Thursday, November 13, 2014

Bundle Up For Badger Football

Public weather briefing

The weather heading into this weekend will leave you digging through storage to find your winter jacket and gloves. An unseasonably cold air mass from the north is here to stay, and will cause temperatures over the weekend to plummet below freezing. This air mass closely resembles the pattern that dominated last winter and caused perpetual frigid conditions through much of January. Intermittent snow overnight Saturday and into Sunday morning will accompany these chilly conditions, with accumulation ranging from 1"-2", and looks give way to light flurrying conditions through Monday. Winds look to be moderate out of the north and west. Kickoff temperatures on Saturday will near 30 degrees. 

Forecast 

Tonight. Continuing slight chance of flurries early in the evening. Cloudy overnight. Low of 18 with light winds from the northwest.

Friday. Mix of sun and clouds with high temperatures nearing 30 degrees. 

Friday Night. Clouds roll in overnight. Winds light ant from the northwest. Low of 19. 

Saturday. Bundle up for Badger Football! Slight chance of snow later in the afternoon/evening. Accumulation nearing 1". 

Sunday. Accumulating snow (up to 1") through the morning will give way to cloudy skies in the afternoon. Highs nearing the middle to upper 20s.

Outlook for Sunday through Tuesday. Cold temperatures persist and don't look to reach above freezing through the early part of next week. Slight chance of flurries late Monday night. [CONFIDENCE: MEDIUM]

Forecast Discussion

A maturing surface cyclone centered east of the Great Lakes will continue to advect cold air into our area through the rest of the week, at which point flows become more zonal. The upper trough seen in the GFS at 700mb made its way through southern Wisconsin over Wednesday night and into Thursday morning,, causing flurries throughout the afternoon with little accumulation. This can be attributed to a very slight amount of positive vorticity advection from the plains.

 

Late Thursday into Friday, the 700mb vertical velocity switches to negative over our area. This subsiding air will keep conditions dry into Friday, at which point an arctic air mass to our west will drop night time temperatures below 20.

 

Come Saturday, slight warm air advection from the Great Plains can be noted as well as increased increased vertical motion at 18Z Saturday. The models are in moderate agreement, hence our medium forecast confidence. GFS and NAM both suggest snow falls nearing 2 inches, while the Canadian model only 1. By Sunday, the 500mb trough axis will move on east from our area. Slight vertical motion at 700mb over the area at 6Z and 9Z Sunday suggest more flurries which taper off later through the night.

 

The beginning of the week unfortunately will be marred with more wind out of the northwest and thus cold temps. The 850mb at 18Z Monday shows Wisconsin situated between a in geopotential minimum northeast of the Great Lakes and a ridge to our southwest. No indication of instability, vertical motion, or precipitation early next week.

 

All in all, Arctic air continues to slam the forecast are over the weekend with weak favorable dynamic conditions for measurable snow Saturday into Sunday.


Rebecca Schultz

Daniel Knuth

2 comments:

  1. Our forecast was successful in identifying some of the notable trends that we experienced throughout the weekend and early week, including unseasonable cold early this week and measurable snow on Saturday night. While this high-level forecast was correct, there exists opportunity to refine predictions in both the scope and magnitude as well as the timing of these events.

    Our initial forecast called for snow starting around 8pm CT, yet snow started as early as 4:30pm CT. Given the weak dynamic environment which led to this precipitation event, we did not feel very confident in forecasting specific magnitudes. In other words, we recognized the potential for action, yet the various variables which indicated said activity yielded uninteresting and unconvincing values. In addition, unfamiliarity with the advantages and disadvantages of different forecast models led us to hedge our forecasted precipitation to be lower than measured.

    In closing, though we were able to successfully predict this minor precipitation event as well as the accompanying early-week cold blast, we see the opportunity to further improve our forecasting abilities by utilizing more exhaustive methods for diagnosing the dynamic environments which lead to various weather events. Going forward, our forecasts can be bettered with a more confident understanding of diagnostic tools, allowing us to be more efficient and effective in our forecasting.

    Dan and Becky

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  2. Dan and Becky - Overall I think that you've done a pretty nice job with this second round of blog posts. You do well to integrate some discussion of the dynamics into your particular forecast discussion as well as provide a nice thoughtful reflection of this particular period. Some areas where I felt there could have been some improvement relate primarily to the inclusion of additional details. For instance, you mention the chance for snow in the briefing section of your forecast, but it would be nice to make a mention of what that snow may be associated with, even though you aren't expected to go into a full on dynamical diagnosis here. In addition, you'll want to make sure that you change up the wording of your forecast a bit between the two posts. It's understandable that things aren't expected to change drastically from the day before, but at the same time, it would have been better if it didn't read almost identically to the day before. Otherwise, the content here is well discussed and a nice way overall to round out your discussions.

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