FXUS63 KILX 281930
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
130 PM CST SAT NOV 28 2009

.DISCUSSION...
ISSUED 110 PM CST SAT NOV 28 2009

LOW LEVEL SOUTHWEST FLOW COUPLED WITH ABUNDANT SUNSHINE HAS BROUGHT
UNSEASONABLY WARM TEMPERATURES TO CENTRAL ILLINOIS THIS AFTN. EARLY
AFTN TEMPS ALREADY WELL INTO THE 50S...WITH MID 60S REPORTED ACRS
THE WESTERN AND SRN COUNTIES. COLD FRONT OVER CENTRAL IOWA IS EXPECTED
TO PUSH INTO OUR AREA SUNDAY MORNING BRINGING AN INCREASE IN CLOUDS
AND CHANCES FOR LIGHT RAIN...ESPECIALLY ALONG AND EAST OF INTERSTATE
55.

SHORT TERM MODELS SHOWING DECENT AGREEMENT WITH THE FROPA ON 
SUNDAY...WITH MEDIUM RANGE MODELS SHOWING A BIT MORE AGREEMENT WITH
THE MID-WEEK SYSTEM/PRECIP CHANCES...ESP ACRS THE SOUTHEAST.

SHORT TERM...TONIGHT THROUGH TUESDAY

COLD FRONT TO PUSH TWDS THE ILLINOIS RIVER VALLEY BY 12Z SUNDAY
WITH A SOUTHERLY WIND FLOW EXPECTED TO KEEP TEMPS WARMER THAN
THE PAST FEW NIGHTS. FORECAST SOUNDINGS CONTINUING TO SHOW AN
INCREASE IN LOW LEVEL MOISTURE AFTER MIDNIGHT ACRS THE SOUTHWEST
AND THEN SPREADING NE OVER THE REMAINDER OF THE AREA DURING THE
MORNING. NOT A GREAT DEAL OF GULF MOISTURE FORECAST AHEAD OF THE
COLD FRONT...AT LEAST UNTIL THE BOUNDARY GETS INTO SE IL. MOISTURE
RETURN ACRS TEXAS EARLY THIS AFTN NOT REAL IMPRESSIVE WITH ONLY LOW
TO MID 50 DEW POINTS SHOWING UP OVER EAST CENTRAL TX...BUT THAT
SHOULD CHANGE SOME AS THE PERSISTENT SOUTHERLY FLOW DRAWS MOISTURE
NWD LATE TONIGHT INTO SUNDAY. WILL CONTINUE TO CARRY ANY MENTIONABLE
POPS ALONG AND EAST OF I-55 TOMORROW ALONG THE COLD FRONT...WITH
SLIGHT CHANCES TO THE NORTHWEST. 

ANY LINGERING PRECIP CHANCES WILL BE CONFINED TO THE SOUTHEAST
SUNDAY EVENING CLOSER TO THE FRONTAL BOUNDARY. COOLER WEATHER TO
FOLLOW THRU TUESDAY AS HIGH PRESSURE BUILDS IN BEHIND THE UPPER
TROF AND SFC COLD FRONT. GUID VALUES SEEM REASONABLE INTO MONDAY
NIGHT BUT IT APPEARS MOS GUID IS TOO AGRESSIVE IN BRINGING TEMPS
BACK UP ON MONDAY BASED ON THE 850 MB TEMP FORECASTS ACRS THE AREA.
WL TEND TO FOLLOW MORE OF A MAV/MET BLEND ON MONDAY WITH ANY WARM
ADVECTION HOLDING OFF UNTIL TUESDAY...AND THAT WOULD BE MAINLY ACRS
OUR WEST. 

LONG TERM...WEDNESDAY THROUGH SATURDAY

MUCH COLDER WEATHER FORECAST TO SHIFT INTO THE MIDWEST AFTER THE
MIDWEEK STORM SYSTEM. 

STARTING TO SEE A BIT MORE CONSISTENCY WITH THE HANDLING OF THE
SPLIT FLOW PATTERN OVER THE LOWER 48 AND THE EVENTUAL MOVEMENT
OF THE NRN AND SRN STREAM SYSTEMS THAT WILL BE AFFECTING PARTS 
OF OUR AREA STARTING ON WEDNESDAY. STILL QUITE A BIT OF
UNCERTAINTY WITH RESPECT TO THE AFFECTS OF THE NRN STREAM WAVE
ON THE UPPER LOW OVER THE SRN MISSISSIPPI VALLEY. QUITE A LARGE
PRECIP SHIELD WL BE SHIFTING NORTH AND EAST INTO PARTS OF THE 
OHIO RIVER VALLEY WITH AREAS ALONG AND SOUTH OF INTERSTATE 70
SEEING THE BEST CHANCES FOR RAIN WEDNESDAY WITH FORECAST SOUNDINGS
SUGGESTING A MIX OR CHANGEOVER TO SNOW WED NIGHT ALONG THE NW
EDGE OF THE PRECIP SHIELD. LATEST ECMWF MORE BULLISH ON THE
DEVELOPMENT OF AN EAST COAST LOW WHICH WILL CUT DOWN ON ANY
SIGNIFICANT RAIN/SNOW ACRS OUR AREA...BUT THE SYSTEM IS STILL TOO
FAR OFF TO PUT MUCH DETAIL IN THE ZONES AT THIS POINT. WL INCREASE
POPS ACRS THE SOUTHEAST STARTING ON WEDNESDAY AND CONTINUE INTO 
THURSDAY WITH PROGRESSIVELY LOWER POPS AS YOU HEAD NW.

ANY LINGERING RAIN/SNOW ACRS THE FAR SOUTHEAST SHOULD MOVE OUT BY
THU AFTERNOON...WITH COLD HIGH PRESSURE SETTLING SOUTHEAST INTO
THE MIDWEST FOR THE REMAINDER OF THE FORECAST PERIOD. 850 MB TEMPS
RANGE FROM -10 TO -13 DEGREES C INTO SATURDAY SUGGESTING AFTN
HIGHS WILL HAVE A TOUGH TIME GETTING OUT OF THE 30S. THE LATEST
ECMWF CONTINUES TO INDICATE LITTLE SUPPORT FOR ANY ADDITIONAL
PRECIP ACRS THE AREA AFTER THURSDAY.

SMITH
&&

.AVIATION...
ISSUED 1113 AM CST SAT NOV 28 2009

SFC RIDGE TO THE EAST OF IL PROVIDING ONLY A FEW CI ACROSS CENTRAL
IL. HOWEVER...CHANGES WILL OCCUR AS COLD FRONT ACROSS CENTRAL IA
APPROACHES EARLY SUNDAY. COLD FRONT EXPECTED TO APPROACH PIA AFTER
12Z SUN...CEILINGS WILL BEGIN TO LOWER IN ADVANCE OF THE FRONT.
HAVE TRENDED CEILINGS DOWNWARD IN ADVANCE OF THIS FRONTAL BOUNDARY.
MOISTURE WL BE LIMITED AT FIRST WITH THIS COLD FRONT...SO LOW
CHANCES OF RA IN PIA. BETTER CHANCES OF RA AND LOWER MVFR CEILINGS
IN THE EASTERN TERMINALS IN THE AFTERNOON HOURS.

DPK
&&

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

$$