Wednesday, December 9, 2015

Is it really December?

Public weather briefing

After fairly cloudy and cool days early in the week, the next few days will be unseasonably warm in Madison.  Expect a high in the low 50's tomorrow, but keep an eye on the thermometer as there is a chance to break the record high for December 10th, which was 55 degrees set way back in 1911.  The rest of the weekend will see highs in the upper 40's and lower 50's, until temperatures begin to fall back towards normal on Sunday.  Look for cloudy skies and windy conditions to accompany the heat.


Tonight. Cloudy and mild, low near 40.

Thursday. Unseasonably warm. Breezy. High 53.

Thursday night. Not quite as mild. Low 35.

Friday. Partly sunny and continued mild. High 51.

Saturday. Cloudy with chance of rain late. High near 50.

Outlook for Sunday through Tuesday. Temperatures start to drop towards normal. Highs around 40. Windy on Monday and Tuesday. Overnight lows in the upper 20's. [CONFIDENCE: MEDIUM]

Forecast Discussion

A trough extending over the United States from a low-pressure system across Saskatchewan will drag across Wisconsin on Thursday, and, due to the available moisture and warm air advection, will lead to cloudy skies for most of the day.  These clouds will keep the already warm temperatures from dropping below around 40 degrees F, reducing the chance for morning fog. As the trough passes through the state, the temperature gradient behind the front is projected to tighten, resulting in high frontogenetic forcing through Wisconsin.  However, due to the low levels of moisture in the troposphere, will likely not result in any precipitation in Madison.

Beginning early Thursday, low-level southwesterly flow will be advecting warm air from the Great Plains into the state, resulting in the near-record high temperatures we are expected to see in the next couple of days.  Additionally, the pressure gradient will tighten thanks to a cyclone over northern Minnesota, leading to windier days heading into the weekend.

Steven Fons

Monday, December 7, 2015

Warm and Rainy Weekend Ahead

Public weather briefing

The start of the week will be cloudy with light winds and some fog in the early morning and night. There is a slight chance of rain Tuesday night. Temperatures will stay in the mid-to-upper 40s through Saturday. The sky will clear slightly from Wednesday through Friday giving us partly cloudy skies. There should be very little to no precipitation during the week with a higher chance of precipitation on Saturday or Sunday. 


Tonight. Cloudy with a low near 34. Some fog overnight.

Tuesday. Fog in the early morning then partly sunny in the afternoon. High near 45.

Tuesday night. Around 30% chance of rain overnight and cloudy with light winds. Low around 34.

Wednesday. Partly sunny during the day and cloudy at night with light winds. Low near 35 and high near 44. 

Thursday. Cloudy with slight chance of showers. High around 51 and low around 36. 

Outlook for Friday through Sunday. Cloudy with a 30% chance showers Friday evening. High in the upper 40s and low in the upper 30s. 30-50% chance of rain Saturday and Sunday with cloudy skies. Sunday's high temperature in the upper 40s on low near the low 30s. Sunday's high in the upper 30s. [CONFIDENCE: MEDIUM]

Forecast Discussion

A shortwave thermal ridge sits over Wisconsin on Monday which is advecting warm temperatures into the area for a few days. Confluence of northwesterly winds causes a weak low pressure system to form Tuesday night over Wisconsin which is the cause of the slight chance of rain during the night. A small thermal trough then propagates eastward on Wednesday causing a slight drop in temperatures. Another thermal ridge propagates over Wisconsin bringing warmer temperatures and slightly stronger winds on Thursday. No strong jets can be found over Wisconsin over the week which corresponds to the lack of strong, organized low pressure systems during the week. 

Alex Delvoye

Thursday, December 3, 2015

A snow no-show

Public weather briefing

The recent cold pool of air over the region has now departed to the east, allowing for slightly warmer temperatures today. This trend looks set to continue for the weekend and into next week, with day temperatures much higher than average for this time of year. There will also be plenty of sunny spells, with mostly clear conditions throughout the week and no obvious signs of precipitation. Cold temperatures at night will result from this lack of cloud cover.


Tonight. Mostly clear and bitterly cold, with lows in the mid 20's.

Friday. Sunny with light winds. High around 45.

Friday night. Mostly clear, with lows in the upper 20's.

Saturday. Continued sunny conditions and above-average temperatures, with highs around 47. Partly cloudy over night and lows around 31.

Sunday. Mostly cloudy. Highs in the mid 40's. Continued cloud cover into the night, with lows in the upper 20's.

