...WITH
THE BOUNDARY ORIENTED FROM NNW TO SE ACROSS THE AREA. COVERAGE
EXPECTED TO REMAIN ISOLATED INITIALLY...WITH MARGINAL LAPSE RATES
AND WEAK FLOW INHIBITING MORE ORGANIZED CONVECTION. DEWPOINTS
QUICKLY DROP FROM THE LOW 60S ACROSS SOUTHERN AREAS TO THE LOWER 40S
ACROSS THE NORTHEAST PORTION OF THE FORECAST AREA...WHICH WILL LIMIT
MUCH NORTHWARD EXTENT OF PRECIPITATION CHANCES THIS AFTERNOON.

MORE ORGANIZED CONVECTION HAS DEVELOPED NEAR INDIANAPOLIS AND POINTS
NORTHWESTWARD...IN AN AREA OF HIGHER DEWPOINTS AND SLIGHTLY MORE
INSTABILITY. PER HRRR/SPC 4KM WRF GUIDANCE...THIS ACTIVITY IS
EXPECTED TO LIFT NORTHWARD INTO THE SOUTHERN AND WESTERN PORTION OF
THE AREA THIS EVENING INTO THE OVERNIGHT. PRECIP ACTIVITY IS
EXPECTED TO QUICKLY WANE WITH THE LOSS OF DAYTIME HEATING...SO
DROPPED POPS SIGNIFICANTLY TOWARD MIDNIGHT AND AFTER. KEPT POPS
UNDER 40 PERCENT THROUGH THE EVENING WITH COVERAGE WORDING...AS
DRIER SURFACE AIRMASS...MARGINAL LAPSE RATES AND WANING INSTABILITY
SHOULD RESULT IN WEAKENING PRECIPITATION AS IT ADVECTS INTO THE
AREA.

NOT MUCH CHANGE TO TEMPERATURES OVERNIGHT. LATEST GUIDANCE SUGGESTS
LOWS NEAR 50 ACROSS A GOOD PORTION OF THE NORTHEAST FORECAST AREA.
NOT OUT OF THE QUESTION WITH EASTERLY FLOW OFF LAKE ERIE AND DRY
AIRMASS...HOWEVER EXPECTED MID/HIGH CLOUDS SHOULD PREVENT TEMPS FROM
SUCH A DROP OFF...SO COMPROMISED WITH LOWER TEMPS SLIGHTLY BUT
STAYING ABOVE GUIDANCE.

FRONTAL BOUNDARY EXPECTED TO LINGER FROM WEST TO EAST ACROSS THE
AREA AGAIN TOMORROW. SIMILAR SETUP EXPECTED...WITH AFTERNOON
INSTABILITY LEADING TO SMALL PRECIPITATION CHANCES. ALTHOUGH MODEL
SBCAPE VALUES OF 1500 J/KG ARE EXPECTED TOMORROW...LACK OF
FLOW...WEAK FORCING AND POOR LAPSE RATES SHOULD LIMIT WIDESPREAD
PRECIPITATION CHANCES. KEPT HIGHEST CHANCES ACROSS SOUTHEAST AREAS
IN THE AFTERNOON...IN CLOSEST VICINITY OF SUBTLE MID LVL IMPULSE AND
HIGHEST MOISTURE/INSTABILITY VALUES.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

FCST PERIOD TO BEGIN MAINLY DRY AS 500MB RIDGE MOVES OVER THE AREA.
FLOW WILL BECOME MORE SOUTHERLY DURING THE DAY SUNDAY AND BRING
INCREASING HUMIDITY AS DEWPOINTS RISE TO THE L-M60S. THIS WILL
RESULT IN INCREASING INSTABILITY DURING THE AFTERNOON HOURS AND
STEEPENING LOW LEVEL LAPSE RATES...BUT IN A WEAK FLOW POORLY FORCED
ENVIRONMENT...SO WILL CONTINUE WITH JUST SLIGHT CHANCE WORDING ON
SUNDAY. DECENT MID-UPPER JET DYNAMICS WILL ROUND THE BASE OF THE
UPPER TROF IN THE PLAINS AND SHOULD PROVIDE NEEDED FORCING FOR
NOCTURNAL CONVECTION IN THE MID MS VALLEY SUNDAY NIGHT. PLENTY OF
ELEVATED INSTABILITY WILL BE PRESENT OVER THE CWA WITH CAPES AOA
2000J/KG. STAUNCH THICKNESS RIDGE AND NO INDICATION OF BREAKDOWN IN
THE MID LEVEL RIDGE SHOULD KEEP MOST OF THE CONVECTION WEST OF OUR
AREA BUT WILL STILL CONTINUE WITH SLIGHT CHANCE OVER WESTERN TWO
THIRDS. ANOTHER DAY OF DIURNALLY DRIVEN CONVECTION POSSIBLE ON
MONDAY AS AREA WILL SIT IN AN UNSTABLE AND RELATIVELY UNCAPPED WARM
SECTOR THAT WILL BE AIDED BY INCREASING LOW-MID LEVEL FLOW. FOCUS
THEN SHIFTS TO ARRIVAL...FINALLY...OF VERTICALLY STACKED SYSTEM
TUE-THU. THIS SYSTEM EXPECTED TO BE WEAKENING AS IT MOVES INTO THE
AREA WITH SFC REFLECTION BECOMING QUASI-STATIONARY WED-THU
TIMEFRAME. THIS WILL EXTEND PRECIP CHANCES THROUGH THE DAY THURSDAY
BEFORE FINALLY CLEARING OUT AND MAKING WAY FOR A COOLER DRIER
CANADIAN HIGH PRESSURE SYSTEM TO SETTLE INTO THE GREAT LAKES REGION
BEGINNING FRIDAY...AND HOPEFULLY LEAD TO A PLEASANT MEMORIAL DAY
WEEKEND. GENERALLY FAVORED WARMER TEMPS MAX AND MIN FOR SUN/MON AS
POTENT LOW LEVEL THERMAL RIDGE NUDGES INTO THE REGION AND INCREASING
HUMIDITY TO KEEP NIGHT TIME LOWS TRENDING WARMER. COOLER MORE
SEASONABLE TEMPS BY THE END OF THE PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 750 PM EDT FRI MAY 17 2013


MEAGER 1000-1500 J/KG SBCAPE ON RAPID DOWNSWING THIS EVENING ACROSS
SOUTHWEST QUARTER OF CWA. NORTHERN REACH OF FLANKING SHRA LINE TO
LIKELY REMAIN QUASI-STATIONARY WHILE EXHIBITING RATHER RAPID DECAY
NEXT COUPLE HOURS. LITTLE IF ANY ADDITIONAL THUNDER LIKELY ACROSS
NORTHERN INDIANA GIVEN NEGLIGIBLY WEAK DEEP LAYER SHEAR ENVIRONMENT
LENDING TO COLD POOL DOMINATION IN AN INCREASINGLY STRATIFORM LOW
TOPPED RAINBAND ALONG RESIDUAL FRONTAL BOUNDARY. INITIALLY HAD A
MINOR CONCERN WITH RESPECT TO LATE NIGHT/NEAR SUNRISE BR FORMATION
AT KFWA...GIVEN PROXIMITY OF EVENING SHRA AND IMMEDIATE UPSTREAM
INCREASE IN SURFACE DEWPOINTS. HOWEVER...RUC/ARW/NMM ALL SHOW
SUFFICIENTLY BACKED SURFACE FLOW THROUGH THE MAUMEE VALLEY THAT
SHOULD MAINTAIN SUFFICIENT T/TD SPREADS OVERNIGHT...THEREFORE WITH
LOW PROBABILITY OF BR OCCURRENCE WILL CONTINUE WITH P6SM THROUGHOUT.
LIKEWISE AT KSBN...WELL REMOVED FROM FRONTAL BOUNDARY WITH VFR
METEOROLOGICAL CONDITIONS TO DOMINATE. SOME MINOR ISOLD/SCT SHRA BY
MIDDAY SATURDAY...THOUGH BEST DIURNAL INSTABILITY AGAIN RELEGATED
WELL SOUTH OF TERMINALS.

&&

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

$$

SYNOPSIS...KG
SHORT TERM...NG
LONG TERM...JAL
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 172205
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
605 PM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 220 PM EDT FRI MAY 17 2013

A WEAK AREA OF LOW PRESSURE OVER SOUTHEAST MISSOURI WILL DRIFT INTO
THE OHIO VALLEY TONIGHT AND ACROSS SOUTHERN INDIANA ON SATURDAY.
THIS WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN PARTS OF STATE TONIGHT AND SATURDAY.

A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON
SUNDAY...HOWEVER WITH A CONTINUED WARM AND HUMID AIR MASS IN PLACE
AN ISOLATED SHOWER OR STORM CANNOT BE RULED OUT ON SUNDAY.

EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER THE WESTERN HALF OF
THE COUNTRY INTO THE WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF
NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY
INTO MID WEEK.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS A FRONTAL BOUNDARY
STRETCHING SOUTH OF LAF AND FRANKFORT TO SOUTH OF MUNCIE. EASTERLY
WINDS WERE FOUND NORTH OF THE FRONT WHILE SOUTHERLY WINDS AND A
MORE MOIST AIR MASS WAS FOUND ACROSS THE SOUTHERN PARTS OF THE
FORECAST AREA. RADAR SHOWS SCATTERED TSRA DEVELOPING AS CONVECTIVE
TEMPS ARE BEING REACHED. WATER VAPOR IMAGERY SHOWS A SHORT WAVE
OVER WESTERN TENNESSEE...SLOWLY EDGING EASTWARD.

DUE TO DAYTIME HEATING AND THE APPROACHING SHORT WAVE...SCATTERED
CONVECTION IS EXPECTED TO CONTINUE INTO THE EVENING HOURS.
FORECAST SOUNDINGS CONTINUE TO INDICATE FAVORABLE STEEP LAPSE
RATES THIS EVENING CAPE FALLING FROM OVER 1000 J/KG THIS AFTERNOON
T LESS THAN 100 J/KG BY 06Z. 305K GFS ISENTROPIC SURFACE CONTINUES
TO INDICATE BROAD...WEAK LIFT ACROSS THE AREA AHEAD OF THE
LOW...HOWEVER A VERY MOIST AIR MASS REMAINS ACROSS THE AREA
THROUGH SUNDAY WITH MIXING RATIOS IN EXCESS OF 7 G/KG. THUS WILL
CONTINUE WITH POPS AT OR ABOVE MAVMOS...HIGHEST SOUTH OF THE
PREVIOUSLY MENTIONED FRONTAL BOUNDARY EARLY DURING THE EVENING
HOURS...THEN WANE THE POPS THROUGH THE EVENING AS INSTABILITY AND
FORCING IS LOST. GIVEN THE WARM...MOIST AIR MASS IN PLACE ALONG
WITH PLENTIFUL CLOUDS WILL TREND LOWS AT OR ABOVE
GUIDANCE...PERHAPS NEAR PERSISTENCE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

MAIN FORECAST CHALLENGE WILL BE POPS

GFS AND NAM SUGGEST A WEAK UPPER LOW PUSHING THROUGH THE OHIO
VALLEY AND SOUTHERN INDIANA SATURDAY AND EXITING THE AREA BY LATE
SATURDAY AFTERNOON. FORECAST SOUNDINGS INDICATE THAT BEST DRYING
DOES NOT ARRIVE UNTIL TOWARD 00Z. TIME HEIGHTS MEANWHILE KEEP A
VERY MOIST AIR MASS IN PLACE ACROSS THE AREA ALONG WITH WEAK
SUBSIDENCE ALOFT. LOWER LEVEL Q VECTORS ALSO INDICATE DIVERGENCE.
THUS ONLY WEAK FORCING ASSOCIATED WITH THE SHORT WAVE AND DAYTIME
HEATING WILL BE OUR TRIGGERING MECHANISMS. BEST FORCING IN THIS
REGARD WILL BE FOUND ACROSS THE SOUTHERN PARTS OF THE FORECAST
AREA THUS WILL ONLY RAISE POPS ACROSS THOSE SPOTS DURING THE DAY
ON SATURDAY. FARTHER NORTH WILL TREND POPS AT OR BELOW MAVMOS AND
ALSO TREND POPS LOWER AS THE LATE AFTERNOON PROGRESSES AS THE
UPPER LOW DEPARTS. WILL TREND HIGHS AT OR BELOW MAVMOS GIVEN THE
EXPECTED CLOUDS AND POSSIBLE PRECIPITATION.

FORECAST SOUNDINGS ON SATURDAY NIGHT AND SUNDAY SHOW MUCH DRIER
AIR ARRIVING ACROSS CENTRAL INDIANA AS DEW POINTS FALL
DRAMATICALLY THROUGH THE COLUMN. THE PREVIOUSLY MENTIONED UPPER
LOW ALSO CONTINUES TO EXIT THE AREA AS WEAK RIDGING BUILDS ACROSS
THE AREA FOR SUNDAY.THUS WILL TREND TOWARD A DRY FORECAST FOR
SATURDAY NIGHT. ON SUNDAY FORECAST SOUNDING ARE NOW HINTING AT A
GOOD CAP IN PLACE AS 700MB TEMPS APPROACH 9-10C BY 00Z MONDAY. THUS
CONFIDENCE FOR A DRY FORECAST ON SUNDAY HAS GROWN. AS FOR TEMPS...A
BLEND WILL WORK NICELY.

GFS AND NAM CONTINUE TO SUGGEST STRONG RIDGING ALOFT OVER THE
REGION ON SUNDAY NIGHT AND MONDAY. MEANWHILE 850MB TEMPS CONTINUE
A SLOW CLIMB TOWARD 18C-20C BY 18Z MONDAY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE LOWER 90S WHICH MAY BE TOO WARM TO TRIGGER
ANY INITIATION. THUS WITHOUT STRONG DYNAMICS AVAILABLE A WARM
SUNDAY NIGHT AND A SUMMER LIKE MONDAY WILL BE EXPECTED. WILL TREND
BOTH LOWS AND HIGHS AT OR ABOVE MAVMOS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

ENSEMBLES ARE COMING INTO BETTER AGREEMENT TODAY WITH RESPECT TO THE
EVOLVING WEATHER PATTERN NEXT WEEK. MAIN FEATURE DURING THIS PERIOD
WILL BE AN UPPER LOW THAT IS EXPECTED TO MOVE SLOWLY EAST FROM THE
PLAINS...CROSSING THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK.
ENSEMBLES SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE ON
TUESDAY AND WEDNESDAY...SO WILL GO WITH HIGHER POPS AT THOSE TIMES.
SOME OF THE SLOWER MEMBERS LINGER A PRECIPITATION THREAT INTO
THURSDAY...SO WILL GO WITH CHANCE POPS AT THAT TIME.

MOST THE ENSEMBLES NOW AGREE THAT THE UPPER TROUGH SHOULD BE EAST OF
THE AREA BY NEXT FRIDAY...WITH A STRONG UPPER RIDGE BUILDING INTO
THE PLAINS AND MIDWEST. WILL GO DRY FOR NEXT FRIDAY.


&&

.AVIATION /DISCUSSION FOR THE 180000Z TAF ISSUANCE/...
ISSUED AT 605 PM EDT FRI MAY 17 2013

ELONGATED UPPER WAVE ON THE FRONT SIDE OF AN UPPER TROUGH NEAR THE
INDIANA AND ILLINOIS BORDER WILL CONTINUE TO LIFT NORTHEAST AND
SHOULD BE NORTH OF LAF BY ISSUANCE TIME. WIDESPREAD BAND OF
THUNDERSTORMS WAS OCCURING JUST NORTH OF THE WAVE AND SHOULD REMAIN
THAT WAY...SO SHOULD NOT PRESENT A PROBLEM FOR ANY OF THE TAF SITES
AFTER 00Z. HOWEVER...ANOTHER WAVE WAS LIFTING NORTHEAST NEAR THE
OHIO RIVER AND SHOULD MOVE SOUTHEASTERN AND EAST CENTRAL INDIANA
OVERNIGHT. THIS FEATURE WAS CURRENTLY HELPING TO PRODUCE ISOLATED TO
SCATTERED SHOWERS ACROSS SOUTH CENTRAL INDIANA. WOULD NOT RULE A
SHOWER OR THUNDERSTORM AT IND AND BMG WITH THIS FEATURE...BUT
CHANCES APPEAR TOO LOW TO GO WITH ANYTHING MORE THAN VCSH OR VCTS
THROUGH JUST BEYOND SUNSET. BY 02Z...ALREADY MARGINAL INSTABILITY
SHOULD BE ABOUT SPENT. FOR THE REST OF THE NIGHT...WITH THE LOW
LEVELS OF THE ATMOSPHERE MOIST...AND LIGHT WINDS...SHOULD SEE AT
LEAST MVFR FOG AND OR CEILINGS AFTER 08Z...IMPROVING BACK TO VFR
AFTER 13Z SATURDAY. WOULD NOT RULE OUT A FEW MORE STORMS ON SATURDAY
AFTER 15Z AS THE UPPER TROUGH MOVES ACROSS...AND INSTABILITY ONCE
AGAIN INCREASES. IN ADDITION...FRONT JUST TO THE NORTH OF LAF COULD
SETTLE BACK SOUTH OVERNIGHT AS THE UPPER FLOW BECOMES NORTHWEST.
WINDS WILL CONTINUE TO 10 KNOTS OR LESS EXCEPT PERHAPS IN THE
THUNDERSTORMS. WINDS WILL SHIFT FROM SOUTHEAST TO EAST AFTER 06Z AS
THE FRONT SETTLES SOUTH OF THE TERMINALS.

&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 172043
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
443 PM EDT FRI MAY 17 2013

.SYNOPSIS...
ISSUED AT 441 PM EDT FRI MAY 17 2013

A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY SHIFT NORTH
TONIGHT...BRINGING A CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS
TO PORTIONS OF NORTHERN INDIANA. THIS FRONT WILL REMAIN IN THE
REGION THROUGH SATURDAY BEFORE SHIFTING NORTH OF THE AREA SUNDAY.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE BY
TUESDAY INTO WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

CONVECTION WAS BEGINNING TO FIRE THIS AFTERNOON ACROSS PORTIONS OF
CENTRAL INDIANA...FROM MARION TO LOGANSPORT AND POINTS SOUTHWARD.
THIS INITIAL LINE OF CONVECTION ACROSS OUR SOUTHERN FCST AREA IS
ASSOCIATED WITH AN AREA OF WEAK 925MB TO 850MB FRONTAL LIFT...WITH
THE BOUNDARY ORIENTED FROM NNW TO SE ACROSS THE AREA. COVERAGE
EXPECTED TO REMAIN ISOLATED INITIALLY...WITH MARGINAL LAPSE RATES
AND WEAK FLOW INHIBITING MORE ORGANIZED CONVECTION. DEWPOINTS
QUICKLY DROP FROM THE LOW 60S ACROSS SOUTHERN AREAS TO THE LOWER 40S
ACROSS THE NORTHEAST PORTION OF THE FORECAST AREA...WHICH WILL LIMIT
MUCH NORTHWARD EXTENT OF PRECIPITATION CHANCES THIS AFTERNOON.

MORE ORGANIZED CONVECTION HAS DEVELOPED NEAR INDIANAPOLIS AND POINTS
NORTHWESTWARD...IN AN AREA OF HIGHER DEWPOINTS AND SLIGHTLY MORE
INSTABILITY. PER HRRR/SPC 4KM WRF GUIDANCE...THIS ACTIVITY IS
EXPECTED TO LIFT NORTHWARD INTO THE SOUTHERN AND WESTERN PORTION OF
THE AREA THIS EVENING INTO THE OVERNIGHT. PRECIP ACTIVITY IS
EXPECTED TO QUICKLY WANE WITH THE LOSS OF DAYTIME HEATING...SO
DROPPED POPS SIGNIFICANTLY TOWARD MIDNIGHT AND AFTER. KEPT POPS
UNDER 40 PERCENT THROUGH THE EVENING WITH COVERAGE WORDING...AS
DRIER SURFACE AIRMASS...MARGINAL LAPSE RATES AND WANING INSTABILITY
SHOULD RESULT IN WEAKENING PRECIPITATION AS IT ADVECTS INTO THE
AREA.

NOT MUCH CHANGE TO TEMPERATURES OVERNIGHT. LATEST GUIDANCE SUGGESTS
LOWS NEAR 50 ACROSS A GOOD PORTION OF THE NORTHEAST FORECAST AREA.
NOT OUT OF THE QUESTION WITH EASTERLY FLOW OFF LAKE ERIE AND DRY
AIRMASS...HOWEVER EXPECTED MID/HIGH CLOUDS SHOULD PREVENT TEMPS FROM
SUCH A DROP OFF...SO COMPROMISED WITH LOWER TEMPS SLIGHTLY BUT
STAYING ABOVE GUIDANCE.

FRONTAL BOUNDARY EXPECTED TO LINGER FROM WEST TO EAST ACROSS THE
AREA AGAIN TOMORROW. SIMILAR SETUP EXPECTED...WITH AFTERNOON
INSTABILITY LEADING TO SMALL PRECIPITATION CHANCES. ALTHOUGH MODEL
SBCAPE VALUES OF 1500 J/KG ARE EXPECTED TOMORROW...LACK OF
FLOW...WEAK FORCING AND POOR LAPSE RATES SHOULD LIMIT WIDESPREAD
PRECIPITATION CHANCES. KEPT HIGHEST CHANCES ACROSS SOUTHEAST AREAS
IN THE AFTERNOON...IN CLOSEST VICINITY OF SUBTLE MID LVL IMPULSE AND
HIGHEST MOISTURE/INSTABILITY VALUES.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

FCST PERIOD TO BEGIN MAINLY DRY AS 500MB RIDGE MOVES OVER THE AREA.
FLOW WILL BECOME MORE SOUTHERLY DURING THE DAY SUNDAY AND BRING
INCREASING HUMIDITY AS DEWPOINTS RISE TO THE L-M60S. THIS WILL
RESULT IN INCREASING INSTABILITY DURING THE AFTERNOON HOURS AND
STEEPENING LOW LEVEL LAPSE RATES...BUT IN A WEAK FLOW POORLY FORCED
ENVIRONMENT...SO WILL CONTINUE WITH JUST SLIGHT CHANCE WORDING ON
SUNDAY. DECENT MID-UPPER JET DYNAMICS WILL ROUND THE BASE OF THE
UPPER TROF IN THE PLAINS AND SHOULD PROVIDE NEEDED FORCING FOR
NOCTURNAL CONVECTION IN THE MID MS VALLEY SUNDAY NIGHT. PLENTY OF
ELEVATED INSTABILITY WILL BE PRESENT OVER THE CWA WITH CAPES AOA
2000J/KG. STAUNCH THICKNESS RIDGE AND NO INDICATION OF BREAKDOWN IN
THE MID LEVEL RIDGE SHOULD KEEP MOST OF THE CONVECTION WEST OF OUR
AREA BUT WILL STILL CONTINUE WITH SLIGHT CHANCE OVER WESTERN TWO
THIRDS. ANOTHER DAY OF DIURNALLY DRIVEN CONVECTION POSSIBLE ON
MONDAY AS AREA WILL SIT IN AN UNSTABLE AND RELATIVELY UNCAPPED WARM
SECTOR THAT WILL BE AIDED BY INCREASING LOW-MID LEVEL FLOW. FOCUS
THEN SHIFTS TO ARRIVAL...FINALLY...OF VERTICALLY STACKED SYSTEM
TUE-THU. THIS SYSTEM EXPECTED TO BE WEAKENING AS IT MOVES INTO THE
AREA WITH SFC REFLECTION BECOMING QUASI-STATIONARY WED-THU
TIMEFRAME. THIS WILL EXTEND PRECIP CHANCES THROUGH THE DAY THURSDAY
BEFORE FINALLY CLEARING OUT AND MAKING WAY FOR A COOLER DRIER
CANADIAN HIGH PRESSURE SYSTEM TO SETTLE INTO THE GREAT LAKES REGION
BEGINNING FRIDAY...AND HOPEFULLY LEAD TO A PLEASANT MEMORIAL DAY
WEEKEND. GENERALLY FAVORED WARMER TEMPS MAX AND MIN FOR SUN/MON AS
POTENT LOW LEVEL THERMAL RIDGE NUDGES INTO THE REGION AND INCREASING
HUMIDITY TO KEEP NIGHT TIME LOWS TRENDING WARMER. COOLER MORE
SEASONABLE TEMPS BY THE END OF THE PERIOD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 109 PM EDT FRI MAY 17 2013

VFR CONDITIONS EXPECTED THROUGH THE TAF PD AT TERMINALS. LIGHT
EASTERLY FLOW WILL PERSIST WITH FRONTAL BOUNDARY SOUTH OF THE AREA
THROUGH THE PERIOD. AFTERNOON SHOWERS/ISOLATED STORMS ARE EXPECTED
TO DEVELOP SOUTH AND SOUTHWEST OF TERMINALS. LATEST MODEL GUIDANCE
SUGGESTS CONVECTION SHOULD REMAIN OUT OF TERMINALS...HOWEVER THERE
IS A SMALL CHANCE THAT DYING THUNDERSTORMS COULD ADVECT INTO THE
VICINITY OF TERMINALS...WITH A RISK OF -SHRA FROM 21Z THROUGH JUST
AFTER 00Z. CONFIDENCE TOO LOW TO INCLUDE -SHRA MENTION IN
TAFS...AND WILL MONITOR CONVECTIVE TRENDS THIS AFTERNOON AND
UPDATE TAFS AS NEEDED.


&&

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

$$

SYNOPSIS...FISHER/KG
SHORT TERM...NG
LONG TERM...JAL
AVIATION...NG


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 172031
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
425 PM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 220 PM EDT FRI MAY 17 2013

A WEAK AREA OF LOW PRESSURE OVER SOUTHEAST MISSOURI WILL DRIFT INTO
THE OHIO VALLEY TONIGHT AND ACROSS SOUTHERN INDIANA ON SATURDAY.
THIS WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN PARTS OF STATE TONIGHT AND SATURDAY.

A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON
SUNDAY...HOWEVER WITH A CONTINUED WARM AND HUMID AIR MASS IN PLACE
AN ISOLATED SHOWER OR STORM CANNOT BE RULED OUT ON SUNDAY.

EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER THE WESTERN HALF OF
THE COUNTRY INTO THE WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF
NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY
INTO MID WEEK.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS A FRONTAL BOUNDARY
STRETCHING SOUTH OF LAF AND FRANKFORT TO SOUTH OF MUNCIE. EASTERLY
WINDS WERE FOUND NORTH OF THE FRONT WHILE SOUTHERLY WINDS AND A
MORE MOIST AIR MASS WAS FOUND ACROSS THE SOUTHERN PARTS OF THE
FORECAST AREA. RADAR SHOWS SCATTERED TSRA DEVELOPING AS CONVECTIVE
TEMPS ARE BEING REACHED. WATER VAPOR IMAGERY SHOWS A SHORT WAVE
OVER WESTERN TENNESSEE...SLOWLY EDGING EASTWARD.

DUE TO DAYTIME HEATING AND THE APPROACHING SHORT WAVE...SCATTERED
CONVECTION IS EXPECTED TO CONTINUE INTO THE EVENING HOURS.
FORECAST SOUNDINGS CONTINUE TO INDICATE FAVORABLE STEEP LAPSE
RATES THIS EVENING CAPE FALLING FROM OVER 1000 J/KG THIS AFTERNOON
T LESS THAN 100 J/KG BY 06Z. 305K GFS ISENTROPIC SURFACE CONTINUES
TO INDICATE BROAD...WEAK LIFT ACROSS THE AREA AHEAD OF THE
LOW...HOWEVER A VERY MOIST AIR MASS REMAINS ACROSS THE AREA
THROUGH SUNDAY WITH MIXING RATIOS IN EXCESS OF 7 G/KG. THUS WILL
CONTINUE WITH POPS AT OR ABOVE MAVMOS...HIGHEST SOUTH OF THE
PREVIOUSLY MENTIONED FRONTAL BOUNDARY EARLY DURING THE EVENING
HOURS...THEN WANE THE POPS THROUGH THE EVENING AS INSTABILITY AND
FORCING IS LOST. GIVEN THE WARM...MOIST AIR MASS IN PLACE ALONG
WITH PLENTIFUL CLOUDS WILL TREND LOWS AT OR ABOVE
GUIDANCE...PERHAPS NEAR PERSISTENCE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

MAIN FORECAST CHALLENGE WILL BE POPS

GFS AND NAM SUGGEST A WEAK UPPER LOW PUSHING THROUGH THE OHIO
VALLEY AND SOUTHERN INDIANA SATURDAY AND EXITING THE AREA BY LATE
SATURDAY AFTERNOON. FORECAST SOUNDINGS INDICATE THAT BEST DRYING
DOES NOT ARRIVE UNTIL TOWARD 00Z. TIME HEIGHTS MEANWHILE KEEP A
VERY MOIST AIR MASS IN PLACE ACROSS THE AREA ALONG WITH WEAK
SUBSIDENCE ALOFT. LOWER LEVEL Q VECTORS ALSO INDICATE DIVERGENCE.
THUS ONLY WEAK FORCING ASSOCIATED WITH THE SHORT WAVE AND DAYTIME
HEATING WILL BE OUR TRIGGERING MECHANISMS. BEST FORCING IN THIS
REGARD WILL BE FOUND ACROSS THE SOUTHERN PARTS OF THE FORECAST
AREA THUS WILL ONLY RAISE POPS ACROSS THOSE SPOTS DURING THE DAY
ON SATURDAY. FARTHER NORTH WILL TREND POPS AT OR BELOW MAVMOS AND
ALSO TREND POPS LOWER AS THE LATE AFTERNOON PROGRESSES AS THE
UPPER LOW DEPARTS. WILL TREND HIGHS AT OR BELOW MAVMOS GIVEN THE
EXPECTED CLOUDS AND POSSIBLE PRECIPITATION.

FORECAST SOUNDINGS ON SATURDAY NIGHT AND SUNDAY SHOW MUCH DRIER
AIR ARRIVING ACROSS CENTRAL INDIANA AS DEW POINTS FALL
DRAMATICALLY THROUGH THE COLUMN. THE PREVIOUSLY MENTIONED UPPER
LOW ALSO CONTINUES TO EXIT THE AREA AS WEAK RIDGING BUILDS ACROSS
THE AREA FOR SUNDAY.THUS WILL TREND TOWARD A DRY FORECAST FOR
SATURDAY NIGHT. ON SUNDAY FORECAST SOUNDING ARE NOW HINTING AT A
GOOD CAP IN PLACE AS 700MB TEMPS APPROACH 9-10C BY 00Z MONDAY. THUS
CONFIDENCE FOR A DRY FORECAST ON SUNDAY HAS GROWN. AS FOR TEMPS...A
BLEND WILL WORK NICELY.

