WINTER STORM TO IMPACT STATE
A Winter Storm Warning is in effect for the northern quarter of Indiana for Friday. About 6 to 12 inches of snow are expected to fall along I-80 in northern Illinois and along the Indiana toll road. Hazardous travel conditions will develop late, well before sunrise Friday and continue through Friday evening.
There is still some debate among computer output snowfall for Chicago. Amounts will be hefty but how high could the totals go? I'm posting below the 46 member NWS Short Range Ensemble Forecast snow for Chicago. The average is just over 9 inches by mid-morning Saturday. These numbers fall in line with our latest RPM model. However, aggressive/outlying (NAM Model) pushes totals over a foot a real possibility.
Now, often the NAM model will be among the wetter models but trends will be monitored. It is very likely that some locations will top 10 to 12 inches locally. The National Weather Service probability of a 12" or greater snowfall is 30% -- a probability that is not often seen in these outlooks. Lots of snow to shovel!
WINTRY WEATHER FOR THE WEEKEND
That is a warm front and it arrives here later tonight. Temperatures are expected to rise into Friday morning. We are also expecting the warm up to be brief. A large north to south temperature spread is expected Friday (30s north to as warm as 50s south). Friday's forecast of 47-degrees will be the warmest of the month. The stalled front sags south Friday afternoon, bringing the snow threat to north-central Indiana by the Friday evening commute.
Travel north Friday will be hazardous. The wind shifting cold front will reach Indianapolis Friday evening with snow and possibly a light wintry mix in tow. Slick roads are possible by midnight over north-central Indiana Saturday and by sunrise Saturday light snow or a combination of a light snow, light wintry mix will have occurred. A lull in activity is expected Saturday with damp, hazy and at times drizzly conditions through the afternoon.
A new system will ride the jet stream into central Indiana late Saturday into Sunday morning. At this distance, a wintry cocktail of snow, sleet and freezing rain and rain will become area-wide by daybreak Sunday. Roads could become quite slick again Sunday with potential of some snow accumulation where more snow falls through the day. We will firm up the details on Sunday on Friday but plan on some slick roads early Saturday and again Sunday.