Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 271530
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1025 AM EST FRI FEB 27 2015

.UPDATE...
NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 303 AM EST FRI FEB 27 2015

HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A
FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY
NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT
THE AREA TOWARDS THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /REST OF TODAY/...
ISSUED AT 1025 AM EST FRI FEB 27 2015

CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING
ADVISORY CRITERIA.

OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST
OF THE AREA.  RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS
AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY.

RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20
SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN
MOST MOS GUIDANCE.  THIS SEEMS REASONABLE.  THERE SHOULD BE A LOT OF
SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS
THIS AFTERNOON.  REST OF NEAR TERM SEEMS TO BE ON TRACK.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 303 AM EST FRI FEB 27 2015

DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH
PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST
DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP
SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE
REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO
IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED
WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT.

WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON
ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT
PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER
ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX
OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS
FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM
AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE
NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE
STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE
PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE
TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS
SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES.

BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE
FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE
GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON
SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL
NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 258 AM EST FRI FEB 27 2015

ACTIVE PATTERN CONTINUES THROUGH THE FIRST HALF OF NEXT WEEK AS
PIECES OF ENERGY ALOFT EJECT OUT OF THE TROUGH OVER THE WESTERN U S
FOLLOWED BY THE TROUGH AXIS ITSELF MOVING EAST INTO THE REGION BY
THE END OF THE PERIOD. HIGH CONFIDENCE IN A SIGNIFICANT WEATHER
IMPACT FOR CENTRAL INDIANA AND THE OHIO VALLEY MONDAY NIGHT THROUGH
WEDNESDAY.

STRONG HIGH PRESSURE ARRIVES IN THE WAKE OF THE LATE WEEKEND SYSTEM
FOR MONDAY...AND SHOULD SERVE TO GIVE THE REGION A BREATHER BETWEEN
WEATHER SYSTEMS ON THE ORDER OF 18 TO 24 HOURS. SURFACE WAVE SET
TO SPIN UP OVER THE CENTRAL ROCKIES MONDAY NIGHT AS ENERGY EJECTS
OUT FROM THE PARENT TROUGH. THIS FEATURE WILL SWING E/NE AND TRACK
QUICKLY INTO THE REGION BY TUESDAY EVENING AND BRING WITH IT A
PLETHORA OF MESSY PROBLEMS FOR CENTRAL INDIANA. RIDGING DEVELOPING
DOWNSTREAM OF THE TROUGH SUPPORTS MORE AMPLIFIED FLOW WITH THE
SURFACE WAVE TRACKING THROUGH OR NORTH OF THE FORECAST AREA. OP GFS
SHOWING ITS USUAL PROGRESSIVE BIAS IN THE MID RANGE IN BRINGING
PRECIP IN TOO QUICKLY...ESPECIALLY CONSIDERING THE STRENGTH OF THE
DEPARTING HIGH. LIKE THE LOOK OF THE ECMWF/GGEM WHICH DELAYS MOST
PRECIP UNTIL AFTER MIDNIGHT MONDAY NIGHT.

WARM ADVECTION WILL ALREADY BE ONGOING WHEN PRECIP STARTS...AND
EXPECT PRECIP TYPE ISSUES FROM THE GET GO WITH A GROWING LIKELIHOOD
THAT FREEZING RAIN IS THE PREDOMINANT PRECIP TYPE INTO TUESDAY
MORNING. THE REFRESHED SNOWPACK COURTESY OF THE WEEKEND STORM WILL
BE A SIGNIFICANT FACTOR IN DURATION OF FROZEN PRECIP AS THE NEAR
SURFACE/GROUND TEMPS WILL LAG THE LOW LEVEL TEMP RISES. MODEL
THERMAL PROFILES ARE ALREADY SUGGESTIVE THAT IT MAY TAKE UNTIL
MIDDAY TUESDAY IN SOME PORTIONS OF THE REGION TO WARM SUFFICIENTLY
FOR ALL RAIN. IF THE IMPACT OF THE SNOWCOVER IS UNDERMINED BY THE
MODELS WHATSOEVER...THE ICING POTENTIAL COULD BE EVEN MORE
SIGNIFICANT. DO NOT EXPECT TO HAVE A GOOD HANDLE ON THIS UNTIL LATER
IN THE WEEKEND.

