Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 270353
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1053 PM EST MON JAN 26 2015

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

&&

.SYNOPSIS...
ISSUED AT 152 PM EST MON JAN 26 2015

A QUICK MOVING WEATHER DISTURBANCE WILL PUSH ACROSS ILLINOIS AND
INDIANA THIS EVENING...BRINGING CHANCES FOR SOME LIGHT SNOW THIS
EVENING TO WESTERN PARTS OF CENTRAL INDIANA.

COLD HIGH PRESSURE IS EXPECTED TO ARRIVE ON TUESDAY AND CONTINUE
TO REMAIN IN THE AREA THROUGH WEDNESDAY NIGHT. THIS WILL RESULT IN
DRY WEATHER WITH BELOW NORMAL TEMPERATURES. ANOTHER QUICK MOVING
AREA OF LOW PRESSURE IS EXPECTED TO ARRIVE AND PASS ACROSS CENTRAL
INDIANA ON EARLY THURSDAY MORNING...ONCE AGAIN RESULTING IN CHANCES
FOR PRECIPITATION.

ANOTHER WEAK LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS THE
REGION THIS WEEKEND...ONCE AGAIN RESULTING IN CHANCES FOR
PRECIPITATION.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 1039 PM EST MON JAN 26 2015

UPDATE...
INSERTED MENTION OF PATCHY FREEZING DRIZZLE ACROSS THE WESTERN
PORTIONS OF CENTRAL INDIANA. FREEZING DRIZZLE HAS BEEN REPORTED
UPSTREAM. CONTINUED TO LEAVE FAR NORTHEAST COUNTIES DRY EXCEPT FOR
A FEW FLURRIES. UPDATED GRIDS HAVE BEEN SENT.

PREVIOUS DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE PRECIP THIS EVENING. GFS SUGGESTS
THE UPPER WAVE RESPONSIBLE FOR THE ONGOING SNOW OVER ILLINOIS WILL
CONTINUE TO DIVE SSE AMID THE QUICK FLOW ALOFT. HRRR SHOW PRECIP
MAINLY CONTAINED TO THE WESTERN PARTS OF THE FORECAST AREA. TIME
HEIGHTS THIS EVENING SHOW BEST SATURATION IN THE WESTERN AND
SOUTHERN PARTS OF THE FORECAST AREA...WITH LESS MOISTURE AVAILABLE
ACROSS THE NORTHEAST. ISENTROPIC SURFACE SHOWS LITTLE TO NO HELP
AS THIS SYSTEM PASSES. FORECAST SOUNDINGS ACROSS WESTERN INDIANA
CONTINUE TO SHOW GOOD LOW AND MID LEVEL SATURATION THROUGH THE
NIGHT.

THUS WILL RAISE POPS...PARTICULARLY ACROSS THE WESTERN PARTS OF
THE FORECAST AREA...TRENDING TOWARD A FLURRY OR DRY FORECAST ACROSS
THE FAR NORTHEAST. AS FOR TEMPS...CLOUDS ARE EXPECTED THROUGH MUCH
OF THE NIGHT AS THE UPPER WAVE PASSES AND TEMPERATURE ADVECTION IS
NEUTRAL. THUS WILL STICK CLOSE TO A BLEND ON TEMPS.


&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 152 PM EST MON JAN 26 2015

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS INITALLY
FOLLOWED BY PRECIPITATION CHANCES ON THURSDAY.

DRY AND COLD WEATHER IS EXPECTED THROUGH WEDNESDAY DUE TO THE
FOLLOWING REASONS:

SURFACE HIGH PRESSURE BUILDING OUT OF CANADA WILL BUILD ACROSS AND
PASS OVER CENTRAL INDIANA THROUGH WEDNESDAY NIGHT. TIME HEIGHT
SECTIONS THROUGH WEDNESDAY NIGHT CONTINUE TO SHOW A DRY COLUMN
AMID SUBSIDENCE. FORECAST SOUNDINGS AGREE...ONLY SHOWING SOME
SATURATION NEAR 12Z THURSDAY. MEANWHILE ALOFT...A DEEP TROUGH OVER
EASTERN 1/2 OF THE UNITED STATES WILL CONTINUE TO PROVIDE A VERY
COLD AND NW FLOW TO CENTRAL INDIANA. THIS WILL HELP IN RESULTING
IN BELOW NORMAL TEMPERATURES. THUS WITH ONLY A FEW QUICK PASSING
HIGH CLOUDS EXPECTED...WILL TREND TOWARD PARTLY CLOUDY ON TUESDAY
THROUGH WEDNESDAY EVENING...ALONG WITH A BLEND ON TEMPS.

