Monday, October 6, 2014

A Perfect Fall Week Ahead

Public weather briefing

Cold temperatures this past weekend have given way to warmer temperatures Monday afternoon. There is a very slight chance of precipitation in the early hours of Tuesday. The warm up will continue into Tuesday as winds from the West make their way into the area, creating a perfect fall day. Mild temperatures persist through the end of the work week, leading into a cooler, but pleasant weekend forecast. The best chance of rain will be seen Sunday night.


Tonight. Partly to mostly cloudy with a slight chance of showers. Low around 44.

Tuesday. Clearing skies, mostly sunny in the afternoon. Winds from the West at 10-15 mph. High around 62.

Tuesday night. Clear skies. Low around 38.

Wednesday. Sunny skies. High around 60. Light winds from the West. Low around 40.

Thursday. Mostly sunny skies. Highs in the upper 50s. Lows in the upper 30s.

Outlook for Friday through Sunday. Start of the weekend looks to have slightly cooler temperatures, falling into the upper-mid-50s. Skies will be mostly sunny on Friday and Saturday. There will be a possibility for frost in the early morning hours. Clouding over on Sunday, with a slight chance of rain towards the close of the weekend. [CONFIDENCE: MEDIUM]

Forecast Discussion

The surface cyclone centered over Western Ontario is experiencing favorable conditions allowing for continuous development. Precipitation from the rear of this cyclone is possible Monday night. This cyclone will propagate eastward, leaving Madison in the presence of an area of high pressure. A very linear band of precipitation propagates eastward, reaching the mid-Atlantic and northeastern states in the mid-morning hours of Tuesday. Tuesday will be the warmest day of the week in Madison, topping out in the low 60s. An anticyclone will approach Wisconsin resulting in sunny skies and cooling temperatures for the remainder of the work week.

Convergence aloft is seen to the west of surface convergence, showing a tilted nature. A jet seen at the 300 hPa level confirms convergence. The cyclone is expected to weaken mid-week, as the cold front intercepts the warm front, cutting off the warm air supply. This will merely be a disturbance by the end of the week. A pleasant weekend in on tap, with highs only reaching the upper 50s Friday, Saturday and Sunday. Temperatures will be below average ( average high 65F; low 40F).

Elizabeth Schenk
Lindsey Nytes


  1. I am looking at the infrared loop and I am noticing that the cyclonic motion that is centered over eastern Canada has almost stayed in the same spot in 48 hours!

    1. Nice observation, Ryan! It really has just been stuck there the past couple days. We definitely have the tools from class to understand why that's the case. Think about the shearing over the surface wind term from Sutcliffe and what it can tell us about the propagation of low and high pressure systems. What do you notice about the thickness field in the vicinity of the cyclone over eastern Canada and what that might mean for where the cyclone will move over the next few hours? Anyone else can feel free to chime in on this answer as well!

  2. Elizabeth and Lindsey,
    What gives you only medium confidence for the forecast for the latter half of the week? What might change? Why do you think temperatures this weekend will be in the 50s?

  3. I'm not sure if my reply went through. I'll repost here:

    Professor Morgan: we had medium confidence because we were not sure how far north the precipitation was going to travel on Sunday. In our next analysis, we decided that the temperature was going to be warmer than initially anticipated due to some warm air advection from the south.

    Ryan and Andrew: the system will propagate towards the northeast, although it may take some time. As we know, the thermal wind vector must have the colder area to its left. This usually means that the vector points eastward, the direction in which it propagates. For this system, we noted that the minimum thickness is directly almost always directly under the minimum pressure, thus we find very little thermal wind. This explains why the system has remained more or less stationary for as long as it has!


All comments will be reviewed before being posted to the blog. Any inappropriate comments will not be tolerated.