FXUS63 KLOT 240948
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
348 AM CST THU DEC 24 2009

.DISCUSSION...
347 AM CST

WILL BE EXTENDING ALL WINTER WEATHER HEADLINES TIL NOON.
FLOOD WATCH WILL REMAIN IN EFFECT AS ORIGINALLY ISSUED. 

DETAILS TO FOLLOW SHORTLY. 

MERZLOCK

&&

.AVIATION...

0600 UTC TAFS...A VERY CHALLENGING FORECAST SITUATION FOR THE
TERMINALS OVERNIGHT.

FREEZING RAIN CONTINUES ACROSS NRN IL. TEMPERATURES HAVE CHANGED
VERY LITTLE OVER THE PAST SEVERAL HOURS AND REMAIN RIGHT AT THE
FREEZING MARK. THUS...WITH SUBSTANTIAL SNOW STILL ON THE GROUND...NO
WARM ADVECTION AND WINDS REMAINING ELE/ESELY...EXPECT THAT
TEMPERATURES WILL REMAIN CONSTANT THROUGH THE NIGHT. THUS HAVE
MAINTAINED FREEZING PCPN IN THE FORECAST AND DELAYED THE CHANGE
OVER FROM FREEZING PCPN TO LIQUID PCPN UNTIL AROUND NOON. MODEL RH
PROFILES SHOW SOME DRIER AIR ADVECTING IN ABOVE 18KFT LATER
TONIGHT...AND TIMING LATEST RADAR TRENDS SHOW THE BACK EDGE OF THE
HEAVIER PCPN MOVING INTO NRN IL BY ARND 08Z...SO HAVE TRANSITIONED
THE PCPN OVER TO FZDZ. DEEP LAYER MOISTURE MOVES BACK OVER THE
AREA BY EARLY AFTERNOON AND SFC TEMPERATURES SHOULD FINALLY RISE
ABOVE FREEZING...SO PCPN CHANGE OVER TO ALL LIQUID. RAIN WILL
CONTINUE FOR THE REMAINDER OF THE DAY...BECOMING HEAVIER DURG THE
EVENING HOURS.

WINDS WILL REMAIN GENERALLY ELE-ESELY THROUGH THE PERIOD AS THE
SFC LOW TRACKS NEWD FROM ERN TEXAS THROUGH THE OZARKS...INTO THE
MIDDLE MISSISSIPPI VALLEY. WITH HIGH PRESSURE REMAIN NRLY STNRY
OVER ERN CANADA AND AND A STRONG SFC LOW APPROACHING FROM THE
SOUTHWEST...WINDS WILL CONTINUE TO STRENGTHEN THROUGH THE NIGHT
AND THROUGH THE DAY TOMORROW. BY TOMORROW AFTERNOON...SUSTAINED
WINDS OF 20-25KT AND GUSTS TO 30KT ARE LIKELY.

KREIN

&&

.MARINE...

218 AM...FORECAST FOCUS CONTINUES TO BE GALE FORCE WINDS THRU
FRIDAY AFTERNOON.

LOW PRESSURE OVER EASTERN TEXAS WILL MOVE NORTHEAST TO WESTERN
ILLINOIS BY FRIDAY MORNING AS IT CONTINUES TO DEEPEN. STRONG 
HIGH PRESSURE OVER JAMES BAY WILL SLOWLY MOVE NORTHEAST ACROSS
NORTHERN QUEBEC TONIGHT. AS THE LOW MOVES NORTHEAST THE GRADIENT
BETWEEN THESE TWO SYSTEMS WILL CONTINUE TO TIGHTEN. CURRENT
OBSERVATIONS ACROSS SOUTHERN LAKE MICHIGAN A BIT PROBLEMATIC AS
MANY WIND SENSORS ARE READING FAR TOO LOW...LIKELY DUE TO ICE
BUILD UP FROM HRS OF FREEZING RAIN. GALE WARNING WAS SCHEDULED TO
GO INTO EFFECT AT 10Z AND WILL START IT AT 09Z WITH THIS MORNINGS
GLF. SUSPECT AT LEAST GUSTS TO LOW END GALES SOON IF NOT ALREADY
OCCURRING. GALES INCREASE TO 45KTS THIS EVENING AS THE STRONGEST
GRADIENT PASSES ACROSS SOUTHERN LAKE MICHIGAN TONIGHT. GALES
SLOWLY RELAX ON FRIDAY BUT PROBABLY NOT UNTIL AFTERNOON OR
EVENING AND HAVE EXTENDED THE GALE WARNING THRU 00Z SAT. THE LOW
WILL DRIFT NORTHEAST ACROSS IOWA FRIDAY THEN BEGIN TO WEAKEN AS 
IT SLOWLY MOVES EAST ACROSS NORTHERN IL SATURDAY INTO SUNDAY. CMS

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...ICE STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
     ILZ011-ILZ012-ILZ013-ILZ020-ILZ022-ILZ023 UNTIL NOON 
     THURSDAY.

     FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
     ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
     ILZ032-ILZ033-ILZ039...NOON THURSDAY TO 6 AM FRIDAY.

     WINTER WEATHER ADVISORY...ILZ014 UNTIL NOON THURSDAY.

IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...NOON THURSDAY 
     TO 6 AM FRIDAY.

     ICE STORM WARNING...INZ001-INZ002-INZ010-INZ011 UNTIL NOON 
     THURSDAY.

LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
     LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878 UNTIL 6 PM FRIDAY.

     GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
     LMZ868...4 PM THURSDAY TO 6 PM FRIDAY.

&&

$$