AREA FORECAST DISCUSSION
NWS CHICAGO IL
AFDCHI 315 AM CDT MON APR 16 2001
WATER VAPOR SATELLITE SHOWS E/W ELONGATED UPPER LOW OVER CENTERED
OVER NORTHERN IND WITH 6HR MODEL FORECASTS ON TRACK. UPPER LOW
FORECAST TO CONTINUE TO ROTATE SOUTHEAST ACROSS THE OH VALLEY THIS
MORNING THEN EAST TO THE MID ATLANTIC COAST BY EVENING. WRAP AROUND
MOISTURE ACROSS LOWER MI INTO SE WI AND NORTHERN IL SHOWING
DISSIPATION ON WESTERN FLANK AS SUBSIDENCE SETS IN. RADAR COMPOSITE
ALSO INDICATING DISSIPATION OF ECHOES IN SOUTHERN WI. EXPECT TREND
OF DECREASE IN CLOUDS AND FLURRIES TO CONTINUE THIS MORNING WITH
MOSTLY SUNNY CONDITIONS PREVAILING ACROSS CWA BY MIDDAY. LAKE EFFECT
TO ALSO BE MINIMAL TODAY WITH ONLY SOME LE CLOUDS EXPECTED IN NW
IND. ACARS DATA CONFIRMS MODEL FORECASTS OF WARMING H8 TEMPS WITH
READINGS CURRENTLY -7 TO -8C. LAKE SURFACE TEMPERATURES OF +2 TO +3C
DOWN FETCH YIELD MAX DELTA T OF 11 WHICH IS NOT ENOUGH TO GENERATE
PRECIP. WINDS ALREADY GUSTING IN 20 TO 25KT RANGE BEHIND SURFACE
TROUGH ENTERING NORTHERN IL WILL GRADUALLY DIMINISH LATER TODAY.
CLEAR SKIES AND LIGHT WINDS OVERNIGHT AS SURFACE RIDGE OUT IN THE
PLAINS REACHES THE MS RIVER BY 12Z WED. SOME CURRENT TEMPERATURE
READINGS IN THE UPPER TEENS RIGHT UNDER THE RIDGE AXIS BUT SHOULD BE
ENOUGH WIND WITH AXIS STILL TO WEST OF CWA AT SUNRISE TO KEEP MINS
FROM REACHING RECORD TERRITORY IN THE LOWER 20S.
MODELS BRING SOME HIGH LEVEL MOISTURE OVER THE UPPER RIDGE WED BUT
STILL MOSTLY SUNNY/PARTLY CLOUDY WITH MODERATION IN TEMPERATURES AS
WAA GETS UNDERWAY.
.CHI...GALE WARNING LM TODAY
TRS