371  
FXUS63 KIND 191622  
AFDIND  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE INDIANAPOLIS IN  
1115 AM EST SAT JAN 19 2019  
   
UPDATE
 
 
THE AVIATION SECTION HAS BEEN UPDATED BELOW.  
 

 
   
SYNOPSIS
 
 
ISSUED AT 252 AM EST SAT JAN 19 2019  
 
A STRONG LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS WILL SWEEP  
ACROSS KENTUCKY TODAY AND REACH THE MIDDLE ATLANTIC STATES BY  
SUNDAY. THE DEEP LOW WILL SPREAD A SWATH OF WINTER PRECIPITATION  
ACROSS CENTRAL INDIANA. THE PRECIPITATION WILL START AS EITHER  
RAIN...SNOW OR A MIX BEFORE CHANGING OVER TO ALL SNOW BY LATE  
AFTERNOON ACROSS THE ENTIRE STATE. SIGNIFICANT SNOWFALL AMOUNTS  
ARE EXPECTED RESULTING IN DIFFICULT TRAVEL CONDITIONS. GUSTY WINDS  
MAY ALSO RESULT IN BLOWING AND DRIFTING SNOW.  
 
ARCTIC HIGH PRESSURE WILL ARRIVE ACROSS THE AREA ON  
SUNDAY...BRINGING SOME OF THE COLDEST TEMPERATURES INDIANA HAS  
SEEN SO FAR THIS WINTER. THESE COLD TEMPERATURES WILL PERSIST  
ACROSS INDIANA THROUGH MONDAY AS THE HIGH PRESSURE PASSES ACROSS  
THE REGION.  
 
RAIN AND WARMER TEMPERTURES ARE THEN EXPECTED TO ARRIVE ON TUESDAY  
AS LOW PRESSURE MOVES THROUGH THE GREAT LAKES...DRAGGING A COLD  
FRONT ACROSS INDIANA.  
 
MORE COLD TEMPERATURES AND PRECIPITATION CHANCES ARE EXPECTED TO  
RETURN NEXT WEEKEND.  
 

 
   
NEAR TERM /TODAY/
 
 
ISSUED AT 950 AM EST SAT JAN 19 2019  
 
AREAS NEAR A SOUTHWEST TO NORTHEAST CORRIDOR FROM NEAR TO FISHERS TO  
NEAR KOKOMO HAVE SEEN SOME ICE ACCUMULATION WITH A FEW POWER OUTAGES  
REPORTED. OTHERWISE, IT HAS BEEN MOSTLY RAIN SOUTH OF THI9S CORRIDOR  
AND MOSTLY SNOW NORTH OF IT. THERE WAS A REPORT IN LAFAYETTE OF AN  
INCH OF SNOW ACCUMULATION. THE PRECIPITATION SHOULD SWITCH TO JUST  
SNOW FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON AS THE COLD AIR  
MOVES IN BEHIND THE DEPARTING LOW PRESSURE SYSTEM. THE HIGHEST SNOW  
ACCUMULATION IS EXPECTED NORTH OF INDIANAPOLIS AND ALSO SOUTHEAST OF  
INDIANAPOLIS WITH LOWER AMOUNTS WEST CENTRAL.  
 
PREVIOUS DISCUSSION FOLLOWS...  
 
ISSUED AT 252 AM EST SAT JAN 19 2019  
 
SURFACE ANALYSIS EARLY THIS MORNING SHOWS DEEP LOW PRESSURE IN  
PLACE ACROSS NW ARKANSAS. A WARM FRONT EXTENDED NE FROM THE  
LOW...INTO WESTERN KENTUCKY AND THEN ACROSS SOUTHERN KENTUCKY.  
WATER VAPOR IMAGERY SHOWS A STREAM OF MOISTURE PUSH NORTHEAST  
ACROSS TX AND INTO THE TENNESSEE VALLEY AHEAD OF A DEEP UPPER  
TROUGH OVER OK AND KS. RADAR SHOWS A FEW ARES OF RAIN SHOWERS OVER  
ILLINOIS PUSHING NE. EARLY RETURNS AT THE MOMENT IN INDIANA WERE  
VIRGA. GFS AND NAM AGREE TO SWEEP THE SURFACE LOW ACROSS KENTUCKY  
TODAY...AGAIN PLACING INDIANA WITHIN A FAVORABLE LOCATION FOR  
SNOW AND PRECIP. 700MB LOW/TROUGH AXIS IS ALSO EXPECTED TO PUSH  
ACROSS CENTRAL INDIANA LATE THIS AFTERNOON. BOTH OF THESE  
FEATURES ARE FAVORABLE FOR SNOW...PARTICULARLY THE LATTER.  
INITIALLY FORECAST SOUNDINGS HAVE TROUBLE FOR A WELL DESIGNED  
FZRA SET-UP. TEMPS APPEAR EITHER TOO WARM AT THE SURFACE OR NOT  
WARM ENOUGH ALOFT WHERE SURFACE TEMPS ARE EXPECTED TO BE COLDER. A  
THIN AREA OF FREEZING PRECIP CANNOT BE RULED OUT BUT A SHARPER  
RAIN/SNOW LINE APPEARS MORE LIKELY.  
 
