Area Forecast Discussion
Issued by NWS Indianapolis, IN

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279
FXUS63 KIND 081645
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1145 AM EST MON FEB 8 2016

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

&&

.SYNOPSIS...
ISSUED AT 244 AM EST MON FEB 8 2016

AN UPPER LOW WILL SETTLE SLOWLY EASTWARD ACROSS THE LOWER GREAT
LAKES EARLY THIS WEEK AND INTERACT WITH INCREASING MOISTURE. THE
RESULT WILL BE SCATTERED TO WIDESPREAD SNOW SHOWERS THIS AFTERNOON
THROUGH TUESDAY WITH CHANCES LINGERING THROUGH WEDNESDAY
EVENING...MAINLY ACROSS NORTHEASTERN PARTS OF CENTRAL INDIANA. GUSTY
WINDS IN THE HEAVIER SNOW SHOWERS COULD RESULT IN SUDDEN REDUCTIONS
IN THE VISIBILITY.

VERY COLD AIR WILL FILTER IN BEHIND THE DEPARTING LOW WITH SUB ZERO
WIND CHILLS POSSIBLE BY OVERNIGHT TUESDAY NIGHT. AFTER THAT...HIGH
PRESSURE WILL BRING IN MAINLY DRY WEATHER TO THE AREA FOR THE LATE
WEEK AND WEEKEND. TEMPERATURES WILL ONLY SLOWLY MODERATE AND REMAIN
BELOW NORMAL THROUGH THE PERIOD.

&&

.NEAR TERM /REST OF TODAY/...
ISSUED AT 1005 AM EST MON FEB 8 2016

INITIAL BAND OF SNOW THAT HAS DROPPED A FEW TENTHS ACROSS EASTERN
COUNTIES THIS MORNING IS NOW ABOUT TO SHIFT INTO WESTERN OHIO.
STARTING TO SEE SLOW EXPANSION TO SCATTERED SNOW SHOWERS BACK
ACROSS THE SOUTHWEST HALF OF THE FORECAST AREA...AND EXPECT THIS
ONLY TO INCREASE AS THE COLD FRONT MOVES INTO THE WABASH VALLEY.
15Z TEMPS REMAIN IN THE 30S.

MAIN FOCUS FOR THE UPDATE IS TO BETTER TIME THE TEMP FALLS AND
MORE INTENSE SNOW SHOWERS LATER TODAY. COLD FRONT WILL SWING
THROUGH THE FORECAST AREA OVER THE NEXT FEW HOURS...WITH WINDS
SHIFTING TO NORTHWEST AND BECOMING GUSTY IN ITS WAKE. AS
STATED...SCATTERED SNOW SHOWERS AND LOCALIZED BURSTS OF SNOW
HIGHLIGHTED BY POCKETS OF 30+ DBZ RETURNS ALREADY EXPANDING OVER
WESTERN COUNTIES. MORE EXPANSIVE AND INTENSE SNOW SHOWERS STILL
SLATED TO ARRIVE FOR LATER THIS AFTERNOON AS LOW LEVEL
THERMODYNAMIC PROFILES BECOME MORE CONDUCIVE FOR SQUALLS. HAVE
SEEN BRIEF DROPS TO UNDER 1SM IN HEAVIER SNOW SHOWERS OVER CENTRAL
AND EASTERN ILLINOIS THIS MORNING AND EXPECT THIS ONLY TO WORSEN
AS IT MOVES INTO THE FORECAST AREA AFTER 18Z.

WHILE TRAVEL IMPACTS WILL INCREASE THROUGH THE AFTERNOON...THEY
WILL LIKELY BE MITIGATED TO SOME DEGREE BY THE NEAR SURFACE TEMPS
REMAINING NEAR TO JUST ABOVE FREEZING WELL INTO THE AFTERNOON. THE
PASSAGE OF THE COLD FRONT OVER THE NEXT FEW HOURS SHOULD END ANY
RISE IN TEMPS...BUT IT APPEARS THE SURGE OF STRONGEST COLD
ADVECTION AND CONSEQUENTLY FASTEST TEMP DROPS LOOKS ORIENTED FOR
THE SOUTHWEST HALF OF THE FORECAST AREA WITH SLOWER TEMP FALLS
ELSEWHERE. UTILIZED HOURLY RAP GUIDANCE AS A STARTING POINT FROM
CURRENT TEMPS AND TRIED TO TIME THE TEMP FALLS LATER THIS
AFTERNOON. EXPECT EVERYONE WILL SLIP BELOW FREEZING NEAR OR JUST
AFTER SUNSET WITH MORE EXTENSIVE TEMP FALLS COMMENCING TONIGHT.

WILL CONTINUE WITH THE SPS FOR THE HIGH IMPACT SNOW SHOWERS AND
SQUALLS EXPECTED LATER TODAY...WITH A MORE INTENSIVE LOOK AT THE
NEED FOR AN IMPACT BASED ADVISORY FOCUSED OVERNIGHT AND INTO
TUESDAY/TUESDAY NIGHT AFTER THE FULL 12Z MODEL SUITE ARRIVES.

ZONE AND GRID UPDATES OUT.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 302 AM EST MON FEB 8 2016

BRIEF SNOW SQUALLS WILL CONTINUE TO BE THE MAIN CONCERN MONDAY NIGHT
AND TUESDAY. AFTER THAT...SNOW CHANCES WILL LOWER AND WILL SHIFT
MAINLY TO OUR NORTHEASTERN COUNTIES AS LAKE EFFECT THREAT CONTINUES.
WIND CHILLS WILL THEN BECOME CENTER STAGE.

