AREA FORECAST DISCUSSION...CORRECTION
NWS CHICAGO IL
AFDCHI 300 AM CST SUN FEB 10 2002
THE NORTHEAST MOVEMENT OF THE SURFACE CYCLONE NOW IN EASTERN IOWA
HAS INCREASED DURING THE PAST 2 HOURS. THE RADAR SHOWS THE MAIN
PRECIPITATION BAND NORTH OF THE FORECAST AREA OF NORTHEAST ILLINOIS
AND NORTHWEST INDIANA. ACARS SOUNDINGS SHOW ABOVE FREEZING
TEMPERATURES UP TO 850 MB OVER ORD AND RFD. WILL KEEP LIGHT AND
SCATTERED RAIN FOR THIS MORNING.
WILL USE THE AVN MODEL. THE MOVEMENT OF THE SURFACE LOW IS
CLOSEST TO THE AVN MODEL FORECASTS. THE WAVE BEHAVIOR DURING THE 24
TO 30 HOUR FORECAST AND TEMPERATURE ADVECTION PATTERNS AT 850 AND 700
MB SHOW THE COLDEST AIR WILL BE OVER THE FORECAST AREA MONDAY. LOW
TEMPERATURES WARM BACK INTO THE 20S TUESDAY.
WILL KEEP SNOW AMOUNTS LOW FOR SUNDAY AFTERNOON. UP TO AN INCH IN
MOST PLACES. THE SNOW WILL BE BRIEF AS THE COLD AIR RUSHES INTO THE
FORECAST AREA. EXPECT TEMPERATURES TO FALL THIS AFTERNOON. NEGATIVE
VALUES OF NET OMEGA FROM THE ISENTROPIC SURFACE 290K ENDS AFTER 18
UTC. POSITIVE VALUES ARE AT A MAXIMUM NEAR 0000 UTC MONDAY.
ANOTHER WAVE PASSES THROUGH ON TUESDAY. SO WILL ADD CLOUDY SKIES
AND LOWER TEMPERATURES. THEN A MORE SHARPER WAVE SEEN ON THE 700 MB
AND 500 MB FORECASTS MOVES THROUGH THE GREAT LAKES ON THURSDAY.
WILL KEEP A CHANCE OF SNOW OR RAIN ON THAT DAY.
.CHI...GALE WARNINGS FOR LAKE MICHIGAN
WHW
MINOR CORRECTIONS AND ADDITIONS.