624 
FXUS63 KILX 311613
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1013 AM CST THU JAN 31 2013

.DISCUSSION...
ISSUED 1013 AM CST THU JAN 31 2013

SHORT-WAVE TROUGH NOTED ON 16Z/10AM WATER VAPOR IMAGERY OVER
SOUTHWEST MINNESOTA WILL TRACK E/SE ACROSS NORTHERN ILLINOIS THIS
AFTERNOON/EVENING. ENOUGH LIFT IS BEING GENERATED AHEAD OF THIS
FEATURE TO PRODUCE SCATTERED SNOW FLURRIES ACROSS THE ENTIRE AREA.
RADAR LOOPS HAVE INDICATED A FEW LOCALIZED BANDS OF HEAVIER SNOW
THIS MORNING...ESPECIALLY ACROSS EAST-CENTRAL ILLINOIS WHERE LIGHT
ACCUMULATIONS OF UP TO ONE HALF INCH HAVE BEEN REPORTED IN
DANVILLE. UPDATED THE FORECAST TO GO WITH SNOW-SHOWERS ALONG/EAST
OF I-57...WITH LIGHT SNOW ACCUMULATIONS FROM A DUSTING UP TO ONE
HALF INCH. ELSEWHERE AROUND THE AREA...WILL MAINTAIN SCATTERED
FLURRIES WITH LITTLE OR NO ACCUMULATION ANTICIPATED. ASIDE FROM
THE FLURRIES...WILL BE A WINDY AND COLD DAY. NORTHWESTERLY WINDS
GUSTING BETWEEN 20 AND 25 MPH WILL PRODUCE WIND-CHILL VALUES BELOW
ZERO ACROSS THE NORTH/NORTHWEST KILX CWA...AND IN THE SINGLE
DIGITS AND TEENS ABOVE ZERO ACROSS THE FAR SOUTHEAST ALONG/SOUTH
OF I-70.  ZONE UPDATE HAS ALREADY BEEN ISSUED.

BARNES
&&

.AVIATION...
ISSUED 553 AM CST THU JAN 31 2013

GUSTY WEST TO NORTHWEST WINDS IN THE WAKE OF A DEPARTING AREA OF
LOW PRESSURE WILL PERSIST ACROSS THE CENTRAL ILLINOIS TERMINALS
THROUGH THE BULK OF THE 12Z TAF VALID TIME. THE STRONGER WINDS
WILL FINALLY LOSE THEIR GRIP ACROSS THE AREA OVERNIGHT.

MOISTURE WRAPPING AROUND THE BACK SIDE OF THE SYSTEM...COUPLED
WITH A REINFORCING SHOT OF ENERGY/COLD AIR ALOFT...WILL KEEP
MVFR/LOW END VFR CIGS IN THE AREA FOR THE BULK OF THE PERIOD.
SCATTERED FLURRIES ARE POSSIBLE AS WELL...BUT THESE SHOULD HAVE
MINIMAL IMPACT ON FLIGHT OPERATIONS. EXPECT A GRADUAL CLEARING OF
SKIES OVERNIGHT AS HIGH PRESSURE STARTS TO BUILD INTO THE AREA.

BAK
&&

.PREV DISCUSSION...
ISSUED 325 AM CST THU JAN 31 2013

SHORT TERM...TODAY THROUGH SATURDAY NIGHT

00Z MODELS ARE IN FAIR AGREEMENT AS SOME OF THE COLDEST AIR OF THE
SEASON ARRIVES TONIGHT WITH WIND CHILLS REACHING CLOSE TO 15 BELOW
ZERO ACROSS THE NORTHERN COUNTIES. MODELS CONTINUE TO SHOW LIGHT
SNOW ACCUMULATIONS FRIDAY NIGHT ESPECIALLY ACROSS OUR NNE COUNTIES 
AND HAVE INCREASE POPS AND SNOWFALL AMOUNTS A BIT HIGHER WITH 1 TO
2 INCHES FROM I-74 NORTH FRIDAY NIGHT. MODELS HAVE TRENDED
STRONGER WITH UPPER LEVEL TROF LINGERING OVER THE EASTERN STATES
INTO NEXT WEEK SO HAVE TRENDED TEMPS DOWNWARD A BIT AND ALSO
INCREASE CLOUD COVER. A FEW WEAK DISTURBANCES IN NW FLOW TO BRING
PERIODIC CHANCES OF LIGHT PRECIPITATION...MOSTLY IN THE FORM OF
LIGHT SNOW/FLURRIES.

EARLY MORNING SURFACE MAP SHOWS STRONG 977 MB LOW PRESSURE STILL
DEEPENING ALONG THE SOUTHERN QUEBEC/ONTARIO PROVINCE LINE NEAR
OTTAWA. TIGHT CYCLONIC PRESSURE GRADIENT REMAINS OVER CENTRAL AND
NE IL GIVING BLUSTERY WEST WINDS GUSTING 25-35 MPH ESPECIALLY OVER
EASTERN IL. A FAIR AMOUNT OF LOW CLOUDS OVER IL WITH SCATTERED
FLURRIES AND VERY LIGHT SNOW SHOWERS ESPECIALLY SE OF I-70 AND
OVER THE IL RIVER VALLEY. TEMPS RANGE FROM AROUND 20F FROM I-74
NORTH TO THE UPPER 20S IN SE IL SOUTH OF I-70 AND FROM
JACKSONVILLE SW. WIND CHILLS WERE IN THE SINGLE DIGITS CENTRAL IL
AND LOW TO MID TEENS SE IL FROM I-70 SOUTH AND FROM SPRINGFIELD
SW. ALOFT A STRONG 508 DM 500 MB LOW WAS OVER LAKE SUPERIOR WITH
DEEP/LARGE UPPER LEVEL TROF OVER THE MS VALLEY...WHILE UPPER LEVEL
RIDGES WERE OFF THE SE ATLANTIC COAST AND OFF THE WEST COAST. 

