Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 010729
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
329 AM EDT FRI AUG 1 2014

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

&&

.SYNOPSIS...
ISSUED AT 329 AM EDT FRI AUG 1 2014

SCATTERED THUNDERSTORMS WILL BE POSSIBLE TODAY AND SATURDAY AS AN
UPPER WAVE TRACKS ACROSS THE LOWER GREAT LAKES. DRIER WEATHER WILL
RETURN FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK AS
HIGH PRESSURE BUILDS INTO THE REGION. THE ARRIVAL OF LOW PRESSURE
AND AN ASSOCIATED FRONTAL BOUNDARY WILL BRING UNSETTLED WEATHER BACK
INTO THE OHIO VALLEY FOR THE SECOND HALF OF THE UPCOMING WEEK.

&&

.NEAR TERM /TODAY/...
ISSUED AT 329 AM EDT FRI AUG 1 2014

MAINLY CLEAR SKIES ACROSS CENTRAL INDIANA EARLY THIS MORNING WITH
SUBTLE RIDGING ALOFT. 07Z TEMPS RANGED FROM THE UPPER 50S TO THE MID
60S.

BROAD UPPER TROUGH REMAINS ENTRENCHED ACROSS THE REGION AND WILL
CONTINUE TO INFLUENCE WEATHER TODAY. A STRONGER WAVE ALOFT WILL
ROTATE THROUGH THE TROUGH AND INTO THE FORECAST AREA DURING THE
AFTERNOON AND EVENING. THE ENHANCED FORCING ALOFT...COMBINED WITH
STEEP LAPSE RATES AND WEAK INSTABILITY SHOULD BE MORE THAN
SUFFICIENT FOR SCATTERED CONVECTIVE DEVELOPMENT FOCUSED DURING PEAK
HEATING THIS AFTERNOON. STRONGER CELLS WILL BE CAPABLE OF GUSTY
WINDS AND HAIL AS MODEL SOUNDINGS SHOW DRY ADIABATIC FLOW TO AROUND
700MB LATER TODAY AND WET BULB ZERO VALUES FROM 9-10KFT. SOUNDINGS
ALSO INDICATE PRESENCE OF AN INVERSION AROUND 600MB LASTING THROUGH
THE AFTERNOON WHICH WOULD LIKELY LIMIT CONVECTIVE INTENSITY TO SOME
DEGREE.

BIGGEST CONCERN FROM CONVECTION HOWEVER IS LIKELY TO BE LOCALIZED
HEAVY RAINFALL WITH PALTRY STORM MOTIONS PROGGED AT 5KTS OR LESS.
WILL CARRY HIGHEST POPS OVER THE NORTHERN HALF OF THE FORECAST AREA
IN CLOSER PROXIMITY TO THE BETTER FORCING ALOFT...BUT CONVECTION IS
POSSIBLE JUST ABOUT ANYWHERE IN THIS KIND OF A SETUP TODAY.

TEMPS...GUIDANCE LOOKS A BIT TOO WARM TODAY CONSIDERING SIMILAR
THERMAL PROFILES TO THURSDAY...WITH THE ADDED POTENTIAL FOR
CLOUDS/RAIN. GENERALLY UNDERCUT MOS GUIDANCE BY A DEGREE OR TWO WITH
MOST AREAS IN THE LOWER TO MID 80S.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 329 AM EDT FRI AUG 1 2014

FORECAST CHALLENGES REMAIN ON PRECIP CHANCES THROUGH THE FIRST HALF
OF THE PERIOD AS THE UPPER TROUGH SLOWLY SHIFTS EAST.

AFOREMENTIONED WAVE ALOFT WILL TRACK ACROSS THE REGION SLOWLY
OVERNIGHT AND SATURDAY. ONGOING CONVECTION THIS EVENING LIKELY TO
CONTINUE INTO THE OVERNIGHT...GRADUALLY DIMINISHING WITH LOSS OF
INSTABILITY. BEST CHANCES FOR PRECIP OVERNIGHT EXPECTED ACROSS
NORTHERN COUNTIES IN CLOSEST PROXIMITY TO THE WAVE. SCATTERED
CONVECTION WILL AGAIN DEVELOP WITH DIURNAL HEATING SATURDAY...WITH
THE GREATEST CONCENTRATION OVER EASTERN COUNTIES NEAREST TO THE
EASTWARD MOVING WAVE AXIS. VERY SLOW STORM MOTIONS WILL AGAIN
PROMOTE LOCALIZED HEAVY SOAKERS.

