Very dry air aloft

[Jeff Duda]

I'm only starting this thread because I've never seen water vapor imagery like this nor the associated dryness:

That's very dry air in place over the central US. The Springfield, MO (SGF) sounding from 12Z this morning is equally impressive, with dewpoint depressions in the 500 - 400 mb layer > 40 C throughout and maxing out at 48.0C! That's a relative humidity of around 1%! Despite surface dewpoints around 70 F in E KS and W MO, current RUC analyzed PWs are < 1", which attests to the incredible dryness of the air. Cool stuff.

 

[Greg Blumberg]

That is very impressive Jeff.

For those who want to see the sounding...

http://w1.spc.woc.noaa.gov/exper/soundings/10082212_OBS/SGF.gif

Per NCEP 18z analysis , the surface pressure of the associated high is an estimated 1019 mb.

I'm curious to find out what we'll see come the 0z observations!

 

[Jeff Duda]

For those who want to see the sounding...

http://w1.spc.woc.noaa.gov/exper/soundings/10082212_OBS/SGF.gif

Good point, Greg. You can get text data from that sounding from a link on that page. I got the data from the text link on this page http://weather.cod.edu/analysis/raob.pl?site=sgf. There's lots of good stuff found in that data for those who want to learn more about skew-Ts.

 

[Lanny Dean]

Interesting information Jeff. Let me pose a question: Did any of the current model data (NAM/WRF or even GFS) for the 00z or 12z time frame depict this? Keep in mind that I have not looked at any output at all today. Just kind of curious as to how well the model output did/was?

 

[Greg Blumberg]

Yeah. I like the detailed output of the SPC soundings.

Lanny, I too was curious about that and took a look.

Here is the TwisterData forecast sounding from the 0z GFS run today.

http://www.twisterdata.com/index.ph...iew=large&archive=false&sounding=y&sndclick=y

Seems like the GFS underestimated the depth of the dry air and dryness of the dry layer but almost nailed the winds. (Try to say that sentence five times fast.) Looks like the NAM also had the same problems.

 

[Patrick Marsh]

Here is a blog post from CIMSS about the dryness aloft.

http://cimss.ssec.wisc.edu/goes/blog/archives/6396

 

[Lanny Dean]

Thanks Greg! I was actually just looking over data and was about to make another post with the graphic from the NAM when I saw your post. Thanks for looking for me lol

 

[Jeff Hawkins]

Jeff, for those of us who are noobs, where did you get that image?

 

[Patrick Marsh]

Jeff, for those of us who are noobs, where did you get that image?

Hi, Jim.

The URL for the image can be found in the image across the top.

I have a script that takes these images and puts them into an interface that allows for java script looping. You can find them here: http://weather.forwarn.org

(Note, even though the page says the satellite feed is dead, it isn't!)

 

[Darrin Rasberry]

It's a cap thank God