GFS AND NAM CONTINUE TO SUGGEST STRONG RIDGING ALOFT OVER THE
REGION ON SUNDAY NIGHT AND MONDAY. MEANWHILE 850MB TEMPS CONTINUE
A SLOW CLIMB TOWARD 18C-20C BY 18Z MONDAY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE LOWER 90S WHICH MAY BE TOO WARM TO TRIGGER
ANY INITIATION. THUS WITHOUT STRONG DYNAMICS AVAILABLE A WARM
SUNDAY NIGHT AND A SUMMER LIKE MONDAY WILL BE EXPECTED. WILL TREND
BOTH LOWS AND HIGHS AT OR ABOVE MAVMOS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

ENSEMBLES ARE COMING INTO BETTER AGREEMENT TODAY WITH RESPECT TO THE
EVOLVING WEATHER PATTERN NEXT WEEK. MAIN FEATURE DURING THIS PERIOD
WILL BE AN UPPER LOW THAT IS EXPECTED TO MOVE SLOWLY EAST FROM THE
PLAINS...CROSSING THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK.
ENSEMBLES SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE ON
TUESDAY AND WEDNESDAY...SO WILL GO WITH HIGHER POPS AT THOSE TIMES.
SOME OF THE SLOWER MEMBERS LINGER A PRECIPITATION THREAT INTO
THURSDAY...SO WILL GO WITH CHANCE POPS AT THAT TIME.

MOST THE ENSEMBLES NOW AGREE THAT THE UPPER TROUGH SHOULD BE EAST OF
THE AREA BY NEXT FRIDAY...WITH A STRONG UPPER RIDGE BUILDING INTO
THE PLAINS AND MIDWEST. WILL GO DRY FOR NEXT FRIDAY.


&&

.AVIATION /DISCUSSION FOR THE 172100Z IND TAF UPDATE/...
ISSUED AT 425 PM EDT FRI MAY 17 2013

RADAR...LIGHTNING AND INSTABILITY TRENDS FAVOR KEEPING MVFR TSTM
THROUGH ABOUT 2130Z WITH VCTS THEREAFTER AS A SECONDARY UPPER WAVE
NEAR THE OHIO RIVER PIVOTS NORTHEAST AHEAD OF UPPER TROUGH NEAR THE
INDIANA AND ILLINOIS BORDER.

PREVIOUS DISCUSSION FOLLOWS...

SCATTERED CONVECTION EXPECTED TO BEGIN DEVELOPING SOON AS CONVECTIVE
TEMPERATURES ARE JUST ABOUT REACHED. INSTABILITY AXIS CURRENTLY RUNS
THROUGH SOUTHWEST INDIANA...SO ANY INITIAL DEVELOPMENT WOULD
PROBABLY OCCUR IN THE VICINITY OF KHUF/KBMG AND THEN PROGRESS NORTH
WITH TIME GIVEN THE STEERING FLOW ALOFT. MODELS INDICATE A WEAK
VORTICITY LOBE MAY SHIFT NORTH ACROSS THE AREA LATER THIS
AFTERNOON/EVENING...WHICH MAY SERVE TO PROLONG THE CONVECTIVE THREAT
A LITTLE LONGER THAN WOULD NORMALLY BE EXPECTED IN A STRICTLY
DIURNAL SITUATION. IN ANY EVENT...AT THIS TIME CAN/T REALLY PIN DOWN
ANYTHING DEFINITIVE...SO WILL KEEP A VCTS AT THE TAF SITES THROUGH
180200Z. BRIEF IFR VISIBILITY RESTRICTIONS AND GUSTY/SHIFTING WINDS
POSSIBLE IN THE HEAVIER CELLS. CONVECTIVE CLOUD BASES AROUND 030.

OUTSIDE OF CONVECTIVE ACTIVITY...CEILINGS ABOVE 050 WITH NO WIND
ISSUES EXPECTED THROUGH 180600Z. SOME MVFR VISIBILITIES IN LIGHT FOG
MAY DEVELOP AFTER 180500Z...ESPECIALLY IN AREAS THAT RECEIVE
RAINFALL THIS AFTERNOON.


&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...JAS/MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 171920
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
320 PM EDT FRI MAY 17 2013

.SYNOPSIS...
ISSUED AT 1039 AM EDT FRI MAY 17 2013

A FRONTAL BOUNDARY WILL SLOWLY SHIFT NORTH TODAY...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF NORTHERN
INDIANA. THIS FRONT WILL REMAIN IN THE GENERAL AREA THROUGH
SATURDAY BEFORE SHIFTING NORTH OF THE REGION SUNDAY. BETTER
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE BY TUESDAY INTO
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

CONVECTION WAS BEGINNING TO FIRE THIS AFTERNOON ACROSS PORTIONS OF
CENTRAL INDIANA...FROM MARION TO LOGANSPORT AND POINTS SOUTHWARD.
THIS INITIAL LINE OF CONVECTION ACROSS OUR SOUTHERN FCST AREA IS
ASSOCIATED WITH AN AREA OF WEAK 925MB TO 850MB FRONTAL LIFT...WITH
THE BOUNDARY ORIENTED FROM NNW TO SE ACROSS THE AREA. COVERAGE
EXPECTED TO REMAIN ISOLATED INITIALLY...WITH MARGINAL LAPSE RATES
AND WEAK FLOW INHIBITING MORE ORGANIZED CONVECTION. DEWPOINTS
QUICKLY DROP FROM THE LOW 60S ACROSS SOUTHERN AREAS TO THE LOWER 40S
ACROSS THE NORTHEAST PORTION OF THE FORECAST AREA...WHICH WILL LIMIT
MUCH NORTHWARD EXTENT OF PRECIPITATION CHANCES THIS AFTERNOON.

MORE ORGANIZED CONVECTION HAS DEVELOPED NEAR INDIANAPOLIS AND POINTS
NORTHWESTWARD...IN AN AREA OF HIGHER DEWPOINTS AND SLIGHTLY MORE
INSTABILITY. PER HRRR/SPC 4KM WRF GUIDANCE...THIS ACTIVITY IS
EXPECTED TO LIFT NORTHWARD INTO THE SOUTHERN AND WESTERN PORTION OF
THE AREA THIS EVENING INTO THE OVERNIGHT. PRECIP ACTIVITY IS
EXPECTED TO QUICKLY WANE WITH THE LOSS OF DAYTIME HEATING...SO
DROPPED POPS SIGNIFICANTLY TOWARD MIDNIGHT AND AFTER. KEPT POPS
UNDER 40 PERCENT THROUGH THE EVENING WITH COVERAGE WORDING...AS
DRIER SURFACE AIRMASS...MARGINAL LAPSE RATES AND WANING INSTABILITY
SHOULD RESULT IN WEAKENING PRECIPITATION AS IT ADVECTS INTO THE
AREA.

NOT MUCH CHANGE TO TEMPERATURES OVERNIGHT. LATEST GUIDANCE SUGGESTS
LOWS NEAR 50 ACROSS A GOOD PORTION OF THE NORTHEAST FORECAST AREA.
NOT OUT OF THE QUESTION WITH EASTERLY FLOW OFF LAKE ERIE AND DRY
AIRMASS...HOWEVER EXPECTED MID/HIGH CLOUDS SHOULD PREVENT TEMPS FROM
SUCH A DROP OFF...SO COMPROMISED WITH LOWER TEMPS SLIGHTLY BUT
STAYING ABOVE GUIDANCE.

FRONTAL BOUNDARY EXPECTED TO LINGER FROM WEST TO EAST ACROSS THE
AREA AGAIN TOMORROW. SIMILAR SETUP EXPECTED...WITH AFTERNOON
INSTABILITY LEADING TO SMALL PRECIPITATION CHANCES. ALTHOUGH MODEL
SBCAPE VALUES OF 1500 J/KG ARE EXPECTED TOMORROW...LACK OF
FLOW...WEAK FORCING AND POOR LAPSE RATES SHOULD LIMIT WIDESPREAD
PRECIPITATION CHANCES. KEPT HIGHEST CHANCES ACROSS SOUTHEAST AREAS
IN THE AFTERNOON...IN CLOSEST VICINITY OF SUBTLE MID LVL IMPULSE AND
HIGHEST MOISTURE/INSTABILITY VALUES.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 PM EDT FRI MAY 17 2013

FCST PERIOD TO BEGIN MAINLY DRY AS 500MB RIDGE MOVES OVER THE AREA.
FLOW WILL BECOME MORE SOUTHERLY DURING THE DAY SUNDAY AND BRING
INCREASING HUMIDITY AS DEWPOINTS RISE TO THE L-M60S. THIS WILL
RESULT IN INCREASING INSTABILITY DURING THE AFTERNOON HOURS AND
STEEPENING LOW LEVEL LAPSE RATES...BUT IN A WEAK FLOW POORLY FORCED
ENVIRONMENT...SO WILL CONTINUE WITH JUST SLIGHT CHANCE WORDING ON
SUNDAY. DECENT MID-UPPER JET DYNAMICS WILL ROUND THE BASE OF THE
UPPER TROF IN THE PLAINS AND SHOULD PROVIDE NEEDED FORCING FOR
NOCTURNAL CONVECTION IN THE MID MS VALLEY SUNDAY NIGHT. PLENTY OF
ELEVATED INSTABILITY WILL BE PRESENT OVER THE CWA WITH CAPES AOA
2000J/KG. STAUNCH THICKNESS RIDGE AND NO INDICATION OF BREAKDOWN IN
THE MID LEVEL RIDGE SHOULD KEEP MOST OF THE CONVECTION WEST OF OUR
AREA BUT WILL STILL CONTINUE WITH SLIGHT CHANCE OVER WESTERN TWO
THIRDS. ANOTHER DAY OF DIURNALLY DRIVEN CONVECTION POSSIBLE ON
MONDAY AS AREA WILL SIT IN AN UNSTABLE AND RELATIVELY UNCAPPED WARM
SECTOR THAT WILL BE AIDED BY INCREASING LOW-MID LEVEL FLOW. FOCUS
THEN SHIFTS TO ARRIVAL...FINALLY...OF VERTICALLY STACKED SYSTEM
TUE-THU. THIS SYSTEM EXPECTED TO BE WEAKENING AS IT MOVES INTO THE
AREA WITH SFC REFLECTION BECOMING QUASI-STATIONARY WED-THU
TIMEFRAME. THIS WILL EXTEND PRECIP CHANCES THROUGH THE DAY THURSDAY
BEFORE FINALLY CLEARING OUT AND MAKING WAY FOR A COOLER DRIER
CANADIAN HIGH PRESSURE SYSTEM TO SETTLE INTO THE GREAT LAKES REGION
BEGINNING FRIDAY...AND HOPEFULLY LEAD TO A PLEASANT MEMORIAL DAY
WEEKEND. GENERALLY FAVORED WARMER TEMPS MAX AND MIN FOR SUN/MON AS
POTENT LOW LEVEL THERMAL RIDGE NUDGES INTO THE REGION AND INCREASING
HUMIDITY TO KEEP NIGHT TIME LOWS TRENDING WARMER. COOLER MORE
SEASONABLE TEMPS BY THE END OF THE PERIOD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 109 PM EDT FRI MAY 17 2013

VFR CONDITIONS EXPECTED THROUGH THE TAF PD AT TERMINALS. LIGHT
EASTERLY FLOW WILL PERSIST WITH FRONTAL BOUNDARY SOUTH OF THE AREA
THROUGH THE PERIOD. AFTERNOON SHOWERS/ISOLATED STORMS ARE EXPECTED
TO DEVELOP SOUTH AND SOUTHWEST OF TERMINALS. LATEST MODEL GUIDANCE
SUGGESTS CONVECTION SHOULD REMAIN OUT OF TERMINALS...HOWEVER THERE
IS A SMALL CHANCE THAT DYING THUNDERSTORMS COULD ADVECT INTO THE
VICINITY OF TERMINALS...WITH A RISK OF -SHRA FROM 21Z THROUGH JUST
AFTER 00Z. CONFIDENCE TOO LOW TO INCLUDE -SHRA MENTION IN
TAFS...AND WILL MONITOR CONVECTIVE TRENDS THIS AFTERNOON AND
UPDATE TAFS AS NEEDED.


&&

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

$$

SYNOPSIS...FISHER
SHORT TERM...NG
LONG TERM...JAL
AVIATION...NG


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 171820
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
220 PM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 220 PM EDT FRI MAY 17 2013

A WEAK AREA OF LOW PRESSURE OVER SOUTHEAST MISSOURI WILL DRIFT INTO
THE OHIO VALLEY TONIGHT AND ACROSS SOUTHERN INDIANA ON SATURDAY.
THIS WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN PARTS OF STATE TONIGHT AND SATURDAY.

A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON
SUNDAY...HOWEVER WITH A CONTINUED WARM AND HUMID AIR MASS IN PLACE
AN ISOLATED SHOWER OR STORM CANNOT BE RULED OUT ON SUNDAY.

EARLY NEXT WEEK A LARGE TROUGH CARVES OUT OVER THE WESTERN HALF OF
THE COUNTRY INTO THE WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF
NEXT WEEK ALONG WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY
INTO MID WEEK.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS A FRONTAL BOUNDARY
STRETCHING SOUTH OF LAF AND FRANKFORT TO SOUTH OF MUNCIE. EASTERLY
WINDS WERE FOUND NORTH OF THE FRONT WHILE SOUTHERLY WINDS AND A
MORE MOIST AIR MASS WAS FOUND ACROSS THE SOUTHERN PARTS OF THE
FORECAST AREA. RADAR SHOWS SCATTERED TSRA DEVELOPING AS CONVECTIVE
TEMPS ARE BEING REACHED. WATER VAPOR IMAGERY SHOWS A SHORT WAVE
OVER WESTERN TENNESSEE...SLOWLY EDGING EASTWARD.

DUE TO DAYTIME HEATING AND THE APPROACHING SHORT WAVE...SCATTERED
CONVECTION IS EXPECTED TO CONTINUE INTO THE EVENING HOURS.
FORECAST SOUNDINGS CONTINUE TO INDICATE FAVORABLE STEEP LAPSE
RATES THIS EVENING CAPE FALLING FROM OVER 1000 J/KG THIS AFTERNOON
T LESS THAN 100 J/KG BY 06Z. 305K GFS ISENTROPIC SURFACE CONTINUES
TO INDICATE BROAD...WEAK LIFT ACROSS THE AREA AHEAD OF THE
LOW...HOWEVER A VERY MOIST AIR MASS REMAINS ACROSS THE AREA
THROUGH SUNDAY WITH MIXING RATIOS IN EXCESS OF 7 G/KG. THUS WILL
CONTINUE WITH POPS AT OR ABOVE MAVMOS...HIGHEST SOUTH OF THE
PREVIOUSLY MENTIONED FRONTAL BOUNDARY EARLY DURING THE EVENING
HOURS...THEN WANE THE POPS THROUGH THE EVENING AS INSTABILITY AND
FORCING IS LOST. GIVEN THE WARM...MOIST AIR MASS IN PLACE ALONG
WITH PLENTIFUL CLOUDS WILL TREND LOWS AT OR ABOVE
GUIDANCE...PERHAPS NEAR PERSISTENCE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

MAIN FORECAST CHALLENGE WILL BE POPS

GFS AND NAM SUGGEST A WEAK UPPER LOW PUSHING THROUGH THE OHIO
VALLEY AND SOUTHERN INDIANA SATURDAY AND EXITING THE AREA BY LATE
SATURDAY AFTERNOON. FORECAST SOUNDINGS INDICATE THAT BEST DRYING
DOES NOT ARRIVE UNTIL TOWARD 00Z. TIME HEIGHTS MEANWHILE KEEP A
VERY MOIST AIR MASS IN PLACE ACROSS THE AREA ALONG WITH WEAK
SUBSIDENCE ALOFT. LOWER LEVEL Q VECTORS ALSO INDICATE DIVERGENCE.
THUS ONLY WEAK FORCING ASSOCIATED WITH THE SHORT WAVE AND DAYTIME
HEATING WILL BE OUR TRIGGERING MECHANISMS. BEST FORCING IN THIS
REGARD WILL BE FOUND ACROSS THE SOUTHERN PARTS OF THE FORECAST
AREA THUS WILL ONLY RAISE POPS ACROSS THOSE SPOTS DURING THE DAY
ON SATURDAY. FARTHER NORTH WILL TREND POPS AT OR BELOW MAVMOS AND
ALSO TREND POPS LOWER AS THE LATE AFTERNOON PROGRESSES AS THE
UPPER LOW DEPARTS. WILL TREND HIGHS AT OR BELOW MAVMOS GIVEN THE
EXPECTED CLOUDS AND POSSIBLE PRECIPITATION.

FORECAST SOUNDINGS ON SATURDAY NIGHT AND SUNDAY SHOW MUCH DRIER
AIR ARRIVING ACROSS CENTRAL INDIANA AS DEW POINTS FALL
DRAMATICALLY THROUGH THE COLUMN. THE PREVIOUSLY MENTIONED UPPER
LOW ALSO CONTINUES TO EXIT THE AREA AS WEAK RIDGING BUILDS ACROSS
THE AREA FOR SUNDAY.THUS WILL TREND TOWARD A DRY FORECAST FOR SATURDAY
NIGHT. ON SUNDAY FORECAST SOUNDING ARE NOW HINTING AT A GOOD CAP
IN PLACE AS 700MB TEMPS APPROACH 9-10C BY 00Z MONDAY. THUS
CONFIDENCE FOR A DRY FORECAST ON SUNDAY HAS GROWN. AS FOR
TEMPS...A BLEND WILL WORK NICELY.

GFS AND NAM CONTINUE TO SUGGEST STRONG RIDGING ALOFT OVER THE
REGION ON SUNDAY NIGHT AND MONDAY. MEANWHILE 850MB TEMPS CONTINUE
A SLOW CLIMB TOWARD 18C-20C BY 18Z MONDAY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE LOWER 90S WHICH MAY BE TOO WARM TO TRIGGER
ANY INITIATION. THUS WITHOUT STRONG DYNAMICS AVAILABLE A WARM
SUNDAY NIGHT AND A SUMMER LIKE MONDAY WILL BE EXPECTED. WILL TREND
BOTH LOWS AND HIGHS AT OR ABOVE MAVMOS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 220 PM EDT FRI MAY 17 2013

ENSEMBLES ARE COMING INTO BETTER AGREEMENT TODAY WITH RESPECT TO THE
EVOLVING WEATHER PATTERN NEXT WEEK. MAIN FEATURE DURING THIS PERIOD
WILL BE AN UPPER LOW THAT IS EXPECTED TO MOVE SLOWLY EAST FROM THE
PLAINS...CROSSING THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK.
ENSEMBLES SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE ON
TUESDAY AND WEDNESDAY...SO WILL GO WITH HIGHER POPS AT THOSE TIMES.
SOME OF THE SLOWER MEMBERS LINGER A PRECIPITATION THREAT INTO
THURSDAY...SO WILL GO WITH CHANCE POPS AT THAT TIME.

MOST THE ENSEMBLES NOW AGREE THAT THE UPPER TROUGH SHOULD BE EAST OF
THE AREA BY NEXT FRIDAY...WITH A STRONG UPPER RIDGE BUILDING INTO
THE PLAINS AND MIDWEST. WILL GO DRY FOR NEXT FRIDAY.


&&

.AVIATION /DISCUSSION FOR THE 171800Z TAFS/...
ISSUED AT 1240 PM EDT FRI MAY 17 2013

SCATTERED CONVECTION EXPECTED TO BEGIN DEVELOPING SOON AS CONVECTIVE
TEMPERATURES ARE JUST ABOUT REACHED. INSTABILITY AXIS CURRENTLY RUNS
THROUGH SOUTHWEST INDIANA...SO ANY INITIAL DEVELOPMENT WOULD
PROBABLY OCCUR IN THE VICINITY OF KHUF/KBMG AND THEN PROGRESS NORTH
WITH TIME GIVEN THE STEERING FLOW ALOFT. MODELS INDICATE A WEAK
VORTICITY LOBE MAY SHIFT NORTH ACROSS THE AREA LATER THIS
AFTERNOON/EVENING...WHICH MAY SERVE TO PROLONG THE CONVECTIVE THREAT
A LITTLE LONGER THAN WOULD NORMALLY BE EXPECTED IN A STRICTLY
DIURNAL SITUATION. IN ANY EVENT...AT THIS TIME CAN/T REALLY PIN DOWN
ANYTHING DEFINITIVE...SO WILL KEEP A VCTS AT THE TAF SITES THROUGH
180200Z. BRIEF IFR VISIBILITY RESTRICTIONS AND GUSTY/SHIFTING WINDS
POSSIBLE IN THE HEAVIER CELLS. CONVECTIVE CLOUD BASES AROUND 030.

OUTSIDE OF CONVECTIVE ACTIVITY...CEILINGS ABOVE 050 WITH NO WIND
ISSUES EXPECTED THROUGH 180600Z. SOME MVFR VISIBILITIES IN LIGHT FOG
MAY DEVELOP AFTER 180500Z...ESPECIALLY IN AREAS THAT RECEIVE
RAINFALL THIS AFTERNOON.


&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 171715
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
115 PM EDT FRI MAY 17 2013

.SYNOPSIS...
ISSUED AT 1039 AM EDT FRI MAY 17 2013

A FRONTAL BOUNDARY WILL SLOWLY SHIFT NORTH TODAY...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF NORTHERN
INDIANA. THIS FRONT WILL REMAIN IN THE GENERAL AREA THROUGH
SATURDAY BEFORE SHIFTING NORTH OF THE REGION SUNDAY. BETTER
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE BY TUESDAY INTO
WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EDT FRI MAY 17 2013

THE CHALLENGES FOR TODAY AND TONIGHT INCLUDE COVERAGE AND TIMING OF
ANY SHOWERS AND THUNDERSTORMS. A NORTHEAST FETCH OF VERY DRY
CANADIAN AIR WILL CONTINUE TO KEEP DEW POINTS IN THE 30S AND 40S
NORTHEAST OF THE FRONT. OVERNIGHT...THE FRONT HAD REMAINED
STATIONARY FROM JUST SOUTH OF LOGANSPORT TO NEAR LIMA. SOME
OVERNIGHT STORMS WEST OF THE AREA OCCURRED SOUTH OF CHICAGO ALONG
THE FRONT NEAR THE INTERSECTION OF LOW LEVEL WIND MAXIMUM AND THE
FRONT. EXPECT THE FRONT TO BECOME ACTIVE THIS AFTERNOON WITH DAYTIME
HEATING...WITH SFC BASED CONVECTION DEVELOPING ALONG AND SOUTH OF
THE FRONT. NAM12 BUFKIT CAPES REACH 1000-1500 J/KG BY LATE
AFTERNOON...AND SHOULD SUPPORT AT LEAST ISOLATED THUNDERSTORMS OVER
SOUTH AND SOUTHWEST AREAS. THEREFORE...ADDED SHOWERS AND ISOLATED
THUNDER OVER THESE AREAS. OTHERWISE...NAM MET/GFS MAV HIGHS LOOK GOOD
TODAY. LOWERED TEMPS FAR NORTH 1-2 DEGREES WITH COOLER NORTHEAST
FETCH. GUT FEELING LOWS IN THE NORTH AND NORTHEAST ARE STILL TOO
WARM AND WILL NEED TO BE LOWERED MORE.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 441 AM EDT FRI MAY 17 2013

SPORADIC INSIPID CONVECTION TO PERSIST INTO SATURDAY...ONCE AGAIN
FOCUSED IN THE SOUTHERN THIRD OF THE CWA AND DURING AFTERNOON PEAK
HEATING. MARGINAL PRECIP CHANCES BEING SUPPORTED BY WEAK
PERTURBATION IN THE MIDLEVEL HEIGHT FIELD DRIFTING ACROSS THE
SOUTHERN OHIO VALLEY. HOWEVER...PALTRY MIDLEVEL LAPSE RATES COUPLED
WITH SURFACE DEWPOINTS BARELY IN THE LOW 60S RESULTS IN ONLY ABOUT
500 J/KG OF 0-1KM MLCAPE. FURTHERMORE...MODEST EASTERLY COMPONENT TO
THE LOW LEVEL FLOW EMANATING FROM EASTERN CANADA ANTICYCLONE WILL
LIKELY CONTINUE ON SATURDAY AND RESULT IN MORE STABLE LAKE-MODIFIED
AIRMASS ACROSS MICHIGAN AND OUR NORTHERN CWA. OLD SURFACE FRONTAL
BOUNDARY AND ASSOCIATED CONVERGENCE ALSO BECOME INCREASINGLY
DIFFICULT TO PINPOINT BY LATE SATURDAY AS THE UPPER WAVE SHIFTS
EAST. GIVEN THESE CONDITIONS...EXPECT SCATTERED THUNDERSTORMS AT
BEST AND MAINLY ACROSS THE SOUTH. WITH A RATHER HOMOGENEOUS AIRMASS
IN PLACE AND NO THERMAL ADVECTIONS TO SPEAK OF...HIGH TEMPS ON
SATURDAY WILL BE VERY SIMILAR TO TODAY AND YESTERDAY...AROUND 80F.

TRANSIENT MID/UPPER LEVEL RIDGING WILL BE IN PLACE ON SUNDAY.
RELATIVELY DRY TROPOSPHERE AND GENERAL SYNOPTIC SUBSIDENCE SHOULD
KEEP MOST AREAS PRECIP-FREE. LATEST NAM AND GFS BUFR SOUNDINGS ARE A
BIT WORRISOME THOUGH WITH MODERATE INSTABILITY AND A VERY WEAK CAP
THAT MAY WELL BE OVERCOME BY STRONG DIURNAL HEATING. LACK OF FORCING
MECHANISM AND DEEPER MOISTURE WILL LIKELY LIMIT COVERAGE BUT CANT
RULE OUT SOME ISOLATED CONVECTION AND WILL CONTINUE WITH BLANKET
SLIGHT CHANCE POPS. WEAK WIND SPEEDS ALOFT/LOW BULK SHEAR VALUES
WILL PREVENT ORGANIZED CONVECTION DESPITE POTENTIAL FOR MODERATELY
HIGH CAPE VALUES. HIGH TEMPS ON SUNDAY MAY CLIMB A FEW DEGREES
HIGHER GIVEN VEERING LOW LEVEL WINDS AND STRONG SOLAR INSOLATION.
850MB TEMPS LOOK TO BE AROUND 16C BY THE AFTERNOON...SUPPORTING
HIGHS IN THE LOW TO MID 80S.

PRECIP CHANCES THEN LOOK TO STEADILY INCREASE EARLY NEXT WEEK AS A
VERTICALLY STACKED SYSTEM SLOWLY APPROACHES THE GREAT LAKES REGION.
DEEP SOUTHWEST FLOW WILL DEVELOP BY MONDAY...ADVECTING HIGH THETA-E
AIR INTO THE REGION. 850MB TEMPS CONTINUE TO CREEP INTO THE UPPER
TEENS AND AFTERNOON SURFACE TEMPS MONDAY WILL LIKELY PUSH INTO THE
MID 80S ONCE AGAIN. INCREASING MOISTURE AND APPROACHING HEIGHT FALLS
WILL LEAD TO INCREASING COVERAGE OF SHOWERS AND THUNDERSTORMS WITH
THE BEST CHANCE FOR WIDESPREAD PRECIP IN THE TUES/WED TIMEFRAME.
INCREASED CLOUDS/PRECIP WILL TEMPER HIGHS A BIT DURING THIS PERIOD
BUT STILL EXPECT AFTERNOON TEMPS AROUND 80F. COOLER/DRIER CONDITIONS
THEN EXPECTED BY THE END OF THE WEEK AS TROUGH AXIS EXITS EASTWARD
AND CANADIAN SURFACE HIGH BUILDS OVER THE GREAT LAKES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 109 PM EDT FRI MAY 17 2013

VFR CONDITIONS EXPECTED THROUGH THE TAF PD AT TERMINALS. LIGHT
EASTERLY FLOW WILL PERSIST WITH FRONTAL BOUNDARY SOUTH OF THE AREA
THROUGH THE PERIOD. AFTERNOON SHOWERS/ISOLATED STORMS ARE EXPECTED
TO DEVELOP SOUTH AND SOUTHWEST OF TERMINALS. LATEST MODEL GUIDANCE
SUGGESTS CONVECTION SHOULD REMAIN OUT OF TERMINALS...HOWEVER THERE
IS A SMALL CHANCE THAT DYING THUNDERSTORMS COULD ADVECT INTO THE
VICINITY OF TERMINALS...WITH A RISK OF -SHRA FROM 21Z THROUGH JUST
AFTER 00Z. CONFIDENCE TOO LOW TO INCLUDE -SHRA MENTION IN
TAFS...AND WILL MONITOR CONVECTIVE TRENDS THIS AFTERNOON AND
UPDATE TAFS AS NEEDED.

&&

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

$$

SYNOPSIS...FISHER
SHORT TERM...SKIPPER
LONG TERM...AGD
AVIATION...NG


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 171640
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1240 PM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 330 AM EDT FRI MAY 17 2013

SURFACE FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. UPPER
LOW LIFTING NORTHEAST FROM ARKANSAS HAS DEVELOPED SMALL AREA OF
SHOWERS OVER SOUTHWEST INDIANA THATS MOVING NORTH TOWARD OUR
SOUTHWEST FORECAST AREA. ALL MODELS IN A GENERAL AGREEMENT ON
LIFTING THE UPPER LOW INTO INDIANA TONIGHT AND THEN MOVE IT ACROSS
THE UPPER OHIO VALLEY RESULTING IN PERIODS OF SHOWERS AND STORMS
THROUGH AT LEAST SATURDAY EVENING. THIS SYSTEM EXITS WHILE LARGE
TROUGH CARVES OUT OVER THE WESTERN HALF OF THE COUNTRY INTO THE
WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF NEXT WEEK ALONG
WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 933 AM EDT FRI MAY 17 2013

SURFACE ANALYSIS THIS MORNING SHOWS THE LINGERING FRONTAL BOUNDARY
STRETCHED ACROSS THE NORTHERN PARTS OF THE FORECAST...JUST SOUTH
OF THE LAFAYETTE AND MUNCIE AREAS. A WARM AND MOIST AIR MASS WAS
IN PLACE ACROSS THE FORECAST AREA WITH DEW POINTS IN THE MIDDLE
AND LOWER 60S.

