The Polar ExpressDecember 4th, 2013 at 3:20 am by Bill Steffen under Bill's Blog, Weather
Enjoy this last mild day with temperatures topping out in the low-mid 50s this evening (mid 40s north). Here’s the model update from early morning: The NAM (only goes out to 72 hours) gives GRR a high of 52 today with an isolated shower. The GFS takes us to 50. the European has 52 after sunset. The European has an additional 0.13″ of rain. The models bring in the cold, with the NAM (caribou) taking us down to 39 by 7 am Thurs. and 30 by evening (watch for any puddle freezing up Thurs. evening). The GFS plot has 37 at daybreak and 28 by 8 pm in the evening Thursday. The Euro. would also be down to 28 by 7 pm Thurs. Friday all the models have us holding in the mid 20s much of the afternoon, with low-mid 20s during the day Saturday and mid-upper 20s at most on Sunday. Despite WNW winds off Lake Michigan Thurs to Sat. – the models don’t print out any measurable snowfall (I think there will be at least flurries). Sunday the wind goes NE-E. We could see snow by Sunday evening. Monday the GFS prints out 0.23″, which would likely be about 3-4″ of snow. The Euro. is 0.16″ precip. or maybe 2 1/2 inches. Monday we reach the low 30s. Then the REALLY cold air gets here. Tuesday at 1 PM, the GFS has a temperature in G.R. of +9 with a wind west wind at 20 mph (the high temperature Tue. may be 20 at 12:01 am). At that wind/temperature some schools won’t do recess. There’s steady snow showers off Lake Michigan and slick roads. The European actually prints out 0.08″ and the GFS about the same. Now, we’ll have a high snow to water ratio and events like this tend to be underdone. A west wind at 20 mph means the air doesn’t spend much time crossing the lake. The flake size will likely be small. There will certainly be blowing and drifting snow. The snow is steady thru Tues. night into early Weds. – long duration. The temperature is back to the low 20s Weds. PM on the GFS and 20 on the Euro. I could easily see the entire period producing 6″+ even in inland areas. The GFS doesn’t take us above freezing again until the 14th. Same story on the Euro. Here’s GFS snow/rain/ice pellets/freezing rain out 5 days. Bottom line…relatively warm today with a few showers…cooler tomorrow…colder still Fri-Sun…snow Sun. night/Monday (prob. plowable for much of the area) and REALLY cold with snow and drifting snow Tue. and Tue. night. BTW, natural gas prices has risen 9 of the last 10 days as people know the cold air is comin’. Here’s the CFS forecast for the rest of December…coast-to-coast cold!
Also: Denver was 56 at noon yesterday…then the cold front went thru…the temp. dropped 19 deg. in an hour, 7 more deg. the next hour and fell 44 deg. in 9 hours. At 1 PM Mon. Cheyenne WY was 50, at 1 PM Tue. they were 16. Rapid City SD was 53 at 1 PM Mon. and 18 at 1 PM Tue. High temps. Tues: 8 at Yellowstone N.P., 5 at Great Falls MT, 6 at Calgary, Alberta, 10 at Minot ND. The Golden Snow Shovel goes to Gibbonsville ID with 30″ of new snow. Two Harbors MN had 20.5″ and Duluth 14″ (both of those with a lake-effect boost from Superior). There was a standing seiche on Lake Superior with a strong ENE wind. Also, massive lake-effect snows off the Black Sea. Significant snow for a large part of Arizona (and it may snow in Las Vegas, Seattle and Dallas).
Midday Weds: NAM (caribou) gives G.R. 2.2″ of snow Monday and 1.9″ on Tues…maybe another inch Weds. GFS plot has snow starting Sunday evening. Enjoy the 50+ deg. this evening. GFS has nothing warmer than mid 30s from Thurs. PM thru the middle of the month. Here’s monster-sized snowdrifts near Calgary, Alberta. Here’s Canadian temps. (in F). The mid-Lake Michigan buoy is still out there! It shows a water temp. of 43.5 at 1 PM. Here’s the National Watch/Warning map. From Dr. Joe D’Aleo: “A polar stratospheric warming sometime between late December and February is favored in the west QBO near the solar max, which would tank the AO/NAO and lock in the cold. It usually starts out of southeastern Asia and blossoms to the pole. It takes a few weeks after to bring the effect down. Meanwhile the cold continues to build and the snowcover is increasing.”