Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 291906
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
305 PM EDT FRI MAY 29 2015

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

&&

.SYNOPSIS...
ISSUED AT 302 PM EDT FRI MAY 29 2015

A COLD FRONT WILL DROP SOUTHEAST ACROSS CENTRAL INDIANA ON SATURDAY.
THE FRONT WILL INTERACT WITH A WARM...MOIST AND UNSTABLE ATMOSPHERE
AND RESULT IN SHOWERS AND THUNDERSTORM CHANCES THIS WEEKEND. THE
MOST WIDESPREAD ACTIVITY IS EXPECTED TO BE ON SATURDAY.

MUCH COOLER AIR WILL MOVE IN BEHIND THE FRONT WITH HIGHS ONLY IN
THE 60S ON SUNDAY. A FEW SHOWERS AND POSSIBLY THUNDERSTORMS MAY WILL
LINGER INTO MONDAY AS THE FRONT SETTLES SLOWLY SOUTH OVER KENTUCKY
AND TENNESSEE AND EVENTUALLY DISSIPATES. TEMPERATURES WILL RETURN TO
THE 80S BY WEDNESDAY AS THE FRONT RETURNS AND AN UPPER RIDGE BUILDS
OVER THE AREA. HOWEVER...AN UPPER LOW OVER THE SOUTHERN STATES MAY
BRING ENOUGH MOISTURE NORTHWARD FOR A FEW AFTERNOON STORMS NEXT
THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 305 PM EDT FRI MAY 29 2015

12Z DETERMINISTIC MODELS IN DECENT AGREEMENT THAT MCV OVER EASTERN
TEXAS WILL LIFT NORTHEAST TO THE OZARKS BY 12Z SATURDAY WITH
SOUTHWEST FLOW AHEAD OF IT ACROSS THE OHIO VALLEY. IN
ADDITION...SOUTH LOW LEVEL FLOW NEAR 10 KNOTS WILL KEEP IT
WARM...MOIST AND UNSTABLE THROUGH THE NIGHT. THIS SHOULD BE ENOUGH
FOR ISOLATED TO SCATTERED EVENING THUNDERSTORMS. WITH ONLY WEAK
SHEAR...COULD SEE A LULL IN THE ACTIVITY LATE THIS EVENING AND EARLY
OVERNIGHT. THEN...THUNDERSTORMS SHOULD INCREASE AGAIN TOWARD OR JUST
AFTER DAYBREAK SATURDAY ACROSS OUR NORTHWESTERN COUNTIES...IN CLOSER
PROXIMITY TO AN ADVANCING COLD FRONT. MODELS AGREE THE FRONT WILL BE
JUST WEST OF A CHICAGO TO ST. LOUIS LINE AT 12Z.

SO...WILL GO WITH GOOD CHANCE POPS NORTHWEST TO SLIGHT CHANCE
SOUTHEAST.

12Z MOS TEMPERATURE VERY CLOSE AND LOOK GOOD WITH CURRENT DEW
POINTS...CONTINUED SOUTHERLY FLOW LEVEL FLOW AND CLOUD COVER
CONSIDERATIONS.

&&

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

ISSUED AT 245 AM EDT FRI MAY 29 2015

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS. GFS AND
NAM BOTH SUGGEST THE UPPER TROUGH SLOWLY BEGINS TO EDGE EAST
TONIGHT...PUSHING DYNAMICS ACROSS THE OHIO VALLEY. FORECAST
SOUNDINGS CONTINUE TO SHOW DEEP SATURATION THROUGH THE NIGHT.
LINGERING DIURNAL CONVECTION MAY ALSO BE A CONTINUED FACTOR.
FORECAST SOUNDINGS CONTINUE TO SHOW DEEP SATURATION ALSO. THUS
WITH PLENTY OF MOISTURE AVAILABLE...WILL CONTINUE TO TREND TOWARD
THE CATEGORICAL POPS OF THE MAVMOS TONIGHT. GIVEN THE EXPECTED RAIN
AND WARM...SOUTHERLY FLOW IN PLACE...WILL TREND LOWS WARMER THAN
MAVMOS.

