WeatherHistorian-SeMI: Super Snow For Super Bowl Sunday...Looking Better!

1/31/15

Super Snow For Super Bowl Sunday...Looking Better!

First of all up front; let's define Super Snow; when I first sent that out in the title I was thinking of one of our bigger snowstorms in Southeast Lower Michigan; particularly in Detroit where the heaviest snow of the three cities was expected (and still is). I had envisioned of snowstorms of a foot or more when looking at the chart below. As one can see by the chart in which I developed years ago at the NWS for the net (and is kept up to date by the NWS), it's not that easy to officially get a foot or more with just 12 times since 1880 it happening (good way to remember; 12 for 12). Therefore; I thought that would be a good place to start when using the play on words and title "Super Snow For Super Bowl Sunday" At that time, the chances looked fairly low for a foot or more when first issued. Now I'm not so sure they are that low...

Detroit's Heaviest Snow Storms
Rank	Date	Amount
1	April 6, 1886	24.5
2	December 1-2, 1974	19.3
3	March 4-5, 1900	16.1
4	February 28-March 1, 1900	14.0
5	December 18-19,1929	13.8
6	February 12-13 1894	12.8
7	February 19, 1908	12.6
8	January 31-February 1,1881	12.5
9	February 9,1911	12.3
10	March 3-4,1895	12.3
11	January 22-23,2005	12.2
12	January 13-14,1927	12.1
13	January 30-31,1982	11.8
14	January 13-14,1910	11.4
15	March 4-5,1899	11.4
16	January 2-3, 1999	11.3
17	December 19-20, 1973	11.2
18	February 3-4,1901	11.2
19	March 7-8, 1931	11.1
20	January 13-14, 1992	11.1
21	December 31, 2013-January 2, 2014	11.1
22	February 25-26, 1965	11.0
23	December 4-5, 1898	10.6
24	January 4-5, 2014	10.6
25	January 6, 1994	10.3

Latest guidance has ramped up a major (or worst - best if you are snowstorm nut) snowstorm for extreme Southeast Lower Michigan; while still somewhat lesser amounts north of the Flint into Port Huron. As mentioned in previous blog last night; the moisture and dynamics with this system were coming together for this to be a better, more developed Ohio Valley storm that actually slows down some as it approaches western Pennsylvania on Monday.

It's been my observation over the years, usually these St Louie lows are good achievers (but still not as good as the Gulf Low) in their own right as they "paddle-boat" moisture in from the Gulf while they form and develop while moving across the Ohio Valley. What was originally missing like many times (or at least was questionable) was the phasing or interaction of the dynamics in the upper levels to affect the lower levels of the atmosphere. These dynamics are in the form of short wave energy from the northern Pacific, southern Canada and the Central Pacific - which is observed as a "Cut-off Low" (cut off from the main jet stream). Therefore; the amount of energy that was needed to come together to lift and support the increasing moisture pulled north from the SW and Gulf was questionable to produce a major storm.

This distant player in this system is indeed, the large upper low system of the Baja area of California into the Southwest. Even while remaining nearly stationary, it still has been able to pinwheel spokes of energy and moisture from the Pacific over the southwest part of the country. This moisture has been pushed broadly upward into the south and even central part of the country. While the main system stays put, still enough energy and moisture is forecast to be tapped to aid in development of this major Ohio Valley system. See maps and explanations below:

Snowfall and weather forecast:

Snow will commence during the early morning hours of Sunday. Look for the snow to become heavy at times as the day wears on along with a stiffening northeast wind at 10 to 20 mph. Snow, heavy at times with considerable blowing and drifting later afternoon into the night. Winds will pick up from northeast at 15 to 25 mph and gusty, becoming north on Monday. Considerable blowing and drifting snow with temperatures dropping into the teens to lower 20s by Monday morning. Ironically, Monday morning is Groundhog Day and I suspect he might be buried and downright crabby if he is pulled out of his hutch; both here and in Punxsutawney Pennsylvania!

Snow Amount Estimates:
I feel the general model trend and intensification are better inline to what I'm seeing most likely for the event: There will be a rather sharp line of demarcation from north to south with this system with highest amounts generally to the south of the delineated area. Look for 2" - 4" north/south in the Saginaw Valley and Thumb Region; 5" - 10" from the Flint area east across to Port Huron and then; south into the Ann Arbor area to Metro Detroit. Further south across the Southeast corner of Lower Michigan 8" - 12" of snow is possible. If the storm deepens further and slows down more - some isolated 12"+ amounts are possible in those areas.