UPDATE ON SNOW...

This storm that is fast approaching is taking a track that will deposit wet snow on far eastern Iowa and the NW third of Illinois. The NWS in the Quad Cities has winter weather advisories in effect for the area just SW of the Quad Cities northeast in EC Iowa and NW Illinois. It's indicating 3-6 inch amounts from about HWY 30 north. Further south totals of 1-4 inches are indicated where advisories are in place in and around the Quad City metro area. Amounts have been upped about an inch Friday evening after initial thoughts of 2-5 in the graphic below.

Here's the NWS official forecast.

As you can see, the hi-resolution modeling late Friday evening does show significantly more in and around the Quad Cities. Take a look.

The 3k NAM

The HRRR

The 12K NAM

Even the EURO and GFS show a similar theme. They look this way.

The GFS

The EURO

Modeling as been consistently showing these higher amounts but there has been a reluctance for forecasters to go higher due to warm ground and surface temperatures and uncertainty regarding the transition from rain to snow. In general, evaporative cooling should be sufficient to change things over between midnight and 2:00am. At that time a period of heavy snow seems likely through the heart of my area centered on a line northeast from the Quad Cities to Freeport and Janesville. I have seen evidence of banding and even some convective traits so very heavy snowfall rates could occur in localized spots.

This is the new HRRR and it really cranks out some big numbers. Probably high but that is FRESH data.

I can't side with just one model but when you have 5 solidly showing 4-8" totals (locally higher) I think you have to pull the trigger and I personally feel that chances are increasing for a band of 5 to perhaps 8+ inches from roughly the Quad Cities northeast. The only thing that could keep amounts lower is if the transition from rain to snow is slower than anticipated. Amounts will be lower in my far SE counties and little if any snow may fall near and NW of a line from Cedar Rapids to about Dubuque.. It's the middle that is under the gun. That area could see some travel woes early Saturday with low visibilities in heavy snow, gusty winds, and slushy roads.

Rain is now spreading into SE Iowa and WC Illinois and will steadily spread NE and then change to snow after midnight ending by noon Saturday. The satellite shows a healthy looking well ventilated storm with a developing deformation band.

I'm out on a limb right now and could be wrong but at least I'm willing to stick my neck out when the evidence is strong. Time will tell