Issued at 8:36 PM CST, Wednesday, December 30th, 2009
Weather History:
On this date in 1996… 10.3″ of snow fell at Duluth, Minnesota.
Weather headlines:
-Big lake effect snow event develops Thursday and persists into early next week for the South Shore of Lake Superior in Northwest Wisconsin
-Arctic air sets up across the Upper Midwest by Friday and persists thru early next week
-Wind chill headlines may be needed at times across parts of our area beginning Thursday Night
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
(Today’s Weather)
A cold front combined with an upper level disturbance tracking through the Upper Midwest caused some light snow and flurries across portions of Northern Minnesota and Northwest Wisconsin. Snow accumulations Today were generally 1″ or less. Highs Today were in the teens to lower 20s with 850 mb temperatures as of 8 PM ranging from -10 to -17 degrees C from northwest to southeast across our local area. Winds Today were out of the south, west, or northwest under 20 mph. Surface map early This Evening featured low pressure of 1006 mb centered in Central Ontario Province with a cold front attached to the low extending southwest through Central Wisconsin. High pressure of 1024 mb was centered in Southern Alberta Province.
(This Evening’s Upper Level Analysis)
Westerly 500 mb flow was in place across the Upper Midwest This Evening per RUC model analysis. Water vapor satellite imagery shows two upper level disturbances. One was lifting east/northeast out of Missouri while another one was heading east across Northwest Minnesota/Southwest Ontario Province. An area of 60 meter 12 hour 500 mb height falls covered most of the Upper Midwest and Central/Northern Great Lakes This Evening in association with the weak disturbances overhead.
…An extended period of lake effect snow expected along the South Shore of Lake Superior…
*LAKE EFFECT SNOW WARNING*
Valid 4 PM CST Thursday until 6 AM CST Saturday for Ashland and Iron Counties in Northwest Wisconsin. This includes the cities of Ashland WI…Marengo WI…High Bridge WI…Mellen WI…Hurley WI…Upson WI…And Montreal WI… Arctic high pressure to our northwest and low pressure off to our east will cause north winds and arctic air air to cross the relatively milder waters of Lake Superior, this will lead to the development of locally heavy lake effect snow showers in the affected areas from Thursday Afternoon through at least early Saturday. Snowfall rates of 1-2″ an hour are possible at times with snowfall accumulations of 1-2 feet expected in most of the warning area between late Thursday and early Saturday.
Travel along Highway 13…77…and 2 in Northwest Wisconsin will become very difficult if not impossible at times due to the snow. Use extreme caution and make sure to have a winter survival kit in your vehicle if you will be doing any traveling in the warning area.
(Tonight through Thursday Night)
Low pressure will be centered to our east while arctic high pressure strengthens to our northwest. A surface trough will develop to our north Tonight and will drift south into our area Tomorrow and Tomorrow Night. Partly-mostly cloudy skies will cover our area during this period with a few flurries possible from time to time. Lows Tonight will be in the single digits and teens but some locales could drop into the zero to 5 below range, mainly in Western areas. Highs Tomorrow will be in the single digits and teens with lows Tomorrow Night in the single digits below to above zero with some minus teens possible in Western areas. Winds during this period will be out of the north or west around 20 mph or less. Wind chills will drop into the 10 below to around 25 below zero range across portions of our area, especially by Tomorrow Night.
(Extended Forecast)
Weather pattern will change little through early next week. Strong arctic high pressure will be draped over the Upper Midwest into Central Canada while low pressure shifts west/northwest through New England toward Eastern Canada from this weekend into early next week. An amplified N/NW 500 mb flow will be in place across our area from Friday into early next week and this will result in arctic air taking up residence across the Upper Midwest.
High temperatures Friday and Saturday will be in the 10 below to 10 above range with lows Friday Night and Saturday Night in the single digits, teens, and 20s below with some 30s below possible in the traditional cold spots.
The overall weather pattern is a dry one for most of our area through early next week with just an occasional flurry from time to time.
There has been some hints over the last few days of milder Pacific air developing across the Northern Rockies and spilling east into the Upper Midwest toward the middle part of January while the bitter cold arctic air reforms across Alaska and Northwestern Canada. Whether this happens or not remains to be seen since this would be out in the 2 week time frame and models tend to flip flop from one day to the next with weather patterns after 4 or 5 days. It’s also going to be interesting to see if the current snow pack, which consists of about 60% of the U.S. having at least 1″ of snow on the ground would play any role in preventing any big temperature rises as we head through January.
5 Day Forecast for Duluth/Superior
.Tonight… Variable cloudiness with flurries possible at times. Low 3 to 8. Wind northwest at 10 to 15 mph.
.New Years Eve… Partly sunny. Flurries possible. High 8 to 13. Wind northwest at 10 to 15 mph.
.Thursday Night… Variable cloudiness. Low 2 below to 7 below. Wind northwest at 10 to 15 mph. Wind chills approaching 25 below.
.New Years Day… Partly cloudy. High zero to 5 above.
.Friday Night… Partly cloudy. Low 12 below to 17 below.
.Saturday… Partly sunny. High zero to 5 below.
.Saturday Night… Partly cloudy. Low 11 below to 16 below.
.Sunday… Partly to mostly cloudy. Flurries possible. High 2 to 7.
Normal High Temperature Tomorrow 18 degrees
Normal Low Temperature Tomorrow 0 degrees
Tim
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