Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 301430
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
930 AM EST FRI JAN 30 2015

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

&&

.SYNOPSIS...
ISSUED AT 329 AM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROGGED FOR SUNDAY/SUNDAY NIGHT. MODELS HAVE A SYSTEM APPROACHING
FROM THE WEST/SOUTHWEST THAT IS EXPECTED TO BRING ACCUMULATING
SNOWFALL LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT. IN THE WAKE OF
THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL ON MONDAY WITH
HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION CHANCES WILL BE
POSSIBLE ON TUESDAY NIGHT/WEDNESDAY AS A COLD FRONT MOVES THROUGH
CENTRAL INDIANA.


&&

.NEAR TERM /TODAY/...

ISSUED AT 329 AM EST FRI JAN 30 2015

HIGH PRESSURE WILL RESULT IN BENIGN CONDITIONS FOR THE NEAR TERM
PERIOD. THE ONLY EXCEPTION WILL BE SOME POSSIBLE EARLY MORNING
LAKE EFFECT SNOW SHOWERS OVER THE NORTHERN COUNTIES...BUT NO
ACCUMULATIONS ARE EXPECTED. AS SUBSIDENCE STRENGTHENS THROUGH THE
COURSE OF THE DAY...STRATOCUMULUS SHOULD BREAK UP BY THIS
AFTERNOON. HIGHS WILL RANGE FROM THE UPPER 20S TO MID 30S FROM
NORTH TO SOUTH...STUCK CLOSE TO GUIDANCE.


&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 329 AM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS SNOWFALL AMOUNTS WITH
SYSTEM PROGGED FOR SUNDAY/SUNDAY NIGHT.

FIRST...PARTLY CLOUDY SKIES AND CALM CONDITIONS WILL PREVAIL
TONIGHT THROUGH SATURDAY. HOWEVER...CLOUDS WILL INCREASE ACROSS
THE FORECAST AREA ON SATURDAY AFTERNOON AS A STORM SYSTEM
APPROACHES FROM THE CENTRAL PLAINS. GFS/EURO/NAM ARE ALL IN DECENT
AGREEMENT WITH THE TRACK OF THIS SYSTEM...TAKING THE 700 MB LOW
ACROSS CENTRAL INDIANA. THE OUTLYING MODEL AT THIS TIME IS THE
EURO...WHICH TAKES THE TRACK JUST SLIGHTLY MORE NORTH THAN THE GFS
AND NAM. EITHER WAY THOUGH...EXPECT SIGNIFICANT SNOW ACCUMULATIONS
OVER CENTRAL AND NORTHERN PORTIONS OF CENTRAL INDIANA AS SWATH
BETWEEN -2C AND -8C ISOTHERMS AT 850 MB LINES UP OVER THE NORTHERN
TWO-THIRDS OF THE FORECAST AREA. IN ADDITION...1000-500MB THICKNESS
LINES OF ALL 3 MODELS POINT TO THE CENTRAL AND NORTHERN COUNTIES.
CONFIDENCE IS SLIGHTLY LOWER FOR THE SOUTHERN COUNTIES WHICH COULD
RECEIVE SOME WINTRY MIX WITH JUST THE SLIGHTEST SHIFT OF TRACK TO
THE NORTH.

WESTERN COUNTIES COULD START SEEING SOME SNOWFALL AROUND SUN
00Z...BUT ISENTROPIC LIFT REALLY STRENGTHENS AFTER SUN 06Z. SO
CURRENT THINKING IS HEAVIEST SNOW WILL FALL BETWEEN SUN 12Z-MON
00Z...QUICKLY TAPERING OFF BY MON 06Z.

