Thursday, December 4, 2014

Chance of Freezing Rain Moves South; Pleasant Weekend Ahead!

Public weather briefing

 Partly cloudy skies prevail into the end of the work week, as chances of precipitation shift further south for Friday.  A very slight chance of precipitation remains for midday Friday.  Saturday will be nicer, with sun and temperatures in the low 30s. Conditions remain pleasant through Sunday evening, when we will see the next chance of precipitation into Monday afternoon.  Agreeable weather returns for Tuesday and Wednesday.


Tonight. Partly cloudy skies with light winds. Lows around 25.

Friday. Cloudy with light winds, with a very slight chance of precipitation. High in the mid-30's.

Friday night. Mostly cloudy skies.  Lows around 25.

Saturday. Clearing skies with light winds. High of 32, low around 20

Sunday. Partly sunny, with light winds. High of 35, low of 28.

Outlook for Monday through Wednesday. Clouds returning on Sunday evening, with a slight chance of snow. Chances of precipitation linger through mid-Monday, with skies partly cloudy for Tuesday and Wednesday. Highs in the lower to mid 30's Monday through Wednesday. Lows in the mid 20's. [CONFIDENCE: MEDIUM-HIGH]

Forecast Discussion

The high pressure system that has influenced the weather over past few days has began to move towards the east. A low pressure system that originated off of the Baja peninsula of California will propagate eastward, passing south of the Madison area by mid-Friday. Warm air advection will accompany the system, with temperatures reaching the mid 30s by the weekend. Subsidence associated with a high pressure system will dominate the weekend weather, with clear skies Saturday. 

The next chance for possible precipitation is Sunday night through Monday afternoon. A maximum in positive vorticity is located over southern Minnesota. Positive vorticity will be advected towards Madison on Monday morning, increasing chances of ascent in the area, and therefore possible precipitation.  The chance of precipitation will end late Monday afternoon as the trough propagates towards the east.  Subsidence will follow once more, due to negative vorticity advection.  Yet another high pressure system will enter the region early Tuesday, bringing partly cloudy skies and temperature highs in the mid 30's

Elizabeth Schenk
Lindsey Nytes


  1. We found a few discrepancies between what we predicted, and what was actually observed. Overall, temperatures were lower than anticipated. Our high temperatures were close to predicted, falling in the mid 30s. On Monday, we predicted that the precipitation would end around midday, when in actuality, it stuck around into the evening. This precipitation fell in the form of rain, instead of snow. We account our errors to the uncertainty of the precipitation event.

  2. Lindsey and Liz - These are a series of solid blog posts that you've put forth for round 2! I particularly appreciate your ability to integrate a discussion of the pertinent dynamical features affecting the area in your forecast discussion and some of the mechanisms that may have facilitated the production of precipitation across southern Wisconsin. With that said, some suggestions for future improvement are centered primarily on sharpening your discussion on these dynamical mechanisms a bit more and on providing some more specificity. For instance, in your discussion on this day make sure to include what that positive vorticity advection is associated with (i.e. an upper-level trough). Also, while you do discuss these features in forecast discussion, you can definitely still identify them within your public briefing section. For instance, you could note that the precipitation forecasted for the end of the weekend is associated with the approach of a developing low pressure center. Finally, in your specific forecast, if you identify a chance for precipitation definitely make sure to specify if you expect that precipitation to be frozen or liquid in nature. Integrating a few more details into your reflection as well with regards to some of those uncertainties you noted may have added a bit more detail into the differences that occurred within the observed conditions. Nevertheless, a nice way to finish off the semester!


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