FXUS63 KILX 110246
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
846 PM CST THU DEC 10 2009

.DISCUSSION...
ISSUED 840 PM CST THU DEC 10 2009

SURFACE HIGH PRESSURE ACRS NE ARKANSAS THIS EVENING WILL CONTINUE
TO DRIFT EWD OVERNIGHT. CLEAR AND COLD CONDITIONS WILL PREVAIL
ACRS CNTRL IL OVERNIGHT WITH A SOUTHWEST WIND PUTTING AN ADDED
CHILL IN THE AIR. EARLY EVENING TEMPERATURES HAVE BEEN HELD UP
SOME BY THE WINDS...BUT MODELS SUGGEST SOME DROP OFF IN THE SPEEDS
LATER TNT WHICH SHOULD ALLOW EARLY MRNG READINGS TO DROP TO THEIR
EXPECTED LOWS. COLDEST READINGS WILL BE ACRS THE FAR NORTHWEST
WHERE THE DEEPER SNOW COVER WAS LOCATED. OTHERWISE...OTHER THAN
SOME MINOR ADJUSTMENTS TO THE EARLY EVENING TEMPERATURES AND
WINDS... THE REST OF THE FORECAST IS IN DECENT SHAPE...AS A
RESULT...NO EVENING UPDATE WILL BE NEEDED.

SMITH
&&

.AVIATION...
ISSUED 530 PM CST THU DEC 10 2009

VFR CONDITIONS WILL PREVAIL THRU THE PERIOD. HIGH PRESSURE TO OUR 
SOUTH THIS EVENING WILL TRACK AWAY FROM THE REGION OVERNIGHT
KEEPING MOSTLY CLEAR SKIES ACRS THE FCST AREA. SFC WINDS WILL BACK
GRDLY FROM THE WEST-SOUTHWEST TNT...MORE INTO A SOUTH TO SOUTHWEST
DIRECTION BY LATE IN THE DAY FRIDAY. SPEEDS WILL RANGE FROM 10 TO
15 KTS TNT AND FRIDAY. 

SMITH
&&

.PREV DISCUSSION...
ISSUED 255 PM CST THU DEC 10 2009

12Z SHORT RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THIS WEEKEND
AND USED A BLEND. ARCTIC HIGH PRESSURE OVER THE CENTRAL/SOUTHERN
PLAINS INTO THE MID MS VALLEY WILL DRIFT INTO THE EASTERN STATES
FRI AND DEVELOP A RETURN SOUTHERLY FLOW OVER IL WITH START OF A
WARM UP. LEANED TOWARD THE COOLER GUIDANCE TEMPS TONIGHT AND FRI
ESPECIALLY OVER THE SNOW PACK NW OF THE IL RIVER WHERE LOWS
TONIGHT WILL BE CLOSER TO COLDER MET OR EVEN A BIT COLDER AROUND
GALESBURG. MODELS CONTINUE TO SHOW A WARM AIR ADVECTION/ISENTROPIC
LIFT PATTERN SAT NIGHT INTO SUNDAY MORNING AS WEAK SHORT WAVES
MOVE INTO IL. SYSTEM IS LACKING DEEP MOISTURE SO PRECIPITATION
WILL BE LIGHT AND CHALLENGE IS PRECIPITATION TYPE. A COLD FRONT
STILL SCHEDULED TO SLIDE EAST ACROSS IL MON AND BRING THE NEXT
CHANCE OF LIGHT PRECIPIATION AND ADDRESSING PRECIPITATION TYPE. 
AFTER A WARMUP THROUGH MON TEMPS WILL COOL BEHIND THE COLD FRONT
TUE AND WED. 

SHORT TERM...TONIGHT THROUGH SUNDAY.

1027 MB ARCTIC/POLAR HIGH PRESSURE FROM EASTERN OK ACROSS AR INTO
WEST TN AND PROVIDING SUNNY BUT COLD CONDITIONS. TEMPS AT MID
AFTERNOON RANGE FROM THE MID TEENS OVER THE SNOW COVERED IL RIVER
VALLEY TO THE MID 20S SE OF I-70 IN SE IL. WSW BREEZES OF 10 TO 20 MPH
WITH GUSTS OF 20 TO 30 MPH GIVING WIND CHILLS FROM ZERO TO 5 BELOW
ZERO FROM MACOMB TO BLOOMINGTON NORTH TO THE SINGLE DIGITS TO
AROUND 10F SOUTH. ALOFT A LARGE/STRONG POLAR VORTEX UPPER LEVEL
LOW WAS OVER CENTRAL CANADA AND INTO THE CENTRAL AND EASTERN USA.

