FXUS63 KILX 150820
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
220 AM CST TUE DEC 15 2009

.DISCUSSION...
ISSUED 220 AM CST TUE DEC 15 2009

BACK EDGE OF CLOUD DECK HAS REACHED THE WESTERN EDGE OF THE CWA. A
FEW FLURRIES HAVE BEEN REPORTED AT GALESBURG RECENTLY...WITH A FEW
ECHOES EVIDENT ON THE DAVENPORT WSR-88D. TEMPERATURES WERE BELOW
20 DEGREES OVER MOST AREAS WEST OF I-55...BUT STILL LINGERED WELL
INTO THE 30S ACROSS THE FAR SOUTHEAST CWA.

MAIN FORECAST ISSUES FOR THIS PACKAGE INVOLVE DURATION AND EXTENT
OF THE COLD WEATHER SPREADING INTO THE AREA...ALONG WITH
PRECIPITATION POTENTIAL THIS WEEKEND.

SHORT TERM...TODAY THROUGH THURSDAY...

NOTHING TOO EXCITING IN THE FIRST PART OF THE FORECAST...AS HIGH
PRESSURE PUSHES EAST THROUGH THE MIDWEST TODAY AND WEDNESDAY.
TEMPERATURES AT 850 MB DROP TO NEAR -10C ACROSS THE NORTHERN CWA
BY THIS AFTERNOON AS CANADIAN AIRMASS PUSHES FURTHER EAST ACROSS
THE REGION. COLDEST WEATHER OF THE PERIOD EXPECTED TODAY AND
TONIGHT...UNTIL THE HIGH IS EAST OF US. THE CLOUDS SHOULD BE OUT
OF MUCH OF THE CWA BY MIDDAY...AND FAIR SKIES EXPECTED AFTERWARD
THROUGH WEDNESDAY. 

WEAK LOW PRESSURE WILL MOVE EAST ACROSS THE CWA THURSDAY...BUT
SHOULD RESULT IN LITTLE MORE THAN AN INCREASE IN CLOUDS AS LOW
LEVEL MOISTURE IS NOT TOO IMPRESSIVE.

LONG TERM...FRIDAY THROUGH MONDAY...

UPPER FLOW EXPECTED TO BECOME MORE AMPLIFIED ACROSS THE WEST
COAST. BOTH LONG RANGE MODELS SUPPORT A SHORTWAVE DROPPING OUT OF
CANADA ON FRIDAY AND DIGGING DEEPER...AS A PIECE OF ENERGY FROM A
CLOSED LOW NEAR MAINE RETROGRADES WESTWARD ACROSS THE GREAT
LAKES. THIS WILL RESULT IN ANOTHER ROUND OF COLD WEATHER SPREADING
ACROSS THE MIDWEST.

PRECIPITATION-WISE...MAIN THREAT WOULD APPEAR TO BE FRIDAY NIGHT
AND SATURDAY...ALTHOUGH THERE IS SOME QUESTION AS TO THE NORTHERN
EXTENT. WILL CONFINE MENTIONABLE POPS TO AREAS GENERALLY SOUTH OF
I-72 FOR NOW...CLOSER TO AN INVERTED TROUGH ASSOCIATED WITH LOW
PRESSURE WHICH WILL MOVE ACROSS FLORIDA.

GEELHART

&&

.AVIATION...
ISSUED 1110 PM CST MON DEC 14 2009

MAIN FORECAST CONCERN CONTINUES TO BE WITH THE TIMING OF THE
BACKEDGE OF THE MVFR AND ISOLD IFR CIGS...WHICH IS CURRENTLY
ALONG THE MISSISSIPPI RIVER. A FEW AREAS TO THE EAST ARE NOW
STARTING TO SEE SOME BREAKS IN THE CLOUD COVER AS WELL. WEAK
SURFACE TROF TO OUR NORTH EMBEDDED IN BROAD CYCLONIC FLOW WAS
PRODUCING SOME SCATTERED FLURRIES OVR SRN WI THIS EVENING BUT
OTHER THAN HOLDING UP THE CLEARING OVERNIGHT...ESP ACRS THE 
EAST...WE ARE NOT EXPECTING ANY PRECIP OF SIGNIFICANCE ACRS THE
TAF SITES. ONCE THE CLOUD BAND PUSHES EAST OF THE STATE TUE
MRNG...VFR CONDITIONS ARE EXPECTED ACRS THE ENTIRE AREA FOR THE
REMAINDER OF THE FCST PERIOD. SURFACE WINDS WL REMAIN OUT OF THE
NW WITH A FEW LOCATIONS SEEING SOME GUSTS APPRCH 20 KTS. NW WINDS
WILL CONTINUE ON TUESDAY WITH SPEEDS OF 10 TO 15 KTS WITH ONCE
AGAIN A FEW GUSTS ARND 20 KTS INTO THE AFTN HOURS.

SMITH

&&

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

$$