646  
FXUS63 KILX 080934  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
334 AM CST MON FEB 8 2016  
   
SHORT TERM
 
(TODAY)  
ISSUED AT 333 AM CST MON FEB 8 2016  
 
SURFACE LOW CENTERED OVER LAKE SUPERIOR EARLY THIS MORNING HAS A  
TRAILING COLD FRONT WHICH HAS ARRIVED IN GALESBURG EARLY THIS  
MORNING AND WILL PUSH SOUTHEASTWARD TO LAWRENCEVILLE BY AROUND NOON.  
AN UPPER LEVEL SHORTWAVE FOLLOWING THE COLD FRONT WILL HELP ENHANCE  
LIFT OVER THE AREA BRINGING THE LIKELIHOOD OF SCATTERED SNOW SHOWERS  
ACROSS CENTRAL IL DEVELOPING THIS MORNING THROUGH AFTERNOON.  
FORECAST SOUNDINGS DEPICT A MIXED LAYER DEEPENING TO THE 800 MB  
LAYER BY AFTERNOON...EXTENDING INTO TEMPERATURES ALOFT -10 C OR  
COLDER...FOR FAVORABLE SNOW CRYSTAL FORMATION. NEVERTHELESS...LIFT  
IS WEAK AND ONLY EXPECTING AMOUNTS TO AROUND 1/2 INCH OR LESS BY  
EVENING. EARLY IN THE MORNING...A FEW SPRINKLES AND SHOWERS  
ASSOCIATED WITH A PRECEDING SHORTWAVE WILL ALSO BE SEEN SOUTH OF I-  
72 BEFORE THE MORE PROMINENT SHORTWAVE AND COLD FRONT ARRIVE.  
 
COLD AIR BEHIND THE FRONT WILL START A DOWNWARD TREND IN  
TEMPERATURES. MOST AREAS NORTH OF I-72 WILL SEE TEMPERATURES FALLING  
THROUGH THE DAY...WHILE AREAS TO THE SOUTH SHOULD SEE A MAX  
TEMPERATURE BEFORE NOON...THEN FALLING THROUGH THE AFTERNOON. EXPECT  
EARLY MORNING TEMPERATURES IN THE UPPER 20S AND LOWER 30S...AND NO  
MORE THAN MID 20S TO LOWER 30S BY MID AFTERNOON. WINDS WSW AROUND 10  
MPH AHEAD OF THE COLD FRONT...SWITCHING TO WNW AND INCREASING TO A  
BLUSTERY 15-20 MPH WITH GUSTS 25-30 MPH.  
 

 
   
LONG TERM
 
(TONIGHT THROUGH SUNDAY)  
ISSUED AT 333 AM CST MON FEB 8 2016  
 
LONG WAVE TROF DIGGING IN OVER THE MIDWEST, WITH GOOD REPRESENTATION  
ON SAT IMAGERY THIS MORNING. THE DEEP TROF OVER THE EASTERN HALF OF  
THE COUNTRY WILL BE THE DRIVING FORCE THROUGH THE END OF THE  
FORECAST PERIOD. VARIATIONS AND CHALLENGES IN THE FORECAST REVOLVE  
AROUND SUBTLE BUT SIGNIFICANT NUANCES BETWEEN MODELS IN HANDLING THE  
TROF.  
 
FOR TONIGHT, WIDESPREAD LIGHT SNOW SHOWERS WILL REMAIN THE RULE AS  
THE SFC SYSTEM MAKES ITS WAY THROUGH THE REGION. MODELS HAVE BEEN  
RELATIVELY CONSISTENT WITH SHOWING A SHOWERY NATURE TO THE  
SNOWFALL...AND TRYING TO SHOW A BIT OF A BREAK TONIGHT BEFORE A  
SECONDARY WAVE COMES IN AND DEVELOPS ANOTHER ROUND. THOUGH MOST  
PLACES SHOULD SEE SNOW AT SOME POINT, THE QPF ASSOCIATED WITH THIS  
STORM IS LIMITED. LIFT IS NOT THAT DEEP THROUGH THE COLUMN, AND THE  
MOISTURE IS ALSO LIMITED. AROUND A WIDESPREAD INCH OR SO COULD BE  
POSSIBLE THROUGH TUESDAY MORNING, WITH THE HIGHER INCH TO TWO TOTALS  
IN THE NE. HOWEVER LIGHT THE SNOWFALL TOTALS ARE EXPECTED TO BE,  
THE BLUSTERY WINDS AND COLD TEMPERATURES WILL STILL RESULT IN A  
TRAVEL MENACE WITH THIS SNOW. 15 TO 20 MPH WINDS GUSTING TO 25 TO  
30 AT TIMES WILL RESULT IN SOME BLOWING SNOW AND VIS REDUCTIONS, AS  
WELL AS CREATING SOME SLIPPERY ROADS.  
 
