YIKES!December 3rd, 2013 at 1:49 pm by Bill Steffen under Bill's Blog, Weather
Click on the image to enlarge. This is the 183-hour GFS model valid for next Tuesday Night. Shiverin’ Snowman! Keep in mind it’s the GFS and the GFS has the tendency to exaggerate cold blasts in the fall and winter in the mid-long term…but if this is anywhere close to being correct…this is brutally cold…with a stiff wind and lake-effect snow for everyone. The thickness is at 494 and our 850 mb temperature to -25! The air/lake temperature difference will be very large…however the flake size may be smaller and the fetch a bit shorter with a west wind. The GFS plot has temperatures during the day Tuesday from 6 to 12 above with a 20 mph west wind! A temperature of 6 with a 20 mph wind is a wind chill of -14. If it’s 6 on this side of the lake, it’s probably -5 to -10 in Wisconsin. The GFS gives G.R. a high of 14 and low of 3 on Weds. I often go a few degrees above the plot numbers. The GFS also gives G.R. about 2″ of snow Sun. night into Monday with temperatures peaking around 32 Monday. The model also has more synoptic snow about 12/16. . The European model gives G.R. low-mid 50s briefly Weds. evening and only low 20s for much of the daytime hours on Saturday. For next Tues. AM, it has a surface temp. of 11 in G.R. with a -21.6C 850 mb. temp. and a thickness of 510 dropping. Certainly lake-effect snow, but again, there are factors that could limit accums. some. The Euro. gives G.R. 0.13″ of precipitation Sun. night and Monday. That should be snow, but could be a freezing rain/snow mix.