FORECAST SOUNDINGS CONTINUE TO REVEAL CONDITIONS IDEAL FOR
CONVECTION WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S AND CAPE
IN EXCESS OF 1000 J/KG. RAPID REFRESH INDICATES THAT CONVECTION
WILL DEVELOP ACROSS CENTRAL INDIANA THIS AFTERNOON. THUS HAVE
TRENDED POPS TOWARD 0 FOR THE NEXT 1-2 HOURS AS RADAR TRENDS SHOW
NOTHING FOR NOW...BUT WILL KEEP LIKELY POPS THIS AFTERNOON AS
CONDITIONS FOR SHOWERS AND THUNDERSTORMS BECOME MORE FAVORABLE.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 313 AM EDT FRI MAY 17 2013

FORECAST ISSUE WILL BE PRECIPITATION CHANCES. MODELS AGAIN HAVE A
GENERAL AGREEMENT BUT DIFFER SLIGHTLY IN HOW FAR NORTH THE UPPER
LOW OVER ARKANSAS LIFTS INTO INDIANA. THIS DIFFERENCE ALSO TIES TO
HOW FAR NORTH LIKELY RAIN AREAS WILL BE. GIVEN UNCERTAINTY WILL
USE A BLEND OF MODELS. WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD CONTINUE OVERNIGHT FRIDAY ON THROUGH AT LEAST
SATURDAY MORNING AS UPPER LOW REACHES ITS FARTHEST PUSH NORTH INTO
SOUTHERN INDIANA. AS THIS LOW MOVES EAST AND RIDGING DEVELOPS IN
ITS WAKE...PRECIPITATION SHOULD DIMINISH OR END IN WESTERN INDIANA
SATURDAY AFTERNOON OR EARLY EVENING. EASTERN COUNTIES THREAT FOR
RAIN WILL CONTINUE INTO SATURDAY NIGHT. SUNDAY REMAINS
QUESTIONABLE REGARDING RAIN. MODELS INCREASINGLY FAVOR DRY WEATHER
AS UPPER LOW EXITS TO THE EAST BUT WET GROUND AND WARMER TEMPS
WITH A BIT MORE SUNSHINE SUNDAY COULD STILL TRIGGER SOME ISOLATED
SHOWERS. ANOTHER MODEL RUN WITH SAME TREND COULD ALLOW REMOVAL OF
RAIN CHANCES FOR SUNDAY.

AS FOR TEMPS...ONGOING FORECAST NUMBERS WERE PRETTY GOOD WITH
MINS IN 62 TO 65 RANGE INTO MONDAY MORNING. MAXS SATURDAY WILL BE
CLOSE TO 80...WARMER THAN TODAY WITH A TAD MORE SUN THEN IN THE
80S SUNDAY AS EVEN MORE SUNSHINE AND RISING THICKNESSES.
INCREASING WINDS SUNDAY NIGHT AHEAD OF STRONG TROUGH SHOULD KEEP
SUNDAY NIGHT MINS IN MID OR EVEN UPPER 60S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 244 AM EDT FRI MAY 17 2013

UNSETTLED CONDITIONS APPEAR SET TO CONTINUE INTO THE COMING WEEK.
ENERGY IS EXPECTED TO DROP INTO THE NORTHERN PLAINS OVER THE
WEEKEND AND THEN VERY SLOWLY MAKE PROGRESS TO THE EAST DURING THE
WEEK. CENTRAL INDIANA SHOULD BE IN THE WARM SECTOR FOR MUCH OF THE
WEEK...BUT BOUNDARIES WILL AT TIMES BE WELL DISPLACED FROM THE
AREA AND UPPER LEVEL SUPPORT IS WEAK AT BEST. THUS...WHILE HAVE
MAINTAINED POPS IN ALL PERIODS BUT THE VERY END WHEN A SURFACE
HIGH IS FORECAST TO DROP INTO THE AREA...HAVE BACKED OFF ON POPS
SLIGHTLY MOST PERIODS...AS LACK OF SUPPORT FOR ORGANIZED
CONVECTION SHOULD LIMIT COVERAGE OF THUNDERSTORMS EXCEPT FOR
TUESDAY NIGHT/WEDNESDAY WHEN IT APPEARS A COLD FRONT SHOULD MOVE
THROUGH THE AREA.

TEMPS FROM INITIALIZATION APPEARED REASONABLE THROUGHOUT WITH ONLY
MINOR TWEAKS. WARMTH SHOULD PEAK EARLY IN THE WEEK WITH A GRADUAL
COOLDOWN IN THE MID TO LATE PORTION OF THE WEEK.

&&

.AVIATION /DISCUSSION FOR THE 171800Z TAFS/...
ISSUED AT 1240 PM EDT FRI MAY 17 2013

SCATTERED CONVECTION EXPECTED TO BEGIN DEVELOPING SOON AS CONVECTIVE
TEMPERATURES ARE JUST ABOUT REACHED. INSTABILITY AXIS CURRENTLY RUNS
THROUGH SOUTHWEST INDIANA...SO ANY INITIAL DEVELOPMENT WOULD
PROBABLY OCCUR IN THE VICINITY OF KHUF/KBMG AND THEN PROGRESS NORTH
WITH TIME GIVEN THE STEERING FLOW ALOFT. MODELS INDICATE A WEAK
VORTICITY LOBE MAY SHIFT NORTH ACROSS THE AREA LATER THIS
AFTERNOON/EVENING...WHICH MAY SERVE TO PROLONG THE CONVECTIVE THREAT
A LITTLE LONGER THAN WOULD NORMALLY BE EXPECTED IN A STRICTLY
DIURNAL SITUATION. IN ANY EVENT...AT THIS TIME CAN/T REALLY PIN DOWN
ANYTHING DEFINITIVE...SO WILL KEEP A VCTS AT THE TAF SITES THROUGH
180200Z. BRIEF IFR VISIBILITY RESTRICTIONS AND GUSTY/SHIFTING WINDS
POSSIBLE IN THE HEAVIER CELLS. CONVECTIVE CLOUD BASES AROUND 030.

OUTSIDE OF CONVECTIVE ACTIVITY...CEILINGS ABOVE 050 WITH NO WIND
ISSUES EXPECTED THROUGH 180600Z. SOME MVFR VISIBILITIES IN LIGHT FOG
MAY DEVELOP AFTER 180500Z...ESPECIALLY IN AREAS THAT RECEIVE
RAINFALL THIS AFTERNOON.

&&

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

$$

SYNOPSIS...TUCEK
NEAR TERM...PUMA
SHORT TERM...TUCEK
LONG TERM....NIELD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 171445
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1039 AM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 330 AM EDT FRI MAY 17 2013

SURFACE FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. UPPER
LOW LIFTING NORTHEAST FROM ARKANSAS HAS DEVELOPED SMALL AREA OF
SHOWERS OVER SOUTHWEST INDIANA THATS MOVING NORTH TOWARD OUR
SOUTHWEST FORECAST AREA. ALL MODELS IN A GENERAL AGREEMENT ON
LIFTING THE UPPER LOW INTO INDIANA TONIGHT AND THEN MOVE IT ACROSS
THE UPPER OHIO VALLEY RESULTING IN PERIODS OF SHOWERS AND STORMS
THROUGH AT LEAST SATURDAY EVENING. THIS SYSTEM EXITS WHILE LARGE
TROUGH CARVES OUT OVER THE WESTERN HALF OF THE COUNTRY INTO THE
WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF NEXT WEEK ALONG
WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 933 AM EDT FRI MAY 17 2013

SURFACE ANALYSIS THIS MORNING SHOWS THE LINGERING FRONTAL BOUNDARY
STRETCHED ACROSS THE NORTHERN PARTS OF THE FORECAST...JUST SOUTH
OF THE LAFAYETTE AND MUNCIE AREAS. A WARM AND MOIST AIR MASS WAS
IN PLACE ACROSS THE FORECAST AREA WITH DEW POINTS IN THE MIDDLE
AND LOWER 60S.

FORECAST SOUNDINGS CONTINUE TO REVEAL CONDITIONS IDEAL FOR
CONVECTION WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S AND CAPE
IN EXCESS OF 1000 J/KG. RAPID REFRESH INDICATES THAT CONVECTION
WILL DEVELOP ACROSS CENTRAL INDIANA THIS AFTERNOON. THUS HAVE
TRENDED POPS TOWARD 0 FOR THE NEXT 1-2 HOURS AS RADAR TRENDS SHOW
NOTHING FOR NOW...BUT WILL KEEP LIKELY POPS THIS AFTERNOON AS
CONDITIONS FOR SHOWERS AND THUNDERSTORMS BECOME MORE FAVORABLE.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 313 AM EDT FRI MAY 17 2013

FORECAST ISSUE WILL BE PRECIPITATION CHANCES. MODELS AGAIN HAVE A
GENERAL AGREEMENT BUT DIFFER SLIGHTLY IN HOW FAR NORTH THE UPPER
LOW OVER ARKANSAS LIFTS INTO INDIANA. THIS DIFFERENCE ALSO TIES TO
HOW FAR NORTH LIKELY RAIN AREAS WILL BE. GIVEN UNCERTAINTY WILL
USE A BLEND OF MODELS. WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD CONTINUE OVERNIGHT FRIDAY ON THROUGH AT LEAST
SATURDAY MORNING AS UPPER LOW REACHES ITS FARTHEST PUSH NORTH INTO
SOUTHERN INDIANA. AS THIS LOW MOVES EAST AND RIDGING DEVELOPS IN
ITS WAKE...PRECIPITATION SHOULD DIMINISH OR END IN WESTERN INDIANA
SATURDAY AFTERNOON OR EARLY EVENING. EASTERN COUNTIES THREAT FOR
RAIN WILL CONTINUE INTO SATURDAY NIGHT. SUNDAY REMAINS
QUESTIONABLE REGARDING RAIN. MODELS INCREASINGLY FAVOR DRY WEATHER
AS UPPER LOW EXITS TO THE EAST BUT WET GROUND AND WARMER TEMPS
WITH A BIT MORE SUNSHINE SUNDAY COULD STILL TRIGGER SOME ISOLATED
SHOWERS. ANOTHER MODEL RUN WITH SAME TREND COULD ALLOW REMOVAL OF
RAIN CHANCES FOR SUNDAY.

AS FOR TEMPS...ONGOING FORECAST NUMBERS WERE PRETTY GOOD WITH
MINS IN 62 TO 65 RANGE INTO MONDAY MORNING. MAXS SATURDAY WILL BE
CLOSE TO 80...WARMER THAN TODAY WITH A TAD MORE SUN THEN IN THE
80S SUNDAY AS EVEN MORE SUNSHINE AND RISING THICKNESSES.
INCREASING WINDS SUNDAY NIGHT AHEAD OF STRONG TROUGH SHOULD KEEP
SUNDAY NIGHT MINS IN MID OR EVEN UPPER 60S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 244 AM EDT FRI MAY 17 2013

UNSETTLED CONDITIONS APPEAR SET TO CONTINUE INTO THE COMING WEEK.
ENERGY IS EXPECTED TO DROP INTO THE NORTHERN PLAINS OVER THE
WEEKEND AND THEN VERY SLOWLY MAKE PROGRESS TO THE EAST DURING THE
WEEK. CENTRAL INDIANA SHOULD BE IN THE WARM SECTOR FOR MUCH OF THE
WEEK...BUT BOUNDARIES WILL AT TIMES BE WELL DISPLACED FROM THE
AREA AND UPPER LEVEL SUPPORT IS WEAK AT BEST. THUS...WHILE HAVE
MAINTAINED POPS IN ALL PERIODS BUT THE VERY END WHEN A SURFACE
HIGH IS FORECAST TO DROP INTO THE AREA...HAVE BACKED OFF ON POPS
SLIGHTLY MOST PERIODS...AS LACK OF SUPPORT FOR ORGANIZED
CONVECTION SHOULD LIMIT COVERAGE OF THUNDERSTORMS EXCEPT FOR
TUESDAY NIGHT/WEDNESDAY WHEN IT APPEARS A COLD FRONT SHOULD MOVE
THROUGH THE AREA.

TEMPS FROM INITIALIZATION APPEARED REASONABLE THROUGHOUT WITH ONLY
MINOR TWEAKS. WARMTH SHOULD PEAK EARLY IN THE WEEK WITH A GRADUAL
COOLDOWN IN THE MID TO LATE PORTION OF THE WEEK.

&&

.AVIATION /DISCUSSION FOR THE 171500Z KIND TAF UPDATE/...
ISSUED AT 1039 AM EDT FRI MAY 17 2013

SCATTERED CONVECTION POSSIBLE AFTER ABOUT 171700Z AS CONVECTIVE
TEMPERATURES ARE REACHED. ALTHOUGH BASED ON THIS MORNING/S UPPER
AIR...AIR MASS IS A LITTLE MORE STABLE THAN YESTERDAY...WHICH MAY
RESULT IN LESS CONVECTION THAN OCCURRED YESTERDAY.

AT THIS TIME...DON/T SEE ANY KIND OF DEFINITIVE FOCUS FOR
CONVECTION...SO WILL KEEP VCTS GOING AFTER 171700Z FOR NOW.

PREVIOUS DISCUSSION FOLLOWS.

BORDERLINE MVFR/IFR FOG AT THE OUTLYING SITES THIS MORNING.
CONDITIONS WILL BECOME VFR LATER EXCEPT FOR POSSIBLE
SHOWERS/THUNDERSTORMS. RESTRICTIONS APPEAR LIKELY AGAIN LATER
TONIGHT AS THE WEAKENING UPPER LOW MOVES ACROSS THE AREA.

AMPLE LOW LEVEL MOISTURE IN PLACE ACROSS THE AREA...AND THIS HAS LED
TO FOG DEVELOPMENT AT THE OUTLYING SITES THIS MORNING. VISIBILITIES
HAVE OCCASIONALLY DIPPED INTO IFR BUT HAVE LARGELY REMAINED MVFR.
THIS WILL IMPROVE THROUGH THE FIRST COUPLE OF HOURS AND BECOME ALL
VFR BY MID MORNING.

AS AN UPPER LOW APPROACHES AND A FEW BOUNDARIES LINGER IN THE
AREA...SHOWERS SHOULD DEVELOP LATER THIS MORNING...WITH
THUNDERSTORMS BECOMING POSSIBLE THIS AFTERNOON AS INSTABILITY
INCREASES. THUNDERSTORMS WILL BE POSSIBLE THROUGH THE EVENING.
RESTRICTIONS MAY OCCUR AT TIMES WITH SHOWERS AND STORMS BUT WILL BE
TOO UNCERTAIN AND TRANSIENT TO INCLUDE AT THIS TIME.

AMPLE MOISTURE WILL REMAIN IN PLACE OVERNIGHT AND THE WEAKENING
UPPER LOW WILL MOVE INTO THE AREA. THUS...EXPECTING RESTRICTIONS TO
REDEVELOP TONIGHT. IFR WILL BE POSSIBLE...BUT FOR NOW WILL CONFINE
TO LOW END MVFR OWING TO UNCERTAINTY.

WINDS WILL GENERALLY BE SOUTHEASTERLY/EASTERLY 10KT OR LESS THROUGH
THE PERIOD.


&&

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

$$

SYNOPSIS...TUCEK
NEAR TERM...PUMA
SHORT TERM...TUCEK
LONG TERM....NIELD
AVIATION...NIELD/JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 171444
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1044 AM EDT FRI MAY 17 2013

.SYNOPSIS...
ISSUED AT 1039 AM EDT FRI MAY 17 2013

A FRONTAL BOUNDARY WILL SLOWLY SHIFT NORTH TODAY...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF NORTHERN
INDIANA. THIS FRONT WILL REMAIN IN THE GENERAL AREA THROUGH
SATURDAY BEFORE SHIFTING NORTH OF THE REGION SUNDAY. BETTER
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE BY TUESDAY INTO
WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EDT FRI MAY 17 2013

THE CHALLENGES FOR TODAY AND TONIGHT INCLUDE COVERAGE AND TIMING OF
ANY SHOWERS AND THUNDERSTORMS. A NORTHEAST FETCH OF VERY DRY
CANADIAN AIR WILL CONTINUE TO KEEP DEW POINTS IN THE 30S AND 40S
NORTHEAST OF THE FRONT. OVERNIGHT...THE FRONT HAD REMAINED
STATIONARY FROM JUST SOUTH OF LOGANSPORT TO NEAR LIMA. SOME
OVERNIGHT STORMS WEST OF THE AREA OCCURRED SOUTH OF CHICAGO ALONG
THE FRONT NEAR THE INTERSECTION OF LOW LEVEL WIND MAXIMUM AND THE
FRONT. EXPECT THE FRONT TO BECOME ACTIVE THIS AFTERNOON WITH DAYTIME
HEATING...WITH SFC BASED CONVECTION DEVELOPING ALONG AND SOUTH OF
THE FRONT. NAM12 BUFKIT CAPES REACH 1000-1500 J/KG BY LATE
AFTERNOON...AND SHOULD SUPPORT AT LEAST ISOLATED THUNDERSTORMS OVER
SOUTH AND SOUTHWEST AREAS. THEREFORE...ADDED SHOWERS AND ISOLATED
THUNDER OVER THESE AREAS. OTHERWISE...NAM MET/GFS MAV HIGHS LOOK GOOD
TODAY. LOWERED TEMPS FAR NORTH 1-2 DEGREES WITH COOLER NORTHEAST
FETCH. GUT FEELING LOWS IN THE NORTH AND NORTHEAST ARE STILL TOO
WARM AND WILL NEED TO BE LOWERED MORE.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 441 AM EDT FRI MAY 17 2013

SPORADIC INSIPID CONVECTION TO PERSIST INTO SATURDAY...ONCE AGAIN
FOCUSED IN THE SOUTHERN THIRD OF THE CWA AND DURING AFTERNOON PEAK
HEATING. MARGINAL PRECIP CHANCES BEING SUPPORTED BY WEAK
PERTURBATION IN THE MIDLEVEL HEIGHT FIELD DRIFTING ACROSS THE
SOUTHERN OHIO VALLEY. HOWEVER...PALTRY MIDLEVEL LAPSE RATES COUPLED
WITH SURFACE DEWPOINTS BARELY IN THE LOW 60S RESULTS IN ONLY ABOUT
500 J/KG OF 0-1KM MLCAPE. FURTHERMORE...MODEST EASTERLY COMPONENT TO
THE LOW LEVEL FLOW EMANATING FROM EASTERN CANADA ANTICYCLONE WILL
LIKELY CONTINUE ON SATURDAY AND RESULT IN MORE STABLE LAKE-MODIFIED
AIRMASS ACROSS MICHIGAN AND OUR NORTHERN CWA. OLD SURFACE FRONTAL
BOUNDARY AND ASSOCIATED CONVERGENCE ALSO BECOME INCREASINGLY
DIFFICULT TO PINPOINT BY LATE SATURDAY AS THE UPPER WAVE SHIFTS
EAST. GIVEN THESE CONDITIONS...EXPECT SCATTERED THUNDERSTORMS AT
BEST AND MAINLY ACROSS THE SOUTH. WITH A RATHER HOMOGENEOUS AIRMASS
IN PLACE AND NO THERMAL ADVECTIONS TO SPEAK OF...HIGH TEMPS ON
SATURDAY WILL BE VERY SIMILAR TO TODAY AND YESTERDAY...AROUND 80F.

TRANSIENT MID/UPPER LEVEL RIDGING WILL BE IN PLACE ON SUNDAY.
RELATIVELY DRY TROPOSPHERE AND GENERAL SYNOPTIC SUBSIDENCE SHOULD
KEEP MOST AREAS PRECIP-FREE. LATEST NAM AND GFS BUFR SOUNDINGS ARE A
BIT WORRISOME THOUGH WITH MODERATE INSTABILITY AND A VERY WEAK CAP
THAT MAY WELL BE OVERCOME BY STRONG DIURNAL HEATING. LACK OF FORCING
MECHANISM AND DEEPER MOISTURE WILL LIKELY LIMIT COVERAGE BUT CANT
RULE OUT SOME ISOLATED CONVECTION AND WILL CONTINUE WITH BLANKET
SLIGHT CHANCE POPS. WEAK WIND SPEEDS ALOFT/LOW BULK SHEAR VALUES
WILL PREVENT ORGANIZED CONVECTION DESPITE POTENTIAL FOR MODERATELY
HIGH CAPE VALUES. HIGH TEMPS ON SUNDAY MAY CLIMB A FEW DEGREES
HIGHER GIVEN VEERING LOW LEVEL WINDS AND STRONG SOLAR INSOLATION.
850MB TEMPS LOOK TO BE AROUND 16C BY THE AFTERNOON...SUPPORTING
HIGHS IN THE LOW TO MID 80S.

PRECIP CHANCES THEN LOOK TO STEADILY INCREASE EARLY NEXT WEEK AS A
VERTICALLY STACKED SYSTEM SLOWLY APPROACHES THE GREAT LAKES REGION.
DEEP SOUTHWEST FLOW WILL DEVELOP BY MONDAY...ADVECTING HIGH THETA-E
AIR INTO THE REGION. 850MB TEMPS CONTINUE TO CREEP INTO THE UPPER
TEENS AND AFTERNOON SURFACE TEMPS MONDAY WILL LIKELY PUSH INTO THE
MID 80S ONCE AGAIN. INCREASING MOISTURE AND APPROACHING HEIGHT FALLS
WILL LEAD TO INCREASING COVERAGE OF SHOWERS AND THUNDERSTORMS WITH
THE BEST CHANCE FOR WIDESPREAD PRECIP IN THE TUES/WED TIMEFRAME.
INCREASED CLOUDS/PRECIP WILL TEMPER HIGHS A BIT DURING THIS PERIOD
BUT STILL EXPECT AFTERNOON TEMPS AROUND 80F. COOLER/DRIER CONDITIONS
THEN EXPECTED BY THE END OF THE WEEK AS TROUGH AXIS EXITS EASTWARD
AND CANADIAN SURFACE HIGH BUILDS OVER THE GREAT LAKES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 720 AM EDT FRI MAY 17 2013

VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH SCT CU AND PATCHES
OF HIGH CLOUDS MOVING TOWARDS BOTH SITES INTO THIS EVENING. A FEW
SHOWERS AND STORMS MAY DEVELOP THIS AFTERNOON AND EVENING...BUT
ARE EXPECTED TO REMAIN SOUTH OF BOTH SITES AT THIS TIME.

&&

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

$$

SYNOPSIS...FISHER
SHORT TERM...SKIPPER
LONG TERM...AGD
AVIATION...SKIPPER/FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 171341
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
941 AM EDT FRI MAY 17 2013

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW

&&

.SYNOPSIS...
ISSUED AT 330 AM EDT FRI MAY 17 2013

SURFACE FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. UPPER
LOW LIFTING NORTHEAST FROM ARKANSAS HAS DEVELOPED SMALL AREA OF
SHOWERS OVER SOUTHWEST INDIANA THATS MOVING NORTH TOWARD OUR
SOUTHWEST FORECAST AREA. ALL MODELS IN A GENERAL AGREEMENT ON
LIFTING THE UPPER LOW INTO INDIANA TONIGHT AND THEN MOVE IT ACROSS
THE UPPER OHIO VALLEY RESULTING IN PERIODS OF SHOWERS AND STORMS
THROUGH AT LEAST SATURDAY EVENING. THIS SYSTEM EXITS WHILE LARGE
TROUGH CARVES OUT OVER THE WESTERN HALF OF THE COUNTRY INTO THE
WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF NEXT WEEK ALONG
WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 933 AM EDT FRI MAY 17 2013

SURFACE ANALYSIS THIS MORNING SHOWS THE LINGERING FRONTAL BOUNDARY
STRETCHED ACROSS THE NORTHERN PARTS OF THE FORECAST...JUST SOUTH
OF THE LAFAYETTE AND MUNCIE AREAS. A WARM AND MOIST AIR MASS WAS
IN PLACE ACROSS THE FORECAST AREA WITH DEW POINTS IN THE MIDDLE
AND LOWER 60S.

FORECAST SOUNDINGS CONTINUE TO REVEAL CONDITIONS IDEAL FOR
CONVECTION WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S AND CAPE
IN EXCESS OF 1000 J/KG. RAPID REFRESH INDICATES THAT CONVECTION
WILL DEVELOP ACROSS CENTRAL INDIANA THIS AFTERNOON. THUS HAVE
TRENDED POPS TOWARD 0 FOR THE NEXT 1-2 HOURS AS RADAR TRENDS SHOW
NOTHING FOR NOW...BUT WILL KEEP LIKELY POPS THIS AFTERNOON AS
CONDITIONS FOR SHOWERS AND THUNDERSTORMS BECOME MORE FAVORABLE.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 313 AM EDT FRI MAY 17 2013

FORECAST ISSUE WILL BE PRECIPITATION CHANCES. MODELS AGAIN HAVE A
GENERAL AGREEMENT BUT DIFFER SLIGHTLY IN HOW FAR NORTH THE UPPER
LOW OVER ARKANSAS LIFTS INTO INDIANA. THIS DIFFERENCE ALSO TIES TO
HOW FAR NORTH LIKELY RAIN AREAS WILL BE. GIVEN UNCERTAINTY WILL
USE A BLEND OF MODELS. WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD CONTINUE OVERNIGHT FRIDAY ON THROUGH AT LEAST
SATURDAY MORNING AS UPPER LOW REACHES ITS FARTHEST PUSH NORTH INTO
SOUTHERN INDIANA. AS THIS LOW MOVES EAST AND RIDGING DEVELOPS IN
ITS WAKE...PRECIPITATION SHOULD DIMINISH OR END IN WESTERN INDIANA
SATURDAY AFTERNOON OR EARLY EVENING. EASTERN COUNTIES THREAT FOR
RAIN WILL CONTINUE INTO SATURDAY NIGHT. SUNDAY REMAINS
QUESTIONABLE REGARDING RAIN. MODELS INCREASINGLY FAVOR DRY WEATHER
AS UPPER LOW EXITS TO THE EAST BUT WET GROUND AND WARMER TEMPS
WITH A BIT MORE SUNSHINE SUNDAY COULD STILL TRIGGER SOME ISOLATED
SHOWERS. ANOTHER MODEL RUN WITH SAME TREND COULD ALLOW REMOVAL OF
RAIN CHANCES FOR SUNDAY.

AS FOR TEMPS...ONGOING FORECAST NUMBERS WERE PRETTY GOOD WITH
MINS IN 62 TO 65 RANGE INTO MONDAY MORNING. MAXS SATURDAY WILL BE
CLOSE TO 80...WARMER THAN TODAY WITH A TAD MORE SUN THEN IN THE
80S SUNDAY AS EVEN MORE SUNSHINE AND RISING THICKNESSES.
INCREASING WINDS SUNDAY NIGHT AHEAD OF STRONG TROUGH SHOULD KEEP
SUNDAY NIGHT MINS IN MID OR EVEN UPPER 60S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 244 AM EDT FRI MAY 17 2013

UNSETTLED CONDITIONS APPEAR SET TO CONTINUE INTO THE COMING WEEK.
ENERGY IS EXPECTED TO DROP INTO THE NORTHERN PLAINS OVER THE
WEEKEND AND THEN VERY SLOWLY MAKE PROGRESS TO THE EAST DURING THE
WEEK. CENTRAL INDIANA SHOULD BE IN THE WARM SECTOR FOR MUCH OF THE
WEEK...BUT BOUNDARIES WILL AT TIMES BE WELL DISPLACED FROM THE
AREA AND UPPER LEVEL SUPPORT IS WEAK AT BEST. THUS...WHILE HAVE
MAINTAINED POPS IN ALL PERIODS BUT THE VERY END WHEN A SURFACE
HIGH IS FORECAST TO DROP INTO THE AREA...HAVE BACKED OFF ON POPS
SLIGHTLY MOST PERIODS...AS LACK OF SUPPORT FOR ORGANIZED
CONVECTION SHOULD LIMIT COVERAGE OF THUNDERSTORMS EXCEPT FOR
TUESDAY NIGHT/WEDNESDAY WHEN IT APPEARS A COLD FRONT SHOULD MOVE
THROUGH THE AREA.

TEMPS FROM INITIALIZATION APPEARED REASONABLE THROUGHOUT WITH ONLY
MINOR TWEAKS. WARMTH SHOULD PEAK EARLY IN THE WEEK WITH A GRADUAL
COOLDOWN IN THE MID TO LATE PORTION OF THE WEEK.

&&

.AVIATION /DISCUSSION FOR THE 17/12Z TAFS/...
ISSUED AT 646 AM EDT FRI MAY 17 2013

BORDERLINE MVFR/IFR FOG AT THE OUTLYING SITES THIS MORNING.
CONDITIONS WILL BECOME VFR LATER EXCEPT FOR POSSIBLE
SHOWERS/THUNDERSTORMS. RESTRICTIONS APPEAR LIKELY AGAIN LATER
TONIGHT AS THE WEAKENING UPPER LOW MOVES ACROSS THE AREA.

AMPLE LOW LEVEL MOISTURE IN PLACE ACROSS THE AREA...AND THIS HAS LED
TO FOG DEVELOPMENT AT THE OUTLYING SITES THIS MORNING. VISIBILITIES
HAVE OCCASIONALLY DIPPED INTO IFR BUT HAVE LARGELY REMAINED MVFR.
THIS WILL IMPROVE THROUGH THE FIRST COUPLE OF HOURS AND BECOME ALL
VFR BY MID MORNING.

AS AN UPPER LOW APPROACHES AND A FEW BOUNDARIES LINGER IN THE
AREA...SHOWERS SHOULD DEVELOP LATER THIS MORNING...WITH
THUNDERSTORMS BECOMING POSSIBLE THIS AFTERNOON AS INSTABILITY
INCREASES. THUNDERSTORMS WILL BE POSSIBLE THROUGH THE EVENING.
RESTRICTIONS MAY OCCUR AT TIMES WITH SHOWERS AND STORMS BUT WILL BE
TOO UNCERTAIN AND TRANSIENT TO INCLUDE AT THIS TIME.

AMPLE MOISTURE WILL REMAIN IN PLACE OVERNIGHT AND THE WEAKENING
UPPER LOW WILL MOVE INTO THE AREA. THUS...EXPECTING RESTRICTIONS TO
REDEVELOP TONIGHT. IFR WILL BE POSSIBLE...BUT FOR NOW WILL CONFINE
TO LOW END MVFR OWING TO UNCERTAINTY.

WINDS WILL GENERALLY BE SOUTHEASTERLY/EASTERLY 10KT OR LESS THROUGH
THE PERIOD.


