Area Forecast Discussion
Issued by NWS Indianapolis, IN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KIND 270800
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
300 AM EST TUE JAN 27 2015

.UPDATE...
THE LONG 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 INITIALLY
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 THE BEST FORCING OFF TO THE
EAST...ANY SNOW AMOUNTS WILL BE QUITE LIGHT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 300 AM EST TUE JAN 27 2015

NORTHWEST FLOW ALOFT AND STRONG CANADIAN HIGH PRESSURE WILL ENSURE
A COLD START TO THE EXTENDED PERIOD ON FRIDAY IN THE WAKE OF THE
COLD FRONTAL PASSAGE ON THURSDAY. THE HIGH WILL DRIFT EAST THROUGH
SATURDAY MAINTAINING DRY CHILLY CONDITIONS ACROSS CENTRAL INDIANA.
HIGHS WILL GENERALLY RANGE FROM THE UPPER 20S TO MID 30S BOTH DAYS.

THE MAIN FOCUS FOR THE EXTENDED PERIOD COMES DURING THE SECOND
HALF OF THE WEEKEND AS A STRENGTHENING SURFACE WAVE TRACKS FROM
THE WESTERN GULF SUNDAY MORNING INTO NEW ENGLAND BY MONDAY. MODEL
GUIDANCE HAS WAVERED WITH THE HANDLING OF THIS SYSTEM OVER THE
LAST FEW DAYS RANGING FROM A SUPPRESSED SYSTEM TRACKING THROUGH
THE SOUTHERN STATES TO A MORE PHASED SOLUTION BRINGING A GREATER
IMPACT NORTH INTO THE OHIO VALLEY. 00Z GUIDANCE IN GENERAL HAS
TRENDED BACK TOWARDS THE MORE PHASED UPPER WAVE WITH A SURFACE
WAVE TRACKING THROUGH THE TENNESSEE VALLEY SUNDAY INTO SUNDAY
NIGHT AND A BROAD AREA OF OVERRUNNING PRECIPITATION SPREADING
ACROSS THE ENTIRE REGION.

WITH COLD AIR LINGERING ACROSS CENTRAL INDIANA AND THE TRACK TO
THE SOUTH OF THE FORECAST AREA...PRECIP WOULD LIKELY FALL AS SNOW
AS IT STANDS NOW WITH POSSIBLY A BRIEF PERIOD OF MIXED PRECIP ON
SUNDAY DEPENDING ON THE AMOUNT OF WARMTH IN THE BOUNDARY LAYER
THAT CAN TAKE PLACE. STILL SEVERAL DAYS OUT AND LIKELY TO SEE
ADDITIONAL CHANGES AS WE NEAR THE WEEKEND. ONE CAVEAT TO KEEP IN
MIND...MODEL GUIDANCE IN GENERAL HAS UNDERDONE LOW LEVEL WARM
INTRUSIONS AND CAUSED PRECIP TYPE CHALLENGES ACROSS THE FORECAST
AREA WITH SURFACE WAVES ALL WINTER LONG. NOT SAYING THIS HAPPENS
HERE IF THE FORECAST TRACK THROUGH THE TENNESSEE AND LOWER OHIO
VALLEYS HOLDS. IT IS JUST SOMETHING TO KEEP IN MIND AS MODELS HONE
IN ON A CONSENSUS SOLUTION IN THE COMING DAYS. SHOULD THINGS COME
TOGETHER FOR A PREDOMINANT SNOW EVENT...POTENTIAL IS THERE FOR A
FEW INCHES OF ACCUMULATION LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT.

ONCE THE SURFACE WAVE PASSES AND DEEPENS OFF THE NEW ENGLAND COAST
MONDAY...A FRESH BATCH OF ARCTIC AIR WILL SPILL INTO THE REGION
FOR EARLY NEXT WEEK. HIGHS MAY STRUGGLE TO GET OUT OF THE TEENS
BOTH MONDAY/TUESDAY ACROSS NORTHERN COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 270600Z TAF ISSUANCE/...

ISSUED AT 1140 PM EST MON JAN 26 2015

IFR OR WORSE CONDITIONS IN LIGHT SNOW EXPECTED MUCH OF THE NIGHT AT
BMG AND HUF. MVFR OR WORSE POSSIBLE AT LAF THROUGH 07Z OR 08Z IN
LIGHT SNOW OR LIGHT DRIZZLE. BUFKIT DOES NOT FAVOR FREEZING DRIZZLE
AT THE OTHER SITES...HOWEVER RECENT REPORTS OF LIGHT FREEZING
DRIZZLE AT LAF AND NORTH AND WEST DEMAND AT LEAST A MENTION.
PRECIPITATION SHOULD BE ENDING FROM NORTHWEST TO SOUTHEAST...AFTER
09Z AT IND AND HUF AND 10Z AT BMG. FLYING CONDITIONS SHOULD IMPROVE
TO MVFR OR VFR AFTER 15Z WITH ONLY CIRRUS AFTER 00Z WEDNESDAY.

WINDS WILL BE LIGHT AND VARIABLE TO CALM OVERNIGHT AND BECOME
NORTHEAST AND NORTH 8 KNOTS OR LESS AFTER 15Z BEFORE BECOMING LIGHT
AND VARIABLE ONCE AGAIN AFTER 00Z WEDNESDAY.

&&

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

&&

$$

SYNOPSIS...PUMA
NEAR TERM...TDUD
SHORT TERM...PUMA
LONG TERM....RYAN
AVIATION...KOCH

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.