FXUS63 KILX 022356
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
556 PM CST WED DEC 2 2009

.DISCUSSION...
ISSUED 235 PM CST WED DEC 2 2009

LATEST SURFACE MAP SHOWED LOW PRESSURE CENTER BEGINNING TO MOVE
INTO SOUTH CENTRAL KENTUCKY. PRECIPITATION SHIELD HAS BEEN
OVERSPREADING THE CWA...BUT LATELY HAS BEEN HAVING SOME DIFFICULTY
MAKING IT MUCH FURTHER THAN A SPRINGFIELD TO RANTOUL LINE. NOT TOO
SURPRISING...AS LATEST LAPS SOUNDINGS FROM PEORIA AND BLOOMINGTON
ARE SHOWING A DECENT AMOUNT OF DRY AIR THAT STILL NEEDS TO BE
OVERCOME IN THIS AREA. TEMPERATURES IN THE 40-45F RANGE HAVE KEPT
THE PRECIPITATION IN THE FORM OF RAIN...EXCEPT FOR A BIT OF SLEET
AND SNOW AT TIMES.

MAIN FORECAST ISSUE FOR THIS PACKAGE INVOLVES PRECIPITATION TYPE
AND DURATION THIS EVENING. PRECIPITATION THREATS TOWARD THE END OF
THE FORECAST PERIOD ARE ALSO A CONCERN.

SHORT TERM...TONIGHT THROUGH SATURDAY...

SHORT-RANGE MODELS IN GOOD AGREEMENT IN LIFTING THE LOW NORTHEAST
TO NEAR CLEVELAND BY LATE EVENING. HIGH-RESOLUTION MODELS
SUGGESTING THAT THE PRECIPITATION PROBABLY WILL NOT MAKE IT MUCH
FURTHER NORTHWEST THAN THE ILLINOIS RIVER THIS EVENING...BEFORE
THE WHOLE AREA SHIFTS EASTWARD. AS SUCH...WILL TAPER POPS OFF
SHARPLY ALONG AND WEST OF THE RIVER THIS EVENING...RANGING TO
MAINLY CATEGORICAL POPS EAST OF I-55. AS FOR THE TYPES...BUFKIT
SOUNDINGS AND TOP-DOWN METHOD SUGGEST THAT THE BULK OF THE
PRECIPITATION WILL REMAIN RAIN...MIXED AT TIMES WITH A BIT OF
SLEET OR SNOW...EXCEPT FOR A SWITCHOVER AT THE TAIL END OF THE
EVENT. ANY ACCUMULATIONS AS A RESULT SHOULD BE QUITE LIMITED.
AFTER MIDNIGHT...THE PRECIPITATION SHOULD MAINLY BE EAST OF I-57
AND CONTINUING TO DIMINISH.

FLURRIES WILL BE POSSIBLE ACROSS THE AREA THURSDAY...AS AN UPPER
LOW PUSHES EAST ACROSS THE UPPER MIDWEST...WITH A SURFACE BOUNDARY
EXTENDING FROM THE ORIGINAL LOW. ANY SIGINFICANT SNOW CHANCES
SHOULD REMAIN TO OUR NORTH CLOSER TO THE TRACK OF THIS LOW. 

BEYOND THAT...DRY WEATHER IS EXPECTED INTO THE WEEKEND...AS HIGH
PRESSURE RIDGES NORTHEAST FROM THE SOUTHERN PLAINS. THE MAIN UPPER
FLOW WILL BE SHUNTED WELL TO OUR SOUTH...KEEPING OUR AREA ON THE
COLD SIDE. COLDEST CONDITIONS STILL EXPECTED TO BE ON FRIDAY...WITH
SOME MODERATION BEGINNING ON SATURDAY AS WINDS SWING TO THE
SOUTHWEST WITH THE HIGH IN THE AREA.

LONG TERM...SUNDAY THROUGH WEDNESDAY...

LONGER RANGE MODELS ADVERTISING MORE OF A ZONAL FLOW ACROSS THE
CONUS BY SATURDAY NIGHT...WITH A SERIES OF SHORTWAVES ZIPPING
ACROSS THE COUNTRY. FIRST ONE IS PROGGED TO ARRIVE IN OUR AREA ON
MONDAY. GFS AND ECMWF HAVE A BIT OF A DISCREPANCY ON THE TRACK OF
THE ASSOCIATED SURFACE LOW...WITH THE ECMWF BEING THE MORE
SOUTHERN OF THE TWO...GOING ACROSS NORTHWEST ILLINOIS. WILL KEEP
MONDAY DRY FOR NOW UNTIL THIS CAN BE RESOLVED FURTHER. NEXT ONE IS
SCHEDULED TO ARRIVE ON TUESDAY NIGHT OR WEDNESDAY...WITH A CHANCE
OF RAIN OR SNOW. HOWEVER...HIGHEST POPS CURRENTLY EXPECTED TO
REMAIN TO OUR SOUTH.

GEELHART 

&&

.AVIATION...
ISSUED 555 PM CST WED DEC 2 2009

LOW PRESSURE CURRENTLY OVER CENTRAL KENTUCKY WILL RAPIDLY LIFT
NORTHEASTWARD TONIGHT...BRINGING A MIXTURE OF RAIN AND SNOW TO
EAST-CENTRAL ILLINOIS. BASED ON RADAR TRENDS...IT APPEARS
KSPI...KDEC...AND KCMI WILL BE THE PRIMARY SITES AFFECTED BY PRECIP
THIS EVENING. A BAND OF PRECIP FURTHER WEST ACROSS THE ILLINOIS
RIVER VALLEY WILL GRADUALLY DISSIPATE OVER THE NEXT COUPLE OF
HOURS...AND SHOULD NOT SIGNIFICANTLY IMPACT KPIA OR KBMI. WITHIN
THE MAIN PRECIP SHIELD EAST OF I-55...CEILINGS WILL HOVER AROUND
2000FT AND VISBYS WILL RANGE BETWEEN 3SM AND 5SM. BUFKIT SOUNDINGS
SHOW PRECIP ENDING BETWEEN 05Z AND 07Z...WITH LOW CEILINGS OF
AROUND 2500FT PERSISTING AT THE EASTERNMOST TERMINALS. FURTHER
WEST...DRIER WILL FILTER INTO LOCATIONS ALONG AND WEST OF I-55
OVERNIGHT...ALLOWING CEILINGS TO RISE TO AROUND 8000FT. AS NEXT
UPPER WAVES SKIRTS ACROSS THE AREA THURSDAY MORNING...CEILINGS
WILL ONCE AGAIN COME DOWN TO AROUND 2500FT AND THERE COULD EVEN BE
A FEW SNOW FLURRIES FROM TIME TO TIME. WINDS WILL INITIALLY BE
GUSTY OUT OF THE N/NW TONIGHT...THEN WILL BACK TO THE NW BY
THURSDAY MORNING.

BARNES
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$