12/31/07-01/01/08 FCST:IA/IL/MO/IN/OH/MI

[Jesse Risley]

A developing winter weather system will move out of Eastern Kansas this morning and push its way ENE, reaching the Great Lakes region by tomorrow. The low will likely follow the I-70 corridor, with a slightly more northeastern track overnight. Given thermal profiles with possible warm air advection in parts of IA and IL, suggest widespread snow amounts of 1”-4” will occur to the WNW of the low pressure system, with enhanced lake effect snows likely as the system intensifies. While moisture is not impressive with this system, accumulations of 6+” are likely in parts of NE Indiana and SE lower Michigan. Arctic air will filter in behind the system from the NW, making for a rather chilly start to the New Year.

The NAM-WRF and GFS both verify this track, although the latest WRF wants to take the low on a more southerly track. Any deviation from the current forecast track will certainly make a difference in snowfall totals, especially for the Great Lakes region.

[Brandon Sullivan]

14z RUC/12z GFS and WRF continue to indicate the low developing over IL before moving out of the area. The heaviest QPF values across the IA/MO border eastward into IL. Here 2-4 Inches look to be a good idea. HPC picking up on this, with the aforementioned area in the slight probability of greater than 4 inches.

Models showing some modest WAA occurring from the southwest which could enhance some totals.

Snow Advisory's issued over all the area.

[Robert Dewey]

Latest 12Z NAM indicating a 1.40 inch QPF bullseye near LAN, with the NAM snow algo's outputting 12-15 inches.

After the last busted event, I'm gonna go with 4-6 inches across southern MI until I can see how things evolve. Call me Mr. Conservative, I suppose.

[rdale]

I'm running about 5-10" for Coldwater to Flint with potential for 1 foot +

http://wlns.com/Global/story.asp?S=1686033

[Robert Dewey]

I'm running about 5-10" for Coldwater to Flint with potential for 1 foot +

I hope you're right... 12Z GFS shows more QPF, so I'm a little more confident. Looking at BUFKIT, the dynamics are extremely good and I suspect some areas might even see thunder-snow.

Since these storms do the opposite of what I say, I'm still going to say 4-6 inches, and I'll revise those amounts when I see the flakes falling in my backyard.

[Robert Dewey]

The grid forecast for LAN says 8-12 tonight, and another 3-7 tomorrow... And the NCEP WRF run has QPF through the roof.

Should be interesting.

[rdale]

I told them about the NDFD issue - it'll be fixed for the next run. NWS is in the 8-12" range for Lansing, which is still a bit high for my liking...

[Robert Dewey]

I told them about the NDFD issue - it'll be fixed for the next run. NWS is in the 8-12" range for Lansing, which is still a bit high for my liking...

When's the next run? I see they lowered totals by one inch... 10-18 inches "expected" now.

[rdale]

4-5" on the ground in Lansing this morning, another 2-3" possible so that matches up well... 11" near Coldwater (along I-69 near the Indiana border)!

[Robert Dewey]

Got about 8.5 inches here... Reports at the NWS office shows 12 inches, with 14-16 inches in far northern Oakland and southern Lapeer. Not sure how they derived the values seen on their snowfall map, especially when I don't see any reports in the LSR from Lapeer county.

Also, this snow is extremely wet... I bet if you melted it down, you would see a snow-to-liquid ratio of 12:1 tops, probably even less. That means the QPF fields of +1 inch on the GFS and NAM most likely verified for at least a few people.

[rdale]

SWE measurements running around 14-16:1, QPF's in Lansing and GRR (where a real observation is made) show the models needed to be cut by nearly 50%

[cdcollura]

Mods: I am not sure if this belongs in this thread ... So please correct if necessary.

I found these conditions near I-65 in northern Indiana at about 1 PM (1-1-2008)...

http://www.sky-chaser.com/data/misc/snow1.jpg

Blowing and drifting snow, 40-MPH NW winds, temperature 18 F

http://www.sky-chaser.com/data/misc/snow3.jpg

Accumulation at this point was roughly 6" (hard to measure with the snow blowing so much).