WHILE THE ICING THREAT IS A GROWING ISSUE...AN EXTENDED PERIOD OF
HEAVY RAIN OVER A FROZEN GROUND AND SNOW COVER POSES EVEN GREATER
CONCERNS. COPIOUS AMOUNTS OF MOISTURE WILL BE DRAWN NORTH INTO THE
REGION AHEAD OF THE APPROACHING SURFACE WAVE TUESDAY AND TUESDAY
NIGHT. PRECIP WATER VALUES ARE PARTICULARLY ALARMING...MAXING OUT
BETWEEN 1.25 AND 1.50 INCHES TUESDAY EVENING. THESE LEVELS WOULD
PLACE THE REGION NEAR AND ABOVE THE 99TH PERCENTILE FOR
CLIMATOLOGICAL PRECIP WATER VALUES IN MARCH. POTENTIAL FOR
CONVECTIVE ELEMENTS TO THE PRECIP AS WELL AND MAY NEED TO ADD AN
ISOLATED THUNDER MENTION INTO THE FORECAST FOR TUESDAY
AFTERNOON/NIGHT. 1-2 INCHES OF RAINFALL CERTAINLY LOOK PLAUSIBLE AND
WITH MOST OF THIS BEING CONVERTED TO PURE RUNOFF WITH THE FROZEN
GROUND...FLOODING CONCERNS ARE VALID. FRONTAL BOUNDARY SHOULD
FINALLY MOVE EAST WEDNESDAY WITH PRECIP ENDING LATE DAY...LIKELY AS
A RAIN/SNOW MIX. MUCH COLDER AIR WILL THEN RETURN FOR THE END OF THE
WEEK.

STILL PLENTY TO HASH OUT AND THE WEEKEND WINTER STORM WILL HAVE SOME
SAY IN HOW THIS ALL TRANSPIRES. AS STATED ABOVE THOUGH...CONFIDENCE
IS HIGH IN SIGNIFICANT WEATHER IMPACTS FOR CENTRAL INDIANA MONDAY
NIGHT THROUGH WEDNESDAY...WITH ICING...HEAVY RAIN AND FLOODING ALL
POTENTIAL CONCERNS. ENCOURAGE HOOSIERS TO STAY ABREAST OF THE
FORECAST OVER THE NEXT FEW DAYS.

&&

.AVIATION /DISCUSSION FOR 271500Z TAF UPDATE/...
ISSUED AT 920 AM EST FRI FEB 27 2015

ONLY TWEAKED KIND WIND DIRECTION. STILL SOME UNCERTAINTY ON WHERE
BROKEN CUMULUS FIELD WILL SET UP...SO LEFT FORECAST ALONE FOR NOW.

PREVIOUS DISCUSSION FOLLOWS...

VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.

HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TODAY WITH PARTLY
CLOUDY SKIES. POCKETS OF STRATOCU CONTINUE TO DROP INTO CENTRAL
INDIANA WITH LOW LEVEL FLOW OFF LAKE MICHIGAN. DESPITE THE DRIER
AIR AND SUBSIDENCE OVERSPREADING THE REGION TODAY...COLD POOL
ALOFT AND PRESENCE OF 850MB THERMAL TROUGH BOTH SUPPORT RENEWED CU
DEVELOPMENT FOR THE AFTERNOON...ESPECIALLY AT KBMG AND KIND.

AS CU SCATTERS OUT LATER THIS AFTERNOON...MID AND HIGH LEVEL
CLOUDS WILL INCREASE FROM THE SOUTHWEST FOR TONIGHT IN ADVANCE OF
A SYSTEM DEVELOPING OVER THE SOUTHERN PLAINS. SKIES WILL BECOME
OVERCAST AFTER MIDNIGHT AS CEILINGS LOWER TO 8-10KFT. NORTHWEST
WINDS AT 5-10KTS TODAY WILL EVENTUALLY BECOME LIGHT AND VARIABLE
OVERNIGHT.

&&

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

&&

$$

SYNOPSIS...JAS
NEAR TERM...JH
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...RYAN/50

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