LINGERING EVENING CONVECTION WILL DIMINISH SATURDAY NIGHT AS WEAK
HIGH PRESSURE AND SLIGHTLY DRIER AIR INFILTRATE THE OHIO VALLEY
BEHIND THE DEPARTING WAVE. THE HIGH WILL REMAIN DRAPED ACROSS THE
REGION SUNDAY WITH MODEL SOUNDINGS SHOWING A STRENGTHENING MID LEVEL
CAP AS TEMPS ALOFT WARM. DESPITE WEAK INSTABILITY...THE LACK OF ANY
APPRECIABLE FORCING SHOULD KEEP ANY CONVECTION FROM FORMING ACROSS
CENTRAL INDIANA. DRY WEATHER WILL PERSIST THROUGH SUNDAY NIGHT AS
THE HIGH DRIFTS THROUGH THE OHIO VALLEY.

TEMPS...MODEL GUIDANCE CONTINUES TO LOOK OVERALL TOO AGGRESSIVE WITH
WARMING THROUGH THE PERIOD. UNDERCUT MOS BY A COUPLE DEGREES BOTH
SATURDAY AND SUNDAY...WITH TEMPS PRIMARILY IN THE LOWER AND MIDDLE
80S. LOW TEMPS WILL REMAIN QUITE COMFORTABLE BY EARLY AUGUST
STANDARDS...RANGING FROM THE UPPER 50S TO MID 60S.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 329 AM EDT FRI AUG 1 2014

HIGH PRESSURE WILL BE IN PLACE OVER CENTRAL INDIANA TO BEGIN THE
LONG TERM PERIOD KEEPING DRY WEATHER IN THE FORECAST FOR MONDAY AND
MONDAY NIGHT. ON TUESDAY THROUGH TUESDAY NIGHT A WEAK UPPER WAVE
WILL MOVE THROUGH THE GREAT LAKES BRINGING SMALL THUNDERSTORM
CHANCES TO NORTHERN PARTS OF THE AREA. FOR WEDNESDAY INTO THURSDAY
THE UPPER PATTERN IS SHOWING MORE VARIABILITY IN THE DIFFERENT MODEL
SOLUTIONS BUT THEY DO SEEM TO BE SHOWING A SURFACE LOW DEVELOPING IN
THE PLAINS AND POSSIBLY A FRONT DEVELOPING SOMEWHERE IN THE VICINITY
OF INDIANA/ILLINOIS...WITH DIFFERENCES ON STRENGTH AND TIMING OF THE
SYSTEM. WILL STICK WITH THE INITIALIZATION SOLUTION OF LOW CHANCE
POPS WEDNESDAY ACROSS THE NORTH INCREASING TO CHANCE POPS ACROSS THE
AREA THURSDAY. INSTABILITY WILL BE ACROSS THE AREA THROUGHOUT SO ALL
POP CHANCES WILL INCLUDE THUNDER. TEMPERATURES WILL WARM TO
NEAR/SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE 80S THROUGHOUT.

&&

.AVIATION /DISCUSSION FOR A 010700Z TAF UPDATE/...

ISSUED AT 240 AM EDT FRI AUG 1 2014

PATCHY FOG HAS DEVELOPED FASTER AND VISIBILITIES HAVE DROPPED LOWER
THAN INITIALLY THOUGHT AT OUTLYING SITES. HAVE ADJUSTED ALL SITES
BUT KIND TO BE PREVAILING MVFR WITH TEMPO IFR. COULD STILL SEE
BOUNCES TO VFR AND THINK VARIABLE VISIBILITIES WILL BE THE RULE FOR
THE NEXT 4-6 HOURS. AT KLAF AND KHUF ENDING TEMPO IFR BY 10Z AS
THINKING THAT APPROACHING CIRRUS CURRENTLY OVER WESTERN/CENTRAL
ILLINOIS COULD ALLOW CONDITIONS TO IMPROVE. PREVIOUS DISCUSSION
FOLLOWS...

TEMPERATURE/DEWPOINT SPREADS HAVE NARROWED OVER THE PAST COUPLE OF
HOURS...SO SOME FOG DEVELOPMENT SEEMS LIKELY. GROUND HAS HAD A
CHANCE TO DRY OUT YESTERDAY...AND WITH LITTLE MOISTURE
ADVECTION...THE PROBABILITY OF IFR RESTRICTIONS SEEMS LOW AT THIS
POINT. WILL GO WITH SOME MVFR VISIBILITY RESTRICTIONS FOR A FEW
HOURS EITHER SIDE OF SUNRISE ON FRIDAY.

SCATTERED DIURNAL CLOUDS DEVELOPMENT BASED AROUND 040 EXPECTED BY
MIDDAY FRIDAY.

SURFACE WINDS GENERALLY 7 KTS OR LESS THROUGH 011800Z.

&&

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

&&

$$

SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....CP
AVIATION...JAS/CP

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