ONE SHORT WAVE EXITING IL EARLY THIS MORNING BUT ANOTHER SHORT
WAVE NEAR THE ND/MN BORDER TO DIVE QUICKLY SE INTO SE IA AND
NORTHERN IL BY SUNSET. THIS FEATURE TO CONTINUE CHANCES OF
FLURRIES TODAY ALONG WITH A FEW LIGHT SNOW SHOWERS BUT LITTLE OR
NO ACCUMULATIONS. BRISK WNW WINDS 15 TO 25 MPH AND GUSTS TO AROUND
30 MPH CONTINUE TODAY AND LITTLE TEMPERATURE RISE DUE TO THIS CAA
AND LOW CLOUDS LINGERING. HIGHS MOSTLY IN THE LOW TO MID 20S OVER
CENTRAL IL AND 30-35F IN SE IL...THOUGH ONLY IN THE UPPER TEENS NW
OF THE IL RIVER. 

1034 MB ARCTIC HIGH PRESSURE OVER WESTERN SASKATCHEWAN TO SETTLE
INTO MO BY DAWN FRIDAY AND INTO KY/TN BY SUNSET FRI. LINGERING A
CHANCE OF FLURRIES THIS EVENING ESPECIALLY OVER CENTRAL AND
EASTERN IL THEN LOW CLOUDS DECREASING OVERNIGHT FROM THE WEST.
STILL BRISK WNW WINDS 10-20 MPH AND GUSTS TO 25 MPH IN THE EVENING.
LOWS TONIGHT RANGE FROM ZERO TO -MINUS 4 NW OF I-55...TO 5-10F IN
SE IL. WIND CHILLS COULD GET AS COLD AS 15-20 BELOW ZERO NORTH OF
I-72 OVERNIGHT INTO MID MORNING FRI...BUT HELD OFF ON ISSUING WIND
CHILL ADVISORY DUE TO UNCERTAINTY OF HOW FAST LOW CLOUDS CLEAR AND
THIS WILL AFFECT LOW TEMPS AS WELL. 

NEXT WEATHER DISTURBANCE ALONG THE BRITISH COLUMBIA COAST TO MOVE
INTO THE MIDWEST FRIDAY NIGHT. THIS TO INCREASE CLOUDS FRI AFTERNOON
AND ANOTHER COLD DAY WITH HIGHS IN THE UPPER TEENS AND LOWER 20S.
THIS FEATURE WILL LIKELY BRING A SWATH OF LIGHT SNOW ACCUMULATIONS
INTO PARTS OF CENTRAL AND NORTHERN IL WHERE 1-2 INCHES WITH
LOCALLY HIGHER AMOUNTS IN NORTHERN IL. WEAK SURFACE LOW PRESSURE
OF 1018 MB MOVES ACROSS NORTHERN IL SAT MORNING AND INTO THE
SOUTHERN GREAT LAKES BY SUNSET SAT. SO LIGHT SNOW CHANCES TO
DIMINISH DURING THE DAY SAT WITH LITTLE OR NO ADDITIONAL
ACCUMULATIONS. TEMPS NOT EXPECTED TO SLIP MUCH FRI NIGHT WITH
CLOUD COVER AND HIGHS SAT RANGE FROM UPPER 20S NORTH OF PEORIA TO
MID TO UPPER 30S IN SE IL. A NORTHERN STREAM SHORT WAVE DIVING
INTO THE WESTERN GREAT LAKES SAT NIGHT TO BRING SMALL CHANCES OF
LIGHT SNOW TO AREAS FROM I-74 NE. 

LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT

HIGH PRESSURE TO SETTLE INTO THE MS VALLEY SUNDAY BRINGING MORE
SUNSHINE AND DRY WEATHER TO CENTRAL/SE IL WHILE MORE CLOUDS LINGER
NE OF I-74 DUE TO STRONG UPPER LEVEL LINGERING IN THE GREAT LAKES
REGION/EASTERN STATES. HIGHS SUNDAY RANGE FROM THE LOWER 30S FROM
I-74 NE TO THE UPPER 30S SW AREAS. HIGH PRESSURE DRIFTS EAST OF IL
SUNDAY NIGHT AND MON WITH BREEZY SOUTHERLY WINDS DEVELOPING MON 
APPEARS TO BE THE MILDEST DAY WITH HIGHS IN THE LOW TO MID 40S
WITH SOME UPPER 40S SW AREAS. 1010 MB LOW PRESSURE MOVING INTO THE
GREAT LAKES REGION MON TO PUSH A COLD FRONT SE THROUGH CENTRAL IL
MON AFTERNOON AND INTO SE IL MON EVENING. MODELS STILL SHOW THIS
FRONT GOING THROUGH AREA DRY WITH LIMITED MOISTURE AND LIFT. COOLER
HIGHS TUE IN THE MID 30S TO LOWER 40S WHICH IS CLOSE TO NORMAL FOR
EARLY FEB. ANOTHER DISTURBANCE DIVES FURTHER SOUTH INTO THE
WESTERN GREAT LAKES AND IL TUE AND TO BRING A BETTER CHANCE OF
LIGHT PRECIPITATION ESPECIALLY TO AREAS FROM I-74 NE. ANOTHER
HIGH PRESSURE AROUND 1025 MB SETTLES INTO IL/IN WED TO RETURN DRY
WEATHER AND MORE SUNSHINE. SEASONABLE HIGHS AGAIN IN THE UPPER
30S AND LOWER 40S.

07

&&

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

$$