TEMPS...GENERALLY STUCK CLOSE TO MODEL BLEND WITH A FEW TWEAKS.
TRENDED SLIGHTLY WARMER ON SATURDAY DUE TO SOUTHWESTERLY SURFACE
FLOW AHEAD OF AFOREMENTIONED SYSTEM. THIS WILL HELP BUMP HIGHS UP
INTO THE UPPER 30S. TEMPS WILL FALL BACK TO NORMAL ON SUNDAY
THOUGH AS WINDS BACK TO THE EAST...AND PLUMMET INTO THE SINGLE
DIGITS ON SUNDAY NIGHT AS WINDS BECOME NORTHERLY.


&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 328 AM EST FRI JAN 30 2015

MUCH QUIETER WEATHER WILL BE THE RULE DURING THE LONG TERM.  THE
SYSTEM WHICH WILL BRING LONG SNOW SUNDAY WILL BE MOVING OFF THE
MIDDLE ATLANTIC COAST MONDAY AND HIGH PRESSURE OVER THE UPPER
MIDWEST WILL MOVE ACROSS OUR REGION LATE MONDAY AND MONDAY NIGHT.
MONDAY AND MONDAY NIGHT WILL BE DRY AND QUITE COLD. TUESDAY WILL BE
DRY AND A LITTLE WARMER AS THIS HIGH PRESSURE MOVES ON TO THE EAST
AND A SOUTHERLY FLOW DEVELOPS ACROSS OUR REGION.

BOTH THE GFS AND GEMNH MODEL BRINGS A COLD FRONT ACROSS OUR REGION
WEDNESDAY WHILE THE EURO IS ABOUT 18 TO 24 HOURS SLOWER.  PREFER THE
FASTER GFS AND GEMNH MODEL AS THE EURO SEEMS TO HOLD UP THE NEXT
SURGE OF ARCTIC AIR TOO LONG.

WILL MENTION A CHANCE OF LIGHT SNOW LATE TUESDAY NIGHT AND WEDNESDAY
WITH THE COLD FRONT.  FAR SOUTHERN SECTIONS MAY SEE A PERIOD OF
MIXED PRECIPITATION ON WEDNESDAY AS LOW LEVEL THICKNESS RISE TO NEAR
OR SLIGHTLY ABOVE CRITICAL VALUES.

I HAVE LOW CONFIDENCE THERE WILL BE ANY PRECIP WEDNESDAY NIGHT EVEN
THOUGH SOME OF THE GUIDANCE INDICATES THIS. FOR NOW WILL ONLY
MENTION A CHANCE OF FLURRIES FOR WEDNESDAY NIGHT.

LOWERED TEMPERATURES A LITTLE MONDAY AND TUESDAY AS MOST AREAS WILL
HAVE A PRETTY GOOD SNOW COVER. OTHERWISE...A MOS BLEND ON
TEMPERATURES SEEM REASONABLE FOR MOST OTHER PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 301500Z TAF UPDATE/...
ISSUED AT 930 AM EST FRI JAN 30 2015

WILL SEE CEILINGS FILL BACK IN BUT THEY WILL DO SO HIGH ENOUGH TO BE
VFR AND CONDITIONS SHOULD REMAIN VFR THROUGH THE REST OF THE
PERIOD.  LOW PRESSURE OFF THE ATLANTIC COAST AND HIGH PRESSURE
ACROSS IOWA WILL PRODUCE A NORTH TO NORTHWEST FLOW UP TO 12 KNOTS
TODAY.  DRIER AIR WILL PUSH INTO WESTERN SECTIONS LATER TODAY AND
ACROSS REST OF OUR REGION TONIGHT AS HIGH PRESSURE BUILDS EASTWARD.

EXPECT CU TO SCATTER OUT OVER WESTERN SECTIONS THIS AFTERNOON AND
ELSEWHERE THIS EVENING WITH MOSTLY CLEAR CONDITIONS ALL AREAS LATER
TONIGHT.

NORTHWEST WINDS UP TO 12 KNOTS WITH GUSTS TO 20 KNOTS WILL GRADUALLY
DECREASE LATER TODAY AND BECOME LIGHT TONIGHT.

&&

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

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...JH/CP

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

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