Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 231035
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
633 AM EDT SAT AUG 23 2014

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

&&

.SYNOPSIS...
ISSUED AT 207 AM EDT SAT AUG 23 2014

HIGH PRESSURE OVER THE TENNESSEE RIVER VALLEY WILL CONTINUE TO
KEEP A VERY WARM AND HUMID AIR MASS OVER CENTRAL INDIANA THE REST
OF THE WEEKEND. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH OF
THE NEXT FEW AFTERNOONS AS THE WARM AND HUMID AIR MASS REMAINS IN
PLACE ACROSS THE AREA.

RAIN CHANCES WILL DIMINISH AT THE BEGINNING OF NEXT WEEK AS THE
HIGH PRESSURE SYSTEM FURTHER ESTABLISHES ACROSS THE OHIO VALLEY.

RAIN CHANCES WILL RETURN DURING THE MIDDLE OF THE NEXT WORK WEEK
AS A COLD FRONT SAGS INTO THE OHIO VALLEY FROM THE UPPER MIDWEST.

&&

.NEAR TERM /TODAY/...

ISSUED AT 207 AM EDT SAT AUG 23 2014

SURFACE ANALYSIS EARLY THIS MORNING SHOWS WEAK...POORLY ORGANIZED
HIGH PRESSURE OVER THE TENNESSEE AND OHIO RIVER VALLEYS EXTENDING
NORTHWARD INTO THE GREAT LAKES. LOW PRESSURE WAS FOUND OVER
WESTERN KANSAS WITH A WARM FRONT EXTENDING EAST ACROSS CENTRAL
MISSOURI TO SOUTHERN ILLINOIS AND SOUTHERN INDIANA. A VERY WARM
AND HUMID AIR MASS WAS IN PLACE ACROSS THE AREA WITH DEW POINT
TEMPS IN THE LOWER 70S. SKIES WERE PARTLY CLOUDY.

MAIN FORECAST CHALLENGE TODAY WILL BE POPS. WE WILL HAVE TWO
CHANCES FOR PRECIPITATION TODAY. THE FIRST WILL BE LATER THIS
MORNING AS THE NAM SUGGESTS MOISTURE FROM THE CONVECTION OVER
IOWA WILL PUSH INTO CENTRAL INDIANA. RAPID REFRESH AND GFS
DISAGREE ON THIS AND CONFIDENCE REMAINS RATHER LOW. HOWEVER THIS
AFTERNOON...DAYTIME HEATING WILL ONCE AGAIN PROVIDE CHANCES FOR
CONVECTION AS FORECAST SOUNDINGS CONTINUE TO SHOW A CONDITIONALLY
UNSTABLE COLUMN. LI/S REMAIN AROUND -5 OR BETTER TODAY AND CAPE IS
OVER 2070 G/KG. FRONTAL BOUNDARY IN THE AREA WILL CONTINUE TO
REMAIN TO BE A FOCUS FOR PRECIP CHANCES THIS AFTERNOON ALSO. THUS
WILL TREND POPS CLOSE TO MAVMOS TODAY...IN THE CHC CATEGORY GIVEN
THE LOW CONFIDENCE BUT NUMEROUS FEATURES AVAILABLE.

AS FOR TEMPS WILL TREND HIGHS CLOSE TO PERSISTENCE AS THERE HAS
BEEN LITTLE CHANGE IN THE AIR MASS.

&&

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

ISSUED AT 207 AM EDT SAT AUG 23 2014

MAIN FORECAST ISSUE DURING THIS PERIOD WILL BE POPS.

GFS AND NAM CONTINUE TO SUGGEST THAT THE STRONG RIDGING IN PLACE
ALOFT OVER THE MISSISSIPPI RIVER VALLEY WILL AMPLIFY AND MOVE EAST
BUILDING ACROSS INDIANA AND THE GREAT LAKES. THIS WILL KEEP ALL
RIDGE RIDING SHORT WAVES WELL TO THE NORTH AND EAST OF INDIANA AND
KEEP INDIANA UNDER THE PROTECTION OF THE RIDGE AXIS. MEANWHILE
FORECAST SOUNDINGS SHOW SOME WARM AIR ARRIVING IN THE MIDDLE
LEVELS AS 700MB TEMPS RISE TO AT OR SLIGHTLY ABOVE 10C. BY SUNDAY
NIGHT AND MONDAY...SUBSIDENCE BEGINS TO TAKE SHAPE WITHIN THE
COLUMN UNDERNEATH THE RIDGE AS FORECAST SOUNDINGS BEGIN TO SHOW
DRY AIR INFILTRATING THE COLUMN.