MODELS IN GENERAL AGREEMENT THAT THE UPPER LOW WILL MOVE SLOWLY INTO
NORTHWESTERN OHIO BY TUESDAY MORNING AND THE APPALACHIANS BY
WEDNESDAY MORNING. THE ASSOCIATE UPPER TROUGH WILL FINALLY MOVE EAST
OF THE AREA LATE WEDNESDAY. MEANWHILE...DECENT NORTHWEST BOUNDARY
LAYER FLOW OFF LAKE MICHIGAN WILL FINALLY WEAKEN TOWARD THURSDAY
MORNING. SO...STARTED OFF WITH LIKELY POPS MONDAY NIGHT AND TUESDAY
MAINLY EAST OF A BEDFORD TO TERRE HAUTE LINE. THEN...CHANCE POPS ARE
IN ORDER FOR TUESDAY NIGHT WITH THE HIGHEST CHANCES IN THE NORTHEAST
COUNTIES. BY WEDNESDAY...WENT DRY EXCEPT CHANCE OF SNOW NORTHEAST.
BOUNDARY LAYER FLOW SHOULD BE BACKING AND LET UP ENOUGH TO PULL LAKE
EFFECT POPS WEDNESDAY NIGHT FAR NORTHEAST.

BUFKIT WAS SHOWING SNOW RATIOS INCREASING TO AROUND 20 TO 1 TONIGHT
AND TUESDAY. THUS...DESPITE WEAK SYNOPTIC FORCING AND RESULTANT LOW
QPF...HIGH SNOW RATIOS...STEEP LAPSE RATES AND SNOW SQUALL
PARAMETERS SUGGEST STORM SNOWFALL TOTALS OF UP TO 3 INCHES AND
LOCALLY HIGHER ARE POSSIBLE NEAR AND EAST OF KOKOMO AND RUSHVILLE
WITH PROJECTED AMOUNTS TAPERING OFF TO AN INCH OR 2 SOUTHWEST OF
BEDFORD AND CLINTON. NORTHWEST WINDS GUSTING TO 25 KNOTS WILL CAUSE
BLOWING SNOW AND REDUCED VISIBILITY AT TIMES.

WITH COLD ADVECTION AND EXPECTED SNOW COVER...WILL GO AT OR BELOW
00Z MOS. SHOULD SEE WIND CHILLS IN THE SINGLE DIGITS OVERNIGHT
TONIGHT AND IN THE NEGATIVE SINGLE DIGITS BY OVERNIGHT TUESDAY
NIGHT. NEGATIVE WIND CHILLS WILL IMPACT CENTRAL INDIANA WEDNESDAY
MORNING AND AGAIN WEDNESDAY NIGHT AND THROUGH THURSDAY MORNING RUSH.

AN ADVISORY WILL BE AN OPTION LATER TODAY OR TONIGHT...BUT AFTER
COORDINATION...FEEL THE BEST OPTION FOR NOW IS UPDATING THE STRONGLY
WORDED SPECIAL WEATHER OUTLOOK...HAZARDOUS WEATHER OUTLOOK...WEATHER
STORY AND TWITTER REGARDING THE SNOW. WILL ALSO HIT THE COLD
TEMPERATURES HARD.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 217 AM EST MON FEB 8 2016

ON THE LARGE SCALE...MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND
INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. DIFFERENCES CONTINUE IN
THE DETAILS.

AN UPPER TROUGH WILL CONTINUE ACROSS THE AREA THROUGH THE LONG
TERM...WITH PERHAPS SOME RISE IN HEIGHTS LATE. MODELS ARE HAVING
DISAGREEMENTS ON ENERGY RIDING AROUND THE TROUGH AND THUS CHANCES
FOR SNOW DURING THE PERIOD.

THAT FAR OUT...CONFIDENCE IS NOT HIGH IN THE DETAILS AND SEE NO
REASON TO PLAY FAVORITES AT THIS TIME. THUS STUCK WITH THE
SUPERBLEND INITIALIZATION.

COLD CONDITIONS WILL PERSIST THROUGH THE LONG TERM WITH SOME
REINFORCING COLD AIR MOVING IN THANKS TO THE TROUGH.

&&

.AVIATION /DISCUSSION FOR 081800Z TAF ISSUANCE/...

ISSUED AT 1128 AM EST MON FEB 8 2016

WIDESPREAD MVFR WITH POCKETS OF IFR WITHIN HEAVIER SNOW BANDS.
WIND GUSTS WILL PICK UP OUT OF THE NORTHWEST TO AROUND 25 KTS OVER
THE NEXT COUPLE OF HOURS AND GUSTS SHOULD REMAIN THROUGH THE REST
OF THE PERIOD. HIGH CONFIDENCE OF PREVAILING MVFR RESTRICTIONS
AND OFF AND ON SNOW THROUGH THE PERIOD BUT CONTINUE TO HAVE LOW
CONFIDENCE IN TIMING OF THE LOWER CONDITIONS. MOST MODEL SOUNDINGS
INDICATE A PERIOD THIS EVENING/TONIGHT WHEN A BREAK OCCURS IN THE
SNOWFALL BUT IT PICKS BACK UP LATE DURING THE OVERNIGHT. SOME
INDICATIONS OF CONDITIONAL INSTABILITY THIS AFTERNOON AT LEAST AT
KIND AND KBMG SO MAY INCLUDE TEMPO IFR GROUPS AT THOSE LOCATIONS
TO COVER AFTERNOON SNOW BAND POTENTIAL THERE. WILL HOLD OFF AT KHUF
AND KLAF WITH INSTABILITY REMAINING EAST OF THOSE SITES.

&&

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

$$

SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....50
AVIATION...CP



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