&&

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

$$

SYNOPSIS...TUCEK
NEAR TERM...PUMA
SHORT TERM...TUCEK
LONG TERM....NIELD
AVIATION...NIELD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 171046
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
646 AM EDT FRI MAY 17 2013

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 330 AM EDT FRI MAY 17 2013

SURFACE FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. UPPER
LOW LIFTING NORTHEAST FROM ARKANSAS HAS DEVELOPED SMALL AREA OF
SHOWERS OVER SOUTHWEST INDIANA THATS MOVING NORTH TOWARD OUR
SOUTHWEST FORECAST AREA. ALL MODELS IN A GENERAL AGREEMENT ON
LIFTING THE UPPER LOW INTO INDIANA TONIGHT AND THEN MOVE IT ACROSS
THE UPPER OHIO VALLEY RESULTING IN PERIODS OF SHOWERS AND STORMS
THROUGH AT LEAST SATURDAY EVENING. THIS SYSTEM EXITS WHILE LARGE
TROUGH CARVES OUT OVER THE WESTERN HALF OF THE COUNTRY INTO THE
WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF NEXT WEEK ALONG
WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /TODAY/...
ISSUED AT 313 AM EDT FRI MAY 17 2013

THOUGH MODELS AGREE IN BROADSCALE FEATURES...SLIGHT DIFFERENCES IN
EACH TRANSLATE TO DIFFERENCES IN RAIN CHANCES DEPENDING ON MODEL
CHOICE. HI RES MODEL HAS DONE WELL LAST COUPLE DAYS AND IS
CAPTURING CURRENT SHOWERS OVER SOUTHWEST INDIANA WITH APPROACHING
UPPER LOW SO WILL LEAN TOWARD THIS MODELS TREND. EXPECT SHOWERS
AND ISOLATED STORMS OVER SOUTHWEST INDIANA TO GRADUALLY SPREAD
NORTH AND INCREASE IN COVERAGE TIED TO UPPER LOWS DYNAMICS MOVING
CLOSER. STILL UNCERTAINTY AS TO WHETHER ANY BANDED PRECIPITATION
FORMS ALONG SURFACE FRONT IN NORTHERN COUNTIES AS HI RES
INDICATES. FOR NOW LEANING TO SOUTHWEST PRECIP AREA EXPANDING AND
MOVING NORTH ACROSS MOST OF FORECAST AREA BEFORE THE END OF THE
DAY.

FAIR AMOUNT OF CLOUD COVER EXPECTED THOUGH MOST AREAS SHOULD HAVE
A PERIOD OR TWO OF DIM SUNSHINE. THIS SHOULD HELP RAISE
TEMPERATURES TO MID AND UPPER 70S WITH NORTHERN COUNTIES SEEING A
BIT MORE SUN AND THE WARMER TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 313 AM EDT FRI MAY 17 2013

FORECAST ISSUE WILL BE PRECIPITATION CHANCES. MODELS AGAIN HAVE A
GENERAL AGREEMENT BUT DIFFER SLIGHTLY IN HOW FAR NORTH THE UPPER
LOW OVER ARKANSAS LIFTS INTO INDIANA. THIS DIFFERENCE ALSO TIES TO
HOW FAR NORTH LIKELY RAIN AREAS WILL BE. GIVEN UNCERTAINTY WILL
USE A BLEND OF MODELS. WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD CONTINUE OVERNIGHT FRIDAY ON THROUGH AT LEAST
SATURDAY MORNING AS UPPER LOW REACHES ITS FARTHEST PUSH NORTH INTO
SOUTHERN INDIANA. AS THIS LOW MOVES EAST AND RIDGING DEVELOPS IN
ITS WAKE...PRECIPITATION SHOULD DIMINISH OR END IN WESTERN INDIANA
SATURDAY AFTERNOON OR EARLY EVENING. EASTERN COUNTIES THREAT FOR
RAIN WILL CONTINUE INTO SATURDAY NIGHT. SUNDAY REMAINS
QUESTIONABLE REGARDING RAIN. MODELS INCREASINGLY FAVOR DRY WEATHER
AS UPPER LOW EXITS TO THE EAST BUT WET GROUND AND WARMER TEMPS
WITH A BIT MORE SUNSHINE SUNDAY COULD STILL TRIGGER SOME ISOLATED
SHOWERS. ANOTHER MODEL RUN WITH SAME TREND COULD ALLOW REMOVAL OF
RAIN CHANCES FOR SUNDAY.

AS FOR TEMPS...ONGOING FORECAST NUMBERS WERE PRETTY GOOD WITH
MINS IN 62 TO 65 RANGE INTO MONDAY MORNING. MAXS SATURDAY WILL BE
CLOSE TO 80...WARMER THAN TODAY WITH A TAD MORE SUN THEN IN THE
80S SUNDAY AS EVEN MORE SUNSHINE AND RISING THICKNESSES.
INCREASING WINDS SUNDAY NIGHT AHEAD OF STRONG TROUGH SHOULD KEEP
SUNDAY NIGHT MINS IN MID OR EVEN UPPER 60S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 244 AM EDT FRI MAY 17 2013

UNSETTLED CONDITIONS APPEAR SET TO CONTINUE INTO THE COMING WEEK.
ENERGY IS EXPECTED TO DROP INTO THE NORTHERN PLAINS OVER THE
WEEKEND AND THEN VERY SLOWLY MAKE PROGRESS TO THE EAST DURING THE
WEEK. CENTRAL INDIANA SHOULD BE IN THE WARM SECTOR FOR MUCH OF THE
WEEK...BUT BOUNDARIES WILL AT TIMES BE WELL DISPLACED FROM THE
AREA AND UPPER LEVEL SUPPORT IS WEAK AT BEST. THUS...WHILE HAVE
MAINTAINED POPS IN ALL PERIODS BUT THE VERY END WHEN A SURFACE
HIGH IS FORECAST TO DROP INTO THE AREA...HAVE BACKED OFF ON POPS
SLIGHTLY MOST PERIODS...AS LACK OF SUPPORT FOR ORGANIZED
CONVECTION SHOULD LIMIT COVERAGE OF THUNDERSTORMS EXCEPT FOR
TUESDAY NIGHT/WEDNESDAY WHEN IT APPEARS A COLD FRONT SHOULD MOVE
THROUGH THE AREA.

TEMPS FROM INITIALIZATION APPEARED REASONABLE THROUGHOUT WITH ONLY
MINOR TWEAKS. WARMTH SHOULD PEAK EARLY IN THE WEEK WITH A GRADUAL
COOLDOWN IN THE MID TO LATE PORTION OF THE WEEK.

&&

.AVIATION /DISCUSSION FOR THE 17/12Z TAFS/...
ISSUED AT 646 AM EDT FRI MAY 17 2013

BORDERLINE MVFR/IFR FOG AT THE OUTLYING SITES THIS MORNING.
CONDITIONS WILL BECOME VFR LATER EXCEPT FOR POSSIBLE
SHOWERS/THUNDERSTORMS. RESTRICTIONS APPEAR LIKELY AGAIN LATER
TONIGHT AS THE WEAKENING UPPER LOW MOVES ACROSS THE AREA.

AMPLE LOW LEVEL MOISTURE IN PLACE ACROSS THE AREA...AND THIS HAS LED
TO FOG DEVELOPMENT AT THE OUTLYING SITES THIS MORNING. VISIBILITIES
HAVE OCCASIONALLY DIPPED INTO IFR BUT HAVE LARGELY REMAINED MVFR.
THIS WILL IMPROVE THROUGH THE FIRST COUPLE OF HOURS AND BECOME ALL
VFR BY MID MORNING.

AS AN UPPER LOW APPROACHES AND A FEW BOUNDARIES LINGER IN THE
AREA...SHOWERS SHOULD DEVELOP LATER THIS MORNING...WITH
THUNDERSTORMS BECOMING POSSIBLE THIS AFTERNOON AS INSTABILITY
INCREASES. THUNDERSTORMS WILL BE POSSIBLE THROUGH THE EVENING.
RESTRICTIONS MAY OCCUR AT TIMES WITH SHOWERS AND STORMS BUT WILL BE
TOO UNCERTAIN AND TRANSIENT TO INCLUDE AT THIS TIME.

AMPLE MOISTURE WILL REMAIN IN PLACE OVERNIGHT AND THE WEAKENING
UPPER LOW WILL MOVE INTO THE AREA. THUS...EXPECTING RESTRICTIONS TO
REDEVELOP TONIGHT. IFR WILL BE POSSIBLE...BUT FOR NOW WILL CONFINE
TO LOW END MVFR OWING TO UNCERTAINTY.

WINDS WILL GENERALLY BE SOUTHEASTERLY/EASTERLY 10KT OR LESS THROUGH
THE PERIOD.

&&

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

&&

$$

SYNOPSIS...TUCEK
NEAR TERM...TUCEK
SHORT TERM...TUCEK
LONG TERM....NIELD
AVIATION...NIELD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 170842
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
442 AM EDT FRI MAY 17 2013

.SYNOPSIS...
ISSUED AT 205 AM EDT FRI MAY 17 2013

A STATIONARY FRONT WILL REMAIN OVER THE AREA WITH A CHANCE FOR
SHOWERS AND THUNDERSTORMS IN THE VICINITY OF THE FRONT AND SOUTH
OF THE FRONT. SHOWER AND THUNDERSTORM CHANCES WILL PERSIST
THROUGH THE WEEKEND AS THE FRONT REMAINS ACROSS THE AREA. ABOVE
NORMAL TEMPERATURES ARE EXPECTED THIS WEEKEND. CHANCES FOR SHOWERS
AND THUNDERSTORMS INCREASE EARLY NEXT WEEK AS A STORM SYSTEM
APPROACHES FROM THE WEST.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EDT FRI MAY 17 2013


THE CHALLENGES FOR TODAY AND TONIGHT INCLUDE COVERAGE AND TIMING OF
ANY SHOWERS AND THUNDERSTORMS. A NORTHEAST FETCH OF VERY DRY
CANADIAN AIR WILL CONTINUE TO KEEP DEW POINTS IN THE 30S AND 40S
NORTHEAST OF THE FRONT. OVERNIGHT...THE FRONT HAD REMAINED
STATIONARY FROM JUST SOUTH OF LOGANSPORT TO NEAR LIMA. SOME
OVERNIGHT STORMS WEST OF THE AREA OCCURRED SOUTH OF CHICAGO ALONG
THE FRONT NEAR THE INTERSECTION OF LOW LEVEL WIND MAXIMUM AND THE
FRONT. EXPECT THE FRONT TO BECOME ACTIVE THIS AFTERNOON WITH DAYTIME
HEATING...WITH SFC BASED CONVECTION DEVELOPING ALONG AND SOUTH OF
THE FRONT. NAM12 BUFKIT CAPES REACH 1000-1500 J/KG BY LATE
AFTERNOON...AND SHOULD SUPPORT AT LEAST ISOLATED THUNDERSTORMS OVER
SOUTH AND SOUTHWEST AREAS. THEREFORE...ADDED SHOWERS AND ISOLATED
THUNDER OVER THESE AREAS. OTHERWISE...NAM MET/GFS MAV HIGHS LOOK GOOD
TODAY. LOWERED TEMPS FAR NORTH 1-2 DEGREES WITH COOLER NORTHEAST
FETCH. GUT FEELING LOWS IN THE NORTH AND NORTHEAST ARE STILL TOO
WARM AND WILL NEED TO BE LOWERED MORE.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 441 AM EDT FRI MAY 17 2013

SPORADIC INSIPID CONVECTION TO PERSIST INTO SATURDAY...ONCE AGAIN
FOCUSED IN THE SOUTHERN THIRD OF THE CWA AND DURING AFTERNOON PEAK
HEATING. MARGINAL PRECIP CHANCES BEING SUPPORTED BY WEAK
PERTURBATION IN THE MIDLEVEL HEIGHT FIELD DRIFTING ACROSS THE
SOUTHERN OHIO VALLEY. HOWEVER...PALTRY MIDLEVEL LAPSE RATES COUPLED
WITH SURFACE DEWPOINTS BARELY IN THE LOW 60S RESULTS IN ONLY ABOUT
500 J/KG OF 0-1KM MLCAPE. FURTHERMORE...MODEST EASTERLY COMPONENT TO
THE LOW LEVEL FLOW EMANATING FROM EASTERN CANADA ANTICYCLONE WILL
LIKELY CONTINUE ON SATURDAY AND RESULT IN MORE STABLE LAKE-MODIFIED
AIRMASS ACROSS MICHIGAN AND OUR NORTHERN CWA. OLD SURFACE FRONTAL
BOUNDARY AND ASSOCIATED CONVERGENCE ALSO BECOME INCREASINGLY
DIFFICULT TO PINPOINT BY LATE SATURDAY AS THE UPPER WAVE SHIFTS
EAST. GIVEN THESE CONDITIONS...EXPECT SCATTERED THUNDERSTORMS AT
BEST AND MAINLY ACROSS THE SOUTH. WITH A RATHER HOMOGENEOUS AIRMASS
IN PLACE AND NO THERMAL ADVECTIONS TO SPEAK OF...HIGH TEMPS ON
SATURDAY WILL BE VERY SIMILAR TO TODAY AND YESTERDAY...AROUND 80F.

TRANSIENT MID/UPPER LEVEL RIDGING WILL BE IN PLACE ON SUNDAY.
RELATIVELY DRY TROPOSPHERE AND GENERAL SYNOPTIC SUBSIDENCE SHOULD
KEEP MOST AREAS PRECIP-FREE. LATEST NAM AND GFS BUFR SOUNDINGS ARE A
BIT WORRISOME THOUGH WITH MODERATE INSTABILITY AND A VERY WEAK CAP
THAT MAY WELL BE OVERCOME BY STRONG DIURNAL HEATING. LACK OF FORCING
MECHANISM AND DEEPER MOISTURE WILL LIKELY LIMIT COVERAGE BUT CANT
RULE OUT SOME ISOLATED CONVECTION AND WILL CONTINUE WITH BLANKET
SLIGHT CHANCE POPS. WEAK WIND SPEEDS ALOFT/LOW BULK SHEAR VALUES
WILL PREVENT ORGANIZED CONVECTION DESPITE POTENTIAL FOR MODERATELY
HIGH CAPE VALUES. HIGH TEMPS ON SUNDAY MAY CLIMB A FEW DEGREES
HIGHER GIVEN VEERING LOW LEVEL WINDS AND STRONG SOLAR INSOLATION.
850MB TEMPS LOOK TO BE AROUND 16C BY THE AFTERNOON...SUPPORTING
HIGHS IN THE LOW TO MID 80S.

PRECIP CHANCES THEN LOOK TO STEADILY INCREASE EARLY NEXT WEEK AS A
VERTICALLY STACKED SYSTEM SLOWLY APPROACHES THE GREAT LAKES REGION.
DEEP SOUTHWEST FLOW WILL DEVELOP BY MONDAY...ADVECTING HIGH THETA-E
AIR INTO THE REGION. 850MB TEMPS CONTINUE TO CREEP INTO THE UPPER
TEENS AND AFTERNOON SURFACE TEMPS MONDAY WILL LIKELY PUSH INTO THE
MID 80S ONCE AGAIN. INCREASING MOISTURE AND APPROACHING HEIGHT FALLS
WILL LEAD TO INCREASING COVERAGE OF SHOWERS AND THUNDERSTORMS WITH
THE BEST CHANCE FOR WIDESPREAD PRECIP IN THE TUES/WED TIMEFRAME.
INCREASED CLOUDS/PRECIP WILL TEMPER HIGHS A BIT DURING THIS PERIOD
BUT STILL EXPECT AFTERNOON TEMPS AROUND 80F. COOLER/DRIER CONDITIONS
THEN EXPECTED BY THE END OF THE WEEK AS TROUGH AXIS EXITS EASTWARD
AND CANADIAN SURFACE HIGH BUILDS OVER THE GREAT LAKES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 441 AM EDT FRI MAY 17 2013


A WELL DEFINED FRONT WAS JUST SOUTHWEST OF THE TERMINALS EARLY THIS
MORNING. THE FRONT SHOULD BE NEARLY STATIONARY TODAY...BUT MAY DRIFT
NORTH AS A WARM FRONT LATER TODAY. ADDED A VICINITY SHOWER AT BOTH
TERMINALS LATE IN THE DAY WITH THE FRONT IN THE VICINITY AND DURING
MAXIMUM DAYTIME INSTABILITY. THERE IS ALSO AN OUTSIDE CHANCE FOR
THUNDER...MAINLY LATE AFTERNOON INTO EARLY EVENING...BUT FOR
NOW...LEFT THUNDER OUT GIVEN THE MORE ISOLATED NATURE OF COVERAGE
EXPECTED. KEPT TAFS VFR.


&&

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

$$

SYNOPSIS...BENTLEY/SKIPPER
SHORT TERM...SKIPPER
LONG TERM...AGD
AVIATION...SKIPPER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 170824
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
424 AM EDT FRI MAY 17 2013

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 330 AM EDT FRI MAY 17 2013

SURFACE FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. UPPER
LOW LIFTING NORTHEAST FROM ARKANSAS HAS DEVELOPED SMALL AREA OF
SHOWERS OVER SOUTHWEST INDIANA THATS MOVING NORTH TOWARD OUR
SOUTHWEST FORECAST AREA. ALL MODELS IN A GENERAL AGREEMENT ON
LIFTING THE UPPER LOW INTO INDIANA TONIGHT AND THEN MOVE IT ACROSS
THE UPPER OHIO VALLEY RESULTING IN PERIODS OF SHOWERS AND STORMS
THROUGH AT LEAST SATURDAY EVENING. THIS SYSTEM EXITS WHILE LARGE
TROUGH CARVES OUT OVER THE WESTERN HALF OF THE COUNTRY INTO THE
WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF NEXT WEEK ALONG
WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /TODAY/...
ISSUED AT 313 AM EDT FRI MAY 17 2013

THOUGH MODELS AGREE IN BROADSCALE FEATURES...SLIGHT DIFFERENCES IN
EACH TRANSLATE TO DIFFERENCES IN RAIN CHANCES DEPENDING ON MODEL
CHOICE. HI RES MODEL HAS DONE WELL LAST COUPLE DAYS AND IS
CAPTURING CURRENT SHOWERS OVER SOUTHWEST INDIANA WITH APPROACHING
UPPER LOW SO WILL LEAN TOWARD THIS MODELS TREND. EXPECT SHOWERS
AND ISOLATED STORMS OVER SOUTHWEST INDIANA TO GRADUALLY SPREAD
NORTH AND INCREASE IN COVERAGE TIED TO UPPER LOWS DYNAMICS MOVING
CLOSER. STILL UNCERTAINTY AS TO WHETHER ANY BANDED PRECIPITATION
FORMS ALONG SURFACE FRONT IN NORTHERN COUNTIES AS HI RES
INDICATES. FOR NOW LEANING TO SOUTHWEST PRECIP AREA EXPANDING AND
MOVING NORTH ACROSS MOST OF FORECAST AREA BEFORE THE END OF THE
DAY.

FAIR AMOUNT OF CLOUD COVER EXPECTED THOUGH MOST AREAS SHOULD HAVE
A PERIOD OR TWO OF DIM SUNSHINE. THIS SHOULD HELP RAISE
TEMPERATURES TO MID AND UPPER 70S WITH NORTHERN COUNTIES SEEING A
BIT MORE SUN AND THE WARMER TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 313 AM EDT FRI MAY 17 2013

FORECAST ISSUE WILL BE PRECIPITATION CHANCES. MODELS AGAIN HAVE A
GENERAL AGREEMENT BUT DIFFER SLIGHTLY IN HOW FAR NORTH THE UPPER
LOW OVER ARKANSAS LIFTS INTO INDIANA. THIS DIFFERENCE ALSO TIES TO
HOW FAR NORTH LIKELY RAIN AREAS WILL BE. GIVEN UNCERTAINTY WILL
USE A BLEND OF MODELS. WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD CONTINUE OVERNIGHT FRIDAY ON THROUGH AT LEAST
SATURDAY MORNING AS UPPER LOW REACHES ITS FARTHEST PUSH NORTH INTO
SOUTHERN INDIANA. AS THIS LOW MOVES EAST AND RIDGING DEVELOPS IN
ITS WAKE...PRECIPITATION SHOULD DIMINISH OR END IN WESTERN INDIANA
SATURDAY AFTERNOON OR EARLY EVENING. EASTERN COUNTIES THREAT FOR
RAIN WILL CONTINUE INTO SATURDAY NIGHT. SUNDAY REMAINS
QUESTIONABLE REGARDING RAIN. MODELS INCREASINGLY FAVOR DRY WEATHER
AS UPPER LOW EXITS TO THE EAST BUT WET GROUND AND WARMER TEMPS
WITH A BIT MORE SUNSHINE SUNDAY COULD STILL TRIGGER SOME ISOLATED
SHOWERS. ANOTHER MODEL RUN WITH SAME TREND COULD ALLOW REMOVAL OF
RAIN CHANCES FOR SUNDAY.

AS FOR TEMPS...ONGOING FORECAST NUMBERS WERE PRETTY GOOD WITH
MINS IN 62 TO 65 RANGE INTO MONDAY MORNING. MAXS SATURDAY WILL BE
CLOSE TO 80...WARMER THAN TODAY WITH A TAD MORE SUN THEN IN THE
80S SUNDAY AS EVEN MORE SUNSHINE AND RISING THICKNESSES.
INCREASING WINDS SUNDAY NIGHT AHEAD OF STRONG TROUGH SHOULD KEEP
SUNDAY NIGHT MINS IN MID OR EVEN UPPER 60S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 244 AM EDT FRI MAY 17 2013

UNSETTLED CONDITIONS APPEAR SET TO CONTINUE INTO THE COMING WEEK.
ENERGY IS EXPECTED TO DROP INTO THE NORTHERN PLAINS OVER THE
WEEKEND AND THEN VERY SLOWLY MAKE PROGRESS TO THE EAST DURING THE
WEEK. CENTRAL INDIANA SHOULD BE IN THE WARM SECTOR FOR MUCH OF THE
WEEK...BUT BOUNDARIES WILL AT TIMES BE WELL DISPLACED FROM THE
AREA AND UPPER LEVEL SUPPORT IS WEAK AT BEST. THUS...WHILE HAVE
MAINTAINED POPS IN ALL PERIODS BUT THE VERY END WHEN A SURFACE
HIGH IS FORECAST TO DROP INTO THE AREA...HAVE BACKED OFF ON POPS
SLIGHTLY MOST PERIODS...AS LACK OF SUPPORT FOR ORGANIZED
CONVECTION SHOULD LIMIT COVERAGE OF THUNDERSTORMS EXCEPT FOR
TUESDAY NIGHT/WEDNESDAY WHEN IT APPEARS A COLD FRONT SHOULD MOVE
THROUGH THE AREA.

TEMPS FROM INITIALIZATION APPEARED REASONABLE THROUGHOUT WITH ONLY
MINOR TWEAKS. WARMTH SHOULD PEAK EARLY IN THE WEEK WITH A GRADUAL
COOLDOWN IN THE MID TO LATE PORTION OF THE WEEK.

&&

.AVIATION /DISCUSSION FOR THE 17/09Z TAF UPDATE/...
ISSUED AT 424 AM EDT FRI MAY 17 2013

REMOVED MVFR FOG FROM IND...AS VISIBILITIES SO FAR HAVE ONLY
DECREASED TO 8SM ONLY TO RISE AGAIN...AND WINDS REMAIN ABOUT 4KT
WITH BROKEN MIDLEVEL CLOUDS. WILL MONITOR...BUT AT THIS TIME
PREVAILING MVFR CONDITIONS APPEAR UNLIKELY AT IND. PREVIOUS
DISCUSSION FOLLOWS.

ISSUED AT 1236 AM EDT FRI MAY 17 2013

WAVY QUASI-STATIONARY FRONT WAS JUST NORTH OF LAF LATE THIS EVENING
AS EVIDENCE BY DEW POINT RISING TO 59 THERE. CONFIDENCE IN EXACT
FRONTAL POSITION NOT GREAT...BUT WITH LIGHT TO CALM WINDS
OVERNIGHT...THE MAIN RESULT COULD BE SOME LIGHT FOG AT LAF AFTER 08Z
IF THE FRONT STAYS WHERE IT IS. OTHERWISE...MID AND HIGH CLOUDS
SHOULD KEEP ANY PROLONGED IFR FOG. WILL...JUST GO WITH MVFR AND
TEMPO IFR AT BMG AND HUF 08Z-12Z AND ONLY TEMPO MVFR AT IND AND LAF.
WEAK WAVE ACROSS SOUTHWEST INDIANA ALONG WITH THE FRONT IN THE AREA
COULD TRIGGER SOME THUNDERSTORMS OVERNIGHT AND THIS MORNING...BUT
BELIEVE COVERAGE WILL SPARSE UNTIL AFTER 15Z WHEN INSTABILITY
INCREASE AND UPPER TROUGH APPROACHES THE ILLINOIS AND INDIANA
BORDER.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

WINDS WILL BECOME SOUTHEAST LESS THAN 10 KNOTS AFTER 15Z AND BECOME
LIGHT AGAIN AFTER 00Z.

&&

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

&&

$$

SYNOPSIS...TUCEK
NEAR TERM...TUCEK
SHORT TERM...TUCEK
LONG TERM....NIELD
AVIATION...MK/NIELD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 170737
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
337 AM EDT FRI MAY 17 2013

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

&&

.SYNOPSIS...
ISSUED AT 330 AM EDT FRI MAY 17 2013

SURFACE FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. UPPER
LOW LIFTING NORTHEAST FROM ARKANSAS HAS DEVELOPED SMALL AREA OF
SHOWERS OVER SOUTHWEST INDIANA THATS MOVING NORTH TOWARD OUR
SOUTHWEST FORECAST AREA. ALL MODELS IN A GENERAL AGREEMENT ON
LIFTING THE UPPER LOW INTO INDIANA TONIGHT AND THEN MOVE IT ACROSS
THE UPPER OHIO VALLEY RESULTING IN PERIODS OF SHOWERS AND STORMS
THROUGH AT LEAST SATURDAY EVENING. THIS SYSTEM EXITS WHILE LARGE
TROUGH CARVES OUT OVER THE WESTERN HALF OF THE COUNTRY INTO THE
WEEKEND WHICH WILL BRING WARMER AIR FOR MUCH OF NEXT WEEK ALONG
WITH ANOTHER COUPLE DAYS OF STORMY WEATHER MONDAY INTO MID WEEK.

&&

.NEAR TERM /TODAY/...

ISSUED AT 313 AM EDT FRI MAY 17 2013

THOUGH MODELS AGREE IN BROADSCALE FEATURES...SLIGHT DIFFERENCES IN
EACH TRANSLATE TO DIFFERENCES IN RAIN CHANCES DEPENDING ON MODEL
CHOICE. HI RES MODEL HAS DONE WELL LAST COUPLE DAYS AND IS
CAPTURING CURRENT SHOWERS OVER SOUTHWEST INDIANA WITH APPROACHING
UPPER LOW SO WILL LEAN TOWARD THIS MODELS TREND. EXPECT SHOWERS
AND ISOLATED STORMS OVER SOUTHWEST INDIANA TO GRADUALLY SPREAD
NORTH AND INCREASE IN COVERAGE TIED TO UPPER LOWS DYNAMICS MOVING
CLOSER. STILL UNCERTAINTY AS TO WHETHER ANY BANDED PRECIPITATION
FORMS ALONG SURFACE FRONT IN NORTHERN COUNTIES AS HI RES
INDICATES. FOR NOW LEANING TO SOUTHWEST PRECIP AREA EXPANDING AND
MOVING NORTH ACROSS MOST OF FORECAST AREA BEFORE THE END OF THE
DAY.

FAIR AMOUNT OF CLOUD COVER EXPECTED THOUGH MOST AREAS SHOULD HAVE
A PERIOD OR TWO OF DIM SUNSHINE. THIS SHOULD HELP RAISE
TEMPERATURES TO MID AND UPPER 70S WITH NORTHERN COUNTIES SEEING A
BIT MORE SUN AND THE WARMER TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 313 AM EDT FRI MAY 17 2013

FORECAST ISSUE WILL BE PRECIPITATION CHANCES. MODELS AGAIN HAVE A
GENERAL AGREEMENT BUT DIFFER SLIGHTLY IN HOW FAR NORTH THE UPPER
LOW OVER ARKANSAS LIFTS INTO INDIANA. THIS DIFFERENCE ALSO TIES TO
HOW FAR NORTH LIKELY RAIN AREAS WILL BE. GIVEN UNCERTAINTY WILL
USE A BLEND OF MODELS. WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD CONTINUE OVERNIGHT FRIDAY ON THROUGH AT LEAST
SATURDAY MORNING AS UPPER LOW REACHES ITS FARTHEST PUSH NORTH INTO
SOUTHERN INDIANA. AS THIS LOW MOVES EAST AND RIDGING DEVELOPS IN
ITS WAKE...PRECIPITATION SHOULD DIMINISH OR END IN WESTERN INDIANA
SATURDAY AFTERNOON OR EARLY EVENING. EASTERN COUNTIES THREAT FOR
RAIN WILL CONTINUE INTO SATURDAY NIGHT. SUNDAY REMAINS
QUESTIONABLE REGARDING RAIN. MODELS INCREASINGLY FAVOR DRY WEATHER
AS UPPER LOW EXITS TO THE EAST BUT WET GROUND AND WARMER TEMPS
WITH A BIT MORE SUNSHINE SUNDAY COULD STILL TRIGGER SOME ISOLATED
SHOWERS. ANOTHER MODEL RUN WITH SAME TREND COULD ALLOW REMOVAL OF
RAIN CHANCES FOR SUNDAY.

AS FOR TEMPS...ONGOING FORECAST NUMBERS WERE PRETTY GOOD WITH
MINS IN 62 TO 65 RANGE INTO MONDAY MORNING. MAXS SATURDAY WILL BE
CLOSE TO 80...WARMER THAN TODAY WITH A TAD MORE SUN THEN IN THE
80S SUNDAY AS EVEN MORE SUNSHINE AND RISING THICKNESSES.
INCREASING WINDS SUNDAY NIGHT AHEAD OF STRONG TROUGH SHOULD KEEP
SUNDAY NIGHT MINS IN MID OR EVEN UPPER 60S.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 244 AM EDT FRI MAY 17 2013

UNSETTLED CONDITIONS APPEAR SET TO CONTINUE INTO THE COMING WEEK.
ENERGY IS EXPECTED TO DROP INTO THE NORTHERN PLAINS OVER THE
WEEKEND AND THEN VERY SLOWLY MAKE PROGRESS TO THE EAST DURING THE
WEEK. CENTRAL INDIANA SHOULD BE IN THE WARM SECTOR FOR MUCH OF THE
WEEK...BUT BOUNDARIES WILL AT TIMES BE WELL DISPLACED FROM THE
AREA AND UPPER LEVEL SUPPORT IS WEAK AT BEST. THUS...WHILE HAVE
MAINTAINED POPS IN ALL PERIODS BUT THE VERY END WHEN A SURFACE
HIGH IS FORECAST TO DROP INTO THE AREA...HAVE BACKED OFF ON POPS
SLIGHTLY MOST PERIODS...AS LACK OF SUPPORT FOR ORGANIZED
CONVECTION SHOULD LIMIT COVERAGE OF THUNDERSTORMS EXCEPT FOR
TUESDAY NIGHT/WEDNESDAY WHEN IT APPEARS A COLD FRONT SHOULD MOVE
THROUGH THE AREA.

