000
FXUS63 KIND 220427
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1227 AM EDT WED MAY 22 2013

.UPDATE...
THE AVIATION 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 220600Z TAF ISSUANCE/...

ISSUED AT 1226 AM EDT WED MAY 22 2013

NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS OVER THE LOWER AND
MIDDLE MISSISSIPPI VALLEY WILL SPREAD INTO CENTRAL INDIANA TOWARDS
DAYBREAK AS AN UPPER DISTURBANCE OVER THE SOUTHERN PLAINS ROTATES
TOWARDS CENTRAL INDIANA.  PRIOR TO DAYBREAK EXPECT MOSTLY SCATTERED
SHOWERS TO BE THE RULE AND WILL MENTION VCSH AND THEN VCTS BY
DAYBREAK AS SHOWERS AND THUNDERSTORM TO BECOME MORE NUMEROUS.

MODELS INDICATE BEST TIMING FOR SHOWERS AND THUNDERSTORMS WILL BE
IN THE MORNING HOURS TO ABOUT MIDDAY.  WILL COVER THIS WITH VCTS AND
MENTION A TEMPO TS GROUP MID TO LATE MORNING.  THE SHOWERS AND
THUNDERSTORMS MAY PRODUCE MVFR CONDITIONS AT TIME BY MID TO LATE
MORNING.  OTHERWISE...TAFS SHOULD BE MAINLY VFR AT OTHER TIMES.

SCATTERED SHOWERS AND THUNDERSTORMS MAY PERSIST WEDNESDAY AFTERNOON
AS A COLD FRONT MOVES THROUGH.  RAPID REFRESH MODEL INDICATES
ANYTHING LEFT OVER SHOULD DIMINISH QUICKLY WEDNESDAY EVENING.

SOUTHWEST WINDS MAY INCREASE UP TO 14 KNOTS WITH GUSTS TO 23 KNOTS
BY WEDNESDAY AFTERNOON.  WINDS MOST OTHER TIMES WILL BE 10 KNOTS OR
LESS.

&&

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

$$

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

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