STRONG ISENTROPIC LIFT IS SEEN THIS MORNING AHEAD OF THE SYSTEM  
ON THE GFS 290K SURFACE WITH SPECIFIC HUMIDITIES OVER 4 G/KG. THIS  
LIFT IS LOST BY 18Z AND AFTER AS THE SURFACE LOW PASSES EAST AND  
AND WRAP AROUND FLOW BECOMES MORE PREDOMINATE. AHEAD OF THE LOW  
THIS MORNING...RAIN WILL BE THE PRIMARY PRECIP TYPE ALONG AND  
SOUTH OF I-70 AS THE LOWER LEVEL LAYER LOOKS WARM ENOUGH TO MELT  
PRECIP. FARTHER NORTH THE WARM LAYER IS MUCH SHALLOWER AND PRECIP  
SHOULD FALL AS SNOW. THIS WILL BE THE INITIAL ROUND OF PRECIP  
THIS MORNING...ASSOCIATED WITH THE WARM AIR ADVECTION ON THE FRONT  
OF THE APPROACHING SYSTEM. THE SECOND ROUND OF OF SNOW LOOKS TO  
COME THIS AFTERNOON AS THE MODELS AGAIN HINT AT A DEFORMATION BAND  
SETTING UP ACROSS INDIANA THIS AFTERNOON AND EARLY EVENING. THIS  
AREA APPEARS WHERE MORE OF OUR HEAVIER SNOW MIGHT COME  
FRONT...PARTICULARLY ACROSS THE SOUTH AND EAST. AS THE LOW PASSES  
THIS AFTERNOON...LOWER LEVEL FLOW BECOMES NORTHERLY AND FORECAST  
SOUNDINGS SHOW ENOUGH COOLING THAT ALL PRECIP WILL FALL AS SNOW  
ACROSS THE FORECAST AREA.  
 
WHEN IT IS COMPLETED THIS EVENING...THESE TWO PUNCHES SHOULD  
BRING 5-7 INCHES OF SNOW NORTH OF I-70 AND 4-6 AMOUNTS SOUTH AND  
EAST OF INDIANAPOLIS. BLOWING AND DRIFTING MAY FURTHER COMPLICATE  
DRIVING CONDITIONS. GIVEN THIS...OUR WARNING MAY NEED TO BE  
EXPANDED TO THE SOUTHEAST.  
 
FORECAST WISE 100 POPS ARE A SLAM DUNK AND WILL LOOK FOR STEADY  
STATE TEMPS THIS MORNING AND FALLING TEMPS THIS AFTERNOON AMID  
PRECIP AND COLD AIR ADVECTION.  
 

 
   
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/
 
 
ISSUED AT 252 AM EST SAT JAN 19 2019  
 
GFS AND NAM CONTINUE TO SUGGEST EXTENSIVE MOISTURE AND LIFT ACRS  
SOUTHEASTERN CENTRAL INDIANA NEAR 00Z AS SEEN IN THE MID LEVEL  
DEFORMATION BAND. TEMPS AT THAT TIME CONTINUE TO SUPPORT  
SNOW...ALTHOUGH THIS PRECIP SHOULD BE EXITING THE AREA QUICKLY  
EAST BETWEEN 00Z AND 06Z. WILL CONTINUE TO USE HIGH POPS AT THAT  
TIME TAPERING TO DRY OVERNIGHT AS FORCING DEPARTS TO THE EAST.  
AGAIN...SNOW AMOUNTS WILL BE TRENDED UPWARD ACROSS THE SOUTHEAST  
FOR THIS EVENING SNOWFALL SET-UP...AND SHOULD PROPEL THE  
SOUTHEAST PARTS OF CENTRAL INDIANA INTO WARNING CRITERIA. STRONG  
COLD AIR ADVECTION IS EXPECTED AS THE DEEP LOW DEPARTS. THIS  
FEATURES WILL RESULT IN SOME GUSTY WINDS THIS AFTERNOON AND  
EVENING...BLOWING AND DRIFTING SNOW MAY CONTINUE TO IMPACT TRAVEL.  
GIVEN THE COLD AIR ADVECTION WILL TREND LOWS AT OR BELOW THE  
FORECAST BUILDER BLENDS.  
 