RAINS FOR RAIN ON SATURDAY APPEAR QUIET FAVORABLE ALSO. GFS AND
NAM SUGGEST THE UPPER TROUGH SAGS SOUTH ACROSS INDIANA ON
SATURDAY PROVIDING GOOD LIFT. FORECAST SOUNDINGS ONCE AGAIN SHOW
DEEP SATURATION...WITH CAPE AVAILABLE LOFT. MEANWHILE AT THE
SURFACE THE FRONTAL BOUNDARY IS EXPECTED TO BE PUSHING ACROSS
CENTRAL INDIANA...PROVIDING GOOD LOW LEVEL CONVERGENCE.
FINALLY...SURFACE LOW PRESSURE IS EXPECTED TO PUSH NORTHEAST ALONG
THE FRONT ON SATURDAY AFTERNOON INTO SATURDAY NIGHT...PROVIDING MORE
FORCING. FORECAST SOUNDINGS SHOW PRECIPITABLE WATER NEAR 1.70-1.80
INCHES. THUS WILL ONCE AGAIN TREND POPS AT OR ABOVE MAVMOS ON
SATURDAY AND AGAIN ON SATURDAY NIGHT. AS FOR TEMPS WILL TREND
SATURDAY HIGHS COOLER THAN MAVMOS AND STICK CLOSE TO MAVMOS FOR
SATURDAY NIGHT LOWS AS A NEW AIR MASS IN INTRODUCED IN THE WAKE OF
THE FRONT.

FORECAST SOUNDINGS ON SUNDAY SHOW SOME LINGERING LOWER LEVEL
MOISTURE DURING THE MORNING HOURS...HOWEVER THE MID AND UPPER
LEVEL DRY OUT QUICKLY AS COLD FRONT SAG FARTHER SOUTHEAST ALONG
WITH THE UPPER SUPPORT. FURTHERMORE...INTO SUNDAY NIGHT THE
TROUGHING ALOFT APPEARS TO FLATTEN SOMEWHAT. MEANWHILE AT THE
SURFACE COOLER AND DRIER...CONTINENTAL NORTHEAST FLOW TAKES
PLACE...PROVIDING FURTHER DRYING AND SUBSIDENCE. THUS OTHER THAN A
FEW LINGERING MORNING SHOWERS/DRIZZLE/SPRINKLES LINGERING ON
SUNDAY MORNING...WILL TREND TOWARD A DRY FORECAST FOR SUNDAY
AFTERNOON AND INTO SUNDAY NIGHT. GIVEN THE EXPECTED CLOUDS AND
COOLER NE FLOW DURING THIS TIME WILL ALSO TREND LOWS AT OR BELOW
MAVMOS/MEXMOS.

&&

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

ISSUED AT 223 PM EDT FRI MAY 29 2015

ENSEMBLES ARE SHOWING GOOD AGREEMENT ON AN UPPER RIDGE BUILDING
ACROSS THE AREA THROUGH THE LONG TERM. ENSEMBLES ARE ALSO AGREEING
ON A WESTERN U.S. UPPER LOW DIGGING SOUTH AND GETTING CUT OFF OVER
THE GULF AS THE AFOREMENTIONED RIDGE BUILDS. IN THE OPERATIONAL RUNS
THERE IS A SUGGESTION THAT MOISTURE/UPPER FORCING FROM THIS UPPER
LOW COULD SWING NORTH INTO THE SOUTHERN COUNTIES AND BRING SOME
THUNDERSTORM CHANCES DESPITE THE PRESENCE OF THE UPPER RIDGE
THURSDAY AND FRIDAY. CHANCES WOULD BE MORE LIKELY DURING THE DAY
WITH DAYTIME HEATING AVAILABLE TO HELP THE FORCING OVERCOME THE
INHIBITION OF THE UPPER RIDGE. TEMPERATURES WILL WARM FROM NEAR
NORMAL TO START THE PERIOD TO ABOUT 10 DEGREES ABOVE NORMAL GOING
INTO THE WEEKEND.

&&

.AVIATION /DISCUSSION FOR 291800Z TAF ISSUANCE/...

ISSUED AT 1252 PM EDT FRI MAY 29 2015

WIDELY SCATTERED SHOWERS ARE POPPING UP AROUND CENTRAL INDIANA
JUST BEFORE 1 PM. THUS FAR NO CLOUD TO GROUND LIGHTNING IS BEING
REPORTED WITH THESE...BUT WITH INSTABILITY AVAILABLE EXPECT THAT
LIGHTNING WILL DEVELOP. WITH SPOTTY COVERAGE AT BEST AT THIS POINT
AND NO IMPETUS FOR MORE WIDESPREAD DEVELOPMENT MAY CONTINUE WITH
VCTS FOR THE SITES THROUGH THE AFTERNOON INTO THE EVENING HOURS.
CONFIDENCE IS LOW REGARDING THUNDER IMPACTING ANY PARTICULAR
SITE...BUT WITH AFOREMENTIONED SHOWERS ALREADY ACROSS CENTRAL
INDIANA THINK DROPPING ANY THUNDER MENTION IS PREMATURE. COULD
INTRODUCE DETERIORATING CONDITIONS OVERNIGHT AND SATURDAY WITH
MORE DEVELOPMENT EXPECTED AHEAD OF THE COLD FRONTAL PASSAGE. WIND
SHIFT FROM THE COLD FRONT WILL LIKELY OCCUR SATURDAY EVENING AND
THUS WILL NOT BE INCLUDED IN THIS ISSUANCE.

&&

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

$$

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

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