Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 281837
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
237 PM EDT SUN SEP 28 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EDT SUN SEP 28 2014

DRY AND WARM CONDITIONS WILL CONTINUE THROUGH MID WEEK ACROSS
CENTRAL INDIANA...THEN A COLD FRONT WILL BRING RAIN CHANCES FOR THE
END OF THE WORK WEEK. NEXT WEEKEND WILL BE DRY BUT MUCH COOLER WITH
TEMPERATURES BELOW AVERAGE FOR THE START OF OCTOBER.

&&

.NEAR TERM /REST OF THIS AFTERNOON AND TONIGHT/...
ISSUED AT 217 PM EDT SUN SEP 28 2014

SATELLITE SHOWS SOME CONVECTIVE CLOUDS ACROSS SOUTHERN
INDIANA...NEAR THE FAR SOUTHERN FORECAST AREA. THIS IS IN AN AREA OF
HIGHER MOISTURE...AND SOME WEAK VORTICITY ADVECTION IS CREATING SOME
FORCING IN THIS AREA. CANNOT RULE OUT AN ISOLATED SHOWER ACROSS THE
FAR SOUTH FOR THE REMAINDER OF THIS AFTERNOON...BUT BELIEVE ODDS ARE
TOO LOW TO MENTION IN THE FORECAST.

OTHERWISE EXPECT CLOUDS TO GRADUALLY CLEAR OUT TONIGHT WITH LOSS OF
HEATING. HIGH PRESSURE WILL KEEP WINDS LIGHT...SO WENT CLOSE TO MOS
FOR LOW TEMPERATURES GIVEN THE GOOD RADIATIONAL COOLING EXPECTED.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 217 PM EDT SUN SEP 28 2014

FOCUS IS ON ANY CHANCES FOR RAIN DURING THE PERIOD...OTHERWISE ON
TEMPERATURES. MODELS ARE PRETTY CLOSE SO USED A BLEND.

A DRY ATMOSPHERE ON MONDAY SHOULD LEAD TO SUNNY SKIES WITH HIGH
PRESSURE STILL IN CONTROL AT THE SURFACE. GIVEN HOW TEMPERATURES
RESPONDED ON SUNDAY...WENT AT OR ABOVE THE WARMEST MOS NUMBERS FOR
HIGHS.

A COLD FRONT WILL MOVE INTO THE AREA MONDAY NIGHT AS AN UPPER LOW
MOVES INTO THE NORTHEAST USA. MOISTURE IS LIMITED ACROSS THE AREA
AND MUCH OF THE FORCING WILL BE NORTHEAST OF THE AREA CLOSER TO THE
UPPER SYSTEM. CONTINUED A DRY FORECAST. WENT NEAR MOS FOR LOWS.

THE FRONT WILL EXIT THE AREA ON TUESDAY FOLLOWED BY UPPER RIDGING
BUILDING IN. CONTINUED A DRY FORECAST FOR SIMILAR REASONS AS MONDAY
NIGHT. QUESTION THEN IS HOW MUCH OF THE COOLER AIR WILL GET INTO THE
AREA. NAM/ECMWF ARE MOST AGGRESSIVE WITH THE COOLER AIR...BUT WITH
BEST PUSH OFF TO THE NORTHEAST WITH THE UPPER SYSTEM...WENT CLOSER
TO THE WARMER GFS/CANADIAN MODELS.

DRY CONDITIONS WILL THEN CONTINUE TUESDAY NIGHT INTO WEDNESDAY WITH
THE APPROACHING COLD FRONT STILL WELL OFF TO THE WEST. CONTINUED
TRENDING TOWARD THE WARMER GFS FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 237 PM EDT SUN SEP 28 2014

AFTER THE RECENT EXTENDED PERIOD OF WARM DRY WEATHER ENJOYED ACROSS
THE OHIO VALLEY...THE LONG TERM WILL BE HIGHLIGHTED BY THE ARRIVAL
AND PASSAGE OF A STRONG COLD FRONT WITH A COOLER...MORE TYPICAL
AUTUMN PATTERN FOR THE REGION SETTING UP NEXT WEEKEND.