TEMPS FROM INITIALIZATION APPEARED REASONABLE THROUGHOUT WITH ONLY
MINOR TWEAKS. WARMTH SHOULD PEAK EARLY IN THE WEEK WITH A GRADUAL
COOLDOWN IN THE MID TO LATE PORTION OF THE WEEK.

&&

.AVIATION /DISCUSSION FOR THE 17/06Z TAFS/...
ISSUED AT 1236 AM EDT FRI MAY 17 2013

WAVY QUASI-STATIONARY FRONT WAS JUST NORTH OF LAF LATE THIS EVENING
AS EVIDENCE BY DEW POINT RISING TO 59 THERE. CONFIDENCE IN EXACT
FRONTAL POSITION NOT GREAT...BUT WITH LIGHT TO CALM WINDS
OVERNIGHT...THE MAIN RESULT COULD BE SOME LIGHT FOG AT LAF AFTER 08Z
IF THE FRONT STAYS WHERE IT IS. OTHERWISE...MID AND HIGH CLOUDS
SHOULD KEEP ANY PROLONGED IFR FOG. WILL...JUST GO WITH MVFR AND
TEMPO IFR AT BMG AND HUF 08Z-12Z AND ONLY TEMPO MVFR AT IND AND LAF.
WEAK WAVE ACROSS SOUTHWEST INDIANA ALONG WITH THE FRONT IN THE AREA
COULD TRIGGER SOME THUNDERSTORMS OVERNIGHT AND THIS MORNING...BUT
BELIEVE COVERAGE WILL SPARSE UNTIL AFTER 15Z WHEN INSTABILITY
INCREASE AND UPPER TROUGH APPROACHES THE ILLINOIS AND INDIANA
BORDER.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

WINDS WILL BECOME SOUTHEAST LESS THAN 10 KNOTS AFTER 15Z AND BECOME
LIGHT AGAIN AFTER 00Z.


&&

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

$$

SYNOPSIS...TUCEK
NEAR TERM...TUCEK
SHORT TERM...TUCEK
LONG TERM....NIELD
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 170644
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
244 AM EDT FRI MAY 17 2013

.UPDATE...

THE LONG TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /REST OF TONIGHT AND FRIDAY/...
ISSUED AT 1244 AM EDT FRI MAY 17 2013

WITH SURFACE BOUNDARY ACROSS OUR NORTHERN COUNTIES AND SOME
BANDING OF MID CLOUD NEAR FRONT THERE IS STILL A SLIGHT CHANCE FOR
STORMS REST OF THIS MORNING. MODELS DIFFER SLIGHTLY AS DAY WEARS
ON AND WILL ADDRESS THIS IN NEXT UPDATE. OTHERWISE CURRENT
FORECAST INTO DAYTIME HOURS APPEARS PRETTY GOOD AND ONLY SLIGHTLY
ADJUSTED DEWPOINTS AND WINDS TO REFLECT CURRENT CONDITIONS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 244 AM EDT FRI MAY 17 2013

UNSETTLED CONDITIONS APPEAR SET TO CONTINUE INTO THE COMING WEEK.
ENERGY IS EXPECTED TO DROP INTO THE NORTHERN PLAINS OVER THE
WEEKEND AND THEN VERY SLOWLY MAKE PROGRESS TO THE EAST DURING THE
WEEK. CENTRAL INDIANA SHOULD BE IN THE WARM SECTOR FOR MUCH OF THE
WEEK...BUT BOUNDARIES WILL AT TIMES BE WELL DISPLACED FROM THE
AREA AND UPPER LEVEL SUPPORT IS WEAK AT BEST. THUS...WHILE HAVE
MAINTAINED POPS IN ALL PERIODS BUT THE VERY END WHEN A SURFACE
HIGH IS FORECAST TO DROP INTO THE AREA...HAVE BACKED OFF ON POPS
SLIGHTLY MOST PERIODS...AS LACK OF SUPPORT FOR ORGANIZED
CONVECTION SHOULD LIMIT COVERAGE OF THUNDERSTORMS EXCEPT FOR
TUESDAY NIGHT/WEDNESDAY WHEN IT APPEARS A COLD FRONT SHOULD MOVE
THROUGH THE AREA.

TEMPS FROM INITIALIZATION APPEARED REASONABLE THROUGHOUT WITH ONLY
MINOR TWEAKS. WARMTH SHOULD PEAK EARLY IN THE WEEK WITH A GRADUAL
COOLDOWN IN THE MID TO LATE PORTION OF THE WEEK.

&&

.AVIATION /DISCUSSION FOR THE 17/06Z TAFS/...
ISSUED AT 1236 AM EDT FRI MAY 17 2013

WAVY QUASI-STATIONARY FRONT WAS JUST NORTH OF LAF LATE THIS EVENING
AS EVIDENCE BY DEW POINT RISING TO 59 THERE. CONFIDENCE IN EXACT
FRONTAL POSITION NOT GREAT...BUT WITH LIGHT TO CALM WINDS
OVERNIGHT...THE MAIN RESULT COULD BE SOME LIGHT FOG AT LAF AFTER 08Z
IF THE FRONT STAYS WHERE IT IS. OTHERWISE...MID AND HIGH CLOUDS
SHOULD KEEP ANY PROLONGED IFR FOG. WILL...JUST GO WITH MVFR AND
TEMPO IFR AT BMG AND HUF 08Z-12Z AND ONLY TEMPO MVFR AT IND AND LAF.
WEAK WAVE ACROSS SOUTHWEST INDIANA ALONG WITH THE FRONT IN THE AREA
COULD TRIGGER SOME THUNDERSTORMS OVERNIGHT AND THIS MORNING...BUT
BELIEVE COVERAGE WILL SPARSE UNTIL AFTER 15Z WHEN INSTABILITY
INCREASE AND UPPER TROUGH APPROACHES THE ILLINOIS AND INDIANA
BORDER.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

WINDS WILL BECOME SOUTHEAST LESS THAN 10 KNOTS AFTER 15Z AND BECOME
LIGHT AGAIN AFTER 00Z.

&&

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

&&

$$

SYNOPSIS...PUMA
NEAR TERM...TUCEK
SHORT TERM...PUMA
LONG TERM....NIELD
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 170624
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
224 AM EDT FRI MAY 17 2013

.SYNOPSIS...
ISSUED AT 205 AM EDT FRI MAY 17 2013

A STATIONARY FRONT WILL REMAIN OVER THE AREA WITH A CHANCE FOR
SHOWERS AND THUNDERSTORMS IN THE VICINITY OF THE FRONT AND SOUTH
OF THE FRONT. SHOWER AND THUNDERSTORM CHANCES WILL PERSIST
THROUGH THE WEEKEND AS THE FRONT REMAINS ACROSS THE AREA. ABOVE
NORMAL TEMPERATURES ARE EXPECTED THIS WEEKEND. CHANCES FOR SHOWERS
AND THUNDERSTORMS INCREASE EARLY NEXT WEEK AS A STORM SYSTEM
APPROACHES FROM THE WEST.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
HIGH PRESSURE HAS KEPT BULK OF MSTR JUST FAR ENOUGH SOUTH OF THE
AREA TODAY TO ALLOW FOR GENERALLY DRY CONDITIONS AND TEMPS MOVING
WELL THROUGH THE 70S IN MOST SPOTS. A FEW LIGHT SHOWERS/SPRINKLES
WERE NOTED ALONG FIRST OF 2 SFC THETA E GRADIENTS ACROSS FAR
SOUTHERN COUNTIES. THIS AREA IS EXPECTED TO SHIFT SOUTH OVER THE
NEXT SEVERAL HOURS AND REMOVE ANY CHANCE FOR PRECIP FOR THE
REMAINDER OF THE NIGHT. SECONDARY GRADIENT WAS LOCATED FURTHER
SOUTH ACROSS SOUTHERN INDIANA WHERE CONVECTION HAS BEEN ONGOING
MUCH OF THE DAY. MODELS TEND TO SUGGEST THAT THIS SECONDARY AREA
OF MSTR/GREATER LIFT SUPPORT WITH MAIN SFC BOUNDARY WILL BRING
INCREASING CHANCES FOR SHOWERS AND STORMS ON FRIDAY. IT WOULD
APPEAR THAT MOST FAVORABLE TIMING WOULD BE MID TO LATE AFTERNOON
FRIDAY IN FAR SW SECTIONS WITH PROGRESSION NE HAMPERED SOMEWHAT BY
DRY AIR/SEMI DRY GROUND CONDITIONS. IF NEW RUN OF SPC 4KM WRF IS
FOLLOWED...CONVECTION WOULD NOT ARRIVE UNTIL AFTER 00Z SAT. HAVE
ADJUSTED GRIDS TO REFLECT THIS WITH SLGT CHC TO CHC POPS CONFINED
TO AFTERNOON.

CLOUD COVER WILL BE ON THE INCREASE...WHICH WILL BUT A DAMPER ON
POTENTIAL CLIMB IN HIGHS. THAT BEING SAID...HIGHS SHOULD STILL END
UP ABOVE NORMAL CLIMBING INTO THE MID AND UPPER 70S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
WATER VAPOR IMAGERY AND LATEST RAP ANALYSIS THAT IS DEPICTING MID
LEVEL CIRCULATION MOVING EASTWARD ACROSS THE SOUTHERN PLAINS THIS
AFTERNOON WILL HAVE AN IMPACT ON THE BEGINNING OF THE EXTENDED
FCST PERIOD AS IT MOVES ACROSS THE TN VALLEY. THIS WILL ACT ON
STATIONARY SFC BOUNDARY IN ADVECTING MOISTURE IN AN OVERRUNNING
FASHION BACK NORTH OF THE BOUNDARY AND LEND SUPPORT TO WIDELY
SCATTERED CONVECTION OVER THE SW HALF OF THE CWA. FOCUS WILL THEN
SHIFT TO AMPLIFICATION OF THE UPPER LEVEL PATTERN AS STRONG JET
DYNAMICS CURRENTLY WELL OUT IN THE PACIFIC ARE PROGGED BY MEDIUM
RANGE MODELS TO COME ONSHORE AND DEVELOP DEEP UPPER TROF OVER THE
WESTERN US. THIS WILL INDUCE DOWNSTREAM RIDGING THAT WILL BUILD
INTO THE REGION SUN/MON BRINGING WARMER AND MAINLY DRY CONDITIONS
TO THE AREA. WESTERN CONUS UPPER TROF THEN EXPECTED TO BECOME
VERTICALLY STACKED CLOSED SYSTEM IN THE NORTHERN PLAINS WHICH
MODELS ARE STRUGGLING WITH TIMING OF THE EVENTUAL EJECTION OF THIS
SYSTEM INTO OUR AREA. AS EXPECTED OVERALL TREND CONTINUES TO BE
SLOWER WITH ARRIVAL OF MAIN SYSTEM NOW DELAYED TO TUE/WED
TIMEFRAME AND BRINGING WITH IT THE BEST CHANCES FOR PRECIP. PRIOR
TO ITS ARRIVAL...BECOMING MORE AND MORE DIFFICULT TO PICK OUT
MODELS HANDLING OF INCREASINGLY DIFFUSE SFC BOUNDARY BUT
INDICATIONS ARE BOUNDARY WILL LIFT NORTH OF THE AREA IN
CONJUNCTION WITH UPPER RIDGE MOVING OVER THE AREA WHICH SHOULD
LEAVE MUCH OF THE FORECAST AREA IN A CAPPED WARM SECTOR SUN/MON.
LOW CONFIDENCE IN ANY ONE PARTICULAR SCENARIO WITH THIS SETUP BUT
WILL STILL INJECT A PERIOD OR TWO OF DRY WEATHER TO REFLECT THIS.
ANTICIPATE TEMPS WELL INTO THE 80S ON MONDAY DEPENDING ON AMOUNT
OF SUN...BUMPED ALLBLEND UP A DEGREE TO START UPWARD TREND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 205 AM EDT FRI MAY 17 2013

A WELL DEFINED FRONT WAS JUST SOUTHWEST OF THE TERMINALS EARLY
THIS MORNING. THE FRONT SHOULD BE NEARLY STATIONARY TODAY...BUT MAY
DRIFT NORTH AS A WARM FRONT LATER TODAY. ADDED A VICINITY SHOWER
AT BOTH TERMINALS LATE IN THE DAY WITH THE FRONT IN THE VICINITY
AND DURING MAXIMUM DAYTIME INSTABILITY. THERE IS ALSO AN OUTSIDE
CHANCE FOR THUNDER...MAINLY LATE AFTERNOON INTO EARLY
EVENING...BUT FOR NOW...LEFT THUNDER OUT GIVEN THE MORE ISOLATED
NATURE OF COVERAGE EXPECTED. KEPT TAFS VFR.

&&

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

$$

SYNOPSIS...BENTLEY
SHORT TERM...FISHER
LONG TERM...JAL
AVIATION...SKIPPER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 170447
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1247 AM EDT FRI MAY 17 2013

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /REST OF TONIGHT AND FRIDAY/...

ISSUED AT 1244 AM EDT FRI MAY 17 2013

WITH SURFACE BOUNDARY ACROSS OUR NORTHERN COUNTIES AND SOME
BANDING OF MID CLOUD NEAR FRONT THERE IS STILL A SLIGHT CHANCE FOR
STORMS REST OF THIS MORNING. MODELS DIFFER SLIGHTLY AS DAY WEARS
ON AND WILL ADDRESS THIS IN NEXT UPDATE. OTHERWISE CURRENT
FORECAST INTO DAYTIME HOURS APPEARS PRETTY GOOD AND ONLY SLIGHTLY
ADJUSTED DEWPOINTS AND WINDS TO REFLECT CURRENT CONDITIONS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 210 PM EDT THU MAY 16 2013

LARGE SPREAD AMONG THE ENSEMBLES WITH RESPECT TO THE EVOLVING
WEATHER PATTERN NEXT WEEK...LEADING TO A BELOW NORMAL CONFIDENCE
FORECAST. MOST OF THE QUESTIONS REVOLVE AROUND SYSTEM THAT IS
EXPECTED TO BE MOVING THROUGH THE PLAINS EARLY NEXT WEEK. SOME
MEMBERS LIFT THIS SYSTEM INTO CANADA...RESULTING IN RIDGING OVER THE
LOCAL AREA. OTHERS CUT THIS SYSTEM OFF OVER THE MIDWEST...WHILE
STILL OTHERS TAKE THIS ENERGY ACROSS THE MIDWEST AND DIG IT OVER THE
EASTERN GREAT LAKES...RESULTING IN A DEEP UPPER TROUGH OVER THE EAST
BY THE MIDDLE OF NEXT WEEK.

TAKING ALL THE VARYING SOLUTIONS INTO ACCOUNT...AN ARGUMENT COULD BE
MADE FOR POPS THROUGHOUT THIS PERIOD. AS A RESULT...WILL KEEP POPS
IN THE FORECAST EVERY DAY AND FINE TINE THINGS LATER AS THE DETAILS
BECOME MORE CLEAR.

&&

.AVIATION /DISCUSSION FOR THE 17/06Z TAFS/...
ISSUED AT 1236 AM EDT FRI MAY 17 2013

WAVY QUASI-STATIONARY FRONT WAS JUST NORTH OF LAF LATE THIS EVENING
AS EVIDENCE BY DEW POINT RISING TO 59 THERE. CONFIDENCE IN EXACT
FRONTAL POSITION NOT GREAT...BUT WITH LIGHT TO CALM WINDS
OVERNIGHT...THE MAIN RESULT COULD BE SOME LIGHT FOG AT LAF AFTER 08Z
IF THE FRONT STAYS WHERE IT IS. OTHERWISE...MID AND HIGH CLOUDS
SHOULD KEEP ANY PROLONGED IFR FOG. WILL...JUST GO WITH MVFR AND
TEMPO IFR AT BMG AND HUF 08Z-12Z AND ONLY TEMPO MVFR AT IND AND LAF.
WEAK WAVE ACROSS SOUTHWEST INDIANA ALONG WITH THE FRONT IN THE AREA
COULD TRIGGER SOME THUNDERSTORMS OVERNIGHT AND THIS MORNING...BUT
BELIEVE COVERAGE WILL SPARSE UNTIL AFTER 15Z WHEN INSTABILITY
INCREASE AND UPPER TROUGH APPROACHES THE ILLINOIS AND INDIANA
BORDER.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

WINDS WILL BECOME SOUTHEAST LESS THAN 10 KNOTS AFTER 15Z AND BECOME
LIGHT AGAIN AFTER 00Z.


&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...TUCEK
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 170436
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1236 AM EDT FRI MAY 17 2013

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 957 PM EDT THU MAY 16 2013

ONLY ISOLATED SHOWERS CONTINUE ACROSS THE FORECAST AREA AT THIS
TIME...AND REGIONAL RADAR SHOWS SIMILAR CONDITIONS IN ILLINOIS AND
KENTUCKY. QUASI-STATIONARY FRONT REMAINS ACROSS THE EXTREME NORTHERN
FORECAST AREA...WHILE AN UPPER LOW SPINS ACROSS ARKANSAS.

DO NOT EXPECT MUCH CONVECTION TO DEVELOP ACROSS THE AREA FOR THE
REST OF THE NIGHT AS FORCING IS WEAK. INSTABILITY REMAINS ACROSS THE
AREA AND IS EXPECTED TO CONTINUE /ALBEIT WEAK/ THROUGH THE NIGHT.
THE APPROACHING UPPER LOW MAY HELP TRIGGER ISOLATED CONVECTION
MAINLY LATE TONIGHT...AND FRONT ACROSS THE NORTH MAY STILL SPAWN AN
ISOLATED SHOWER OR STORM.

HI RES SHORT TERM MODELS HINT AT THE POSSIBILITY OF ISOLATED
CONVECTION THROUGH THE NIGHT AS WELL. THUS HAVE DECIDED TO GO 20
POPS ALL AREAS ALL NIGHT AND USE ISOLATED WORDING. ALSO ADDED PATCHY
FOG TO THE FAR SOUTHWEST FORECAST AREA THAT SAW HEAVIER RAIN EARLIER
TODAY. CLOUDS SHOULD KEEP WIDESPREAD FOG FROM FORMING THERE.

MADE SOME MINOR TWEAKS TO TEMPERATURES...BUT NOTHING SIGNIFICANT.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 210 PM EDT THU MAY 16 2013

LARGE SPREAD AMONG THE ENSEMBLES WITH RESPECT TO THE EVOLVING
WEATHER PATTERN NEXT WEEK...LEADING TO A BELOW NORMAL CONFIDENCE
FORECAST. MOST OF THE QUESTIONS REVOLVE AROUND SYSTEM THAT IS
EXPECTED TO BE MOVING THROUGH THE PLAINS EARLY NEXT WEEK. SOME
MEMBERS LIFT THIS SYSTEM INTO CANADA...RESULTING IN RIDGING OVER THE
LOCAL AREA. OTHERS CUT THIS SYSTEM OFF OVER THE MIDWEST...WHILE
STILL OTHERS TAKE THIS ENERGY ACROSS THE MIDWEST AND DIG IT OVER THE
EASTERN GREAT LAKES...RESULTING IN A DEEP UPPER TROUGH OVER THE EAST
BY THE MIDDLE OF NEXT WEEK.

TAKING ALL THE VARYING SOLUTIONS INTO ACCOUNT...AN ARGUMENT COULD BE
MADE FOR POPS THROUGHOUT THIS PERIOD. AS A RESULT...WILL KEEP POPS
IN THE FORECAST EVERY DAY AND FINE TINE THINGS LATER AS THE DETAILS
BECOME MORE CLEAR.

&&

.AVIATION /DISCUSSION FOR THE 17/06Z TAFS/...
ISSUED AT 1236 AM EDT FRI MAY 17 2013

WAVY QUASI-STATIONARY FRONT WAS JUST NORTH OF LAF LATE THIS EVENING
AS EVIDENCE BY DEW POINT RISING TO 59 THERE. CONFIDENCE IN EXACT
FRONTAL POSITION NOT GREAT...BUT WITH LIGHT TO CALM WINDS
OVERNIGHT...THE MAIN RESULT COULD BE SOME LIGHT FOG AT LAF AFTER 08Z
IF THE FRONT STAYS WHERE IT IS. OTHERWISE...MID AND HIGH CLOUDS
SHOULD KEEP ANY PROLONGED IFR FOG. WILL...JUST GO WITH MVFR AND
TEMPO IFR AT BMG AND HUF 08Z-12Z AND ONLY TEMPO MVFR AT IND AND LAF.
WEAK WAVE ACROSS SOUTHWEST INDIANA ALONG WITH THE FRONT IN THE AREA
COULD TRIGGER SOME THUNDERSTORMS OVERNIGHT AND THIS MORNING...BUT
BELIEVE COVERAGE WILL SPARSE UNTIL AFTER 15Z WHEN INSTABILITY
INCREASE AND UPPER TROUGH APPROACHES THE ILLINOIS AND INDIANA
BORDER.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

WINDS WILL BECOME SOUTHEAST LESS THAN 10 KNOTS AFTER 15Z AND BECOME
LIGHT AGAIN AFTER 00Z.

&&

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

&&

$$

SYNOPSIS...PUMA
NEAR TERM...50
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 170222
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1021 PM EDT THU MAY 16 2013

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

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 957 PM EDT THU MAY 16 2013

ONLY ISOLATED SHOWERS CONTINUE ACROSS THE FORECAST AREA AT THIS
TIME...AND REGIONAL RADAR SHOWS SIMILAR CONDITIONS IN ILLINOIS AND
KENTUCKY. QUASI-STATIONARY FRONT REMAINS ACROSS THE EXTREME NORTHERN
FORECAST AREA...WHILE AN UPPER LOW SPINS ACROSS ARKANSAS.

DO NOT EXPECT MUCH CONVECTION TO DEVELOP ACROSS THE AREA FOR THE
REST OF THE NIGHT AS FORCING IS WEAK. INSTABILITY REMAINS ACROSS THE
AREA AND IS EXPECTED TO CONTINUE /ALBEIT WEAK/ THROUGH THE NIGHT.
THE APPROACHING UPPER LOW MAY HELP TRIGGER ISOLATED CONVECTION
MAINLY LATE TONIGHT...AND FRONT ACROSS THE NORTH MAY STILL SPAWN AN
ISOLATED SHOWER OR STORM.

HI RES SHORT TERM MODELS HINT AT THE POSSIBILITY OF ISOLATED
CONVECTION THROUGH THE NIGHT AS WELL. THUS HAVE DECIDED TO GO 20
POPS ALL AREAS ALL NIGHT AND USE ISOLATED WORDING. ALSO ADDED PATCHY
FOG TO THE FAR SOUTHWEST FORECAST AREA THAT SAW HEAVIER RAIN EARLIER
TODAY. CLOUDS SHOULD KEEP WIDESPREAD FOG FROM FORMING THERE.

MADE SOME MINOR TWEAKS TO TEMPERATURES...BUT NOTHING SIGNIFICANT.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

LARGE SPREAD AMONG THE ENSEMBLES WITH RESPECT TO THE EVOLVING
WEATHER PATTERN NEXT WEEK...LEADING TO A BELOW NORMAL CONFIDENCE
FORECAST. MOST OF THE QUESTIONS REVOLVE AROUND SYSTEM THAT IS
EXPECTED TO BE MOVING THROUGH THE PLAINS EARLY NEXT WEEK. SOME
MEMBERS LIFT THIS SYSTEM INTO CANADA...RESULTING IN RIDGING OVER THE
LOCAL AREA. OTHERS CUT THIS SYSTEM OFF OVER THE MIDWEST...WHILE
STILL OTHERS TAKE THIS ENERGY ACROSS THE MIDWEST AND DIG IT OVER THE
EASTERN GREAT LAKES...RESULTING IN A DEEP UPPER TROUGH OVER THE EAST
BY THE MIDDLE OF NEXT WEEK.

TAKING ALL THE VARYING SOLUTIONS INTO ACCOUNT...AN ARGUMENT COULD BE
MADE FOR POPS THROUGHOUT THIS PERIOD. AS A RESULT...WILL KEEP POPS
IN THE FORECAST EVERY DAY AND FINE TINE THINGS LATER AS THE DETAILS
BECOME MORE CLEAR.

&&

.AVIATION /DISCUSSION FOR THE 170300Z IND TAF UPDATE/...

ISSUED AT 1021 PM EDT THU MAY 16 2013

ONLY MADE MINOR TWEAK TO MID DECK...OTHERWISE NO CHANGES.

PREVIOUS DISCUSSION FOLLOWS...

QUASI-STATIONARY FRONT JUST SOUTH OF LAF IS EXPECTED TO MOVE LITTLE
TONIGHT AND PERHAPS JUST NORTH OF LAF ON FRIDAY. SOUTH OF THE
FRONT...DEW POINTS IN THE MID 60S AT HUF AND BMG...ALONG WITH LIGHT
TO CALM WINDS TONIGHT...SUGGEST SOME FOG IS POSSIBLE THERE AFTER 08Z
ESPECIALLY IF CONVECTIVE CLOUDS ARE NOT TOO PREVALENT. WILL GO WITH
MVFR AND TEMPO IFR FROM 08Z-12Z THERE AND ONLY MVFR AT IND AFTER
09Z.

WEAK UPPER DISTURBANCE AHEAD OF UPPER LOW ACROSS SOUTHWEST
MISSOURI AND NORTHWEST ARKANSAS...COULD HELP TRIGGER A FEW
THUNDERSTORMS MAINLY THIS EVENING WHEN INSTABILITY WILL BE GREATER
THAN IT WILL BE OVERNIGHT. HOWEVER...COVERAGE EXPECTED TO BE MORE
ISOLATED...SO WILL KEEP THUNDER OUT OF THE TAFS UNTIL AFTER 15Z
FRIDAY...WHEN INSTABILITY ONCE AGAIN INCREASES...AND THE UPPER LOW
OPENS UP WITH RESULTANT TROUGH AXIS MOVING INTO THE MISSISSIPPI
VALLEY.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...50
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 170157
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
957 PM EDT THU MAY 16 2013

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 957 PM EDT THU MAY 16 2013

ONLY ISOLATED SHOWERS CONTINUE ACROSS THE FORECAST AREA AT THIS
TIME...AND REGIONAL RADAR SHOWS SIMILAR CONDITIONS IN ILLINOIS AND
KENTUCKY. QUASI-STATIONARY FRONT REMAINS ACROSS THE EXTREME NORTHERN
FORECAST AREA...WHILE AN UPPER LOW SPINS ACROSS ARKANSAS.

DO NOT EXPECT MUCH CONVECTION TO DEVELOP ACROSS THE AREA FOR THE
REST OF THE NIGHT AS FORCING IS WEAK. INSTABILITY REMAINS ACROSS THE
AREA AND IS EXPECTED TO CONTINUE /ALBEIT WEAK/ THROUGH THE NIGHT.
THE APPROACHING UPPER LOW MAY HELP TRIGGER ISOLATED CONVECTION
MAINLY LATE TONIGHT...AND FRONT ACROSS THE NORTH MAY STILL SPAWN AN
ISOLATED SHOWER OR STORM.

HI RES SHORT TERM MODELS HINT AT THE POSSIBILITY OF ISOLATED
CONVECTION THROUGH THE NIGHT AS WELL. THUS HAVE DECIDED TO GO 20
POPS ALL AREAS ALL NIGHT AND USE ISOLATED WORDING. ALSO ADDED PATCHY
FOG TO THE FAR SOUTHWEST FORECAST AREA THAT SAW HEAVIER RAIN EARLIER
TODAY. CLOUDS SHOULD KEEP WIDESPREAD FOG FROM FORMING THERE.

MADE SOME MINOR TWEAKS TO TEMPERATURES...BUT NOTHING SIGNIFICANT.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

LARGE SPREAD AMONG THE ENSEMBLES WITH RESPECT TO THE EVOLVING
WEATHER PATTERN NEXT WEEK...LEADING TO A BELOW NORMAL CONFIDENCE
FORECAST. MOST OF THE QUESTIONS REVOLVE AROUND SYSTEM THAT IS
EXPECTED TO BE MOVING THROUGH THE PLAINS EARLY NEXT WEEK. SOME
MEMBERS LIFT THIS SYSTEM INTO CANADA...RESULTING IN RIDGING OVER THE
LOCAL AREA. OTHERS CUT THIS SYSTEM OFF OVER THE MIDWEST...WHILE
STILL OTHERS TAKE THIS ENERGY ACROSS THE MIDWEST AND DIG IT OVER THE
EASTERN GREAT LAKES...RESULTING IN A DEEP UPPER TROUGH OVER THE EAST
BY THE MIDDLE OF NEXT WEEK.

TAKING ALL THE VARYING SOLUTIONS INTO ACCOUNT...AN ARGUMENT COULD BE
MADE FOR POPS THROUGHOUT THIS PERIOD. AS A RESULT...WILL KEEP POPS
IN THE FORECAST EVERY DAY AND FINE TINE THINGS LATER AS THE DETAILS
BECOME MORE CLEAR.

&&

.AVIATION /DISCUSSION FOR THE 170000Z TAF ISSUANCE/...

ISSUED AT 606 PM EDT THU MAY 16 2013

QUASI-STATIONARY FRONT JUST SOUTH OF LAF IS EXPECTED TO MOVE LITTLE
TONIGHT AND PERHAPS JUST NORTH OF LAF ON FRIDAY. SOUTH OF THE
FRONT...DEW POINTS IN THE MID 60S AT HUF AND BMG...ALONG WITH LIGHT
TO CALM WINDS TONIGHT...SUGGEST SOME FOG IS POSSIBLE THERE AFTER 08Z
ESPECIALLY IF CONVECTIVE CLOUDS ARE NOT TOO PREVALENT. WILL GO WITH
MVFR AND TEMPO IFR FROM 08Z-12Z THERE AND ONLY MVFR AT IND AFTER
09Z.

