Tuesday, September 23, 2014

Continued Sunny Weather for the Rest of the Week

Public weather briefing

After a very nice Monday, the great weather continues for most of the week. Warm temperatures will be continue throughout the week.  Temperatures will stay in the low 70's for the middle of the week and rise to the mid to high 70's for the end of the week and start of the weekend.  Lows will be in the low to mid 50's throughout the week as well.  It should be, for the most part, a clear and sunny week due to the high pressure system located over the area.  However, with a system to the west-southwest, the outlook for rain is now possible for Wednesday night into Thursday morning's forecast.  Along with early morning fog for the middle of the week, these should be the only threats to what should be an overall excellent week and weekend outlook.


Tonight. Clear skies with light wind from the south. Low around 50.

Wednesday. Clear morning with clouds increasing throughout the day becoming mostly cloudy. Possibility of showers in the evening.  High around 70.

Wednesday night. Cloudy with light southerly winds.  Lows in the lower 50's. Chance of showers into Thursday morning.

Thursday. Chance of showers in the early morning. Continued cloudiness throughout the morning and into the afternoon.  Calm winds.  High in the mid to low 70's.  Low around 50. 

Friday. Clear conditions and warm temperatures.  High in the mid 70's.  Low in the low 50's.  Chance of patchy fog in the early morning.

Outlook for Saturday through Monday. Mostly sunny all weekend into the early week. Temperature highs in the low to mid 70's with lows in the 50's throughout the weekend. [CONFIDENCE: MEDIUM-HIGH]

Forecast Discussion

The high pressure anticyclone continues to stay in the eastern midwest crawling further east.  It will continue to bring warm air advection, which will be felt later in the week.  Currently, the state of Wisconsin in under a very large high pressure ridge stretching into Canada creating very nice conditions for the area.

Temperatures will continue to slowly rise throughout the week, going from the low 70's in the middle of the week to the mid to high 70's later in the week.  This is due to the warm air advection coming from the south carried north to the upper midwest region.  Low's will be consistently in low 50's bringing on the chance of condensation at the low levels of the atmosphere.  This could pose a threat for fog into Friday morning's forecast. 

Yesterday's forecast showed a low pressure trough that looked to be dying out before reaching the Madison area.  However, models now show that this system will continue to move northeast into the area giving the chance for precipitation in the central and northern regions of Wisconsin stretching into Madison for Wednesday night and into Thursday morning before finally dying out shortly after.  This is due to the severe curvature of the cyclone in Minnesota-South Dakota-Iowa region creating divergence in the upper atmosphere to the east causing lifting, which leads to precipitation in this western region.

Will Hahn and Andrew Goenner


  1. Nice thoughts the past couple of days, guys! You mention both in this discussion and during your forecast yesterday that the precipitation associated with the trough had some trouble maintaining itself (i.e. it was falling apart). What might be causing this? Think about the environment that the precipitation might be falling into (i.e. the difference in the temperature vs. the dew point)

  2. To start off, temperatures, for the most part, were higher than we expected as they actually reached high 70's and low 80's into the weekend. We think this may have been due to the amount of extra solar radiation that happened throughout the week that may have lead to the warmer temps. Another thought is that it may be due to higher than expected warm air advection. Our lows for the overnight were very close to the actual as well.

    Our conditions, especially after the edit on Tuesday, were pretty accurate with a lot of sun in the weekends and the only cloudy day being Wednesday. The fog that occurred over Friday and slightly into the weekend was accurate as well.

    The only day we were off was our last day on Monday, which went from a beautiful day to a pretty ugly one. Our conditions were accurate for most of the day until the cold front moved through in the late afternoon, which was earlier than the models predicted on Tuesday. Other than that, our forecast was overall pretty good.

  3. Andrew, I know this is a week late, but going off your question and hints, I would have to think that the precipitation associated with the trough ran into some dry air, which is why you would look at the actual temp vs. dew point temp. Usually when a line of storms is moving through an area, you can try and make an educated guess or at least a good assumption of the future of that line and how it will hold up simply by looking at the dew points ahead of the storm and whether they are close to the actual or not, hinting at either moist or dry air ahead.

  4. Hi Will and Andrew, Overall, I'm pleased to see that, for the most part, your forecast was in the ballpark of what actually happened. When you discuss the possible dynamical mechanisms that may have allowed for warmer temperatures over the weekend, definitely elaborate more on what may have allowed for that increased solar insolation. For example, did the models forecast more additional cloud cover than what actually occurred? Off of this point, two primary ways that I think you guys can elevate your next forecast is to really tighten up your dynamical descriptions surrounding the features of interest. For example, if you mention an anticyclone, you could talk about subsidence or if you're forecasting fog, what conditions are allowing for that (e.g. calm winds/higher dewpoints)? Secondly, the narrative of your discussions can be a bit more polished. This can be done by trying to stick more to technical language and to make sure the text flows a bit more freely. It is definitely great that you were able to zero in on the important features, though, and I'm looking forward to your second installment in a few weeks!


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