Now that's a warm front!

Posted at 3:52 PM on May 20, 2009 by Paul Huttner (3 Comments)

Twin Cities NWS Doppler radar detects the warm front Tuesday.

Weather technology always amazes me.

Everyone knows we can see storms or even rotation on doppler radars these days. But did you know Doppler can see birds, insects or even warm fronts?

The image above front Tuesday clearly shows the record warm front that surged into the Twin Cities. Radar can see discontinuities in the atmosphere, especially when they are collecting "scatterers" such as dust or bugs. Yesterday's warm front is that east to west oriented line in the southern Twin Cities.

The warm surge brought the warmest temperatures ever recorded so early in the season for the Twin Cities and much of Minnesota.

It's nice to know our "tax dollars at work" can see other things in addition to storms.

PH

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Comments (3)

Coming south on 169 today towards the Minnesota river you could see a thick haze in the air. I'm not sure it if was moisture from the river or dust that was kicked up from the wind. I believe both of the green snakey clouds in your picture roughly correspond to rivers.

What are your thoughts Paul?

Posted by David | May 20, 2009 8:58 PM

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listening to the weather radio yesterday and today I noticed the heat index was lower than the thermometer temp. (due to low humidity I guess). How often does that happen in MN when it's 90+ degrees ? My guess is not too often.

Posted by paulm | May 20, 2009 10:19 PM

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Hi David:

I'm not sure which lines you refer to here. I don't know why the doppler would pick up returns over a river valley unless something (dust?) was getting funneled up the valley. It is possible I suppose.

paulm:

I think you're right. We usually have plenty of humidity when we have 90 degree heat.

Roughly speaking, a dew point of about 55 degrees gives you a heat index equal to the air temperature. Anything lower and the HI is lower than air temp. Anything higher and the HI climbs above ambient air temp.

Dew points yesterday were around 40 degrees in the metro, thus the lower than air temperature HI readings. It felt like my 9 years in Arizona! In fact this air mass was advected in from the Desert Southwest.

PH

Posted by Paul Huttner | May 21, 2009 8:11 AM

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