WEAK UPPER DISTURBANCE AHEAD OF UPPER LOW ACROSS SOUTHWEST
MISSOURI AND NORTHWEST ARKANSAS...COULD HELP TRIGGER A FEW
THUNDERSTORMS MAINLY THIS EVENING WHEN INSTABILITY WILL BE GREATER
THAN IT WILL BE OVERNIGHT. HOWEVER...COVERAGE EXPECTED TO BE MORE
ISOLATED...SO WILL KEEP THUNDER OUT OF THE TAFS UNTIL AFTER 15Z
FRIDAY...WHEN INSTABILITY ONCE AGAIN INCREASES...AND THE UPPER LOW
OPENS UP WITH RESULTANT TROUGH AXIS MOVING INTO THE MISSISSIPPI
VALLEY.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...50
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 162311
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
711 PM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 655 PM EDT THU MAY 16 2013

A FRONTAL BOUNDARY WHICH HAS BROUGHT SHOWERS AND THUNDERSTORMS TO
PORTIONS OF SOUTHERN INDIANA AND OHIO TODAY WILL BEGIN TO SHIFT
NORTH BY FRIDAY AFTERNOON WHICH WILL BRING A LOW CHANCE OF SHOWERS
AND THUNDERSTORMS TO AREAS SOUTH OF US 30. SHOWER AND THUNDERSTORM
CHANCES WILL PERSIST THROUGH THE WEEKEND AS THE FRONTAL BOUNDARY REMAINS
ACROSS THE AREA. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS
WEEK INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE
WEST.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
HIGH PRESSURE HAS KEPT BULK OF MSTR JUST FAR ENOUGH SOUTH OF THE
AREA TODAY TO ALLOW FOR GENERALLY DRY CONDITIONS AND TEMPS MOVING
WELL THROUGH THE 70S IN MOST SPOTS. A FEW LIGHT SHOWERS/SPRINKLES
WERE NOTED ALONG FIRST OF 2 SFC THETA E GRADIENTS ACROSS FAR
SOUTHERN COUNTIES. THIS AREA IS EXPECTED TO SHIFT SOUTH OVER THE
NEXT SEVERAL HOURS AND REMOVE ANY CHANCE FOR PRECIP FOR THE
REMAINDER OF THE NIGHT. SECONDARY GRADIENT WAS LOCATED FURTHER
SOUTH ACROSS SOUTHERN INDIANA WHERE CONVECTION HAS BEEN ONGOING
MUCH OF THE DAY. MODELS TEND TO SUGGEST THAT THIS SECONDARY AREA
OF MSTR/GREATER LIFT SUPPORT WITH MAIN SFC BOUNDARY WILL BRING
INCREASING CHANCES FOR SHOWERS AND STORMS ON FRIDAY. IT WOULD
APPEAR THAT MOST FAVORABLE TIMING WOULD BE MID TO LATE AFTERNOON
FRIDAY IN FAR SW SECTIONS WITH PROGRESSION NE HAMPERED SOMEWHAT BY
DRY AIR/SEMI DRY GROUND CONDITIONS. IF NEW RUN OF SPC 4KM WRF IS
FOLLOWED...CONVECTION WOULD NOT ARRIVE UNTIL AFTER 00Z SAT. HAVE
ADJUSTED GRIDS TO REFLECT THIS WITH SLGT CHC TO CHC POPS CONFINED
TO AFTERNOON.

CLOUD COVER WILL BE ON THE INCREASE...WHICH WILL BUT A DAMPER ON
POTENTIAL CLIMB IN HIGHS. THAT BEING SAID...HIGHS SHOULD STILL END
UP ABOVE NORMAL CLIMBING INTO THE MID AND UPPER 70S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
WATER VAPOR IMAGERY AND LATEST RAP ANALYSIS THAT IS DEPICTING MID
LEVEL CIRCULATION MOVING EASTWARD ACROSS THE SOUTHERN PLAINS THIS
AFTERNOON WILL HAVE AN IMPACT ON THE BEGINNING OF THE EXTENDED
FCST PERIOD AS IT MOVES ACROSS THE TN VALLEY. THIS WILL ACT ON
STATIONARY SFC BOUNDARY IN ADVECTING MOISTURE IN AN OVERRUNNING
FASHION BACK NORTH OF THE BOUNDARY AND LEND SUPPORT TO WIDELY
SCATTERED CONVECTION OVER THE SW HALF OF THE CWA. FOCUS WILL THEN
SHIFT TO AMPLIFICATION OF THE UPPER LEVEL PATTERN AS STRONG JET
DYNAMICS CURRENTLY WELL OUT IN THE PACIFIC ARE PROGGED BY MEDIUM
RANGE MODELS TO COME ONSHORE AND DEVELOP DEEP UPPER TROF OVER THE
WESTERN US. THIS WILL INDUCE DOWNSTREAM RIDGING THAT WILL BUILD
INTO THE REGION SUN/MON BRINGING WARMER AND MAINLY DRY CONDITIONS
TO THE AREA. WESTERN CONUS UPPER TROF THEN EXPECTED TO BECOME
VERTICALLY STACKED CLOSED SYSTEM IN THE NORTHERN PLAINS WHICH
MODELS ARE STRUGGLING WITH TIMING OF THE EVENTUAL EJECTION OF THIS
SYSTEM INTO OUR AREA. AS EXPECTED OVERALL TREND CONTINUES TO BE
SLOWER WITH ARRIVAL OF MAIN SYSTEM NOW DELAYED TO TUE/WED
TIMEFRAME AND BRINGING WITH IT THE BEST CHANCES FOR PRECIP. PRIOR
TO ITS ARRIVAL...BECOMING MORE AND MORE DIFFICULT TO PICK OUT
MODELS HANDLING OF INCREASINGLY DIFFUSE SFC BOUNDARY BUT
INDICATIONS ARE BOUNDARY WILL LIFT NORTH OF THE AREA IN
CONJUNCTION WITH UPPER RIDGE MOVING OVER THE AREA WHICH SHOULD
LEAVE MUCH OF THE FORECAST AREA IN A CAPPED WARM SECTOR SUN/MON.
LOW CONFIDENCE IN ANY ONE PARTICULAR SCENARIO WITH THIS SETUP BUT
WILL STILL INJECT A PERIOD OR TWO OF DRY WEATHER TO REFLECT THIS.
ANTICIPATE TEMPS WELL INTO THE 80S ON MONDAY DEPENDING ON AMOUNT
OF SUN...BUMPED ALLBLEND UP A DEGREE TO START UPWARD TREND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 707 PM EDT THU MAY 16 2013

DRY AIRMASS REMAINS OVER NORTHERN INDIANA THIS EVE AND WILL PERSIST
THROUGH THE NIGHT ENSURING VFR CONDITIONS CONTG WITH NO LOW
CLOUDS OR VSBY OBSCURATION. LOW PRESSURE OVER THE SRN PLAINS IS
EXPECTED TO LIFT SLOWLY NE OVER THE NEXT 24HRS. THIS SHOULD RESULT
IN SFC WINDS VEERING TO SE BY FRI AFTN. SOME POTENTIAL FOR AFTN
SHRA/TS BUT MODELS DIFFER CONSIDERABLY IN AMOUNT OF
MOISTURE/INSTABILITY THAT WILL RETURN TO THE AREA AND IN EITHER
CASE BEST CHANCES SW OF THE TERMINALS SO HAVE NOT INCLUDED
CONVECTION IN TAFS... BUT DID FCST CU FIELD IN THE AFTN.

&&

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

$$

SYNOPSIS...BENTLEY
SHORT TERM...FISHER
LONG TERM...JAL
AVIATION...JT


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIWX 162259
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
659 PM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 655 PM EDT THU MAY 16 2013

A FRONTAL BOUNDARY WHICH HAS BROUGHT SHOWERS AND THUNDERSTORMS TO
PORTIONS OF SOUTHERN INDIANA AND OHIO TODAY WILL BEGIN TO SHIFT
NORTH BY FRIDAY AFTERNOON WHICH WILL BRING A LOW CHANCE OF SHOWERS
AND THUNDERSTORMS TO AREAS SOUTH OF US 30. SHOWER AND THUNDERSTORM
CHANCES WILL PERSIST THROUGH THE WEEKEND AS THE FRONTAL BOUNDARY REMAINS
ACROSS THE AREA. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS
WEEK INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE
WEST.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
HIGH PRESSURE HAS KEPT BULK OF MSTR JUST FAR ENOUGH SOUTH OF THE
AREA TODAY TO ALLOW FOR GENERALLY DRY CONDITIONS AND TEMPS MOVING
WELL THROUGH THE 70S IN MOST SPOTS. A FEW LIGHT SHOWERS/SPRINKLES
WERE NOTED ALONG FIRST OF 2 SFC THETA E GRADIENTS ACROSS FAR
SOUTHERN COUNTIES. THIS AREA IS EXPECTED TO SHIFT SOUTH OVER THE
NEXT SEVERAL HOURS AND REMOVE ANY CHANCE FOR PRECIP FOR THE
REMAINDER OF THE NIGHT. SECONDARY GRADIENT WAS LOCATED FURTHER
SOUTH ACROSS SOUTHERN INDIANA WHERE CONVECTION HAS BEEN ONGOING
MUCH OF THE DAY. MODELS TEND TO SUGGEST THAT THIS SECONDARY AREA
OF MSTR/GREATER LIFT SUPPORT WITH MAIN SFC BOUNDARY WILL BRING
INCREASING CHANCES FOR SHOWERS AND STORMS ON FRIDAY. IT WOULD
APPEAR THAT MOST FAVORABLE TIMING WOULD BE MID TO LATE AFTERNOON
FRIDAY IN FAR SW SECTIONS WITH PROGRESSION NE HAMPERED SOMEWHAT BY
DRY AIR/SEMI DRY GROUND CONDITIONS. IF NEW RUN OF SPC 4KM WRF IS
FOLLOWED...CONVECTION WOULD NOT ARRIVE UNTIL AFTER 00Z SAT. HAVE
ADJUSTED GRIDS TO REFLECT THIS WITH SLGT CHC TO CHC POPS CONFINED
TO AFTERNOON.

CLOUD COVER WILL BE ON THE INCREASE...WHICH WILL BUT A DAMPER ON
POTENTIAL CLIMB IN HIGHS. THAT BEING SAID...HIGHS SHOULD STILL END
UP ABOVE NORMAL CLIMBING INTO THE MID AND UPPER 70S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
WATER VAPOR IMAGERY AND LATEST RAP ANALYSIS THAT IS DEPICTING MID
LEVEL CIRCULATION MOVING EASTWARD ACROSS THE SOUTHERN PLAINS THIS
AFTERNOON WILL HAVE AN IMPACT ON THE BEGINNING OF THE EXTENDED
FCST PERIOD AS IT MOVES ACROSS THE TN VALLEY. THIS WILL ACT ON
STATIONARY SFC BOUNDARY IN ADVECTING MOISTURE IN AN OVERRUNNING
FASHION BACK NORTH OF THE BOUNDARY AND LEND SUPPORT TO WIDELY
SCATTERED CONVECTION OVER THE SW HALF OF THE CWA. FOCUS WILL THEN
SHIFT TO AMPLIFICATION OF THE UPPER LEVEL PATTERN AS STRONG JET
DYNAMICS CURRENTLY WELL OUT IN THE PACIFIC ARE PROGGED BY MEDIUM
RANGE MODELS TO COME ONSHORE AND DEVELOP DEEP UPPER TROF OVER THE
WESTERN US. THIS WILL INDUCE DOWNSTREAM RIDGING THAT WILL BUILD
INTO THE REGION SUN/MON BRINGING WARMER AND MAINLY DRY CONDITIONS
TO THE AREA. WESTERN CONUS UPPER TROF THEN EXPECTED TO BECOME
VERTICALLY STACKED CLOSED SYSTEM IN THE NORTHERN PLAINS WHICH
MODELS ARE STRUGGLING WITH TIMING OF THE EVENTUAL EJECTION OF THIS
SYSTEM INTO OUR AREA. AS EXPECTED OVERALL TREND CONTINUES TO BE
SLOWER WITH ARRIVAL OF MAIN SYSTEM NOW DELAYED TO TUE/WED
TIMEFRAME AND BRINGING WITH IT THE BEST CHANCES FOR PRECIP. PRIOR
TO ITS ARRIVAL...BECOMING MORE AND MORE DIFFICULT TO PICK OUT
MODELS HANDLING OF INCREASINGLY DIFFUSE SFC BOUNDARY BUT
INDICATIONS ARE BOUNDARY WILL LIFT NORTH OF THE AREA IN
CONJUNCTION WITH UPPER RIDGE MOVING OVER THE AREA WHICH SHOULD
LEAVE MUCH OF THE FORECAST AREA IN A CAPPED WARM SECTOR SUN/MON.
LOW CONFIDENCE IN ANY ONE PARTICULAR SCENARIO WITH THIS SETUP BUT
WILL STILL INJECT A PERIOD OR TWO OF DRY WEATHER TO REFLECT THIS.
ANTICIPATE TEMPS WELL INTO THE 80S ON MONDAY DEPENDING ON AMOUNT
OF SUN...BUMPED ALLBLEND UP A DEGREE TO START UPWARD TREND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 125 PM EDT THU MAY 16 2013

MAIN FLUX OF MOISTURE AND LIFT TO REMAIN REMOVED TO THE SOUTH OF
BOTH TAF SITES THROUGH THE PERIOD. THIS WILL ALLOW FOR VFR
CONDITIONS ACROSS THE ARE WITH OCCASIONAL MID/HIGH CLOUDS AND
WINDS 10 KNOTS OR LESS.


&&

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

$$

SYNOPSIS...BENTLEY
SHORT TERM...FISHER
LONG TERM...JAL
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIWX 162256
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
656 PM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 1031 AM EDT THU MAY 16 2013

A FRONTAL BOUNDARY WHICH HAS BROUGHT SHOWERS AND THUNDERSTORMS TO
PORTIONS OF SOUTHERN INDIANA AND OHIO TODAY WILL BEGIN TO SHIFT
NORTH BY FRIDAY AFTERNOON WHICH WILL BRING A LOW CHANCE OF SHOWERS
AND THUNDERSTORMS TO AREAS SOUTH OF US 30. SHOWER AND THUNDERSTORM
CHANCES WILL PERSIST THROUGH THE WEEKEND AS THE FRONTAL BOUNDARY REMAINS
ACROSS THE AREA. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS
WEEK INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE
WEST.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
HIGH PRESSURE HAS KEPT BULK OF MSTR JUST FAR ENOUGH SOUTH OF THE
AREA TODAY TO ALLOW FOR GENERALLY DRY CONDITIONS AND TEMPS MOVING
WELL THROUGH THE 70S IN MOST SPOTS. A FEW LIGHT SHOWERS/SPRINKLES
WERE NOTED ALONG FIRST OF 2 SFC THETA E GRADIENTS ACROSS FAR
SOUTHERN COUNTIES. THIS AREA IS EXPECTED TO SHIFT SOUTH OVER THE
NEXT SEVERAL HOURS AND REMOVE ANY CHANCE FOR PRECIP FOR THE
REMAINDER OF THE NIGHT. SECONDARY GRADIENT WAS LOCATED FURTHER
SOUTH ACROSS SOUTHERN INDIANA WHERE CONVECTION HAS BEEN ONGOING
MUCH OF THE DAY. MODELS TEND TO SUGGEST THAT THIS SECONDARY AREA
OF MSTR/GREATER LIFT SUPPORT WITH MAIN SFC BOUNDARY WILL BRING
INCREASING CHANCES FOR SHOWERS AND STORMS ON FRIDAY. IT WOULD
APPEAR THAT MOST FAVORABLE TIMING WOULD BE MID TO LATE AFTERNOON
FRIDAY IN FAR SW SECTIONS WITH PROGRESSION NE HAMPERED SOMEWHAT BY
DRY AIR/SEMI DRY GROUND CONDITIONS. IF NEW RUN OF SPC 4KM WRF IS
FOLLOWED...CONVECTION WOULD NOT ARRIVE UNTIL AFTER 00Z SAT. HAVE
ADJUSTED GRIDS TO REFLECT THIS WITH SLGT CHC TO CHC POPS CONFINED
TO AFTERNOON.

CLOUD COVER WILL BE ON THE INCREASE...WHICH WILL BUT A DAMPER ON
POTENTIAL CLIMB IN HIGHS. THAT BEING SAID...HIGHS SHOULD STILL END
UP ABOVE NORMAL CLIMBING INTO THE MID AND UPPER 70S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
WATER VAPOR IMAGERY AND LATEST RAP ANALYSIS THAT IS DEPICTING MID
LEVEL CIRCULATION MOVING EASTWARD ACROSS THE SOUTHERN PLAINS THIS
AFTERNOON WILL HAVE AN IMPACT ON THE BEGINNING OF THE EXTENDED
FCST PERIOD AS IT MOVES ACROSS THE TN VALLEY. THIS WILL ACT ON
STATIONARY SFC BOUNDARY IN ADVECTING MOISTURE IN AN OVERRUNNING
FASHION BACK NORTH OF THE BOUNDARY AND LEND SUPPORT TO WIDELY
SCATTERED CONVECTION OVER THE SW HALF OF THE CWA. FOCUS WILL THEN
SHIFT TO AMPLIFICATION OF THE UPPER LEVEL PATTERN AS STRONG JET
DYNAMICS CURRENTLY WELL OUT IN THE PACIFIC ARE PROGGED BY MEDIUM
RANGE MODELS TO COME ONSHORE AND DEVELOP DEEP UPPER TROF OVER THE
WESTERN US. THIS WILL INDUCE DOWNSTREAM RIDGING THAT WILL BUILD
INTO THE REGION SUN/MON BRINGING WARMER AND MAINLY DRY CONDITIONS
TO THE AREA. WESTERN CONUS UPPER TROF THEN EXPECTED TO BECOME
VERTICALLY STACKED CLOSED SYSTEM IN THE NORTHERN PLAINS WHICH
MODELS ARE STRUGGLING WITH TIMING OF THE EVENTUAL EJECTION OF THIS
SYSTEM INTO OUR AREA. AS EXPECTED OVERALL TREND CONTINUES TO BE
SLOWER WITH ARRIVAL OF MAIN SYSTEM NOW DELAYED TO TUE/WED
TIMEFRAME AND BRINGING WITH IT THE BEST CHANCES FOR PRECIP. PRIOR
TO ITS ARRIVAL...BECOMING MORE AND MORE DIFFICULT TO PICK OUT
MODELS HANDLING OF INCREASINGLY DIFFUSE SFC BOUNDARY BUT
INDICATIONS ARE BOUNDARY WILL LIFT NORTH OF THE AREA IN
CONJUNCTION WITH UPPER RIDGE MOVING OVER THE AREA WHICH SHOULD
LEAVE MUCH OF THE FORECAST AREA IN A CAPPED WARM SECTOR SUN/MON.
LOW CONFIDENCE IN ANY ONE PARTICULAR SCENARIO WITH THIS SETUP BUT
WILL STILL INJECT A PERIOD OR TWO OF DRY WEATHER TO REFLECT THIS.
ANTICIPATE TEMPS WELL INTO THE 80S ON MONDAY DEPENDING ON AMOUNT
OF SUN...BUMPED ALLBLEND UP A DEGREE TO START UPWARD TREND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 125 PM EDT THU MAY 16 2013

MAIN FLUX OF MOISTURE AND LIFT TO REMAIN REMOVED TO THE SOUTH OF
BOTH TAF SITES THROUGH THE PERIOD. THIS WILL ALLOW FOR VFR
CONDITIONS ACROSS THE ARE WITH OCCASIONAL MID/HIGH CLOUDS AND
WINDS 10 KNOTS OR LESS.


&&

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

$$

SYNOPSIS...STEINWEDEL/KG
SHORT TERM...FISHER
LONG TERM...JAL
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 162206
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
606 PM EDT THU MAY 16 2013

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

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 210 PM EDT THU MAY 16 2013

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS A FRONTAL BOUNDARY
STRETCHING FROM NORTH OF HUF TO NEAR ANDERSON AND MUNCIE. OUTFLOW
WINDS FROM THE SHOWERS AND STORMS ACROSS SOUTHWEST INDIANA HAVE
BROUGHT SOUTHERLY WINDS TO THE INDY ALONG WITH DEW POINTS INTO THE
LOWER 60S.

MAIN FORECAST CHALLENGE TONIGHT WILL BE RAIN CHANCES. SEVERAL
FAVORABLE ELEMENTS IN PLACE FOR PRECIPITATION TONIGHT. GFS AND NAM
CONTINUE TO SUGGEST THAT THE FRONTAL BOUNDARY WILL REMAIN IN THE
AREA OVERNIGHT. GFS AND NAM SUGGEST A WEAK WAVE PUSHING OUT OF THE
CENTRAL MISSISSIPPI RIVER VALLEY PUSHING INTO THE OHIO VALLEY
OVERNIGHT PROVIDING FORCING. 305K ISENTROPIC SURFACE INDICATES PLENTY
OF MOISTURE BUT MINIMAL LIFT. DIURNAL HEATING WILL STILL PROVIDE
SOME FORCING MECHANISM THROUGH THE LATE AFTERNOON AND EVENING
HOURS. THUS WILL RAISE POPS FOR THE TONIGHT PERIOD...PARTICULARLY
DURING THE EVENING HOURS AS DIURNAL FORCING WILL SLOWLY WANE
THROUGH THE NIGHT. WILL AIM FOR HIGHEST POPS ALONG AND SOUTH OF
THE FRONTAL BOUNDARY...WITH LESSER POPS FOUND NORTH ACROSS THE
LAF..OKK AREAS.

GIVEN THE LITTLE CHANGE IN THE AIR MASS...WILL TREND TEMPS TOWARD
PERSISTENCE OR GENERALLY WARMER THAN MAVMOS GIVEN THE EXPECTED
CLOUDS AND RAIN.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

LARGE SPREAD AMONG THE ENSEMBLES WITH RESPECT TO THE EVOLVING
WEATHER PATTERN NEXT WEEK...LEADING TO A BELOW NORMAL CONFIDENCE
FORECAST. MOST OF THE QUESTIONS REVOLVE AROUND SYSTEM THAT IS
EXPECTED TO BE MOVING THROUGH THE PLAINS EARLY NEXT WEEK. SOME
MEMBERS LIFT THIS SYSTEM INTO CANADA...RESULTING IN RIDGING OVER THE
LOCAL AREA. OTHERS CUT THIS SYSTEM OFF OVER THE MIDWEST...WHILE
STILL OTHERS TAKE THIS ENERGY ACROSS THE MIDWEST AND DIG IT OVER THE
EASTERN GREAT LAKES...RESULTING IN A DEEP UPPER TROUGH OVER THE EAST
BY THE MIDDLE OF NEXT WEEK.

TAKING ALL THE VARYING SOLUTIONS INTO ACCOUNT...AN ARGUMENT COULD BE
MADE FOR POPS THROUGHOUT THIS PERIOD. AS A RESULT...WILL KEEP POPS
IN THE FORECAST EVERY DAY AND FINE TINE THINGS LATER AS THE DETAILS
BECOME MORE CLEAR.

&&

.AVIATION /DISCUSSION FOR THE 170000Z TAF ISSUANCE/...

ISSUED AT 606 PM EDT THU MAY 16 2013

QUASI-STATIONARY FRONT JUST SOUTH OF LAF IS EXPECTED TO MOVE LITTLE
TONIGHT AND PERHAPS JUST NORTH OF LAF ON FRIDAY. SOUTH OF THE
FRONT...DEW POINTS IN THE MID 60S AT HUF AND BMG...ALONG WITH LIGHT
TO CALM WINDS TONIGHT...SUGGEST SOME FOG IS POSSIBLE THERE AFTER 08Z
ESPECIALLY IF CONVECTIVE CLOUDS ARE NOT TOO PREVALENT. WILL GO WITH
MVFR AND TEMPO IFR FROM 08Z-12Z THERE AND ONLY MVFR AT IND AFTER
09Z.

WEAK UPPER DISTURBANCE AHEAD OF UPPER LOW ACROSS SOUTHWEST
MISSOURI AND NORTHWEST ARKANSAS...COULD HELP TRIGGER A FEW
THUNDERSTORMS MAINLY THIS EVENING WHEN INSTABILITY WILL BE GREATER
THAN IT WILL BE OVERNIGHT. HOWEVER...COVERAGE EXPECTED TO BE MORE
ISOLATED...SO WILL KEEP THUNDER OUT OF THE TAFS UNTIL AFTER 15Z
FRIDAY...WHEN INSTABILITY ONCE AGAIN INCREASES...AND THE UPPER LOW
OPENS UP WITH RESULTANT TROUGH AXIS MOVING INTO THE MISSISSIPPI
VALLEY.

SHOULD SEE VFR IN ANY CEILING TONIGHT...WITH BORDERLINE MVFR/VFR
AFTER 15Z FRIDAY BASED ON SOUNDING LIFTED CONDENSATION LEVEL AND
CONVECTIVE CONDENSATION LEVELS FORECASTS.

&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 162027
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
420 PM EDT THU MAY 16 2013

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

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 210 PM EDT THU MAY 16 2013

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS A FRONTAL BOUNDARY
STRETCHING FROM NORTH OF HUF TO NEAR ANDERSON AND MUNCIE. OUTFLOW
WINDS FROM THE SHOWERS AND STORMS ACROSS SOUTHWEST INDIANA HAVE
BROUGHT SOUTHERLY WINDS TO THE INDY ALONG WITH DEW POINTS INTO THE
LOWER 60S.

MAIN FORECAST CHALLENGE TONIGHT WILL BE RAIN CHANCES. SEVERAL
FAVORABLE ELEMENTS IN PLACE FOR PRECIPITATION TONIGHT. GFS AND NAM
CONTINUE TO SUGGEST THAT THE FRONTAL BOUNDARY WILL REMAIN IN THE
AREA OVERNIGHT. GFS AND NAM SUGGEST A WEAK WAVE PUSHING OUT OF THE
CENTRAL MISSISSIPPI RIVER VALLEY PUSHING INTO THE OHIO VALLEY
OVERNIGHT PROVIDING FORCING. 305K ISENTROPIC SURFACE INDICATES PLENTY
OF MOISTURE BUT MINIMAL LIFT. DIURNAL HEATING WILL STILL PROVIDE
SOME FORCING MECHANISM THROUGH THE LATE AFTERNOON AND EVENING
HOURS. THUS WILL RAISE POPS FOR THE TONIGHT PERIOD...PARTICULARLY
DURING THE EVENING HOURS AS DIURNAL FORCING WILL SLOWLY WANE
THROUGH THE NIGHT. WILL AIM FOR HIGHEST POPS ALONG AND SOUTH OF
THE FRONTAL BOUNDARY...WITH LESSER POPS FOUND NORTH ACROSS THE
LAF..OKK AREAS.

GIVEN THE LITTLE CHANGE IN THE AIR MASS...WILL TREND TEMPS TOWARD
PERSISTENCE OR GENERALLY WARMER THAN MAVMOS GIVEN THE EXPECTED
CLOUDS AND RAIN.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

LARGE SPREAD AMONG THE ENSEMBLES WITH RESPECT TO THE EVOLVING
WEATHER PATTERN NEXT WEEK...LEADING TO A BELOW NORMAL CONFIDENCE
FORECAST. MOST OF THE QUESTIONS REVOLVE AROUND SYSTEM THAT IS
EXPECTED TO BE MOVING THROUGH THE PLAINS EARLY NEXT WEEK. SOME
MEMBERS LIFT THIS SYSTEM INTO CANADA...RESULTING IN RIDGING OVER THE
LOCAL AREA. OTHERS CUT THIS SYSTEM OFF OVER THE MIDWEST...WHILE
STILL OTHERS TAKE THIS ENERGY ACROSS THE MIDWEST AND DIG IT OVER THE
EASTERN GREAT LAKES...RESULTING IN A DEEP UPPER TROUGH OVER THE EAST
BY THE MIDDLE OF NEXT WEEK.

TAKING ALL THE VARYING SOLUTIONS INTO ACCOUNT...AN ARGUMENT COULD BE
MADE FOR POPS THROUGHOUT THIS PERIOD. AS A RESULT...WILL KEEP POPS
IN THE FORECAST EVERY DAY AND FINE TINE THINGS LATER AS THE DETAILS
BECOME MORE CLEAR.

&&

.AVIATION /DISCUSSION FOR THE 162100Z IND TAF UPDATE/...

ISSUED AT 420 AM EDT THU MAY 16 2013

SHOULD BE A LULL IN THUNDERSTORMS UNTIL AT LEAST LATER THIS EVENING
WHEN A WEAK WAVE LIFTS NORTHEAST FROM SOUTHEASTERN MISSOURI.
SO...PULLED VCTS. OTHERWISE...NO CHANGES.

PREVIOUS DISCUSSION FOLLOWS...

SCATTERED CONVECTION CONTINUES OVER SOUTHERN INDIANA AHEAD OF A
FRONTAL ZONE AND A WEAK VORTICITY LOBE THAT APPEARS TO BE MOVING
INTO SOUTHWEST INDIANA AT THIS TIME. INSTABILITY AXIS IS SHIFTING
SOUTH OF KIND...SO EXPECTING THE HIGHEST THREAT OF A DIRECT
CONVECTIVE IMPACT WILL BE AT KHUF/KBMG...WITH LESSER CHANCES AT
KIND. DON/T THINK THERE WILL BE MUCH OF A CONVECTIVE THREAT AT KLAF
AS FRONT APPEARS TO HAVE PUSHED SOUTH OF THAT AREA.
OVERALL...CONVECTION SHOULD PEAK OVER THE NEXT FEW HOURS...WITH A
DIMINISHING TREND BY 162000Z-162100Z AS VORTICITY CENTER MOVES OFF
TO THE EAST. BRIEF IFR VISIBILITY RESTRICTIONS AND GUSTY SHIFTING
WINDS POSSIBLE IN THE STRONGER CELLS. CONVECTIVE CLOUD BASES
025-030.

OUTSIDE OF CONVECTION...CEILINGS GENERALLY ABOVE 050. COULD BE SOME
VISIBILITY RESTRICTIONS DEVELOP DUE TO FOG TOWARDS
170600Z...ESPECIALLY OVER KHUF/KBMG WHERE RAINFALL LOOKS LIKELY THIS
AFTERNOON.


&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...JAS/MK

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 161830
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
230 PM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 1031 AM EDT THU MAY 16 2013

A FEW LIGHT SHOWERS OR ISOLATED THUNDERSTORMS COULD SKIM THE FAR
SOUTHWEST PORTION OF THE AREA THIS AFTERNOON. OTHERWISE, MOSTLY
DRY CONDITIONS ARE EXPECTED TODAY INTO FRIDAY MORNING, AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES FORCING A FRONTAL BOUNDARY
SOUTH INTO CENTRAL INDIANA. THIS FRONT IS EXPECTED TO BUCKLE BACK
NORTH LATER FRIDAY INTO THE WEEKEND WITH A LOW CHANCE FOR SHOWERS
AND THUNDERSTORMS MAINLY SOUTH OF ROUTE 30 IN INDIANA AND MICHIGAN
EACH DAY. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS WEEK
INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE WEST.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
HIGH PRESSURE HAS KEPT BULK OF MSTR JUST FAR ENOUGH SOUTH OF THE
AREA TODAY TO ALLOW FOR GENERALLY DRY CONDITIONS AND TEMPS MOVING
WELL THROUGH THE 70S IN MOST SPOTS. A FEW LIGHT SHOWERS/SPRINKLES
WERE NOTED ALONG FIRST OF 2 SFC THETA E GRADIENTS ACROSS FAR
SOUTHERN COUNTIES. THIS AREA IS EXPECTED TO SHIFT SOUTH OVER THE
NEXT SEVERAL HOURS AND REMOVE ANY CHANCE FOR PRECIP FOR THE
REMAINDER OF THE NIGHT. SECONDARY GRADIENT WAS LOCATED FURTHER
SOUTH ACROSS SOUTHERN INDIANA WHERE CONVECTION HAS BEEN ONGOING
MUCH OF THE DAY. MODELS TEND TO SUGGEST THAT THIS SECONDARY AREA
OF MSTR/GREATER LIFT SUPPORT WITH MAIN SFC BOUNDARY WILL BRING
INCREASING CHANCES FOR SHOWERS AND STORMS ON FRIDAY. IT WOULD
APPEAR THAT MOST FAVORABLE TIMING WOULD BE MID TO LATE AFTERNOON
FRIDAY IN FAR SW SECTIONS WITH PROGRESSION NE HAMPERED SOMEWHAT BY
DRY AIR/SEMI DRY GROUND CONDITIONS. IF NEW RUN OF SPC 4KM WRF IS
FOLLOWED...CONVECTION WOULD NOT ARRIVE UNTIL AFTER 00Z SAT. HAVE
ADJUSTED GRIDS TO REFLECT THIS WITH SLGT CHC TO CHC POPS CONFINED
TO AFTERNOON.