ON LATE WEDNESDAY NIGHT THE GFS INDICATES A WELL ORGANIZED SHORT
WAVE ALOFT PUSHING INTO INDIANA FROM THE WEST. ONCE
AGAIN...FORECAST SOUNDINGS HINT AT LOWER LEVEL SATURATION AHEAD OF
THIS SYSTEM. SOUNDINGS ALSO SHOW WARM AIR ADVECTION IN THE LOWEST
LEVELS THAT WILL ALLOW ANY PRECIP ON THURSDAY MORNING TO FALL AS
RAIN. 300K GFS ISENTROPIC SURFACE SHOWS GOOD UPGLIDE ALONG WITH A
SURGE OF SPECIFIC HUMIDITIES OF 2 G/KG. THUS ROUND OF LIGHT PRECIP
IS EXPECTED. BY THURSDAY AFTERNOON THE UPPER SHORT WAVE LOOKS TO
BE WELL EAST OF INDIANA AND COLD AIR ADVECTION WILL ONCE AGAIN BE
IN PLAY. FORECAST SOUNDINGS SHOW THE SATURATED LOWER PARTS OF THE
COLUMN FALLING BELOW FREEZING...THUS A CHANGE OVER TO SNOW DURING
THE AFTERNOON FOR ANY LINGERING PRECIP LOOKS REASONABLE. HOWEVER
WITH A LACK OF DEEP MOISTURE AND TEH BEST FORCING OFF TO THE
EAST...ANY SNOW AMOUNTS WILL BE QUITE LIGHT.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 250 PM EST MON JAN 26 2015

ONE SYSTEM WILL BE EXITING OUR REGION THURSDAY EVENING...THUS WILL
CONTINUE A SLIGHT CHANCE OF SNOW EAST AND CENTRAL THURSDAY EVENING.
HIGH PRESSURE BEHIND THIS SYSTEM WILL MOVE ACROSS OUR REGION FRIDAY
NIGHT AND IT NOW LOOKS LIKE DRY WEATHER WILL BE THE RULE THROUGH
SATURDAY.

ANOTHER SYSTEM WILL BRING US A CHANCE OF SNOW SATURDAY NIGHT INTO
SUNDAY AS THE MODELS HAVE TRENDED SLOWER WITH THIS SYSTEM.

FINALLY COLDER AND DRY WEATHER WILL BE THE RULE REST OF THE LONG
TERM AS A LONG WAVE TROUGH AMPLIFIES OVER THE EASTERN U.S. THE
MODELS HAVE TRENDED A LITTLE COLDER DURING THIS PERIOD.  BUT ALL AND
ALL WENT CLOSE TO A MOS BLEND ON TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 270300Z IND TAF UPDATE/...
ISSUED AT 935 PM EST MON JAN 26 2015

EXTENDED THE FLURRIES THROUGH 06Z BASED ON UPSTREAM OBS AND RADAR.
MAY NEED TO EVENTUALLY THROW SOME FREEZING DRIZZLE IN THERE AS WELL
IF TRENDS CONTINUE. ALSO...WENT WITH VFR CEILINGS AS THERE HAS NOT
BEEN AN MVFR CEILING IN 2 HOURS AND UPSTREAM LAF ALSO IS STILL VFR
AT THIS TIME.

PREVIOUS DISCUSSION FOLLOWS...

IT LOOKS LIKE THE BULK OF THE LIGHT SNOW OR FLURRIES WILL REMAIN
JUST WEST OF IND TONIGHT AS AN UPPER DISTURBANCE SLIDES SOUTHEAST OF
THE AREA. MODELS AND RADAR TRENDS SUGGEST LINGERING POCKETS OF LIGHT
SNOW SHOULD END AT LAF AFTER 02Z...HUF AFTER 04Z AND BMG AFTER 05Z.
WENT WITH MVFR CEILINGS THROUGH THE NIGHT PER MODEL RH TIME SECTIONS
AND OBSERVATIONAL TRENDS...ALTHOUGH BRIEF VFR OR BRIEF IFR IN SNOW
SHOWERS CAN NOT BE RULED OUT. CONDITIONS SHOULD IMPROVE TO VFR AFTER
15Z TUESDAY.

WINDS WILL BE VARIABLE AT 3 KNOTS OR LESS TONIGHT AND NORTHEAST AND
NORTH LESS THAN 8 KNOTS ON TUESDAY.


&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...TDUD
SHORT TERM...PUMA
LONG TERM....JH
AVIATION...MK

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