BROAD UPPER TROUGH OVER THE WESTERN U S WILL PROGRESS EAST AND
FACILITATE THE SHIFT TO COOLER WEATHER BY NEXT WEEKEND. EXTENDED
MODELS IN AGREEMENT OVER THE LAST FEW RUNS ON A FASTER BREAKDOWN OF
THE UPPER RIDGE WITH ARRIVAL OF RAIN AHEAD OF THE APPROACHING COLD
FRONT NOW POTENTIALLY AS EARLY AS LATE WEDNESDAY NIGHT IN THE WABASH
VALLEY. OP GFS CONTINUES TO BE THE MOST WRAPPED UP WITH SURFACE
CYCLOGENESIS IN THE GREAT LAKES THURSDAY EVENING AND AT LEAST AT
THIS POINT...DOES NOT HAVE MUCH SUPPORT FROM THE GLOBAL SOLUTIONS OR
THE GFS ENSEMBLES WITH RESPECT TO HOW QUICKLY THE LOW STRENGTHENS.
GREATER MODEL CONSENSUS FOR A SLOWER DEEPENING OF THE WAVE TAKING
PLACE FURTHER NORTH AND WEST AS THE UPPER ENERGY CATCHES UP AND
AMPLIFIES THE FLOW. REGARDLESS OF THE LOCATION AND STRENGTH OF THE
SURFACE LOW...THE PRESENCE OF STRONG FORCING AND CONVERGENCE ALONG
THE FRONT AIDED BY A 40KT LOW LEVEL JET WILL ENSURE GOOD POTENTIAL
FOR WIDESPREAD RAIN AND CONVECTION THURSDAY INTO THE FIRST PART OF
FRIDAY. WILL MAINTAIN LIKELY POPS FOR THURSDAY OVER THE WESTERN HALF
OF THE FORECAST AREA AND THURSDAY NIGHT OVER ALL OF CENTRAL INDIANA.

FRONT WILL BE EAST OF OR ON THE VERGE OF DEPARTING THE FORECAST AREA
BY FRIDAY MORNING WITH LINGERING PRECIP ENDING FROM WEST TO EAST.
COLD ADVECTION WILL STEADILY EXPAND AS THE UPPER TROUGH ARRIVES ON
FRIDAY...WITH THE CORE OF THE COOLEST AIR SETTLING OVER THE REGION
ON SATURDAY AS 850MB TEMPS FLIRT WITH 0C IN THE NORTH. THE TROUGH
AXIS WILL MOVE TO THE EAST COAST BY SUNDAY...BUT PRESENCE OF
NORTHWEST FLOW ALOFT WITH WEAK SURFACE RIDGING WILL PROVIDE A DRY
AND COOLER WEEKEND FOR CENTRAL INDIANA. AFTER HIGHS AROUND 80 ON
THURSDAY...TEMPS WILL FALL BACK MAINLY INTO THE 60S FOR THE
WEEKEND. OVERNIGHT LOWS WILL DROP INTO THE 40S BEHIND THE FRONT AS
WELL...WITH THE POTENTIAL FOR A FEW LOCATIONS TO SLIP INTO THE
UPPER 30S SATURDAY NIGHT.

&&

.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
ISSUED AT 1252 PM EDT SUN SEP 28 2014

OTHER THAN BRIEF PERIODS OF SHALLOW GROUND FOG AT OUTLYING
TERMINALS AGAIN LATE TONIGHT...VFR CONDITIONS ARE EXPECTED.

GULF MOISTURE PLUME CONTINUES TO RIDE INTO THE OHIO AND TENNESSEE
VALLEYS EARLY THIS AFTERNOON...BUT HIGH PRESSURE AND DEEP
SUBSIDENCE MAINTAINING MOSTLY SUNNY SKIES ACROSS CENTRAL INDIANA.
HAVE SEEN SOME VFR CU FORM AND EXPECT THAT TO LINGER INTO THE
EVENING AS MODEL SOUNDINGS INDICATE LIMITED MOISTURE IN THE
BOUNDARY LAYER.

MOISTURE PLUME WILL SHIFT EAST TONIGHT AS UPPER LEVEL LOW OPENS
UP AND MOVES THROUGH THE REGION. SHOULD SEE CIRRUS GRADUALLY
DIMINISH OVERNIGHT WITH MAINLY CLEAR SKIES INTO MONDAY. LIGHT AND
VARIABLE FLOW THROUGH TONIGHT WILL BECOME NORTH-NORTHWEST AT 5KTS
OR LESS ON MONDAY.

&&

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

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN

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