FXUS63 KLOT 221157
AFDCHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO IL
557 AM CST MON MAR 22 2004

.DISCUSSION...

THE WORKSTATION ETA MODEL HAS NONCONVECTIVE PRECIPITATION FORECAST 
THIS MORNING FOR THE COUNTIES IN NORTHWEST INDIANA. SURFACE ANALYSIS 
SHOWS AN AREA OF CONVERGENCE NORTH OF VALPARAISO. THIS CONVERGENCE 
AREA WILL MOVE EAST DURING THE DAY AS NORTHWEST WINDS MOVE INTO 
PORTER COUNTY INDIANA. WILL LEAVE THE SCATTERED SNOW SHOWERS IN THE 
FORECAST FOR THIS MORNING IN NORTHWEST INDIANA. USING THE ETA FOR 
TIMING OF THE HIGH AS IT MOVES EAST AND SOUTHWEST WINDS ARE 
FORECAST FOR TUESDAY. THE TEMPERATURE FORECAST WAS ADJUSTED TO 
RAISE THE MAXIMUM TEMPERATURE FOR TUESDAY. 

BOTH MODELS DEVELOP A LOW IN THE GREAT PLAINS. HOWEVER THE ETA AND 
CANADIAN MODELS ARE THE PREFER SOLUTIONS. 500 MB ANALYSIS OF THE 
LONG WAVE AND WATER VAPOR LOOPS SHOW THAT THE ETA FORECAST MOVEMENT 
OF JET STREAK OVER ILLINOIS THIS MORNING IS A BETTER FORECAST. WILL 
LEAVE A CHANCE OF RAIN TUESDAY NIGHT. WILL EXPAND THE THUNDERSTORMS 
FOR WEDNESDAY AS MORE INSTABILITY AS SEEN IN THE IN THE MODEL LIFTED 
INDEX FORECAST. WHW 

&&

.AVIATION...

FOR 12Z TAFS...SKC THIS AM EXCEPT FOR LAKE EFFECT CLOUDS AND 
FLURRIES IN NORTHWEST INDIANA. THIS ACTIVITY TO SLOWLY DIMINISH 
DURING THE MORNING HRS AS HIGH PRESSURE MOVES SOUTHEAST ACROSS THE 
MIDWEST TODAY. LIGHT WNW WINDS TURN WSW BY AFTERNOON THEN SSW THIS 
EVENING. MAY BE A PERIOD OF LIGHT AND VRB WINDS THIS MORNING AS THE 
HIGH APPROACHES FROM THE WEST. INCREASING HIGH CLOUDS LATER TODAY 
AND TONIGHT.

&&

.LOT...WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LK MI...NONE.

$$