BY MONDAY AFTERNOON AND MONDAY NIGHT...THE UPPER RIDGE AXIS IS
EXPECTED TO PIVOT EAST TO NEW ENGLAND...BUT OHIO VALLEY REMAINS
PROTECTED ALOFT BY A LARGE CLOSED UPPER HIGH PRESSURE
SYSTEM...PROVIDING SUBSIDENCE. THUS WILL CONTINUE THE TREND TOWARD
A DRY FORECAST THROUGH MONDAY NIGHT. GIVEN THE LITTLE CHANGE IN
850MB TEMPS OVERALL...WILL TREND HIGHS AT OR SLIGHTLY ABOVE
PERSISTENCE...WITH WARMEST TEMPS COMING ON MONDAY AND INTO TUESDAY
AS SUBSIDENCE ALLOWS FOR BETTER HEATING OF DRIER AIR.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...

ISSUED AT 207 AM EDT SAT AUG 23 2014

ENSEMBLES SUGGEST UPPER RIDGE INITIALLY OVER THE AREA AT THE
BEGINNING OF THE PERIOD WILL GET SUPPRESSED BACK TO THE SOUTH AS AN
UPPER TROUGH MOVES INTO THE GREAT LAKES BY THE END OF NEXT WEEK.

ENSEMBLES SUGGEST PRECIPITATION POTENTIAL WILL MOVE BACK INTO THE
AREA STARTING TUESDAY AS UPPER RIDGE BEGINS TO FLATTEN OUT...WITH
THE BEST CHANCES NEXT WEDNESDAY AND THURSDAY AS A FRONTAL SYSTEM
ASSOCIATED WITH THE APPROACHING UPPER TROUGH MOVES IN. WILL KEEP
CHANCE POPS GOING IN THE FORECAST FROM TUESDAY THROUGH THURSDAY.

SOME OF THE ENSEMBLE MEMBERS HANG THE SOUTHERN END OF THE UPPER
TROUGH BACK ACROSS THE AREA INTO FRIDAY...WITH AN ATTENDANT
PRECIPITATION THREAT AT THAT TIME. WILL ADD SOME POPS FOR FRIDAY AS
WELL TO COVER THIS POSSIBILITY.


&&

.AVIATION /DISCUSSION FOR THE 231200Z TAFS/...
ISSUED AT 633 AM EDT SAT AUG 23 2014

QUITE A BIT OF LIFR VISIBILITY RESTRICTIONS/INDEFINITE CEILINGS
AROUND 005 AGL ACROSS THE AREA...EXCEPT FOR KIND WHERE LOW
CONDITIONS HAVE YET TO MATERIALIZE DUE TO THE URBAN HEAT ISLAND.
MOISTURE LAYER LOOKS QUITE SHALLOW...SO EXPECTING THESE LOWER
CONDITIONS TO BURN OFF AROUND 231400Z. LOWER CONFIDENCE IN
THE LIFR/IFR CONDITIONS MOVING INTO THE KIND AREA...BUT THE
POTENTIAL EXISTS FOR A PERIOD OF LIFR/IFR CEILINGS OR VISIBILITIES
AT KIND AROUND OR JUST AFTER SUNRISE AS NOCTURNAL INVERSION BEGINS
TO MIX OUT.

OTHERWISE...CONVECTIVE PARAMETERS REMAIN RATHER HIGH TODAY...SO
EXPECTING THE POTENTIAL FOR SCATTERED TO WIDELY SCATTERED CONVECTION
BY THE MID AFTERNOON HOURS. HOWEVER...THERE DOESN/T SEEM TO BE TOO
MUCH OF A FOCUS FOR ORGANIZED ACTIVITY AT THIS POINT...SO WILL KEEP
OUT AN EXPLICIT MENTION OF CONVECTION IN THE FORECAST FOR NOW.

OUTSIDE OF ANY CONVECTION...SURFACE WINDS GENERALLY AT OR BELOW 7
KTS TODAY.

&&

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

$$

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

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