Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 200745
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
345 AM EDT SUN APR 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 345 AM EDT SUN APR 20 2014

HIGH PRESSURE WILL MAINTAIN PLEASANT WEATHER ACROSS THE OHIO VALLEY
INTO MONDAY. A COLD FRONT WILL MOVE THROUGH THE OHIO VALLEY MONDAY
NIGHT WITH SHOWERS AND ISOLATED THUNDERSTORMS. DRY AND COOLER
WEATHER IS EXPECTED FOR MIDWEEK...WITH A RETURN TO WARMER AND MORE
UNSETTLED CONDITIONS THURSDAY AND FRIDAY AS ANOTHER COLD FRONT
TRACKS INTO THE OHIO VALLEY. COOLER AND DRIER WEATHER RETURNS AGAIN
FOR NEXT WEEKEND.

&&

.NEAR TERM /TODAY/...
ISSUED AT 345 AM EDT SUN APR 20 2014

SURFACE HIGH PRESSURE RIDGE RESIDES ACROSS THE OHIO VALLEY EARLY
THIS MORNING WITH MAINLY CLEAR SKIES ACROSS THE REGION. WIDE
RANGE OF TEMPS AS OF 07Z...RANGING FROM THE UPPER 30S TO THE LOWER
50S.

THE SURFACE RIDGE WILL REMAIN FIRMLY ENTRENCHED ACROSS THE OHIO AND
TENNESSEE VALLEYS TODAY WITH BLOCKING LOW PRESSURE OFF THE SOUTHEAST
COAST. OTHER THAN PERIODS OF CIRRUS THROUGHOUT THE DAY...EXPECT
ABUNDANT SUNSHINE WITH MODEL SOUNDINGS INDICATING CONTINUED DRY AIR
AND SUBSIDENCE BELOW 15-20KFT. SURFACE FLOW WILL GRADUALLY VEER TO
S/SE DURING THE AFTERNOON AS THE RIDGE AXIS SHIFTS EAST INTO THE MID
ATLANTIC AND APPALACHIANS.

TEMPS...ANOTHER OUTSTANDING DAY WITH AFTERNOON HIGHS RISING WELL
INTO THE 70S AS 850MB TEMPS CLIMB TO AROUND 10C. FOLLOWED
PERSISTENCE YET AGAIN...GOING ABOVE MOS BY A DEGREE OR TWO FOR HIGH
TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 345 AM EDT SUN APR 20 2014

FORECAST CHALLENGES FOCUS ON PRECIP CHANCES WITH A COLD FRONT MONDAY
AFTERNOON AND NIGHT.

LOW PRESSURE WILL FINALLY BEGIN TO PULL AWAY FROM THE CAROLINA COAST
TONIGHT AND MOVE FURTHER OUT INTO THE ATLANTIC OCEAN ON MONDAY.
RIDGING ALOFT AND THE SURFACE WILL SHIFT TO THE EAST COAST BY
MONDAY...ENABLING A WAVE ALOFT MOVING THROUGH THE CENTRAL PLAINS
TONIGHT WITH AN ASSOCIATED COLD FRONT TO TRACK INTO THE OHIO VALLEY
BY LATE MONDAY. THE UPPER WAVE WILL BECOME ABSORBED BY A STRONGER
WAVE MOVING ACROSS THE NORTHERN GREAT LAKES WITH LOW PRESSURE
DEEPENING AS IT TRACKS INTO UPSTATE NEW YORK ON TUESDAY MORNING.
WEAK LOW LEVEL CONVERGENCE ALONG THE BOUNDARY IN TANDEM WITH A
PERIOD OF ISENTROPIC LIFT MONDAY NIGHT WILL BE THE PRIMARY
CATALYSTS FOR SHOWERS. INSTABILITY REMAINS WEAK AT BEST WITH ANY
THUNDER ANTICIPATED TO BE ISOLATED AND EMBEDDED WITHIN THE RAIN.

