FXUS63 KILX 030536
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1136 PM CST WED DEC 2 2009

.DISCUSSION...
ISSUED 840 PM CST WED DEC 2 2009

LIGHT PRECIPITATION CONTINUES TO FALL OVER THE EASTERN TWO-THIRDS
OF THE KILX CWA...AS LOW PRESSURE TRACKS ACROSS SOUTHEAST INDIANA.
THE PRECIP HAS MAINLY BEEN IN THE FORM OF RAIN...ALTHOUGH NUMEROUS
REPORTS INDICATE SNOW ON THE BACK EDGE OF THE PRECIP SHIELD. LOW
WILL RAPIDLY TRACK NORTHEASTWARD OVERNIGHT...BRINGING AN END TO
THE PRECIP BY AROUND MIDNIGHT. HAVE UPDATED FORECAST TO CARRY
CATEGORICAL POPS FOR A RAIN/SNOW MIX ALONG AND EAST OF I-57...WITH
ONLY SCATTERED FLURRIES FURTHER WEST ACROSS THE REMAINDER OF THE
AREA. AFTER MIDNIGHT...WILL BRING AN END TO THE PRECIP...EXCEPT
FOR A FEW LINGERING FLURRIES ACROSS THE EAST. HAVE ALSO RAISED
LOW TEMPS A FEW DEGREES...WITH READINGS RANGING FROM THE UPPER 20S
WEST...TO THE LOWER 30S EAST.

&&

.AVIATION...
ISSUED 1136 PM CST WED DEC 2 2009

A FEW SPRINKLES OR SNOW FLURRIES WILL LINGER AT KCMI FOR ANOTHER
HOUR OR TWO...BEFORE THE BACK EDGE OF THE PRECIP SHIELD ASSOCIATED
WITH DEPARTING LOW PRESSURE EXITS THE REGION. SATELLITE IMAGERY
SHOWS PLENTY OF CLOUD COVER REMAINING IN THE WAKE OF THE
SYSTEM...ALTHOUGH SEVERAL LARGE BREAKS IN THE OVERCAST HAVE
DEVELOPED...PARTICULARLY ACROSS SOUTHEAST IOWA/NORTHEAST MISSOURI.
LOW-LEVEL PROFILERS ARE SHOWING N/NW WINDS ALOFT...SO CLEAR PATCH
WILL STAY JUST WEST OF THE TERMINALS. END RESULT WILL BE A
CONTINUATION OF MOSTLY CLOUDY SKIES...WITH AN OCCASIONAL BREAK IN
THE CLOUD COVER. WILL CARRY A PREDOMINANT CEILING OF 2000 TO
2500FT INITIALLY...RISING TO 3000FT ACROSS THE BOARD AFTER 08Z.
WITH UPPER LOW CURRENTLY OVER THE DAKOTAS PROGGED TO TRACK E/SE
INTO NORTHERN ILLINOIS BY THURSDAY EVENING...MOSTLY CLOUDY
CONDITIONS WILL PREVAIL. NAM-WRF 1000-850MB RH SUGGESTS A PARTIAL
CLEARING TREND AT THE I-72 TERMINALS BY LATE AFTERNOON/EARLY
EVENING...WITH HIGHER LOW-LEVEL RH AND CLOUD COVER HOLDING FIRM
FURTHER NORTH AT BOTH KPIA AND KBMI THROUGH 06Z FRI. WINDS WILL
INITIALLY BE GUSTY FROM THE NORTHWEST TONIGHT...THEN WILL BACK TO
WESTERLY ON THURSDAY. 

BARNES
&&

.PREV 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 

&&

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

$$