CLOUD COVER WILL BE ON THE INCREASE...WHICH WILL BUT A DAMPER ON
POTENTIAL CLIMB IN HIGHS. THAT BEING SAID...HIGHS SHOULD STILL END
UP ABOVE NORMAL CLIMBING INTO THE MID AND UPPER 70S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
WATER VAPOR IMAGERY AND LATEST RAP ANALYSIS THAT IS DEPICTING MID
LEVEL CIRCULATION MOVING EASTWARD ACROSS THE SOUTHERN PLAINS THIS
AFTERNOON WILL HAVE AN IMPACT ON THE BEGINNING OF THE EXTENDED
FCST PERIOD AS IT MOVES ACROSS THE TN VALLEY. THIS WILL ACT ON
STATIONARY SFC BOUNDARY IN ADVECTING MOISTURE IN AN OVERRUNNING
FASHION BACK NORTH OF THE BOUNDARY AND LEND SUPPORT TO WIDELY
SCATTERED CONVECTION OVER THE SW HALF OF THE CWA. FOCUS WILL THEN
SHIFT TO AMPLIFICATION OF THE UPPER LEVEL PATTERN AS STRONG JET
DYNAMICS CURRENTLY WELL OUT IN THE PACIFIC ARE PROGGED BY MEDIUM
RANGE MODELS TO COME ONSHORE AND DEVELOP DEEP UPPER TROF OVER THE
WESTERN US. THIS WILL INDUCE DOWNSTREAM RIDGING THAT WILL BUILD
INTO THE REGION SUN/MON BRINGING WARMER AND MAINLY DRY CONDITIONS
TO THE AREA. WESTERN CONUS UPPER TROF THEN EXPECTED TO BECOME
VERTICALLY STACKED CLOSED SYSTEM IN THE NORTHERN PLAINS WHICH
MODELS ARE STRUGGLING WITH TIMING OF THE EVENTUAL EJECTION OF THIS
SYSTEM INTO OUR AREA. AS EXPECTED OVERALL TREND CONTINUES TO BE
SLOWER WITH ARRIVAL OF MAIN SYSTEM NOW DELAYED TO TUE/WED
TIMEFRAME AND BRINGING WITH IT THE BEST CHANCES FOR PRECIP. PRIOR
TO ITS ARRIVAL...BECOMING MORE AND MORE DIFFICULT TO PICK OUT
MODELS HANDLING OF INCREASINGLY DIFFUSE SFC BOUNDARY BUT
INDICATIONS ARE BOUNDARY WILL LIFT NORTH OF THE AREA IN
CONJUNCTION WITH UPPER RIDGE MOVING OVER THE AREA WHICH SHOULD
LEAVE MUCH OF THE FORECAST AREA IN A CAPPED WARM SECTOR SUN/MON.
LOW CONFIDENCE IN ANY ONE PARTICULAR SCENARIO WITH THIS SETUP BUT
WILL STILL INJECT A PERIOD OR TWO OF DRY WEATHER TO REFLECT THIS.
ANTICIPATE TEMPS WELL INTO THE 80S ON MONDAY DEPENDING ON AMOUNT
OF SUN...BUMPED ALLBLEND UP A DEGREE TO START UPWARD TREND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 125 PM EDT THU MAY 16 2013

MAIN FLUX OF MOISTURE AND LIFT TO REMAIN REMOVED TO THE SOUTH OF
BOTH TAF SITES THROUGH THE PERIOD. THIS WILL ALLOW FOR VFR
CONDITIONS ACROSS THE ARE WITH OCCASIONAL MID/HIGH CLOUDS AND
WINDS 10 KNOTS OR LESS.

&&

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

$$

SYNOPSIS...STEINWEDEL/KG
SHORT TERM...FISHER
LONG TERM...JAL
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 161810
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
210 PM EDT THU MAY 16 2013

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

&&

.SYNOPSIS...
ISSUED AT 210 PM EDT THU MAY 16 2013

A LINGERING FRONTAL BOUNDARY COMBINED WITH A SLOW MOVING AREA OF
LOW PRESSURE MOVING THROUGH THE OHIO VALLEY THROUGH SATURDAY WILL
START THE WEEKEND ON A WET NOTE ACROSS CENTRAL INDIANA. THESE
SYSTEMS WILL COMBINE TO PRODUCE SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH SATURDAY.

THE LOW IS EXPECTED TO DEPART THE AREA ON SATURDAY AND
SUNDAY...HOWEVER A WARM AND MOIST AIR MASS LOOKS TO REMAIN IN THE
AREA ON SUNDAY. THIS COULD LEAD TO SOME SCATTERED AFTERNOON POP UP
SHOWERS AND THUNDERSTORMS THEN.

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED MUCH OF THE NEXT WORK
WEEK AS SEVERAL UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO
PUSH ACROSS CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 210 PM EDT THU MAY 16 2013

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS A FRONTAL BOUNDARY
STRETCHING FROM NORTH OF HUF TO NEAR ANDERSON AND MUNCIE. OUTFLOW
WINDS FROM THE SHOWERS AND STORMS ACROSS SOUTHWEST INDIANA HAVE
BROUGHT SOUTHERLY WINDS TO THE INDY ALONG WITH DEW POINTS INTO THE
LOWER 60S.

MAIN FORECAST CHALLENGE TONIGHT WILL BE RAIN CHANCES. SEVERAL
FAVORABLE ELEMENTS IN PLACE FOR PRECIPITATION TONIGHT. GFS AND NAM
CONTINUE TO SUGGEST THAT THE FRONTAL BOUNDARY WILL REMAIN IN THE
AREA OVERNIGHT. GFS AND NAM SUGGEST A WEAK WAVE PUSHING OUT OF THE
CENTRAL MISSISSIPPI RIVER VALLEY PUSHING INTO THE OHIO VALLEY
OVERNIGHT PROVIDING FORCING. 305K ISENTROPIC SURFACE INDICATES PLENTY
OF MOISTURE BUT MINIMAL LIFT. DIURNAL HEATING WILL STILL PROVIDE
SOME FORCING MECHANISM THROUGH THE LATE AFTERNOON AND EVENING
HOURS. THUS WILL RAISE POPS FOR THE TONIGHT PERIOD...PARTICULARLY
DURING THE EVENING HOURS AS DIURNAL FORCING WILL SLOWLY WANE
THROUGH THE NIGHT. WILL AIM FOR HIGHEST POPS ALONG AND SOUTH OF
THE FRONTAL BOUNDARY...WITH LESSER POPS FOUND NORTH ACROSS THE
LAF..OKK AREAS.

GIVEN THE LITTLE CHANGE IN THE AIR MASS...WILL TREND TEMPS TOWARD
PERSISTENCE OR GENERALLY WARMER THAN MAVMOS GIVEN THE EXPECTED
CLOUDS AND RAIN.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. MODELS
ARE IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.

GFS AND NAM BOTH SUGGEST A SHORT WAVE PUSHING THROUGH THE OHIO
VALLEY QUITE SLOWLY DURING THE DAY ON FRIDAY. MEANWHILE THE
LINGERING SURFACE BOUNDARY LOOKS TO REMAIN MEANDERING IN CENTRAL
INDIANA. MEANWHILE FORECAST SOUNDINGS ON FRIDAY HINT AT DEEPLY
SATURATED COLUMN WITH CONVECTIVE TEMPERATURES IN THE MIDDLE 70S
WITH CAPE IN EXCESS OF 1000 J/KG. THUS EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ON FRIDAY. WILL ONCE AGAIN
RAISE POPS AND GIVEN THE LITTLE CHANGE IN AIR MASS WILL TREND
HIGHS TOWARD EXPECTED PERSISTENCE.

ONCE AGAIN LINGERING MOISTURE...HEATING AND FORCING WILL CONTINUE
INTO THE EVENING HOURS ACROSS CENTRAL INDIANA ON FRIDAY NIGHT AS
LITTLE FROM THE PREVIOUSLY MENTION SET-UP CHANGES. ONCE AGAIN
FORCING FROM HEATING WILL WANE AS THE EVENING PROGRESSES. HOWEVER
THE UPPER LOW WILL BE IN IDEAL POSITION AS IT SLOWLY PASSES ACROSS
INDIANA. THUS WILL ONCE AGAIN TREND POPS HIGHER THAN MAVMOS ALONG
WITH WARMER LOWS GIVEN THE EXPECTED CLOUDS AND RAIN.

THE UPPER LOW DEPARTS THE AREA ON SATURDAY AFTERNOON...AND
FORECAST SOUNDINGS FINALLY BEGIN TO HINT AT SOME DRYING WORKING
INTO THE COLUMN DURING THE LATE AFTERNOON HOURS. WILL TREND POPS
LOWER DURING THE LATE AFTERNOON HOURS AS FORCING AND MOISTURE
FINALLY BEINGS TO DEPART THE AREA BUT WILL STILL KEEP POPS CLOSE
TO MAVMOS FOR THE MORNING AND EARLY AFTERNOON.

MUCH DRIER AIR WORKS INTO THE STATE ON SATURDAY NIGHT AND SUNDAY
MORNING AND STRONG RIDGING BUILDS ACROSS THE AREA ALOFT. MINIMAL
CHANGE IN TEMPERATURES OCCURS AS THE LOW DEPARTS AS YET ANOTHER
LOW BEGINS TO DEEPEN ACROSS THE PLAINS STATE AND A LINGERING
FRONTAL BOUNDARY LOOKS TO REMAIN IN THE VICINITY OF CENTRAL
INDIANA. FORECAST SOUNDINGS ON SUNDAY AFTERNOON REVEAL CONVECTIVE
TEMPERATURES IN THE UPPER 70S WITH CAPE IN EXCESS OF 1000 G/KG.
THUS WILL KEEP MUCH OF SATURDAY NIGHT AND SUNDAY MORNING DRY...BUT
GIVEN THE STEEP LAPSE AND ATTAINABLE CONVECTIVE TEMPERATURES WILL
INCLUDE CHANCES FOR SUNDAY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...

ISSUED AT 210 PM EDT THU MAY 16 2013

LARGE SPREAD AMONG THE ENSEMBLES WITH RESPECT TO THE EVOLVING
WEATHER PATTERN NEXT WEEK...LEADING TO A BELOW NORMAL CONFIDENCE
FORECAST. MOST OF THE QUESTIONS REVOLVE AROUND SYSTEM THAT IS
EXPECTED TO BE MOVING THROUGH THE PLAINS EARLY NEXT WEEK. SOME
MEMBERS LIFT THIS SYSTEM INTO CANADA...RESULTING IN RIDGING OVER THE
LOCAL AREA. OTHERS CUT THIS SYSTEM OFF OVER THE MIDWEST...WHILE
STILL OTHERS TAKE THIS ENERGY ACROSS THE MIDWEST AND DIG IT OVER THE
EASTERN GREAT LAKES...RESULTING IN A DEEP UPPER TROUGH OVER THE EAST
BY THE MIDDLE OF NEXT WEEK.

TAKING ALL THE VARYING SOLUTIONS INTO ACCOUNT...AN ARGUMENT COULD BE
MADE FOR POPS THROUGHOUT THIS PERIOD. AS A RESULT...WILL KEEP POPS
IN THE FORECAST EVERY DAY AND FINE TINE THINGS LATER AS THE DETAILS
BECOME MORE CLEAR.

&&

.AVIATION /DISCUSSION FOR THE 161800Z TAFS/...

ISSUED AT 1240 PM EDT THU MAY 16 2013

SCATTERED CONVECTION CONTINUES OVER SOUTHERN INDIANA AHEAD OF A
FRONTAL ZONE AND A WEAK VORTICITY LOBE THAT APPEARS TO BE MOVING
INTO SOUTHWEST INDIANA AT THIS TIME. INSTABILITY AXIS IS SHIFTING
SOUTH OF KIND...SO EXPECTING THE HIGHEST THREAT OF A DIRECT
CONVECTIVE IMPACT WILL BE AT KHUF/KBMG...WITH LESSER CHANCES AT
KIND. DON/T THINK THERE WILL BE MUCH OF A CONVECTIVE THREAT AT KLAF
AS FRONT APPEARS TO HAVE PUSHED SOUTH OF THAT AREA.
OVERALL...CONVECTION SHOULD PEAK OVER THE NEXT FEW HOURS...WITH A
DIMINISHING TREND BY 162000Z-162100Z AS VORTICITY CENTER MOVES OFF
TO THE EAST. BRIEF IFR VISIBILITY RESTRICTIONS AND GUSTY SHIFTING
WINDS POSSIBLE IN THE STRONGER CELLS. CONVECTIVE CLOUD BASES
025-030.

OUTSIDE OF CONVECTION...CEILINGS GENERALLY ABOVE 050. COULD BE SOME
VISIBILITY RESTRICTIONS DEVELOP DUE TO FOG TOWARDS
170600Z...ESPECIALLY OVER KHUF/KBMG WHERE RAINFALL LOOKS LIKELY THIS
AFTERNOON.


&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 161725
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
125 PM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 1031 AM EDT THU MAY 16 2013

A FEW LIGHT SHOWERS OR ISOLATED THUNDERSTORMS COULD SKIM THE FAR
SOUTHWEST PORTION OF THE AREA THIS AFTERNOON. OTHERWISE, MOSTLY
DRY CONDITIONS ARE EXPECTED TODAY INTO FRIDAY MORNING, AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES FORCING A FRONTAL BOUNDARY
SOUTH INTO CENTRAL INDIANA. THIS FRONT IS EXPECTED TO BUCKLE BACK
NORTH LATER FRIDAY INTO THE WEEKEND WITH A LOW CHANCE FOR SHOWERS
AND THUNDERSTORMS MAINLY SOUTH OF ROUTE 30 IN INDIANA AND MICHIGAN
EACH DAY. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS WEEK
INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE WEST.

&&

.UPDATE...
ISSUED AT 1132 AM EDT THU MAY 16 2013

GRIDS/ZONES WERE UPDATED EARLIER TO ADJUST TEMP TRENDS AND MAKE
SOME ADJUSTMENTS TO POPS.

TEMPS REBOUNDING NICELY INTO THE 70S ACROSS MOST OF THE AREA AND
ON TRACK TO HEAD TOWARDS 80 IN MOST LOCATIONS. MAIN FRONTAL
BOUNDARY WAS DRAPED ACROSS SOUTHERN INDIANA WHERE STORMS CONTINUE
TO DEVELOP. NOSE OF DECENT THETA E GRADIENT LAID JUST SOUTH OF THE
CWA REFLECTED BY LARGE DEWPT CHANGES WITH SOUTHERN PARTS OF THE
CWA IN THE LOW TO MID 40S COMPARED TO A FEW COUNTIES SOUTH IN THE
MID 60S. NORTHERLY FLOW AND HIGH PRESSURE SHOULD KEEP THIS MSTR
FURTHER SOUTH...BUT CLOSE ENOUGH TO CONTINUE THREAT FOR AT LEAST
SPRINKLES/LGT SHOWERS. GRIDS WERE UPDATED TO ADD MENTION OF
SPRINKLES FAR S/SW INTO THIS AFTERNOON. CHANCES FOR LATE AFTERNOON
CONVECTION RATHER BLEAK BUT WITH PROXIMITY OF MSTR COULDN`T
JUSTIFY COMPLETE REMOVAL YET.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT THU MAY 16 2013

STALLED SFC TROUGH JUST SOUTH OF CWA HAD CONVECTIVELY
ACTIVATED LT LAST EVE FM SE NE EWD INTO CNTRL OH AND XPC A CONTD NR
TERM SWD PUSH IN RESPONSE TO BOTH AUGMENTED CONV OUTFLW AND CANADIAN
SFC RIDGING BLDG SEWD ACRS THE LAKES.

LTL DRIVING IMPEDES GOING FWD FOR ADDNL ACTIVITY ACRS SRN PORTION OF
CWA AFT DAYBREAK AS BNDRY REMAINS HUNG UP ACRS CNTRL IL/IN. HWVR NRN
TERMINUS OF SUFFICIENT LL THETA-E GRADIENT REMAINS JUST CLOSE ENOUGH TO
HOLD W/ISOLD MENTION EXTREME SRN IN COUNTIES THIS AFTN TIMED
W/BRIEF/WK FNTL SCALE CIRC DURING PK HEATING.

OTRWS VERY DRY MONTH SO FAR YIELDING A GROWING POS FEEDBACK LOOP IN
DIURNAL TEMP TRENDS AND THUS ADJUSTED MAXES HIGHER/MINS LOWER.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU MAY 16 2013

MID LEVEL CIRCULATION DEPICTED NICELY ON MORNING WATER VAPOR IN
COLORADO WILL PROPAGATE EAST-NORTHEAST INTO THE UPPER MIDWEST AND
WESTERN GREAT LAKES FRIDAY INTO FRIDAY NIGHT. WEAK/BROAD ISENTROPIC
UPGLIDE IN ADVANCE OF THIS FEATURES WILL HELP FORCE/MIX A CENTRAL
IN/IL QUASI STATIONARY BOUNDARY BACK NORTH INTO THE SOUTHWEST
PORTION OF THE IWX CWA BY FRIDAY AFTERNOON/NIGHT. MODEST
DESTABILIZATION INVOF THE FRONTAL BOUNDARY MAY SUPPORT ISO/SCT
SURFACE BASED CONVECTION FRI AFTN/EVE HERE WHILE A FEW
SHOWERS/SPRINKLES ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE MAY
SURVIVE INTO THE REST OF THE FA OVER DRY SUB CLOUD WEDGE. ONLY LOW
CHANCE POPS WARRANTED AS DEEPER MOISTURE/FORCING WITH AN OKLAHOMA
CONVECTIVELY ENHANCED WAVE TRACKS SOUTH OF THE FA INTO THE OH/TN
VALLEYS WITH GRADUAL HEIGHT RISES LOCALLY.

BUCKLING OF THE UPPER LEVEL FLOW IS ANTICIPATED OVER THE WEEKEND AS
STRONG PACIFIC JET ENERGY CARVES OUT A FORMIDABLE UPPER TROUGH
ACROSS THE INTERMOUNTAIN WEST AND HIGH PLAINS. THIS AMPLIFICATION
WILL ALLOW AN UPPER RIDGE TO BUILD INTO THE MIDWEST/GREAT LAKES WITH
MAINLY DRY/WARMER CONDITIONS ANTICIPATED. CANNOT RULE OUT ISO/SCT
AFTERNOON CONVECTION ON SATURDAY WITH INCREASINGLY DIFFUSE SFC
BOUNDARY STILL IN THE VICINITY AND MODEST INSTABILITY. LOWERED POPS
ON SUNDAY AS CAPPING LIKELY LIMITS VERTICAL GROWTH UNDER MID LVL
RIDGE AXIS.

THE DEEP LAYERED TROUGH ENTERING THE PLAINS ON SUNDAY WILL EVOLVE
INTO A CLOSED LOW ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
MONDAY INTO TUESDAY AS HIGH LATITUDE BLOCK SETS UP OVER CENTRAL
CANADA. 00Z MODEL SUITE CONTINUED TO SLOW THIS SYSTEM WITH MONDAY
NOW LOOKING DRIER/WARMER WITH CAPPED RIDGE POSSIBLY HOLDING ON FOR
ONE MORE DAY. SYSTEM FILLS EASTWARD TUESDAY INTO WEDNESDAY WHICH
WILL BRING INCREASING CHANCES FOR SHOWERS/STORMS (POSSIBLY STRONG TO
SEVERE) TO THE AREA AS A FRONTAL BOUNDARY NEARS AND SHORTWAVES
ROTATE THROUGH AMID INCREASING INSTABILITY/FLOW.

TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH THE PERIOD.
ONLY MADE MINOR TWEAK TO LOWS STAYING CLOSE TO THE 00Z MODEL
CONSENSUS INITIALIZATION. BUMPED UP HIGHS EACH DAY...GENERALLY ABOVE
CLIMO/GFS BIASED CONSENSUS BLEND...ESPECIALLY SUNDAY THROUGH TUESDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 125 PM EDT THU MAY 16 2013

MAIN FLUX OF MOISTURE AND LIFT TO REMAIN REMOVED TO THE SOUTH OF
BOTH TAF SITES THROUGH THE PERIOD. THIS WILL ALLOW FOR VFR
CONDITIONS ACROSS THE ARE WITH OCCASIONAL MID/HIGH CLOUDS AND
WINDS 10 KNOTS OR LESS.

&&

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

$$

UPDATE...FISHER
SYNOPSIS...STEINWEDEL/KG
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 161641
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1240 PM EDT THU MAY 16 2013

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

&&

.SYNOPSIS...
ISSUED AT 416 AM EDT THU MAY 16 2013

WEAK UPPER WAVES MOVING ALONG A STALLED FRONTAL BOUNDARY
WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS CENTRAL
INDIANA FOR THE NEXT SEVERAL DAYS. ABOVE NORMAL TEMPERATURES WILL
REMAIN IN PLACE DURING THIS TIME.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 928 AM EDT THU MAY 16 2013

SURFACE ANALYSIS LATE THIS MORNING SHOWS AND STATIONARY BOUNDARY
STRETCHING FROM NORTH OF TERRE HAUTE TO NORTH OF INDIANAPOLIS TO
NEAR NEW CASTLE. SHOWERS WERE LINGERING ALONG THE NORTH SIDE OF
THAT BOUNDARY WHILE MORE SHOWERS AND THUNDERSTORMS WERE
DEVELOPING ON THE WARMER AND MORE MOIST SOUTHERLY SIDE OF THE
BOUNDARY.

FORECAST SOUNDINGS INDICATE STEEP LAPSE RATES TODAY WITH EASILY
REACHABLE CONVECTIVE TEMPERATURES IN THE LOWER 70S. FORECAST
SOUNDINGS SHOW CAPE OF 1K-2K AVAILABLE ALSO. THUS HAVE INCREASE
POPS IN SEVERAL AREAS THIS MORNING BASED UPON RECENT RADAR TRENDS.
ADDITIONAL UPDATES MAY BE NEED SOON SHOULD COVERAGE CONTINUE TO
EXPAND...WHICH SEEMS LIKELY. ONGOING TEMP FORECAST APPEARS IN GOOD
SHAPE AND ONLY MINOR CHANGES MADE THERE.

&&

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

ISSUED AT 416 AM EDT THU MAY 16 2013

FORECAST FOCUS IS ON THUNDERSTORM CHANCES THROUGH THE PERIOD. WITH
THE FRONT STALLED NEAR THE AREA AND VARIOUS WAVES MOVING ALONG IT
KEPT CHANCES GOING THROUGH THE SHORT TERM. WITH THESE WAVES COMING
OUT OF AN UPPER LOW TO THE SOUTHWEST TRENDED THE HIGHEST POPS IN THE
SOUTH CLOSEST TO THE ENHANCED FORCING. GENERALLY USED A GUIDANCE
AVERAGE FOR POPS WHICH TRENDED LOWER AT NIGHT WITH LOSS OF HEATING.
ALSO TRENDED LOWER FOR SATURDAY NIGHT WITH THE BOUNDARY MOVING OUT
OF THE AREA AND UPPER RIDGING MOVING IN MOMENTARILY.

FOR TEMPERATURES THOUGHT A GUIDANCE CONSENSUS WORKED WELL FOR A
RELATIVELY UNCHANGING AIRMASS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

ISSUED AT 416 AM EDT THU MAY 16 2013

A WARM MOIST AIRMASS WILL BE ACROSS THE REGION AT LEAST UNTIL THE
MIDDLE OF NEXT WEEK.  MODELS INDICATE A WEAK UPPER DISTURBANCE OVER
KENTUCKY AT THE START OF THE LONG TERM. MEANWHILE AN UPPER RIDGE
WILL ALSO BE ACROSS THE REGION AT THE START OF THE LONG TERM.
EXPECT ONLY SLIGHT CHANCE OF THUNDERSTORMS AT BEST SUNDAY WITH
POSSIBLE CHANCE FAR SOUTHEAST.  SUNDAY NIGHT SHOULD BE DRY AS WE
WILL BE BETWEEN SYSTEMS AND AN UPPER RIDGE WILL BE OVERHEAD.

AN UPPER TROUGH OVER THE NORTHERN PLAINS WILL MOVE TO THE GREAT
LAKES AND MID MISSISSIPPI VALLEY BY THE MIDDLE OF NEXT WEEK.  A COLD
FRONT OVER THE PLAINS MONDAY WILL MOVE TO OUR REGION MONDAY NIGHT
AND TO OHIO BY DAY 7. RAIN CHANCES WILL INCREASE TO LIKELY CATEGORY
BY TUESDAY WHICH GOES WELL TO ALL BLEND POPS.

CONCERNING TEMPERATURES WILL GO CLOSER TO WARMER MEX MOS SUNDAY AND
MONDAY GIVEN THE WARM AIRMASS ACROSS OUR REGION AND THE UPPER RIDGE
ACROSS OUR REGION EARLY IN THE EXTENDED.  I SUSPECT THERE MAY BE TOO
MUCH WEIGHTING TOWARDS CLIMATOLOGY IN THIS PATTERN. TEMPERATURES
WILL COOL OFF SOME TUESDAY WITH MORE CLOUDS AND BETTER CHANCE OF
PRECIP AND EVEN MORE WEDNESDAY AS COOLER AIR MOVES IN. HOWEVER ALL
BLEND TEMPERATURES MAY STILL BE A BIT TOO COOL.

&&

.AVIATION /DISCUSSION FOR THE 161800Z TAFS/...

ISSUED AT 1240 PM EDT THU MAY 16 2013

SCATTERED CONVECTION CONTINUES OVER SOUTHERN INDIANA AHEAD OF A
FRONTAL ZONE AND A WEAK VORTICITY LOBE THAT APPEARS TO BE MOVING
INTO SOUTHWEST INDIANA AT THIS TIME. INSTABILITY AXIS IS SHIFTING
SOUTH OF KIND...SO EXPECTING THE HIGHEST THREAT OF A DIRECT
CONVECTIVE IMPACT WILL BE AT KHUF/KBMG...WITH LESSER CHANCES AT
KIND. DON/T THINK THERE WILL BE MUCH OF A CONVECTIVE THREAT AT KLAF
AS FRONT APPEARS TO HAVE PUSHED SOUTH OF THAT AREA.
OVERALL...CONVECTION SHOULD PEAK OVER THE NEXT FEW HOURS...WITH A
DIMINISHING TREND BY 162000Z-162100Z AS VORTICITY CENTER MOVES OFF
TO THE EAST. BRIEF IFR VISIBILITY RESTRICTIONS AND GUSTY SHIFTING
WINDS POSSIBLE IN THE STRONGER CELLS. CONVECTIVE CLOUD BASES
025-030.

OUTSIDE OF CONVECTION...CEILINGS GENERALLY ABOVE 050. COULD BE SOME
VISIBILITY RESTRICTIONS DEVELOP DUE TO FOG TOWARDS
170600Z...ESPECIALLY OVER KHUF/KBMG WHERE RAINFALL LOOKS LIKELY THIS
AFTERNOON.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...PUMA
SHORT TERM...CP
LONG TERM....JH
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIWX 161538
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1138 AM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 1031 AM EDT THU MAY 16 2013

A FEW LIGHT SHOWERS OR ISOLATED THUNDERSTORMS COULD SKIM THE FAR
SOUTHWEST PORTION OF THE AREA THIS AFTERNOON. OTHERWISE, MOSTLY
DRY CONDITIONS ARE EXPECTED TODAY INTO FRIDAY MORNING, AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES FORCING A FRONTAL BOUNDARY
SOUTH INTO CENTRAL INDIANA. THIS FRONT IS EXPECTED TO BUCKLE BACK
NORTH LATER FRIDAY INTO THE WEEKEND WITH A LOW CHANCE FOR SHOWERS
AND THUNDERSTORMS MAINLY SOUTH OF ROUTE 30 IN INDIANA AND MICHIGAN
EACH DAY. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS WEEK
INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE WEST.

&&

.UPDATE...
ISSUED AT 1132 AM EDT THU MAY 16 2013

GRIDS/ZONES WERE UPDATED EARLIER TO ADJUST TEMP TRENDS AND MAKE
SOME ADJUSTMENTS TO POPS.

TEMPS REBOUNDING NICELY INTO THE 70S ACROSS MOST OF THE AREA AND
ON TRACK TO HEAD TOWARDS 80 IN MOST LOCATIONS. MAIN FRONTAL
BOUNDARY WAS DRAPED ACROSS SOUTHERN INDIANA WHERE STORMS CONTINUE
TO DEVELOP. NOSE OF DECENT THETA E GRADIENT LAID JUST SOUTH OF THE
CWA REFLECTED BY LARGE DEWPT CHANGES WITH SOUTHERN PARTS OF THE
CWA IN THE LOW TO MID 40S COMPARED TO A FEW COUNTIES SOUTH IN THE
MID 60S. NORTHERLY FLOW AND HIGH PRESSURE SHOULD KEEP THIS MSTR
FURTHER SOUTH...BUT CLOSE ENOUGH TO CONTINUE THREAT FOR AT LEAST
SPRINKLES/LGT SHOWERS. GRIDS WERE UPDATED TO ADD MENTION OF
SPRINKLES FAR S/SW INTO THIS AFTERNOON. CHANCES FOR LATE AFTERNOON
CONVECTION RATHER BLEAK BUT WITH PROXIMITY OF MSTR COULDN`T
JUSTIFY COMPLETE REMOVAL YET.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT THU MAY 16 2013

STALLED SFC TROUGH JUST SOUTH OF CWA HAD CONVECTIVELY
ACTIVATED LT LAST EVE FM SE NE EWD INTO CNTRL OH AND XPC A CONTD NR
TERM SWD PUSH IN RESPONSE TO BOTH AUGMENTED CONV OUTFLW AND CANADIAN
SFC RIDGING BLDG SEWD ACRS THE LAKES.