ARCTIC/POLAR HIGH PRESSURE TO DRIFT EAST ACROSS THE TN VALLEY
OVERNIGHT AND MAINTAIN CLEAR SKIES OVER CENTRAL/SE IL WITH BRISK
WSW WINDS DIMINISHING TO 8 TO 15 MPH AFTER SUNSET. LOWS TO RANGE
FROM THE SINGLES DIGITS FROM LINCOLN NW WITH GALESBURG DOWN TO
4F. WIND CHILLS OF ZERO TO 10 BELOW SO NOT QUITE TO WIND CHILL
ADVISORY CRITERIA OF MINUS 15F LIKE EARLY THIS MORNING. LOWS IN
THE MID TEENS IN SE IL.

HIGH PRESSURE DRIFTS INTO THE MID ATLANTIC STATES/CAROLINAS BY
SUNSET FRI WITH SOUTHERLY FLOW RETURNING TO IL AND STARTING A WARMUP.
HIGHS TO RANGE FROM THE MID 20S NW OF THE IL RIVER OVER SNOW PACK
TO 34 TO 38F IN SE IL. MOSTLY SUNNY SKIES FRI WITH MORE CLOUDS
NORTH OF I-74 CLOSER TO WEAK SHORT WAVES PIVOTING EAST ACROSS THE
SOUTHERN GREAT LAKES AROUND POLAR VORTEX IN CANADA. LOWS FRI NIGHT
IN THE TEENS RANGING FROM NEAR 10F IN GALESBURG TO AROUND 20F IN
SE IL. 

HIGH PRESSURE DRIFTS EAST OFF THE MID ATLANTIC COAST SAT WITH
INCREASING INSENTROPIC LIFT/WARM AIR ADVECTION PATTERN OVER IL AND
SOME INCREASING MOISTURE. CLOUDS TO INCREASE DURING THE DAY SAT.
HIGHS SAT TO RANGE FROM THE LOWER 30S NW OF THE IL RIVER WHERE
SNOW PACK LINGERS TO THE LOWER 40S SOUTH OF I-70.  

LOW PRESSURE ACROSS THE NORTHERN PLAINS BY SAT NIGHT WITH WEAK
SHORT WAVES MOVING INTO IL SHOULD DEVELOP LIGHT QPF DURING SAT
EVENING AND DIMINISH SUNDAY MORNING. MODELS HAVE TRENDED A BIT
WARMER IN SE IL WHERE MOSTLY LIGHT RAIN BUT NORTH OF I-70 WILL SEE
LIGHT SNOW AND LIGHT FREEZING RAIN CHANCES SAT EVENING CHANGE TO
LIGHT FREEZING RAIN/DRIZZLE OVERNIGHT SAT NIGHT. LIGHT FREEZING
DRIZZLE WILL LINGER SUN MORNING OVER CENTRAL IL WITH PATCHY
DRIZZLE IN SE IL. HIGHS SUNDAY TO RANGE FROM THE MID 30S FROM
PEORIA NORTH TO 40 TO 45F SOUTH OF I-72. 

LONG TERM...SUNDAY NIGHT THROUGH THURSDAY.

COLD FRONT TO APPROACH NW IL BY DAWN MON AND RETURN SMALL CHANCES
OF MIXED PRECIPITATION AFTER MIDNIGHT SUNDAY NIGHT AND CONTINUE
MON AS THE COLD FRONT MOVES EAST ACROSS IL. MODELS AGAIN HAVE
TRENDED A BIT MILDER IN SE IL WHERE JUST LIGHT RAIN CHANCES FROM
CHARLESTON/MATTOON SE WHILE MIX OF LIGHT RAIN/LIGHT SNOW AND
POSSIBLY EVEN LIGHT FREEZING RAIN OVER CENTRAL IL. HIGHS MON TO
RANGE FROM MID 30S FROM PEORIA NW TO AROUND 50F ALONG THE WABASH
RIVER BY LAWRENCEVILLE WHERE COLD FRONT REACHES BY EARLY MON
EVENING. CANADIAN HIGH PRESSURE OVER THE CANADIAN ROCKIES SETTLES
INTO THE MIDWEST TUE/WED COOLING TEMPS BACK DOWN WITH DRY WEATHER
AND MORE SUNSHINE. HIGH PRESSURE DRIFTING EAST OF IL THU WILL
MODIFY TEMPS BACK UP A BIT AS SOUTHERLY WINDS SET UP AGAIN. 

HUETTL

&&

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

$$