Prompts winter weather advisories as cold air moves in Friday night

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 recorded in Milwaukee, Detroit, Chicago, Buffalo, Cleveland

 again Friday & Saturday in southern Minnesota & the metro

The surreal start to 2012 continues. Madison and Milwaukee are off and running on the warmest start ever this year.

Milwaukee is a full 2 degrees warmer than the warmest year on record so far in 2012!

Unprecedented March heat wave continues to rewrite record books:

How out of whack is the March heat wave? The Detroit NWS is going to start issuing frost advisories....

Unprecedented Warm March Weather and the Possible Negative Impacts to Michigan

While it is common to talk about extreme weather events, there is usually a comparable weather event in the record books.  The same cannot be said about the current warm stretch for its strength, length and timing so early in the spring season.  This current extreme weather event truly has never happened in recorded history in Southeast Michigan!

"While many residents are enjoying the long period of record warm weather, Southeast Michigan's agricultural interests will be bracing for potentially severe negative impacts.  The average last freeze for most locations in Southeast Michigan is not until late April.  Over 90% of Aprils for all locations in Southeast Michigan have a hard freeze, a temperature of 28 degrees or lower, sometime during the month.

The growing season has started in Southeast Michigan, about 5 weeks ahead of schedule.  Therefore, the NWS Detroit/Pontiac office will start issuing frost advisories and freeze warnings as conditions warrant. 

The unprecedented stretch of warm March weather will continue for the rest of the week.  This stretch of warm weather comes on the heels of Detroit's 5th warmest winter on record, the 12th warmest Autumn, and a summer which featured July as the hottest month ever recorded in Detroit.  In fact, the jet stream has been displaced well north of its typical position since the middle of last year.  Now, with none of the typical ice on the Great Lakes to insulate Michigan from the effects of this unusually warm spring, record warmth has been allowed to surge into the state like never before."

Here's a great exapmle of how sensitive doppler is...and how tall some of those wind turbines are!

Area Wind Farms Showing Up Clearly On Radar

"Atmospheric conditions, along with a favorable wind direction, has resulted in the area wind farms showing up clearly on the radar display overnight (see image below.)  Given the low level inversion that was in place, and the superrefraction of the radar beam that was likely occurring, the radar energy was intercepting the large blades of the wind turbines.  See this related web page about how our radar "sees" these wind farms. The returned energy is plotted on the display and looks just like precipitation, or even thunderstorms.  Also, due to the easterly flow, the motion of the wind turbine blades is generally parallel to the radar beam, maximizing the radars ability to interpret their motion.  The radar has the ability to remove "targets" that aren't moving (something we call clutter suppression.)  This is why you generally won't see the interference from the terrain surrounding the radar.  But, the wind turbines are moving and therefore the radar assumes they are real precipitation targets." 

Our stubborn low pressure system is finally beginning to pull away toi the east Friday. The system has brought us several grey days with some welcome rain.

Skies will begin to clear Friday and sunshine should return fully for Saturday.

A cool front will slide south Sunday, and you may notice the cooler breezes from the east. The cooling trend will continue next week. We could see a shot of frost by next Thursday morning in the metro suburbs!

Warmest year ever so far in Milwaukee & Madison; Wind farms visible on doppler

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