CHILLY TEMPERATURES AS ARCTIC AIR MOVES INTO THE REGION BEHIND THE  
SNOWFALL, WITH WEDNESDAYS HIGHS ONLY GETTING INTO THE TEENS. MID  
WEEK IS ALSO ABOUT THE TIME THAT THE MODELS START EJECTING A SERIES  
OF WAVES INTO THE NWRLY FLOW OVER THE REGION. GFS IS QUICKER WITH  
ONE ON WED AFTERNOON, AND THE ECMWF IS A LITTLE BIT DELAYED INTO  
EARLY FRIDAY. NEITHER OF THE WAVES HAVE MUCH IN THE WAY OF  
CONFIDENCE JUST YET AS FAR AS POTENTIAL PRECIP MAKERS, BUT POSSIBLY  
WAVES TO HELP DIG THE TROF FURTHER. WHICH BRINGS THE FORECAST  
AROUND TO THE NEXT BIG QUESTION...TEMPERATURES GOING INTO THE NEXT  
WEEKEND. ECMWF IS FAR COLDER AND DEEPER WITH ANOTHER BIG SURGE OF  
ARCTIC AIR INTO THE LONG WAVE THAT HAS REMAINED OVER THE EASTERN  
CONUS FOR THE ENTIRE FORECAST. GFS IS A LITTLE LESS AGGRESSIVE.  
TELECONNECTIONS FORECAST HAS THE AO GOING NEGATIVE, SO THE MOVEMENT  
OF ARCTIC AIR INTO THE CONUS IS LIKELY. THE GFS/ENSEMBLE FORECAST  
FOR THE NAO IS POSITIVE, HOWEVER, LEANING TO A WEAKER ICELANDIC LOW  
AND LESS AMPLIFIED PATTERN OVER THE EASTERN HALF OF THE COUNTRY.  
LESS EMPHASIS PUT ON THE GFS FORECAST WITH A WHICH CAME FIRST  
ARGUMENT. THE ENSEMBLES GIVE A LITTLE MORE CREDIT...BUT IN REALITY,  
THE TREND ANALYSIS ALONE IN THE TELECONNECTIONS HAS BEEN TROUBLESOME  
THIS WINTER. THE LAST SITUATION THAT SET UP THIS WAY, THE ECMWF  
PICKED UP ON A DEEP COLD TREND BEFORE THE GFS (AND HENCE, THE NAO  
FORECASTS WERE ALSO LAGGING). WITH ALL THAT IN MIND, HAVE TRENDED  
THE FORECAST SLIGHTLY COLDER THAN THE SUPERBLEND HAS INTO THE  
WEEKEND, BUT NOT QUITE AS AGGRESSIVE AS THE INCREDIBLY COLD ECMWF.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)  
ISSUED AT 1133 PM CST SUN FEB 7 2016  
 
CIGS ACROSS THE CENTRAL ILLINOIS TERMINALS WILL CONTINUE TO THICKEN  
AND LOWER, WITH MVFR CIGS DEVELOPING OVERNIGHT IN THE WAKE OF A  
STRONG COLD FRONT. SNOW SHOWERS WILL ALSO ACCOMPANY THE COLDER  
AIR, BUT GIVEN EXPECTED COVERAGE WILL ONLY CARRY VCSH FOR THE  
REMAINDER OF THE NIGHT. SNOW SHOWERS WILL BE MORE WIDESPREAD AFTER  
SUNRISE MONDAY, SO WILL CARRY RESTRICTED VISIBILITY IN SNOW DURING  
THE DAYTIME HOURS. THE GUSTY WINDS HAVE SUBSIDED FOR NOW, BUT WILL  
DEVELOP AGAIN MONDAY MORNING.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...ONTON  
LONG TERM...HJS  
AVIATION...BAK  
 
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