INITIALLY...DRIER AIR THROUGH THE BOUNDARY LAYER WILL BE SLOW
TO ERODE...WITH PRECIP CHANCES NOT ARRIVING UNTIL LATE AFTERNOON
MONDAY AND BECOMING MORE WIDESPREAD MONDAY EVENING. WILL MAINTAIN
LIKELY POPS MONDAY NIGHT WITH RAINFALL ENDING BY 12Z TUESDAY AS THE
FRONT QUICKLY MOVES EAST. HIGH PRESSURE WILL REESTABLISH DURING THE
DAY TUESDAY AS MUCH DEEPER SUBSIDENCE EXPANDS BACK INTO THE REGION
FROM THE NORTHWEST. PRESENCE OF COLD ADVECTION AND A WEAK WAVE ALOFT
TRAILING THE BOUNDARY WOULD ARGUE FOR CU DEVELOPMENT DURING THE
COURSE OF THE DAY...BUT THE AMOUNT OF DRY AIR ADVECTING IN MAY KEEP
CLOUD COVERAGE LIMITED TO SOME DEGREE. REGARDLESS OF THE AMOUNT OF
CLOUDS ON TUESDAY...SKIES WILL CLEAR TUESDAY NIGHT AS THE HIGH
CENTERS OVER THE REGION.

TEMPS...WITH MOST OF THE RAIN LIKELY TO HOLD OFF UNTIL LATE DAY AT
THE EARLIEST...ONCE AGAIN GOING AT OR JUST ABOVE WARMER METMOS
GUIDANCE FOR HIGHS MONDAY. LOW LEVEL THERMALS SUPPORT HIGHS INTO THE
MID/UPPER 60S. ENDED UP TAKING A SPLIT OF THE COOLER MAV AND WARMER
MET. PRESENCE OF DRY AIR THROUGH THE BOUNDARY LAYER TONIGHT WILL
SUPPORT A DECENT RANGE IN LOWS FROM THE UPPER 40S TO MID 50S BETWEEN
THE RURAL LOCALES AND THE CITIES. NEAR MOS GUIDANCE ON MONDAY NIGHT
WITH RAIN AND CLOUDS...THEN UNDERCUT MOS TUESDAY NIGHT WITH COLD
ADVECTION AND NORTHERLY FLOW. DEPENDING ON HOW QUICKLY THE LOWER
LEVELS DECOUPLE...SOME FROST ACCRUAL POSSIBLE WITH LOWS FALLING INTO
THE MID/UPPER 30S.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 307 AM EDT SUN APR 20 2014

FAIRLY TYPICAL SPRINGTIME WEATHER EXPECTED ACROSS CENTRAL INDIANA
FOR THE LONG TERM PORTION OF THE FORECAST. MODELS INDICATE ONE
SYSTEM TO MOVE FAIRLY QUICKLY THROUGH THE AREA THURSDAY INTO FRIDAY.
PROGRESSIVE NATURE OF THE SYSTEM SUGGESTS POPS SHOULD BE CONFINED TO
THURSDAY AFTERNOON AND PERHAPS LINGER AS LONG AS FRIDAY
MORNING...BUT WILL CARRY THEM NO FURTHER. TOWARD THE VERY END OF THE
PERIOD A WARM FRONT IS DEPICTED APPROACHING THE AREA AND WILL CARRY
CHANCE POPS FOR THAT.

MODEL PROGS FOR BULK SHEAR...K INDEX AND CONVECTIVE PRECIP INDICATE
ORGANIZED CONVECTION IS A DISTINCT POSSIBILITY THURSDAY AFTERNOON
AND EVENING...BUT THERE REMAINS TOO MUCH MODEL AND RUN TO RUN
DISCREPANCY TO SUGGEST AN ORGANIZED SEVERE THREAT.

MAX TEMPS NEEDED BUMPED UP ACROSS THE BOARD AS MODEL 850 MB TEMPS
AND LOW LEVEL THICKNESSES SUGGESTED THEY WERE A BIT LOW. OTHERWISE
ALLBLEND WAS FINE.

&&

.AVIATION /DISCUSSION FOR THE 20/09Z TAF UPDATE/...
ISSUED AT 305 AM EDT SUN APR 20 2014

WX NIL SO ANTICIPATE NO MAJOR CHANGES TO TAFS FOR UPDATE. PREVIOUS
DISCUSSION FOLLOWS.

ISSUED AT 1230 AM EDT SUN APR 20 2014

NO SIGNIFICANT CLOUD COVER...UNRESTRICTED VISIBILITY...SURFACE WINDS
AT OR BELOW 8 KTS EXPECTED AT THE TAF SITES THROUGH 201800Z.

&&

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

&&

$$

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

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