• After witnessing the continued decrease of involvement in the SpotterNetwork staff in serving SN members with troubleshooting issues recently, I have unilaterally decided to terminate the relationship between SpotterNetwork's support and Stormtrack. I have witnessed multiple users unable to receive support weeks after initiating help threads on the forum. I find this lack of response from SpotterNetwork officials disappointing and a failure to hold up their end of the agreement that was made years ago, before I took over management of this site. In my opinion, having Stormtrack users sit and wait for so long to receive help on SpotterNetwork issues on the Stormtrack forums reflects poorly not only on SpotterNetwork, but on Stormtrack and (by association) me as well. Since the issue has not been satisfactorily addressed, I no longer wish for the Stormtrack forum to be associated with SpotterNetwork.

    I apologize to those who continue to have issues with the service and continue to see their issues left unaddressed. Please understand that the connection between ST and SN was put in place long before I had any say over it. But now that I am the "captain of this ship," it is within my right (nay, duty) to make adjustments as I see necessary. Ending this relationship is such an adjustment.

    For those who continue to need help, I recommend navigating a web browswer to SpotterNetwork's About page, and seeking the individuals listed on that page for all further inquiries about SpotterNetwork.

    From this moment forward, the SpotterNetwork sub-forum has been hidden/deleted and there will be no assurance that any SpotterNetwork issues brought up in any of Stormtrack's other sub-forums will be addressed. Do not rely on Stormtrack for help with SpotterNetwork issues.

    Sincerely, Jeff D.

Thermal Ridges and troughs

  • Thread starter Thread starter Tim Johnson
  • Start date Start date

Tim Johnson

Also known as Temperature ridges or troughs, I had a question regarding the operational use of this data.

weatherprediction.com lists the following in relation to this.

thermal ridges often are indicators of higher instability regions especially if WAA and moisture advection are associated with the thermal ridge.
Click to expand...


Looking at the big picture, when does it become pertinant to analize thermal ridges (and troughs) in the grand scheme of forcasting severe wx? Is it something that should just be glanced at to determine its importance, or something that should be included as a rule?
 
It can be looked at as a part of identifying the main instability axis when used in concert with other features in a composite map. Here is an example of what a typical composite map might look like for the morning before a severe weather event in the southern plains:

[Broken External Image]:http://www.atmos.uiuc.edu/~romine/img/sp_spring_svr_wx.png

The 850 mb thermal axis is the same thing as the thermal ridge - as in the axis of warmest temperatures. You can see that it is west of the surface moisture axis - and the greatest instability is located between these two axes.

Glen
 
Is it better to view this feature on the 850 mb chart or surface (or both)?
 
Is it better to view this feature on the 850 mb chart or surface (or both)?
Click to expand...

Short answer - use 850 mb. Long answer - above is a chart for a morning condition that would be favorable for a severe wx event later in the day. As such, if you looked at the surface at this time - you'd probably find the warmest axis to be to the right or along the moist axis where the air didn't cool as greatly, whereas the dry air to the west of the dryline is likely very cool in the morning, with a shallow radiation inversion, but will rapidly warm by later in the day. In fact, the 850 mb temperatures are generally used by mets to forecast the days high temperatures. So, since we are most interested in what conditions will be like during peak heating - it is more valuable to look at the 850 thermal ridge. I've also overlayed in the image above the 700 mb temerature - the magnitude of the contour varies seasonally - but the countour clearly peaks northward to the east of the 850 mb axis. the closer these two axes are to each other - the more of a problem capping might be over the instability axis.

Glen
 
Thanks for the info Glen. The graphic helps quite a bit. The more I lean about weather and forcasting the more it amazes me; all the various components that can change a given scenario. Seems like the more I grasp about wx the more I realize I don't know. I think thats part of what keeps me plugging along though.

Thanks again for taking time to share some insight on this!
 
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