Outlook for Monday through Wednesday. Steady conditions, with little change from day to day for the first half of next week. During the day it will be mostly sunny and temperatures will reach the mid 40's - still much higher than average for this time of year. By night, temperatures will fall to the lower 30's and some cloud will be present, but no precipitation.  [CONFIDENCE: MEDIUM]

Forecast Discussion

The cold pool of air over southern Wisconsin has departed to the east, allowing for warmer air to fill in from the central plains. A strong ridge to the west of the Rockies will move eastward, providing favourable conditions for a high pressure system over the central plains to intensify. Over the weekend, this high will develop into a strong anticyclone and moves north-eastward towards the Midwest, causing subsidence over our area. This factor, plus continued warm air advection from the south, will cause the temperatures for the week ahead to be much warmer than average for this time of year.

Rich Johnson

Wednesday, December 2, 2015

Mild and Mundane...

Public weather briefing

Following a very light snowfall event this morning and light snow on and off throughout today with temps in the 30s, we may expect a precipitation-free evening with lows dropping to 28.  The departure of a cold air mass moving to the east will mean mild days into next week with highs consistently in the low to mid 40s peaking on Saturday with a high of 47.  In addition to temperatures well above freezing, mostly-clear to clear conditions are expected to last throughout the forecast duration.  


Tonight. Mostly Cloudy with a low around 28.

Thursday. Mostly sunny.  High around 40.

Thursday night. Mostly clear with fog developing after midnight.  Lows around 25.

Friday. Fog in the morning followed by mostly sunny skies and a hight in the low 40s.

Saturday. Sunny with a high in the upper 40s.

Outlook for Sunday and Monday. Both days are expected to be mostly sunny with highs in the lower 40s. [CONFIDENCE: MEDIUM]

Forecast Discussion

The cyclone that has brought light snow to the midwest has moved out of the region but the cold pool it formed has lingered in the area and now slowly moves east.  With its departure, moderate low level winds will push warmer air into the region from the plains.  A high originating in the south will develop into an intensifying anticyclone as a ridge west of the Rockies moves eastward.  The high pressure center will move slowly east-northeastward into the weekend and will result in subsidence and more warm air advection for our region.  

As the short wave trough trailing behind the broad ridge moves in to the area Saturday, vorticity advection is forecasted to drive moderate ascent in the region but there will be inadequate moisture for precipitation.  

Alexander Fox

Tuesday, December 1, 2015

Doesn't December mean winter?

Public weather briefing

After a lovely Thanksgiving weekend Madison was greeted with a dreary Monday, filled with scattered rain showers. Unfortunately (or fortunately, depending on your precipitation preference for December 1st) winter storm Delphi passed to the west, dumping snow on much of Minnesota and the Dakotas, but only clipping northern Wisconsin. Once this system moves out, moderate December temperatures will move in. Temperatures will consistently reach the mid 40s during the day and hover around 30 at night. There will be little hope for snow in the upcoming week.


Tonight. Mostly cloudy with lows around 30. Slight chance of rain/snow mix with minimal accumulation.

Wednesday. Mostly overcast with light winds. Highs in the mid 30s.

Wednesday night. Clouds clearing overnight.  Lows in the upper 20s.

Thursday. Sunny and slightly warmer. High around 40. Low around 30.

Friday. Continued sunny. Highs in the low 40s.

Outlook for Saturday and Sunday. Saturday will be mostly sunny and the temperature could reach close to 50. Sunday will be comparable, only slightly more cloudy and reaching the mid to upper 40s. Each night will dip down to around 30. [CONFIDENCE: MEDIUM]

Forecast Discussion

Winter storm Delphi showed some interesting development. The storm is characterized by a cold pool of air that has been sequestered from its origin in Canada due to a thermal ridge. The same circular region exhibited high vorticity, as the jet pattern across the US wrapped itself around the cyclone. 
The storm will continue to move through the Northern Plains/Upper Midwest for the rest of the day, bringing sizable snowfall to many of our neighboring states. The cold front associated with Delphi might bring minor precipitation to our area tonight, but it would be a rain/snow mix - nothing like others have seen from this storm. 

Once the cold pool moves out of our area on Wednesday evening, we will see uniformly sunny and moderately warm days through the rest of the week. Much of the Midwest will be located in a thermal ridge, bringing us these relatively warm temperatures for the first week of December. We will also be located in a broad anticyclone, with minimal expectations for precipitation, rain or snow.

Kaitlyn Krzyzaniak