MODELS SUGGEST ARCTIC HIGH PRESSURE WILL SETTLE ACROSS THE OHIO  
VALLEY ON SUNDAY IN THE WAKE OF THE DEPARTING LOW. STRONG RIDGING  
ALOFT BEGINS TO DEVELOP OVER THE PLAINS STATES AND THIS FEATURE  
PERSISTS UNTIL MONDAY NIGHT...KEEPING SUBSIDENCE IN PLACE ACROSS  
INDIANA AND THE OHIO VALLEY. THUS WILL TREND TOWARD A DRY FORECAST  
ON SUNDAY THROUGH MONDAY NIGHT...BUT WILL KEEP SOME CLOUD COVER  
AROUND GIVEN THE COLD AIR ADVECTION. WILL TREND TEMPS AT OR BELOW  
THE BLENDS.  
 

 
   
LONG TERM /TUESDAY THROUGH SATURDAY/
 
 
ISSUED AT 325 AM EST SAT JAN 19 2019  
 
THE LONG TERM PORTION OF THE FORECAST LOOKS TO BE SOMEWHAT ACTIVE  
WITH ONE WELL ORGANIZED LOW PRESSURE SYSTEM IMPACTING THE AREA  
EARLY IN THE PERIOD, AND THEN LINGERING CHANCES FOR LIGHT SNOW  
FROM TIME TO TIME AS WEAKER UPPER LEVEL DISTURBANCES MOVE THROUGH  
THE REGION IN THE LARGER SCALE CYCLONIC FLOW ALOFT. TEMPERATURES  
EARLY IN THE PERIOD WILL RECOVER BRIEFLY FROM THE VERY COOL  
READINGS DURING LATE WEEKEND INTO THE START OF THE WORK WEEK,  
BEFORE ANOTHER SHOT OF ARCTIC AIR LATER IN THE WEEK REINFORCES THE  
COLD AIR MASS IN PLACE ACROSS THE AREA.  
 
BLENDED INITIALIZATION PERFORMED REASONABLY WELL AND REQUIRED ONLY  
MINOR ADJUSTMENT.  
 

 
   
AVIATION /DISCUSSION FOR 19/18Z TAF ISSUANCE/
 
 
ISSUED AT 1115 AM EST SAT JAN 19 2019  
 
THE SREF AND GFS LAMP SUGGEST THE IFR AND WORST CONDITIONS IN RAIN  
AND SNOW WILL IMPROVE TO MVFR AFTER 04Z AT IND AND BMG AFTER 04Z AT  
IND AND BMG AND A FEW HOURS EARLIER AT THE OTHER SITES. HOWEVER,  
THIS IS ONLY LOW TO MODERATE CONFIDENCE ON TIMING. THE SNOW SHOULD  
END AFTER 00Z AT LAF AND SEVERAL HOURS LATER AT THE OTHER SITES.  
 
IT WILL BE WINDY WITH NORTHEAST WINDS BECOMING NORTH AND GUSTS TO 30  
KNOTS OR MORE THROUGH 06Z WITH SLIGHTLY LESSER GUSTS TO 10Z.  
 

 
   
IND WATCHES/WARNINGS/ADVISORIES
 
 
WINTER STORM WARNING UNTIL 4 AM EST SUNDAY FOR INZ021-028>031-  
035>049-054>057-065.  
 
WINTER WEATHER ADVISORY UNTIL 4 AM EST SUNDAY FOR INZ051>053.  
 
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST SUNDAY  
FOR INZ062>064-067>072.  
 
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST  
SUNDAY FOR INZ060-061.  
 

 
 

 
 
SYNOPSIS...PUMA  
NEAR TERM...PUMA/MK  
SHORT TERM...PUMA  
LONG TERM...NIELD  
AVIATION...MK  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab IN Page Main Text Page