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000
FXUS63 KIND 220216
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1016 PM EDT TUE MAY 21 2013

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

&&

.SYNOPSIS...
ISSUED AT 227 PM EDT TUE MAY 21 2013

A LARGE UPPER LOW CURRENTLY OVER THE NORTHERN PLAINS IS EXPECTED
TO BRING UNSETTLED WEATHER TO THE AREA THROUGH THURSDAY AS IT
SLOWLY MOVES EAST AND WEAKENS WITH TIME. IN THE WAKE OF THIS
SYSTEM...HIGH PRESSURE IS EXPECTED TO BUILD IN FOR FRIDAY AND
SATURDAY. A FRONTAL SYSTEM MAY MOVE INTO THE AREA BY SUNDAY AND ON
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 1005 PM EDT TUE MAY 21 2013

UPDATE...
SPC HAS REMOVED ALL OF FORECAST AREA FROM SLIGHT RISK FOR TONIGHT
AS PARAMETERS CONTINUE TO WANE. SHOWER/THUNDERSTORM ACTIVITY HAS
BEEN SLOW TO ENTER CENTRAL INDIANA...SO CUT BACK ON POPS WITH
EARLIER UPDATES. IT HAS SINCE BEGUN PUSHING INTO SOUTHWEST
PORTIONS OF CENTRAL INDIANA THOUGH AND WILL CONTINUE TO FILTER
INTO THE REMAINDER OF CENTRAL INDIANA THROUGH THE COURSE OF THE
NIGHT...BECOMING MORE WIDESPREAD IN NATURE. A FEW EMBEDDED
THUNDERSTORMS COULD BECOME STRONG AT TIMES...ESPECIALLY AS A
SURFACE COLD FRONT ENTERS LATE TONIGHT. THE MAIN THREATS ARE
EXPECTED TO BE GUSTY WINDS...SMALL HAIL...LIGHTNING...AND BRIEF
DOWNPOURS. CURRENTLY...TEMPS ACROSS THE AREA ARE GENERALLY IN THE
LOW 70S WITH DEWPOINTS OF UPPER 50S/LOW 60S. WINDS ARE SOUTHERLY
AT 5 TO 10 MPH.  UPDATED GRIDS HAVE BEEN SENT.


&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 227 PM EDT TUE MAY 21 2013

COMBINATION OF UPPER ENERGY MOVING THROUGH DURING THE MORNING AND
PASSAGE OF COLD FRONT DURING THE DAY SUGGEST HIGH POPS ARE IN ORDER
AT THAT TIME. WILL ALSO KEEP SOME LINGERING CHANCE POPS FOR SHOWERS
WEDNESDAY NIGHT AND THURSDAY AS THE REMNANTS OF THE PLAINS UPPER LOW
IS PROGGED TO MOVE THROUGH.

BY THURSDAY NIGHT AND FRIDAY...HIGH PRESSURE BEGINS TO BUILD OVER
THE AREA FROM THE NORTH IN THE WAKE OF THE UPPER SYSTEM. WILL GO DRY
AT THOSE TIMES.

GIVEN THE CONSIDERABLE CLOUD COVER/PRECIPITATION EXPECTED TO BE
AROUND ON WEDNESDAY...THE GFS MOS HIGHS LOOK TOO WARM. WILL CUT
ABOUT 5 DEGREES OFF OF THE GUIDANCE. THE REMAINDER OF THE
TEMPERATURE GUIDANCE IN THE LATER PERIODS LOOK REASONABLE AT THIS
TIME BASED ON PROGGED LOW LEVEL THICKNESSES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 227 PM EDT TUE MAY 21 2013

ECMWF AND GFS BOTH BUILD A LARGE AREA OF HIGH PRESSURE ACROSS THE
OHIO VALLEY ON FRIDAY INTO SATURDAY. THIS SHOULD LEAD TO DRY AND
COOL WEATHER AS THE WEEKEND BEGINS.

ECMWF AND GFS ALSO BOTH INDICATE SOME LOWER LEVEL CONVERGENCE
ACROSS THE SOUTHWEST PARTS OF THE FORECAST AREA ON SUNDAY INTO
MONDAY. GULF REMAINS PRIMARILY SHUT OFF AND RIDGING APPEARS IN
PLACE ALOFT WHILE THE MODELS DO EJECT A RIDGE RIDING SHORT WAVE
OVER THE LOWER LEVEL CONVERGENCE AREA. THUS WITH LIMITED MOISTURE
CONFIDENCE REMAINS LOW. HAVE DECIDED TO INCLUDE SOME LOW CHC POPS
GIVEN THIS FOR SUNDAY AND MONDAY FOR NOW.

DRY WEATHER RETURNS ON TUESDAY AS STRONG RIDGING BUILDS ACROSS THE
OHIO VALLEY AND THE WEAK UPPER SHORT WAVE DRIFTS EAST OF INDIANA.

&&

.AVIATION /DISCUSSION FOR THE 220000Z TAF ISSUANCE/...
ISSUED AT 700 PM EDT TUE MAY 21 2013

NUMEROUS SHOWERS AND THUNDERSTORMS POSSIBLE LATE TONIGHT THROUGH
MIDDAY WEDNESDAY. GENERALLY VFR REST OF THE TIME.

LOW PRESSURE IN THE UPPER ATMOSPHERE WAS OVER THE UPPER MIDWEST. AN
UPPER DISTURBANCE ROTATING AROUND THE SOUTH SIDE OF THE UPPER LOW
WAS PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS OVER MIDDLE AND
LOWER MISSISSIPPI VALLEY FROM THE SOUTHERN TIP OF ILLINOIS AND
SOUTHWARD.  RAPID REFRESH MODEL INDICATES ONLY WIDELY SCATTERED
THUNDERSTORMS UNTIL LATE TONIGHT ACROSS CENTRAL INDIANA AND WILL
KEEP TAFS MOSTLY VFR UNTIL AROUND 08Z. AFTER THAT WILL MENTION VCTS
AND CEILINGS AND VISIBILITIES MAY BECOME MOSTLY MVFR BY SUNRISE
WEDNESDAY.  RAPID REFRESH MODEL INDICATES NUMEROUS SHOWERS AND
THUNDERSTORMS FIRST HALF OF THE DAY WEDNESDAY WITH ACTIVITY BECOMING
A LITTLE LESS NUMEROUS LATER ON.  MODEL SOUNDINGS INDICATE
PREVAILING CEILINGS AND VISIBILITIES SHOULD BECOME MOSTLY VFR
BY WEDNESDAY AFTERNOON.

WINDS TONIGHT WILL BE SOUTH TO SOUTHWEST DECREASING TO 8 TO 10 KNOTS
BY 01Z AND WITH DAYTIME MIXING SOUTH TO SOUTHWEST WINDS OF 15 KNOTS
AND GUSTS UP TO 25 KNOTS WILL BE THE RULE.


&&

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


&&

$$

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

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