000
FXUS63 KIND 042041
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
341 PM EST WED MAR 4 2015

.UPDATE...
AVIATION SECTION UPDATED.

&&

.SYNOPSIS...
ISSUED AT 330 PM EST WED MAR 4 2015

LIGHT SNOW ON THE NORTHERN FRINGES OF A BAND OF PRECIPITATION
ASSOCIATED WITH A FRONT TO OUR SOUTH WILL CONTINUE INTO THIS
EVENING AND THE EARLY PORTION OF THE OVERNIGHT BEFORE TAPERING
OFF. A VERY TIGHT GRADIENT IS EXPECTED AND THUS SIGNIFICANT
VARIATION COULD OCCUR WITHIN A VERY SHORT DISTANCE. BEYOND
TONIGHT...DRY WEATHER IS THE RULE FOR THE REMAINDER OF THE SEVEN
DAY FORECAST. HIGH PRESSURE WILL CREATE VERY COLD CONDITIONS
THROUGH FRIDAY...WITH SUB ZERO TEMPERATURES POSSIBLE THURSDAY
NIGHT INTO FRIDAY MORNING...BEFORE TEMPERATURES MODERATE
SIGNIFICANTLY ACROSS THE REGION.

&&

.NEAR TERM /THIS AFTERNOON AND TONIGHT/...
ISSUED AT 330 PM EST WED MAR 4 2015

SNOW FORECAST ACROSS THE SOUTH ESSENTIALLY A NOWCASTING ISSUE AT
THIS POINT. BASED ON HRRR AND NATIONAL RADAR MOSAIC TRENDS...HAVE
TIGHTENED UP GRADIENT EVEN MORE ACROSS THE SOUTH...EFFECTIVELY
DECREASING EXPECTED SNOW HERE IN THE INDY METRO DOWN TO A FEW
TENTHS AT BEST. AMOUNTS ARE BASICALLY THE SAME ACROSS THE
SOUTH...1 TO 3 ALONG A SULLIVAN TO BLOOMINGTON AND GREENSBURG
LINE...AND 2 TO 5 ALONG A VINCENNES TO NORTH VERNON LINE. COULD
SEE ISOLATED SPOTS PUSH 6 ACROSS OUR FAR SOUTHERN/SOUTHEASTERN
FRINGE. HIGHER RESOLUTION MODELS MOVE THE SNOW OUT FASTER LATE
TONIGHT AND HAVE GENERALLY TRENDED TOWARD A SLIGHTLY FASTER END.

WILL KEEP ADVISORY GOING AS IS AS CHANGES HAVE BEEN RELATIVELY
MINOR AND SEE NO REASON TO DEVIATE FROM CURRENT COURSE OF ACTION.

TIGHTENED UP TEMPERATURE GRADIENT DEPICTED BY CONSENSUS TEMPS ON
MINS TONIGHT...WITH MID SINGLE DIGITS NORTH TO MID TEENS SOUTH.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 330 PM EST WED MAR 4 2015

DRY WEATHER RETURNS TOMORROW AND WILL PERSIST THROUGH THE PERIOD.
THIS LEAVES TEMPERATURES AS THE SIGNIFICANT FOCUS.

CONSENSUS NUMBERS REQUIRED SOME SLIGHT DOWNWARD
TWEAKS...ESPECIALLY ON MIN TEMPS WITH A STILL FAIRLY DEEP SNOWPACK
AND HIGH PRESSURE BUILDING INTO THE REGION. SUB ZERO TEMPERATURES
ARE IN PLAY FOR THURSDAY NIGHT...SOMETHING THAT HAS ONLY HAPPENED
ON TEN OTHER OCCASIONS OF RECORD AT INDIANAPOLIS IN MARCH...AND NOT
SINCE 9 MARCH 1984.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 145 PM EST WED MAR 4 2015

THIS IS A HIGH CONFIDENCE FORECAST. THE INITIALIZATION FROM THE
REGIONAL SOFTWARE IS ACCEPTED.

THE GFS ENSEMBLE SPREAD IS QUITE LOW FOR THE PERIOD...SO THERE IS A
HIGH CHANCE THE INITIALIZATION WILL VERIFY.

ALSO...WHILE THE EUROPEAN AND GFS MODELS HAVE SOME DIFFERENCES IN
THEIR DETERMINISTIC FIELDS...THEIR STATISTICAL GUIDANCE IS CLOSE. IN
A SENSE IT DOESNT MATTER WHICH VERIFIES BETTER...WE CAN EXPECT THE
SAME SENSIBLE WEATHER EITHER WAY.

&&

.AVIATION /DISCUSSION FOR THE 032000Z IND TAF/...

RADAR CONTINUES TO SHOW VIRGA ACROSS THE IND TAF SITE WITH COOLER
AND DRIER AIR CONTINUING TO FILTER IN ON LOW LEVEL NORTHWEST WINDS.
EXPECT SOME FLURRIES TO STILL DEVELOP THIS EVENING AS LOWER LEVELS
CONTINUE TO SATURATED THE NEXT 2-4 HOURS.

PREVIOUS DISCUSSION BELOW

/DISCUSSION FOR THE 041800Z TAF ISSUANCE/...
ISSUED AT 1158 AM EST WED MAR 4 2015

AN UPPER LEVEL DISTURBANCE WILL CAUSE SNOW OVER ABOUT THE SOUTHERN
HALF OF THE AREA THIS AFTERNOON. EXPECT CEILINGS AND VISIBILITY TO
BE MAINLY MVFR...BUT IFR AT TIMES. BY 01Z THE SNOW WILL BE
OVER...CEILINGS WILL BE LOW END VFR...AND VISIBILITY SHOULD BE
UNRESTRICTED.

IN THE NORTH THE AFTERNOON SHOULD HAVE CEILINGS AROUND 35 HUNDRED
FEET WITH UNRESTRICTED VISIBILITY.

AS THE UPPER LEVEL DISTURBANCE MOVES AWAY...DURING THE NIGHT CLOUDS
WILL RISE TO NEAR 10 THOUSAND FEET AND THEN BREAK FROM NORTH TO
SOUTH.

WINDS CAN BE EXPECTED TO REMAIN NORTHWEST WITH SPEEDS 10-15 KNOTS
DAYTIME AND 5-10 KNOTS AT NIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 AM EST THURSDAY FOR INZ061>065-
067>072.

&&

$$

SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...JK
AVIATION...JK/JP

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