LTL DRIVING IMPEDES GOING FWD FOR ADDNL ACTIVITY ACRS SRN PORTION OF
CWA AFT DAYBREAK AS BNDRY REMAINS HUNG UP ACRS CNTRL IL/IN. HWVR NRN
TERMINUS OF SUFFICIENT LL THETA-E GRADIENT REMAINS JUST CLOSE ENOUGH TO
HOLD W/ISOLD MENTION EXTREME SRN IN COUNTIES THIS AFTN TIMED
W/BRIEF/WK FNTL SCALE CIRC DURING PK HEATING.

OTRWS VERY DRY MONTH SO FAR YIELDING A GROWING POS FEEDBACK LOOP IN
DIURNAL TEMP TRENDS AND THUS ADJUSTED MAXES HIGHER/MINS LOWER.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU MAY 16 2013

MID LEVEL CIRCULATION DEPICTED NICELY ON MORNING WATER VAPOR IN
COLORADO WILL PROPAGATE EAST-NORTHEAST INTO THE UPPER MIDWEST AND
WESTERN GREAT LAKES FRIDAY INTO FRIDAY NIGHT. WEAK/BROAD ISENTROPIC
UPGLIDE IN ADVANCE OF THIS FEATURES WILL HELP FORCE/MIX A CENTRAL
IN/IL QUASI STATIONARY BOUNDARY BACK NORTH INTO THE SOUTHWEST
PORTION OF THE IWX CWA BY FRIDAY AFTERNOON/NIGHT. MODEST
DESTABILIZATION INVOF THE FRONTAL BOUNDARY MAY SUPPORT ISO/SCT
SURFACE BASED CONVECTION FRI AFTN/EVE HERE WHILE A FEW
SHOWERS/SPRINKLES ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE MAY
SURVIVE INTO THE REST OF THE FA OVER DRY SUB CLOUD WEDGE. ONLY LOW
CHANCE POPS WARRANTED AS DEEPER MOISTURE/FORCING WITH AN OKLAHOMA
CONVECTIVELY ENHANCED WAVE TRACKS SOUTH OF THE FA INTO THE OH/TN
VALLEYS WITH GRADUAL HEIGHT RISES LOCALLY.

BUCKLING OF THE UPPER LEVEL FLOW IS ANTICIPATED OVER THE WEEKEND AS
STRONG PACIFIC JET ENERGY CARVES OUT A FORMIDABLE UPPER TROUGH
ACROSS THE INTERMOUNTAIN WEST AND HIGH PLAINS. THIS AMPLIFICATION
WILL ALLOW AN UPPER RIDGE TO BUILD INTO THE MIDWEST/GREAT LAKES WITH
MAINLY DRY/WARMER CONDITIONS ANTICIPATED. CANNOT RULE OUT ISO/SCT
AFTERNOON CONVECTION ON SATURDAY WITH INCREASINGLY DIFFUSE SFC
BOUNDARY STILL IN THE VICINITY AND MODEST INSTABILITY. LOWERED POPS
ON SUNDAY AS CAPPING LIKELY LIMITS VERTICAL GROWTH UNDER MID LVL
RIDGE AXIS.

THE DEEP LAYERED TROUGH ENTERING THE PLAINS ON SUNDAY WILL EVOLVE
INTO A CLOSED LOW ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
MONDAY INTO TUESDAY AS HIGH LATITUDE BLOCK SETS UP OVER CENTRAL
CANADA. 00Z MODEL SUITE CONTINUED TO SLOW THIS SYSTEM WITH MONDAY
NOW LOOKING DRIER/WARMER WITH CAPPED RIDGE POSSIBLY HOLDING ON FOR
ONE MORE DAY. SYSTEM FILLS EASTWARD TUESDAY INTO WEDNESDAY WHICH
WILL BRING INCREASING CHANCES FOR SHOWERS/STORMS (POSSIBLY STRONG TO
SEVERE) TO THE AREA AS A FRONTAL BOUNDARY NEARS AND SHORTWAVES
ROTATE THROUGH AMID INCREASING INSTABILITY/FLOW.

TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH THE PERIOD.
ONLY MADE MINOR TWEAK TO LOWS STAYING CLOSE TO THE 00Z MODEL
CONSENSUS INITIALIZATION. BUMPED UP HIGHS EACH DAY...GENERALLY ABOVE
CLIMO/GFS BIASED CONSENSUS BLEND...ESPECIALLY SUNDAY THROUGH TUESDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 350 AM EDT THU MAY 16 2013

VFR CONDS THROUGH THE PD. SFC RIDGING BLDG SEWD OUT OF
CANADA ACRS THE GREAT LAKES THIS PD WILL KEEP STALLED SFC TROUGH AND
ASSOCD CONVN AT BAY SOUTH OF THE TERMINALS.


&&

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

$$

UPDATE...FISHER
SYNOPSIS...STEINWEDEL/KG
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIWX 161433
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1033 AM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 1031 AM EDT THU MAY 16 2013

A FEW LIGHT SHOWERS OR ISOLATED THUNDERSTORMS COULD SKIM THE FAR
SOUTHWEST PORTION OF THE AREA THIS AFTERNOON. OTHERWISE, MOSTLY
DRY CONDITIONS ARE EXPECTED TODAY INTO FRIDAY MORNING, AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES FORCING A FRONTAL BOUNDARY
SOUTH INTO CENTRAL INDIANA. THIS FRONT IS EXPECTED TO BUCKLE BACK
NORTH LATER FRIDAY INTO THE WEEKEND WITH A LOW CHANCE FOR SHOWERS
AND THUNDERSTORMS MAINLY SOUTH OF ROUTE 30 IN INDIANA AND MICHIGAN
EACH DAY. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS WEEK
INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE WEST.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT THU MAY 16 2013

STALLED SFC TROUGH JUST SOUTH OF CWA HAD CONVECTIVELY
ACTIVATED LT LAST EVE FM SE NE EWD INTO CNTRL OH AND XPC A CONTD NR
TERM SWD PUSH IN RESPONSE TO BOTH AUGMENTED CONV OUTFLW AND CANADIAN
SFC RIDGING BLDG SEWD ACRS THE LAKES.

LTL DRIVING IMPEDES GOING FWD FOR ADDNL ACTIVITY ACRS SRN PORTION OF
CWA AFT DAYBREAK AS BNDRY REMAINS HUNG UP ACRS CNTRL IL/IN. HWVR NRN
TERMINUS OF SUFFICIENT LL THETA-E GRADIENT REMAINS JUST CLOSE ENOUGH TO
HOLD W/ISOLD MENTION EXTREME SRN IN COUNTIES THIS AFTN TIMED
W/BRIEF/WK FNTL SCALE CIRC DURING PK HEATING.

OTRWS VERY DRY MONTH SO FAR YIELDING A GROWING POS FEEDBACK LOOP IN
DIURNAL TEMP TRENDS AND THUS ADJUSTED MAXES HIGHER/MINS LOWER.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU MAY 16 2013

MID LEVEL CIRCULATION DEPICTED NICELY ON MORNING WATER VAPOR IN
COLORADO WILL PROPAGATE EAST-NORTHEAST INTO THE UPPER MIDWEST AND
WESTERN GREAT LAKES FRIDAY INTO FRIDAY NIGHT. WEAK/BROAD ISENTROPIC
UPGLIDE IN ADVANCE OF THIS FEATURES WILL HELP FORCE/MIX A CENTRAL
IN/IL QUASI STATIONARY BOUNDARY BACK NORTH INTO THE SOUTHWEST
PORTION OF THE IWX CWA BY FRIDAY AFTERNOON/NIGHT. MODEST
DESTABILIZATION INVOF THE FRONTAL BOUNDARY MAY SUPPORT ISO/SCT
SURFACE BASED CONVECTION FRI AFTN/EVE HERE WHILE A FEW
SHOWERS/SPRINKLES ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE MAY
SURVIVE INTO THE REST OF THE FA OVER DRY SUB CLOUD WEDGE. ONLY LOW
CHANCE POPS WARRANTED AS DEEPER MOISTURE/FORCING WITH AN OKLAHOMA
CONVECTIVELY ENHANCED WAVE TRACKS SOUTH OF THE FA INTO THE OH/TN
VALLEYS WITH GRADUAL HEIGHT RISES LOCALLY.

BUCKLING OF THE UPPER LEVEL FLOW IS ANTICIPATED OVER THE WEEKEND AS
STRONG PACIFIC JET ENERGY CARVES OUT A FORMIDABLE UPPER TROUGH
ACROSS THE INTERMOUNTAIN WEST AND HIGH PLAINS. THIS AMPLIFICATION
WILL ALLOW AN UPPER RIDGE TO BUILD INTO THE MIDWEST/GREAT LAKES WITH
MAINLY DRY/WARMER CONDITIONS ANTICIPATED. CANNOT RULE OUT ISO/SCT
AFTERNOON CONVECTION ON SATURDAY WITH INCREASINGLY DIFFUSE SFC
BOUNDARY STILL IN THE VICINITY AND MODEST INSTABILITY. LOWERED POPS
ON SUNDAY AS CAPPING LIKELY LIMITS VERTICAL GROWTH UNDER MID LVL
RIDGE AXIS.

THE DEEP LAYERED TROUGH ENTERING THE PLAINS ON SUNDAY WILL EVOLVE
INTO A CLOSED LOW ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
MONDAY INTO TUESDAY AS HIGH LATITUDE BLOCK SETS UP OVER CENTRAL
CANADA. 00Z MODEL SUITE CONTINUED TO SLOW THIS SYSTEM WITH MONDAY
NOW LOOKING DRIER/WARMER WITH CAPPED RIDGE POSSIBLY HOLDING ON FOR
ONE MORE DAY. SYSTEM FILLS EASTWARD TUESDAY INTO WEDNESDAY WHICH
WILL BRING INCREASING CHANCES FOR SHOWERS/STORMS (POSSIBLY STRONG TO
SEVERE) TO THE AREA AS A FRONTAL BOUNDARY NEARS AND SHORTWAVES
ROTATE THROUGH AMID INCREASING INSTABILITY/FLOW.

TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH THE PERIOD.
ONLY MADE MINOR TWEAK TO LOWS STAYING CLOSE TO THE 00Z MODEL
CONSENSUS INITIALIZATION. BUMPED UP HIGHS EACH DAY...GENERALLY ABOVE
CLIMO/GFS BIASED CONSENSUS BLEND...ESPECIALLY SUNDAY THROUGH TUESDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 350 AM EDT THU MAY 16 2013

VFR CONDS THROUGH THE PD. SFC RIDGING BLDG SEWD OUT OF
CANADA ACRS THE GREAT LAKES THIS PD WILL KEEP STALLED SFC TROUGH AND
ASSOCD CONVN AT BAY SOUTH OF THE TERMINALS.


&&

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

$$

SYNOPSIS...STEINWEDEL/KG
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA

000
FXUS63 KIND 161432
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1030 AM EDT THU MAY 16 2013

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

&&

.SYNOPSIS...
ISSUED AT 416 AM EDT THU MAY 16 2013

WEAK UPPER WAVES MOVING ALONG A STALLED FRONTAL BOUNDARY
WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS CENTRAL
INDIANA FOR THE NEXT SEVERAL DAYS. ABOVE NORMAL TEMPERATURES WILL
REMAIN IN PLACE DURING THIS TIME.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 928 AM EDT THU MAY 16 2013

SURFACE ANALYSIS LATE THIS MORNING SHOWS AND STATIONARY BOUNDARY
STRETCHING FROM NORTH OF TERRE HAUTE TO NORTH OF INDIANAPOLIS TO
NEAR NEW CASTLE. SHOWERS WERE LINGERING ALONG THE NORTH SIDE OF
THAT BOUNDARY WHILE MORE SHOWERS AND THUNDERSTORMS WERE
DEVELOPING ON THE WARMER AND MORE MOIST SOUTHERLY SIDE OF THE
BOUNDARY.

FORECAST SOUNDINGS INDICATE STEEP LAPSE RATES TODAY WITH EASILY
REACHABLE CONVECTIVE TEMPERATURES IN THE LOWER 70S. FORECAST
SOUNDINGS SHOW CAPE OF 1K-2K AVAILABLE ALSO. THUS HAVE INCREASE
POPS IN SEVERAL AREAS THIS MORNING BASED UPON RECENT RADAR TRENDS.
ADDITIONAL UPDATES MAY BE NEED SOON SHOULD COVERAGE CONTINUE TO
EXPAND...WHICH SEEMS LIKELY. ONGOING TEMP FORECAST APPEARS IN GOOD
SHAPE AND ONLY MINOR CHANGES MADE THERE.

&&

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

ISSUED AT 416 AM EDT THU MAY 16 2013

FORECAST FOCUS IS ON THUNDERSTORM CHANCES THROUGH THE PERIOD. WITH
THE FRONT STALLED NEAR THE AREA AND VARIOUS WAVES MOVING ALONG IT
KEPT CHANCES GOING THROUGH THE SHORT TERM. WITH THESE WAVES COMING
OUT OF AN UPPER LOW TO THE SOUTHWEST TRENDED THE HIGHEST POPS IN THE
SOUTH CLOSEST TO THE ENHANCED FORCING. GENERALLY USED A GUIDANCE
AVERAGE FOR POPS WHICH TRENDED LOWER AT NIGHT WITH LOSS OF HEATING.
ALSO TRENDED LOWER FOR SATURDAY NIGHT WITH THE BOUNDARY MOVING OUT
OF THE AREA AND UPPER RIDGING MOVING IN MOMENTARILY.

FOR TEMPERATURES THOUGHT A GUIDANCE CONSENSUS WORKED WELL FOR A
RELATIVELY UNCHANGING AIRMASS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

ISSUED AT 416 AM EDT THU MAY 16 2013

A WARM MOIST AIRMASS WILL BE ACROSS THE REGION AT LEAST UNTIL THE
MIDDLE OF NEXT WEEK.  MODELS INDICATE A WEAK UPPER DISTURBANCE OVER
KENTUCKY AT THE START OF THE LONG TERM. MEANWHILE AN UPPER RIDGE
WILL ALSO BE ACROSS THE REGION AT THE START OF THE LONG TERM.
EXPECT ONLY SLIGHT CHANCE OF THUNDERSTORMS AT BEST SUNDAY WITH
POSSIBLE CHANCE FAR SOUTHEAST.  SUNDAY NIGHT SHOULD BE DRY AS WE
WILL BE BETWEEN SYSTEMS AND AN UPPER RIDGE WILL BE OVERHEAD.

AN UPPER TROUGH OVER THE NORTHERN PLAINS WILL MOVE TO THE GREAT
LAKES AND MID MISSISSIPPI VALLEY BY THE MIDDLE OF NEXT WEEK.  A COLD
FRONT OVER THE PLAINS MONDAY WILL MOVE TO OUR REGION MONDAY NIGHT
AND TO OHIO BY DAY 7. RAIN CHANCES WILL INCREASE TO LIKELY CATEGORY
BY TUESDAY WHICH GOES WELL TO ALL BLEND POPS.

CONCERNING TEMPERATURES WILL GO CLOSER TO WARMER MEX MOS SUNDAY AND
MONDAY GIVEN THE WARM AIRMASS ACROSS OUR REGION AND THE UPPER RIDGE
ACROSS OUR REGION EARLY IN THE EXTENDED.  I SUSPECT THERE MAY BE TOO
MUCH WEIGHTING TOWARDS CLIMATOLOGY IN THIS PATTERN. TEMPERATURES
WILL COOL OFF SOME TUESDAY WITH MORE CLOUDS AND BETTER CHANCE OF
PRECIP AND EVEN MORE WEDNESDAY AS COOLER AIR MOVES IN. HOWEVER ALL
BLEND TEMPERATURES MAY STILL BE A BIT TOO COOL.

&&

.AVIATION /DISCUSSION FOR THE 161500Z KIND TAF UPDATE/...
ISSUED AT 1030 AM EDT THU MAY 16 2013

EVOLUTION OF CONVECTIVE POTENTIAL IN THE VICINITY OF KIND FOR THE
REST OF THE DAY STILL A LITTLE MURKY. APPEARS THE MOST LIKELY
SCENARIO BASED ON RECENT MODEL DATA WILL BE DEVELOPMENT EITHER NEAR
THE FRONTAL ZONE NORTH OF KIND OR ON OUTFLOW BOUNDARIES THAT MAY
MOVE UP FROM THE CONVECTION OVER SOUTHWEST INDIANA. SURFACE
INSTABILITY AXIS CURRENTLY LOCATED OVER CENTRAL INDIANA. IN EITHER
INSTANCE...THIS DEVELOPMENT WOULD STILL BE A FEW HOURS AWAY BASED ON
CONVECTIVE TEMPERATURES.

NO SIGNIFICANT CHANGES MADE AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

LOOK FOR SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP BY MIDDAY
ALONG A DIFFUSE FRONTAL BOUNDARY CURRENTLY OVER NORTHERN PORTIONS
OF CENTRAL INDIANA.  THIS FRONT WILL STALL OVER SOUTHERN PORTIONS OF
CENTRAL INDIANA BY THIS AFTERNOON AND TONIGHT. BECAUSE OF SCATTERED
NATURE OF THUNDERSTORMS WILL MENTION VCTS KIND...KHUF AND KBMG TAFS
FROM ABOUT 17Z TO 01Z.  FRONT MAY BE FAR ENOUGH SOUTH TO LEAVE OUT
MENTION OF VCTS AT KLAF AS CHANCES WILL BE LESS THERE.

EVEN WITH SCATTERED THUNDERSTORMS...CONDITIONS WILL REMAIN MOSTLY
VFR UNTIL 09Z FRIDAY.  WITH LOSS OF DAYTIME HEATING THUNDERSTORMS
WILL DIMINISH THIS EVENING.  AREAS OF MVFR FOG MAY DEVELOP TOWARDS
FRIDAY MORNING.  WINDS WILL BE 8 KNOTS OR LESS.


&&

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

$$

SYNOPSIS...CP
NEAR TERM...PUMA
SHORT TERM...CP
LONG TERM....JH
AVIATION...JH/JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 161338
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
938 AM EDT THU MAY 16 2013

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW

&&

.SYNOPSIS...
ISSUED AT 416 AM EDT THU MAY 16 2013

WEAK UPPER WAVES MOVING ALONG A STALLED FRONTAL BOUNDARY
WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS CENTRAL
INDIANA FOR THE NEXT SEVERAL DAYS. ABOVE NORMAL TEMPERATURES WILL
REMAIN IN PLACE DURING THIS TIME.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 928 AM EDT THU MAY 16 2013

SURFACE ANALYSIS LATE THIS MORNING SHOWS AND STATIONARY BOUNDARY
STRETCHING FROM NORTH OF TERRE HAUTE TO NORTH OF INDIANAPOLIS TO
NEAR NEW CASTLE. SHOWERS WERE LINGERING ALONG THE NORTH SIDE OF
THAT BOUNDARY WHILE MORE SHOWERS AND THUNDERSTORMS WERE
DEVELOPING ON THE WARMER AND MORE MOIST SOUTHERLY SIDE OF THE
BOUNDARY.

FORECAST SOUNDINGS INDICATE STEEP LAPSE RATES TODAY WITH EASILY
REACHABLE CONVECTIVE TEMPERATURES IN THE LOWER 70S. FORECAST
SOUNDINGS SHOW CAPE OF 1K-2K AVAILABLE ALSO. THUS HAVE INCREASE
POPS IN SEVERAL AREAS THIS MORNING BASED UPON RECENT RADAR TRENDS.
ADDITIONAL UPDATES MAY BE NEED SOON SHOULD COVERAGE CONTINUE TO
EXPAND...WHICH SEEMS LIKELY. ONGOING TEMP FORECAST APPEARS IN GOOD
SHAPE AND ONLY MINOR CHANGES MADE THERE.

&&

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

ISSUED AT 416 AM EDT THU MAY 16 2013

FORECAST FOCUS IS ON THUNDERSTORM CHANCES THROUGH THE PERIOD. WITH
THE FRONT STALLED NEAR THE AREA AND VARIOUS WAVES MOVING ALONG IT
KEPT CHANCES GOING THROUGH THE SHORT TERM. WITH THESE WAVES COMING
OUT OF AN UPPER LOW TO THE SOUTHWEST TRENDED THE HIGHEST POPS IN THE
SOUTH CLOSEST TO THE ENHANCED FORCING. GENERALLY USED A GUIDANCE
AVERAGE FOR POPS WHICH TRENDED LOWER AT NIGHT WITH LOSS OF HEATING.
ALSO TRENDED LOWER FOR SATURDAY NIGHT WITH THE BOUNDARY MOVING OUT
OF THE AREA AND UPPER RIDGING MOVING IN MOMENTARILY.

FOR TEMPERATURES THOUGHT A GUIDANCE CONSENSUS WORKED WELL FOR A
RELATIVELY UNCHANGING AIRMASS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

ISSUED AT 416 AM EDT THU MAY 16 2013

A WARM MOIST AIRMASS WILL BE ACROSS THE REGION AT LEAST UNTIL THE
MIDDLE OF NEXT WEEK.  MODELS INDICATE A WEAK UPPER DISTURBANCE OVER
KENTUCKY AT THE START OF THE LONG TERM. MEANWHILE AN UPPER RIDGE
WILL ALSO BE ACROSS THE REGION AT THE START OF THE LONG TERM.
EXPECT ONLY SLIGHT CHANCE OF THUNDERSTORMS AT BEST SUNDAY WITH
POSSIBLE CHANCE FAR SOUTHEAST.  SUNDAY NIGHT SHOULD BE DRY AS WE
WILL BE BETWEEN SYSTEMS AND AN UPPER RIDGE WILL BE OVERHEAD.

AN UPPER TROUGH OVER THE NORTHERN PLAINS WILL MOVE TO THE GREAT
LAKES AND MID MISSISSIPPI VALLEY BY THE MIDDLE OF NEXT WEEK.  A COLD
FRONT OVER THE PLAINS MONDAY WILL MOVE TO OUR REGION MONDAY NIGHT
AND TO OHIO BY DAY 7. RAIN CHANCES WILL INCREASE TO LIKELY CATEGORY
BY TUESDAY WHICH GOES WELL TO ALL BLEND POPS.

CONCERNING TEMPERATURES WILL GO CLOSER TO WARMER MEX MOS SUNDAY AND
MONDAY GIVEN THE WARM AIRMASS ACROSS OUR REGION AND THE UPPER RIDGE
ACROSS OUR REGION EARLY IN THE EXTENDED.  I SUSPECT THERE MAY BE TOO
MUCH WEIGHTING TOWARDS CLIMATOLOGY IN THIS PATTERN. TEMPERATURES
WILL COOL OFF SOME TUESDAY WITH MORE CLOUDS AND BETTER CHANCE OF
PRECIP AND EVEN MORE WEDNESDAY AS COOLER AIR MOVES IN. HOWEVER ALL
BLEND TEMPERATURES MAY STILL BE A BIT TOO COOL.

&&

.AVIATION /DISCUSSION FOR 161200Z TAF ISSUANCE/...
ISSUED AT 655 AM EDT THU MAY 16 2013

LOOK FOR SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP BY MIDDAY
ALONG A DIFFUSE FRONTAL BOUNDARY CURRENTLY OVER NORTHERN PORTIONS
OF CENTRAL INDIANA.  THIS FRONT WILL STALL OVER SOUTHERN PORTIONS OF
CENTRAL INDIANA BY THIS AFTERNOON AND TONIGHT. BECAUSE OF SCATTERED
NATURE OF THUNDERSTORMS WILL MENTION VCTS KIND...KHUF AND KBMG TAFS
FROM ABOUT 17Z TO 01Z.  FRONT MAY BE FAR ENOUGH SOUTH TO LEAVE OUT
MENTION OF VCTS AT KLAF AS CHANCES WILL BE LESS THERE.

EVEN WITH SCATTERED THUNDERSTORMS...CONDITIONS WILL REMAIN MOSTLY
VFR UNTIL 09Z FRIDAY.  WITH LOSS OF DAYTIME HEATING THUNDERSTORMS
WILL DIMINISH THIS EVENING.  AREAS OF MVFR FOG MAY DEVELOP TOWARDS
FRIDAY MORNING.  WINDS WILL BE 8 KNOTS OR LESS.


&&

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

$$

SYNOPSIS...CP
NEAR TERM...PUMA
SHORT TERM...CP
LONG TERM....JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS

000
FXUS63 KIND 161055
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
655 AM EDT THU MAY 16 2013

.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW

&&

.SYNOPSIS...
ISSUED AT 416 AM EDT THU MAY 16 2013

WEAK UPPER WAVES MOVING ALONG A STALLED FRONTAL BOUNDARY
WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS CENTRAL
INDIANA FOR THE NEXT SEVERAL DAYS. ABOVE NORMAL TEMPERATURES WILL
REMAIN IN PLACE DURING THIS TIME.

&&

.NEAR TERM /TODAY/...

ISSUED AT 416 AM EDT THU MAY 16 2013

OVER THE NEXT FEW HOURS SCATTERED CONVECTION ALONG THE FRONT SHOULD
DISSIPATE AS AN UPPER WAVE MOVES AWAY FROM THE AREA AND 850 MB WINDS
LESSEN. AFTER THAT...WILL SEE CHANCES FOR THUNDERSTORMS INCREASE
THROUGHOUT THE DAY FROM THE SOUTHWEST AS AN UPPER WAVE APPROACHES
FROM THERE AND ENHANCES CONVERGENCE SOUTH OF THE BOUNDARY. THE BEST
CHANCES WON/T ARRIVE UNTIL AFTERNOON AS THE WAVE GETS CLOSER AND
INSTABILITY INCREASES AHEAD OF IT. WHILE GFS QPF NUMBERS LOOK
OVERBLOWN /AS THEY WERE FOR YESTERDAY EVENING/ THE MAV GUIDANCE POPS
LOOK REASONABLE AND GENERALLY STUCK CLOSE TO THOSE. FOR HIGHS PICKED
THE WARMER GUIDANCE NUMBERS BASED ON RECENT VERIFICATION TRENDS
WHICH YIELDED LOWER TEMPERATURES IN THE SOUTHERN COUNTIES BASED ON
MORE CONVECTION THERE AND CONVECTION BEGINNING EARLIER TO CUT OFF
HEATING.

&&

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

ISSUED AT 416 AM EDT THU MAY 16 2013

FORECAST FOCUS IS ON THUNDERSTORM CHANCES THROUGH THE PERIOD. WITH
THE FRONT STALLED NEAR THE AREA AND VARIOUS WAVES MOVING ALONG IT
KEPT CHANCES GOING THROUGH THE SHORT TERM. WITH THESE WAVES COMING
OUT OF AN UPPER LOW TO THE SOUTHWEST TRENDED THE HIGHEST POPS IN THE
SOUTH CLOSEST TO THE ENHANCED FORCING. GENERALLY USED A GUIDANCE
AVERAGE FOR POPS WHICH TRENDED LOWER AT NIGHT WITH LOSS OF HEATING.
ALSO TRENDED LOWER FOR SATURDAY NIGHT WITH THE BOUNDARY MOVING OUT
OF THE AREA AND UPPER RIDGING MOVING IN MOMENTARILY.

FOR TEMPERATURES THOUGHT A GUIDANCE CONSENSUS WORKED WELL FOR A
RELATIVELY UNCHANGING AIRMASS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

ISSUED AT 416 AM EDT THU MAY 16 2013

A WARM MOIST AIRMASS WILL BE ACROSS THE REGION AT LEAST UNTIL THE
MIDDLE OF NEXT WEEK.  MODELS INDICATE A WEAK UPPER DISTURBANCE OVER
KENTUCKY AT THE START OF THE LONG TERM. MEANWHILE AN UPPER RIDGE
WILL ALSO BE ACROSS THE REGION AT THE START OF THE LONG TERM.
EXPECT ONLY SLIGHT CHANCE OF THUNDERSTORMS AT BEST SUNDAY WITH
POSSIBLE CHANCE FAR SOUTHEAST.  SUNDAY NIGHT SHOULD BE DRY AS WE
WILL BE BETWEEN SYSTEMS AND AN UPPER RIDGE WILL BE OVERHEAD.

AN UPPER TROUGH OVER THE NORTHERN PLAINS WILL MOVE TO THE GREAT
LAKES AND MID MISSISSIPPI VALLEY BY THE MIDDLE OF NEXT WEEK.  A COLD
FRONT OVER THE PLAINS MONDAY WILL MOVE TO OUR REGION MONDAY NIGHT
AND TO OHIO BY DAY 7. RAIN CHANCES WILL INCREASE TO LIKELY CATEGORY
BY TUESDAY WHICH GOES WELL TO ALL BLEND POPS.

CONCERNING TEMPERATURES WILL GO CLOSER TO WARMER MEX MOS SUNDAY AND
MONDAY GIVEN THE WARM AIRMASS ACROSS OUR REGION AND THE UPPER RIDGE
ACROSS OUR REGION EARLY IN THE EXTENDED.  I SUSPECT THERE MAY BE TOO
MUCH WEIGHTING TOWARDS CLIMATOLOGY IN THIS PATTERN. TEMPERATURES
WILL COOL OFF SOME TUESDAY WITH MORE CLOUDS AND BETTER CHANCE OF
PRECIP AND EVEN MORE WEDNESDAY AS COOLER AIR MOVES IN. HOWEVER ALL
BLEND TEMPERATURES MAY STILL BE A BIT TOO COOL.

&&

.AVIATION /DISCUSSION FOR 161200Z TAF ISSUANCE/...
ISSUED AT 655 AM EDT THU MAY 16 2013

LOOK FOR SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP BY MIDDAY
ALONG A DIFFUSE FRONTAL BOUNDARY CURRENTLY OVER NORTHERN PORTIONS
OF CENTRAL INDIANA.  THIS FRONT WILL STALL OVER SOUTHERN PORTIONS OF
CENTRAL INDIANA BY THIS AFTERNOON AND TONIGHT. BECAUSE OF SCATTERED
NATURE OF THUNDERSTORMS WILL MENTION VCTS KIND...KHUF AND KBMG TAFS
FROM ABOUT 17Z TO 01Z.  FRONT MAY BE FAR ENOUGH SOUTH TO LEAVE OUT
MENTION OF VCTS AT KLAF AS CHANCES WILL BE LESS THERE.

EVEN WITH SCATTERED THUNDERSTORMS...CONDITIONS WILL REMAIN MOSTLY
VFR UNTIL 09Z FRIDAY.  WITH LOSS OF DAYTIME HEATING THUNDERSTORMS
WILL DIMINISH THIS EVENING.  AREAS OF MVFR FOG MAY DEVELOP TOWARDS
FRIDAY MORNING.  WINDS WILL BE 8 KNOTS OR LESS.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLS