409 FXUS63 KILX 111147 AFDILX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 547 AM CST FRI JAN 11 2013 .DISCUSSION... ISSUED 235 AM CST FRI JAN 11 2013 UPPER LOW WAS JUST MOVING INTO THE ST LOUIS METRO AREA AT 2 AM PER WATER VAPOR IMAGERY. BACK EDGE OF THE RAIN EXTENDED FROM ABOUT LACON TO FLORA. HAVE SEEN OVER 3/4 INCH IN MANY AREAS WEST OF I-55 AND ALSO ALONG THE WABASH RIVER...WITH RADAR ESTIMATING A NARROW CORRIDOR OF 1 TO 2 INCHES FROM NORTHWEST MASON COUNTY TO THE EAST SIDE OF THE PEORIA METRO. TEMPERATURES AND DEWPOINTS HAVE SURGED WELL INTO THE 50S ACROSS THE ENTIRE CWA EXCEPT NEAR GALESBURG...AND SOME LOWER 60S HAVE PUSHED INTO THE FAR SOUTHEAST CWA. MUCH OF THE EARLIER FOG HAS LIFTED AS THE WARMER TEMPERATURES MOVED IN... EXCEPT IN THE FAR NORTHWEST CWA WEST OF THE ILLINOIS RIVER. WILL NEED TO ISSUE A DENSE FOG ADVISORY FOR THIS PARTICULAR AREA. THE MAIN FORECAST ISSUES FOR THIS PACKAGE INCLUDE POTENTIAL RECORD WARMTH TODAY...AS WELL AS PRECIPITATION TYPES SATURDAY NIGHT BEHIND A COLD FRONT. SHORT TERM...TODAY THROUGH SUNDAY... HAVE MADE LITTLE CHANGE TO FORECAST HIGHS FOR TODAY...AS TEMPERATURES SHOULD DIP A BIT EARLY THIS MORNING...BEFORE RISING AGAIN. SOME LOCATIONS WILL BREAK THEIR RECORDS BEFORE SUNRISE. RECORDS FOR SPRINGFIELD AND CHAMPAIGN ARE IN THE MID 60S AND PROBABLY JUST OUT OF REACH. ONCE THE RAIN MOVES OUT...DRY WEATHER IS EXPECTED THROUGH TONIGHT. WILL MAKE A LAST MINUTE CALL ON WHETHER TO MENTION ANY IN THE FAR EAST EARLY THIS MORNING. DEEP TROUGHING WEST OF THE ROCKIES WAS EVIDENT ON WATER VAPOR IMAGERY EARLY THIS MORNING...AND A DEVELOPING UPPER LOW OVER SOUTHERN IDAHO SHOULD EJECT NORTHEAST INTO THE DAKOTAS TONIGHT. AS SURFACE LOW PRESSURE RAPIDLY MOVES NORTHEAST INTO MINNESOTA TONIGHT...AN ASSOCIATED COLD FRONT WILL SURGE EASTWARD ACROSS THE STATE SATURDAY MORNING. THIS FRONT IS STILL EXPECTED TO STALL JUST SOUTH OF THE OHIO RIVER THIS AFTERNOON AS IT BECOMES PARALLEL TO THE UPPER FLOW...THEN PERHAPS DRIFT A BIT NORTHWARD AS LOW PRESSURE RIDES NORTHEAST ALONG THE BOUNDARY. PRECIPITATION WILL OVERSPREAD THE FORECAST AREA DURING THE AFTERNOON AND EVENING HOURS...AND CONTINUE MUCH OF THE NIGHT BEFORE DIMINISHING EARLY SUNDAY. CONCERN REMAINS WITH PRECIP TYPES. LATEST MODEL GUIDANCE IS PUSHING THE WEDGE OF WARMER AIR AT 850 MB A BIT FURTHER SOUTH...WITH FORECAST SOUNDINGS SHOWING SOME GOOD POTENTIAL FOR SLEET ACROSS THE EASTERN CWA...ESPECIALLY AFTER MIDNIGHT. THE COLD AIR LAYER AT THE SURFACE MAY BE A BIT TOO THICK FOR FREEZING RAIN...BUT WILL CONTINUE TO MONITOR FOR THIS POSSIBILITY. SOUNDINGS FAVOR ALL SNOW FROM ABOUT I-55 WESTWARD. CURRENTLY LOOKS LIKE A COUPLE INCHES OF SNOW WILL BE POSSIBLE IN THIS AREA...WITH LESSER AMOUNTS NORTHWEST OF THE ILLINOIS RIVER. LONG TERM...MONDAY THROUGH THURSDAY... MAIN CONCERN WILL BE WITH POSITION OF LINGERING FRONTAL BOUNDARY. LATEST MODELS CONTINUE TO SINK IT FAR ENOUGH SOUTH THAT THE PRECIPITATION SHOULD REMAIN SOUTH OF OUR FORECAST AREA DURING THIS PERIOD. SPLIT UPPER FLOW SHOWS SOME ATTEMPTS AT PHASING ACROSS THE CENTRAL UNITED STATES...WHICH MAY BE COMPLETE TOWARD THE SECOND HALF OF THE WEEK. TEMPERATURES WILL FLUCTUATE DEPENDING ON PLACEMENT OF THIS PHASING...WHICH WILL MARK THE SOUTHERN EDGE OF AN ARCTIC AIR MASS. LATEST ECMWF SHOWS A 500 MB JET OF AROUND 100 KNOTS DROPPING INTO FAR NORTHERN ILLINOIS LATE IN THE WEEK...WITH THE COLDEST AIR CLOSER TO THE GREAT LAKES. GEELHART && .AVIATION... ISSUED 547 AM CST FRI JAN 11 2013...FOR THE 12Z TAFS IFR CLOUD HEIGHTS WILL LINGER FOR PIA THIS MORNING...WHILE A BRIEF BREAK IN CLOUDS FOR THE OTHER TERMINALS IS FOLLOWED BY MVFR CLOUDS MOVING RAPIDLY INTO CENTRAL ILLINOIS ON VERY FAST MID-LEVEL SOUTHWEST WINDS. AS THE MVFR CIGS RETURN...IT COULD BE ACCOMPANIED BY A SHORT PERIOD OF MVFR VIS 3-5SM BR. BY AFTERNOON...SKIES SHOULD BEGIN TO CLEAR OUT FROM SW TO NORTHEAST AND A WAVE OF DRY AIR ALOFT PUSHES INTO C IL. GUSTY SW WINDS ARE EXPECTED ALL DAY TODAY...THEN BECOMING SOUTH AND INCREASING TONIGHT. VFR CONDITIONS ARE EXPECTED THROUGH THE NIGHT TONIGHT...BUT CANT RULE OUT SOME LIGHT FOG LATE. SHIMON && .CLIMATE... ISSUED 156 AM CST FRI JAN 11 2013 SEVERAL LOCATIONS ARE EXPECTED TO APPROACH OR BREAK RECORD HIGHS TODAY...IN SOME CASES BEFORE SUNRISE. HERE ARE THE RECORDS FOR JANUARY 12. BLOOMINGTON.... 57 IN 2012 CHAMPAIGN...... 66 IN 1890 CHARLESTON..... 60 IN 1911 DECATUR........ 56 IN 1980 EFFINGHAM...... 59 IN 1923 JACKSONVILLE... 65 IN 1911 LINCOLN........ 59 IN 1911 OLNEY.......... 66 IN 1911 PEORIA......... 62 IN 1890 SPRINGFIELD.... 67 IN 1890 WHILE MUCH OF EASTERN ILLINOIS SHOULD REACH THE 50S TO AROUND 60 ON SATURDAY BEFORE THE FRONT ARRIVES...RECORD HIGHS FOR JANUARY 12 ARE LARGELY IN THE UPPER 60S. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR ILZ027-028-036-040. && $$